U.S. patent application number 13/832454 was filed with the patent office on 2013-12-12 for power tool having multiple operating modes.
This patent application is currently assigned to BLACK & DECKER INC.. The applicant listed for this patent is BLACK & DECKER INC.. Invention is credited to Shaun Lovelass, Marco A. Mattucci, Jason McRoberts, David Miller, Christopher J. Murray, Wong Kun Ng, Steven J. Phillips, Jonathan Priestly, Fugen Qin, Oleksiy Sergyeyenko, Christopher W. Shook, Kevin Stones.
Application Number | 20130327552 13/832454 |
Document ID | / |
Family ID | 48625798 |
Filed Date | 2013-12-12 |
United States Patent
Application |
20130327552 |
Kind Code |
A1 |
Lovelass; Shaun ; et
al. |
December 12, 2013 |
POWER TOOL HAVING MULTIPLE OPERATING MODES
Abstract
A handheld power tool is configured to receive an input
indicative of a clutch setting for an electronic clutch from the
tool operator, where the clutch setting is selectable from a drill
mode, an automated drive mode and one or more user-defined drive
modes. Each of the user-defined drive modes specifies a different
value of torque at which to interrupt transmission of torque to the
output spindle. In an automated drive mode, the controller
interrupt torque to the output spindle in an automated manner when
a fastener being driven reaches a desired stopping position. In a
selected one of the user-defined drive modes, the controller sets a
value of a maximum current threshold in accordance with the
selected one of the user-defined drive modes and interrupts torque
to the output spindle when current measures exceeding the maximum
current threshold.
Inventors: |
Lovelass; Shaun; (Newton
Aycliffe, GB) ; Mattucci; Marco A.; (Baltimore,
MD) ; McRoberts; Jason; (Windsor, PA) ;
Miller; David; (Baltimore, MD) ; Murray; Christopher
J.; (Philadelphia, PA) ; Ng; Wong Kun; (New
York, NY) ; Phillips; Steven J.; (Ellicott City,
MD) ; Priestly; Jonathan; (Darlington, GB) ;
Qin; Fugen; (Timonium, MD) ; Sergyeyenko;
Oleksiy; (Baldwin, MD) ; Shook; Christopher W.;
(Bel Air, MD) ; Stones; Kevin; (Bishop Aukland,
GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BLACK & DECKER INC. |
Newark |
DE |
US |
|
|
Assignee: |
BLACK & DECKER INC.
Newark
DE
|
Family ID: |
48625798 |
Appl. No.: |
13/832454 |
Filed: |
March 15, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61657269 |
Jun 8, 2012 |
|
|
|
Current U.S.
Class: |
173/1 ;
173/176 |
Current CPC
Class: |
B25B 23/147 20130101;
B25F 5/00 20130101; B25F 5/02 20130101; B25F 5/001 20130101; B23Q
5/10 20130101 |
Class at
Publication: |
173/1 ;
173/176 |
International
Class: |
B25F 5/00 20060101
B25F005/00; B23Q 5/10 20060101 B23Q005/10 |
Claims
1. A method of controlling operation of a power tool having an
electric motor drivably connected to an output spindle to impart
rotary motion thereto, comprising: receiving, by a controller
residing in the power tool, an input indicative of a clutch setting
for an electronic clutch, the clutch setting being selectable from
a drill mode and a drive mode; monitoring, by the controller,
torque applied to the output spindle when the clutch setting is in
a drive mode by sampling periodically current delivered to the
electric motor; storing a sequence of current measures most
recently sampled, the sequence of current measures being stored in
a memory of the power tool; and determining a slope for the
sequence of current measures by way of linear regression;
interrupting, by the controller, transmission of torque to the
output spindle based in part on the slope of the sequence of
current measures and when the clutch setting is in a drive mode;
and disregarding, by the controller, torque applied to the output
spindle when the clutch setting is in drill mode.
2. The method of claim 1 further comprises detecting, by the
controller, an occurrence of a trigger switch being released and
subsequently depressed by the tool operator, where the trigger
switch controls quantity of electric power delivered to the
electric motor and the occurrence of the trigger switch being
released and subsequently depressed by the tool operator occurs
within a time limit of interrupting transmission of torque; and
energizing, by the controller, the electric motor for a period of
time after generating haptic feedback and in response to detecting
the occurrence of the trigger switch being released and
subsequently depressed by the tool operator.
3. The method of claim 1 further comprises comparing, by the
controller, the slope to a minimum slope threshold; incrementing,
by the controller, a slope counter by one when the slope exceeds
the minimum slope threshold; evaluating, by the controller, the
slope counter in relation to a setting criteria, where the setting
criteria is indicative of a desired stopping position for a
fastener being driven by the power tool; and interrupting, by the
controller, transmission of torque to the output spindle when the
slope counter meets the setting criteria.
4. The method of claim 3 further comprises storing, by the
controller, a sequence of values for the slope counter; and
evaluating, by the controller, the sequence of values for the slope
counter in relation to the setting criteria.
5. The method of claim 4 further comprises interrupting
transmission of torque when values in the sequence of values for
the slope counter are increasing from an oldest value to a most
recent value.
6. The method of claim 4 further comprises interrupting
transmission of torque when values in the sequence of values for
the slope counter increase from an oldest value to an intermediate
value and decrease from the intermediate value to a most recent
value.
7. The method of claim 1 further comprises providing a visual
indicator for the clutch setting during the operation of the
tool.
8. The method of claim 1 wherein receiving an input further
comprises receiving a signal from one or two buttons provided on a
housing of the power tool, where one of the two buttons is
associated with the drill mode and other of the two buttons is
associated with the drive mode.
9. The method of claim 8 further comprises illuminating an icon
integrated into one of the two buttons actuated by the tool
operator, where the icon is indicative of the operating mode
associated with the actuated button.
10. The method of claim 1 further comprising determining, by the
controller, a magnitude of current being delivered to the electric
motor immediately prior to interrupting transmission of torque;
storing, by the controller, the magnitude of current in a storage
device in response to an input from the tool operator; interrupting
transmission of torque to the output spindle during a subsequent
operation of the tool when the amount of current being delivered to
the electric motor is equal to or exceeds the stored magnitude of
current.
11. A portable, hand held power tool, comprising: a housing; an
electric motor drivable connected to an output spindle to impart
rotary motion thereto; a current sensor configured to sample
current being delivered to the electric motor; an input component
operable by the tool operator to set a clutch setting for tool, the
clutch setting being selectable from a drill mode, an automated
drive mode and one or more user-defined drive modes, where each of
the user-defined drive modes specifies a different value of torque
at which to interrupt transmission of torque to the output spindle;
and a controller configured to receive the clutch setting from the
input component and current measures from the current sensor,
wherein the controller operates, when the clutch setting is an
automated drive mode, to interrupt torque to the output spindle
monitor rate of change of the current measures and interrupt torque
to the output spindle in response to the rate of change of current
measures exceeding a rate change threshold, the controller further
operates, when the clutch setting is in a selected one of the
user-defined drive modes, to set a value of a maximum current
threshold in accordance with the selected one of the user-defined
drive modes and interrupt torque to the output spindle in response
to the current measures exceeding the maximum current
threshold.
12. The power tool of claim 11 wherein the controller, when the
clutch setting is an automated drive mode, operates to receive
current measure from the current sensor, stores a sequence of
current measures most recently sampled in a memory of the power
tool, and determine a slope for the sequence of current measures by
way of linear regression and operates to interrupt transmission of
torque based in part on the slope of the sequence of current
measures.
13. The power tool of claim of claim 12 wherein the controller
further operates to compare the slope to a minimum slope threshold;
adjust a slope counter in accordance with the comparison of the
slope with the minimum slope threshold, evaluate the slope counter
in relation to a setting criteria, and interrupt transmission of
torque to the output spindle when the slope counter meets the
setting criteria, where the setting criteria is indicative of a
desired stopping position for a fastener being driven by the power
tool.
14. The power tool of claim 10 wherein the controller, when the
clutch setting is a drill mode, ignores torque applied to the
output spindle.
15. The power tool of claim 10 wherein the controller provides
haptic feedback to the tool operator concurrently with interrupting
transmission of torque to the output spindle.
16. The power tool of claim 10 wherein the input component is
further defined as two pushbuttons integrated into the housing,
such that actuation of one pushbutton sets the clutch setting to a
drill mode and actuation of the other pushbutton sets the clutch
setting to a drive mode.
17. The power tool of claim 16 wherein one of the two pushbuttons
actuated by the tool operator is illuminated during operation of
the tool.
18. The power tool of claim 10 wherein the input component is
further defined as a rotary potentiometer switch assembly
including: an assembly platform rotatably mounted to the body; a
rotary device rotatably mounted to the assembly platform such that
manual axial rotation of the rotary device acts to create a clutch
setting; and opposed first and second directional switches mounted
to the assembly platform, wherein when one of the first or second
directional switches contacts the body during a manual rotation of
the assembly platform, either a forward or a reverse operating
direction of rotation command for the output spindle is
created.
19. The power tool of claim 10 further comprising a display port
located on the housing including multiple bi-color light emitting
diodes (LEDs) each operating to display three colors, including two
primary colors and a third color which is a mix of the two primary
colors, each LED color providing visual indication of multiple
different operating modes of the power tool.
20. The power tool of claim 10 further comprising a display port
located on the housing, wherein a numeric value for the selected
one of the user-defined drive modes is presented on the display
port.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/657,269, filed on Jun. 8, 2012. The entire
disclosure of the above application is incorporated herein by
reference.
FIELD
[0002] The present disclosure relates to portable hand held power
tools including drills and drill drivers.
BACKGROUND
[0003] It is known to provide a power tool with switches, knobs,
and other controls. For example, a power drill or driver typically
includes a trigger that the user actuates to cause rotation of a
tool held in a chuck. Power drills or drivers also typically
include a forward/reverse selector switch located near the trigger
that the user actuates to change a rotation direction of the tool.
Some power drills or drivers also include a clutch control (e.g., a
dial) that is used to change a clutch torque setting such that the
amount of resistance necessary to stop rotation of the chuck can be
set or changed by the user.
[0004] Conventional power tool controls suffer from certain
disadvantages. For example, conventional controls can be awkward to
manipulate while holding the power tool. The user is often required
to hold the tool with a first hand and set or change operating
controls with a second hand, and controls may take up substantial
space or be awkwardly located, thereby making setting or changing
control operations difficult. Moreover, these power tools may have
a manual only or an automatic only operated clutch, thereby
limiting operational control of the clutch and tool.
[0005] This section provides background information related to the
present disclosure which is not necessarily prior art.
SUMMARY
[0006] This section provides a general summary of the disclosure,
and is not a comprehensive disclosure of its full scope or all of
its features.
[0007] In one aspect of this disclosure, a method is provide for
operating a power tool having an electric motor drivably connected
to an output spindle. The tool is configured to receive an input
indicative of a clutch setting for an electronic clutch form the
tool operator, where the clutch setting is selectable from a drill
mode and a drive mode. In a drill mode, torque applied to the
output spindle is ignored; whereas, in the drive mode, the torque
applied to the output spindle is monitored and interrupted in an
automated manner by a controller when a fastener being driven
reaches a desired stopping position.
[0008] In other aspects of this disclosure, the clutch setting is
selectable from a drill mode, an automated drive mode and one or
more user-defined drive modes, where each of the user-defined drive
modes specifies a different value of torque at which to interrupt
transmission of torque to the output spindle. In an automated drive
mode, the controller interrupt torque to the output spindle in an
automated manner when a fastener being driven reaches a desired
stopping position. In a selected one of the user-defined drive
modes, the controller sets a value of a maximum current threshold
in accordance with the selected one of the user-defined drive modes
and interrupts torque to the output spindle when current measures
exceeding the maximum current threshold.
[0009] An improved technique for detecting when a fastener has
reaches a desired stopping position is also presented. The improved
techniques generally includes: sampling periodically current
delivered to the electric motor; storing a sequence of current
measures most recently sampled; and determining a slope for the
sequence of current measures by way of linear regression.
Transmission of torque to the output spindle can be interrupted
based in part on the slope of the current measures.
[0010] Further areas of applicability will become apparent from the
description provided herein. The description and specific examples
in this summary are intended for purposes of illustration only and
are not intended to limit the scope of the present disclosure.
DRAWINGS
[0011] The drawings described herein are for illustrative purposes
only of selected embodiments and not all possible implementations,
and are not intended to limit the scope of the present
disclosure.
[0012] FIG. 1 is a front left perspective view of a drill/driver of
the present disclosure;
[0013] FIG. 2 is a partial cross sectional front left perspective
view taken at section 2 of FIG. 1;
[0014] FIG. 3 is a front left perspective view of a rotary
potentiometer and switch assembly of the present disclosure;
[0015] FIG. 4 is a top left perspective view of the rotary
potentiometer and switch assembly of FIG. 3;
[0016] FIG. 5 is a top plan view of the rotary potentiometer and
switch assembly of FIG. 3;
[0017] FIG. 6 is a left side elevational view of the rotary
potentiometer and switch assembly of FIG. 3;
[0018] FIG. 7 is a flow diagram defining a forward/reverse clutch
operation using a rotary potentiometer/switch assembly of the
present disclosure;
[0019] FIG. 8 is a left rear elevational perspective view of the
drill/driver of FIG. 1;
[0020] FIG. 9A is a flow diagram defining a battery state of charge
operation of the present disclosure;
[0021] FIG. 9B is a table providing exemplary battery voltages at
various capacity levels associated with the flow diagram of FIG.
9A;
[0022] FIG. 10 is a current vs. time graph depicting a change in
current rate during operation in a drive mode;
[0023] FIG. 11A is a front left perspective view of the
drill/driver of FIG. 1;
[0024] FIG. 11B is a top view of the drill/driver depicting an
alternative display interface for selecting between a drill mode
and a drive mode;
[0025] FIG. 11C is an exploded view of the alternative display
interface module;
[0026] FIGS. 12A and 12B are first and second portions of a flow
diagram of the operating steps differentiating the drill mode from
the drive mode, including use of algorithms;
[0027] FIG. 13 is a left side elevational view of the drill/driver
of FIG. 1 during installation of a fastener through two
components;
[0028] FIG. 14 is a top left perspective view of the drill/driver
of FIG. 1;
[0029] FIG. 15 is a partial cross sectional left side elevational
view of the drill/driver of FIG. 13;
[0030] FIG. 16 is a flow diagram of a timed operation mode of the
drill driver of FIG. 1;
[0031] FIG. 17 is a voltage versus time graph identifying a current
flow during timed operation mode;
[0032] FIG. 18 is a left side perspective view of the drill/driver
of FIG. 1 during remote operation with a user interface device;
[0033] FIG. 19 is a flow diagram of an initialization operation of
the drill driver of FIG. 1 for selection of an operating mode;
[0034] FIG. 20 is a diagram of the electronic control system for
the drill driver of FIG. 1;
[0035] FIG. 21 is a flow diagram of drill driver operation in a
motor control mode;
[0036] FIG. 22A is a flow diagram of LED illumination corresponding
to selected clutch torque settings;
[0037] FIG. 22B is a table of selected input level, torque level
and corresponding LED display data corresponding to the clutch
torque flow diagram FIG. 22A;
[0038] FIG. 23 is a flow diagram for LED illumination indicated
during each of a forward and a reverse clutch operation;
[0039] FIG. 24 is a flowchart illustrating an improved technique
for setting a fastener in a workpiece;
[0040] FIGS. 25 and 26 are diagrams depicting an exemplary
embodiment for controlling operation of the drill driver to set a
fastener;
[0041] FIG. 27 is a diagram depicting another exemplary embodiment
for controller operation of the drill driver to set a fastener;
[0042] FIG. 28 is a perspective view of a drill driver having an
alternative display.
[0043] Corresponding reference numerals indicate corresponding
parts throughout the several views of the drawings.
DETAILED DESCRIPTION
[0044] Referring to FIG. 1, a portable hand-held power tool which
in one form is a drill driver 10 includes a body 12 having a handle
14 shaped to be grasped in a single hand of a user, a rechargeable
battery pack 16 that is releasably connected to a battery mounting
portion 18 of body 12, and a chuck 20 having two or more clutch
jaws 22 which are axially rotated with respect to a rotational axis
24. A clutch sleeve 26 is also rotatable with respect to rotational
axis 24 that is used to manually open or close clutch jaws 22.
While the following description is provided with reference to a
drill driver, it is readily understood that some of the features
set forth below are applicable to other types of power tools.
[0045] A manually depressible and return biased trigger 28 is
provided to initiate and control operation of drill driver 10.
Trigger 28 is operated by manually depressing in a trigger
engagement direction "A" and returns in a trigger release direction
"B" upon release. Trigger 28 is provided in a motor housing 30 that
according to several aspects is divisible into individual halves,
including a motor housing first half 30a and a motor housing second
half 30b which can be made for example of molded polymeric
material. Positioned adjacent to trigger 28 is a rotary
potentiometer/switch assembly 32. A portion 33b of rotary
potentiometer/switch assembly 32 extends freely outwardly from body
second half 30b on a second or left hand side of body 12. A similar
portion 33a (shown in reference to FIG. 5) extends freely outwardly
from body first half 30a on a first or right hand side of body 12.
Rotary potentiometer/switch assembly 32 provides several functions
which will be described in reference to subsequent figures. A
display port 80 is also provided with body 12 which will be
described in greater detail in reference to FIG. 8.
[0046] Referring to FIG. 2 and again to FIG. 1, with the motor
housing second half 30b removed for clarity, drill driver 10
further includes a DC motor 34 and a motor transmission 35, the
motor 34 operable using DC current from battery pack 16 and
controlled by trigger 28. Motor 34 and motor transmission 35 are
mounted in motor housing 30 and are drivably connected via an
output spindle (not shown) to chuck 20 for rotation of chuck 20. It
is readily understood that broader aspects of this disclosure are
applicable to corded tool as well as battery powered tools.
[0047] Rotary potentiometer/switch assembly 32 includes a rotary
member 36 in the shape of a circular disk wherein portion 33b
extending outward from body 12 is a portion of rotary member 36
extending freely outwardly with respect to body 12 on the left hand
side of body 12. The outwardly extending portions 33a, 33b of
rotary member 36 allow manual rotation and a side-to-side
displacement of rotary member 36 by the user of drill driver 10
from either the right hand side or left hand side of body 12.
Rotary member 36 is positioned in a housing space 38 of motor
housing 30 providing clearance for both axial rotation of rotary
member 36, and side-to-side displacement of rotary member 36 in
either a left hand or a right hand displacement such that rotary
potentiometer/switch assembly 32 performs at least dual functions
as will be described in reference to FIGS. 3-6. According to
further aspects, rotary member 36 can be replaced by a sliding
member, a rocking member, or other types in input components.
[0048] A printed circuit board (PCB) 40 is positioned in handle 14.
PCB 40 defines an electronic control circuit and includes multiple
components including a microcontroller 42 such as a microchip,
having a central processing unit (CPU) or the like for performing
multiple functions of drill driver 10, at least one electrically
erasable programmable read-only memory (EEPROM) function providing
storage of data or selected inputs from the user of drill driver
10, and at least one memory device function for storing both
temporarily and permanently saved data such as data lookup tables,
torque values and the like for use by drill driver 10. According to
other aspects (not shown), microcontroller 42 can be replaced by
separate components including a microprocessor, at least one
EEPROM, and at least one memory device.
[0049] Rotary member 36 is rotatable with respect to a rotary
member axis of rotation 43. Rotation of rotary member 36 can be in
either a first rotational direction "C" or a second rotational
direction "D" which is opposite to first rotational direction "C".
It is noted that the rotary member axis of rotation 43 can displace
when rotary member 36 is moved in the side-to-side displacement
described above and which will be described in greater detail in
reference to FIG. 5.
[0050] Referring to FIG. 3 and again to FIG. 2, the rotary
potentiometer/switch assembly 32 has rotary member 36 rotatably
connected to an assembly platform 44 such as a circuit board which
is housed within body 12. A connector 46 is fixed to assembly
platform 44 providing for electrical communication between assembly
platform 44 and printed circuit board 40, thereby including
assembly platform 44 with the electronic control circuit defined by
PCB 40. Assembly platform 44 includes an assembly platform first
end 48 having a first axle 50 extending from a first side of first
end 48 and a second axle 52 oppositely directed with respect to
assembly platform first end 48. First and second axles 50, 52 are
coaxially aligned defining an axle axis of rotation 54. The first
and second axles 50, 52 allow the assembly platform 44 as a unit to
rotate with respect to axle axis of rotation 54. The assembly
platform 44 further includes an assembly platform second end 56
having a mount member 58. Mount member 58 provides attachment and
support for each of a first biasing member 60 and an oppositely
directed second biasing member 62.
[0051] Referring to FIG. 4 and again to FIGS. 2 and 3, the first
biasing member 60, which according to several aspects can be a
compressible spring, contacts and is supported against a mount
member first face 64 of mount member 58. First biasing member 60 is
shown in its normally extended, non-biased condition. From this
position, first biasing member 60 is compressible in a first
compression direction "E". The second biasing member 62 is similar
to first biasing member 60 and therefore provides a substantially
mirror image configuration of a compressible spring which contacts
and is supported against a mount member second face 66 of mount
member 58. From its normally non-biased position shown in FIG. 4,
second biasing member 62 is elastically compressible in a second
compression direction "F" which is oppositely oriented with respect
to first compression direction "E". During axial rotation of
assembly platform 44 with respect to axle axis of rotation 54,
either the first or the second biasing member 60, 62 is elastically
depressed against one of the motor housing first or second halves
30a, 30b. The biasing force generated by compression of either
first or second biasing member 60, 62 acts to return the assembly
platform 44 to a neutral position when the manual force applied to
rotate assembly platform 44 is released.
[0052] Referring to FIG. 5 and again to FIGS. 2-4, as previously
noted assembly platform 44 is rotatable with respect to axle axis
of rotation 54 using first axle 50 and second axle 52 (not visible
in this view). With the assembly platform 44 positioned in a
neutral position, rotary member 36 is axially rotatable with
respect to rotary member axis of rotation 43 to either increase or
decrease an operating torque created as a torque limit command or
signal by the rotational position of rotary member 36 and applied
to chuck 20. Rotary member 36 can be rotated in each of a first
rotational direction "G", which is clockwise as viewed with respect
to FIG. 5, or in a second rotational direction "H", which is
opposite with respect to first rotational direction "G" and is
therefore counterclockwise as viewed in FIG. 5. Axial rotation of
rotary member 36 can be used, for example, to predetermine a torque
setting of chuck 20 between a minimum and a maximum predetermined
torque value as the torque limit command. For example, rotation of
rotary member 36 in the first rotational direction "G" can be used
to increase the torque setting or torque limit command, and
rotation of rotary member 36 in the opposite second rotational
direction "H" can be used to reduce the torque setting or torque
limit command. Rotary member 36 can therefore act as a rotary
potentiometer generating commands or signals transferred via
connector 46 to PCB 40. The first and second portions 33a, 33b of
rotary member 36 that extend outwardly from first and second halves
30a, 30b (shown in phantom) of body 12 are shown.
[0053] With continuing reference to FIG. 5, assembly platform 44
further includes mirror image switches which are actuated when
assembly platform 44 is manually rotated with respect to axle axis
of rotation 54. For example, when the operator applies a force to
rotary member 36 in a first force acting direction "J", rotation of
assembly platform 44 with respect to axle axis of rotation 54 acts
to elastically compress first biasing member 60 in the first
compression direction "E" until a first displacement member 68 of a
first directional switch 70 is depressed/closed. When the operator
applies a force to rotary member 36 from a second force acting
direction "K", the assembly platform 44 rotates with respect to
axle axis of rotation 54 such that second biasing member 62 is
elastically compressed in the second compression direction "F"
until a second displacement member 72 of a second directional
switch 74 is depressed/closed. When the force applied in either the
first or second force acting directions "J", "K" is removed, the
biasing force of either of the first or second biasing members 60,
62 causes the assembly platform 44 to return to its original or
neutral position, opening either the first or the second
directional switch 70, 74. Circuits closed by operation of either
the first or the second directional switch 70, 74 generate signals
or commands used to determine a rotational direction of chuck 20,
for example by setting either a forward (clockwise) rotation or a
reverse (counter clockwise) directional rotation. The "dual mode"
of operation provided by rotary potentiometer/switch assembly 32 in
one aspect is first to control clutch torque and second to control
the chuck rotation direction. The "dual mode" of operation can also
include multiple variations of torque application, directional
control, timed operation, clutch speed settings, motor current
control, operation from data saved in memory from previous
operations, and others as further defined herein.
[0054] The electronic control provided by microcontroller 42 and
the electronic control circuit of PCB 40 determines multiple
operations of drill driver 10. As previously noted, when first
directional switch 70 is closed, chuck 20 will operate in a forward
or clockwise operating rotational direction. In addition, by
subsequent rotation of rotary member 36 following the actuation of
first directional switch 70, additional modes of operation of drill
driver 10 can be selected, including selecting a speed setting of
motor 34, selecting an automatic torque cutout setting, selecting a
speed control response, selecting a fastening seating algorithm,
and additional modes which will be described later herein. If
second directional switch 74 is closed, chuck 20 will be rotated in
a reverse or counter-clockwise direction of rotation and subsequent
rotation of rotary member 36 can have similar control mode
selection features for operation of drill driver 10 in the reverse
direction. In addition, the electronic control provided by
operation of rotary member 36 and first and second directional
switches 70, 74 can also be used to customize the operation of
rotary member 36 through a series of operations of rotary member 36
and trigger 28 to suit either a left or right handed user of drill
driver 10.
[0055] For example, once the user has set a left or right hand mode
of operation, subsequent rotation of rotary member 36 can always
result in a forward mode being selected such that the operation of
drill driver 10 for either a right or left handed operator becomes
intuitive for the operator. An advantage of placing rotary member
36 adjacent to handle 14, where the control of rotary member 36 is
achieved for example by the thumb of the operator, provides for
one-handed operation of drill driver 10, allowing control of
multiple modes of operation in a one-handed operation. The same
one-handed operation is also permitted by the rotational
displacement provided by first and second axles 50, of assembly
platform 44 such that physical side-to-side rotational displacement
of assembly platform 44 about the axle axis of rotation 54 provides
additional functions for the accessible positions of rotary member
36.
[0056] Referring to FIG. 6 and again to FIGS. 2-5, the various
components of assembly platform 44 can be fixed. For example, first
and second axles 50, 52 and mount member 58 can be fixed using
adhesives or integrally connected to assembly platform 44 during a
molding process, creating assembly platform 44. First and second
directional switches 70, 74 (only second directional switch 74 is
clearly visible in this view) are also fixed to assembly platform
44. A mount member 75 fixed to assembly platform 44 allows for
axial rotation of rotary member 36. According to several aspects, a
planar surface 76 is defined by assembly platform 44 such that the
components mounted to assembly platform 44 are retained in the same
relative positions during axial rotation of rotary member 36 and
also during axial rotation of assembly platform 44. A plurality of
grip slots 78 can also be provided with rotary member 36 to assist
in the axial rotation of rotary member 36. Grip slots 78 can also
be positioned about the perimeter of rotary member 36 at locations
corresponding to individual rotary positions that visually indicate
to the operator the degree of rotation required to achieve a next
torque setting of drill driver 10.
[0057] Referring to FIG. 7, operation of the rotary
potentiometer/switch assembly 32 is depicted in a flow diagram. In
an initializing step 82, variables and hardware that may be in an
off or standby mode are initialized. In a next trigger timing step
83, a time period following initiation of trigger pull is measured
to determine if trigger 28 has been depressed for a minimum or
required time period. If following the trigger timing step 83 it is
determined that the minimum required time of trigger pull has not
been met, this step repeats itself until the required minimum time
period has been met. If following the trigger timing step 83 the
required minimum time of depression of trigger 28 has been met, a
latching step 84 is performed wherein the power supply to the motor
is latched, thereby providing electrical power to the electrical
components of drill driver 10. Following latching step 84, a read
EEPROM step 85 is performed wherein data saved in the EEPROM of
microcontroller 42 is accessed to initialize mode selection and to
illuminate appropriate ones of the first through sixth LEDs
102-112. Following read EEPROM step 85, a shutdown check step 86 is
performed wherein it is determined whether any of a power off
timeout has occurred, an under-voltage cutoff has occurred, or a
high temperature cutoff has occurred. If none of the conditions are
present as determined in shutdown check step 86, a trigger position
determination step 87 is performed wherein a trigger position ADC
(analog-digital converter) is read to determine if it is greater
than a predetermined start limit. If so, drill driver 10 is
positioned in motor control mode in a motor controlling step 88. If
the trigger position ADC reading is not greater than the
predetermined start limits, a forward wheel determining step 89 is
performed to determine if rotary member 36 has been rotated in a
forward rotational direction. If so, in a check forward mode step
90, a determination is made if drill driver 10 is already
positioned in a forward operating mode. If not, drill driver 10 is
returned to a previous forward mode in a return step 91. If drill
driver 10 is already in the forward operating mode, a next mode is
selected in a select next mode step 92. Following either return
step 91 or select next mode step 92, a setting step 93 is performed
wherein the LEDs, an H-bridge forming a portion of PCB 40, and a
maximum PWM (pulse width modulation) value are set. Following
setting step 93, or if the forward wheel determining step 89
indicates that rotary member 36 has not been rotated in a forward
rotating direction, a reverse wheel determining step 94 is
performed. It is initially determined if drill driver 10 is in a
forward operating mode in a check forward mode step 95, and if the
forward mode is indicated the current forward operating mode is
stored in a store mode step 96. Following either check forward mode
step 95 or store mode step 96, a setting step 97 is performed which
is similar to setting step 93 with the exception that the reverse
mode is set in addition to setting the LEDs, the "H" bridge
direction, and the maximum PWM. Returning to the shutdown check
step 86, if any of the power off timeout, under-voltage cutoff, or
high temperature cutoff indicators is present, a save to EEPROM
step 98 is performed wherein values presently set for operation of
drill driver 10 are saved to EEPROM of microcontroller 42.
Following save to EEPROM step 98, an unlatch step 99 is performed
wherein the power supply is unlatched.
[0058] Referring to FIG. 8, display port 80 can be provided on an
upper surface of motor housing 30 and extend across both first and
second halves 30a, 30b of motor housing 30. Display port 80
includes multiple bi-color light emitting diodes (LEDs) that are
capable of displaying three colors, as two pure or primary colors
plus a third color which is a mix of the two primary colors. Each
LED color can therefore provide visual indication of multiple
different operating modes of drill driver 10. The multiple LEDs
include a first, second, third, fourth, fifth, and sixth LED 102,
104, 106, 108, 110, 112, all positioned on an LED display screen
100. For example, the LEDs of display port 80 can represent
functions including a live torque reading, the status of battery
16, a direction of rotation of chuck 20, and a changing (increasing
or decreasing) torque signal as rotary member 36 is rotated.
[0059] In one example, first through sixth LEDs 102-112 can be used
to indicate the status of battery 16 as follows. If battery 16 is
fully charged and therefore at maximum voltage potential, all of
LEDs 102-112 will be illuminated. If battery 16 is at its lowest
voltage potential, only first LED 102 will be illuminated.
Successive ones of the LEDs, such as first, second and third LEDs
102, 104, 106, will be illuminated when battery 16 is at a capacity
greater than the minimum but less than the maximum. The color used
for illumination of the LEDs, for example during the battery status
display check, can be different from the color used for other mode
checks. For example, the battery state of charge indication can
illuminate the LEDs using a green color while torque indication can
use a blue color.
[0060] Referring to FIGS. 9A, 9B and again to FIG. 8, the battery
state of charge display of display port 80 is depicted on a battery
state of charge flow diagram 113 with corresponding voltages
provided in a table 142 of FIG. 9B. In an initial LED de-energizing
step 114, all of the LEDs 102-112 are turned off. In a next reading
step 116, a stack voltage of battery 16 is read. In a first voltage
determination step 118, if the battery voltage is above a
predetermined value, for example 20.2 volts, all of the LEDs
102-112 are turned on in a LED energizing step 120. If, following
the first voltage determination step 118, the voltage of battery 16
is less than 20.2 volts but greater than 19.7 volts, in a five LED
energizing step 124 LEDs 102-110 are turned on. Following the
second voltage determination step 122, if the voltage of battery 16
is less than 19.7 volts but greater than 19.2 volts, LEDs 102-108
are turned on in a four LED energizing step 128. Following the
third voltage determination step 126, if the voltage of battery 16
is less than 19.2 volts but greater than 18.7 volts as determined
in a fourth voltage determination step 130, LEDs 102-106 are turned
on in a three LED energizing step 132. Similarly, following fourth
voltage determination step 130, if a voltage of battery 16 is less
than 18.7 volts but greater than 18.2 volts, in a fifth voltage
determination step 134 LEDs 102-104 are turned on in a two LED
energizing step 136. Finally, in a sixth voltage determination step
138, if the voltage of battery 16 is less than 18.2 volts but
greater than 17.7 volts, only first LED 102 is turned on in a one
LED energizing step 140.
[0061] The battery status check can be performed by the operator of
drill driver 10 any time operation of drill driver 10 is initiated,
and will repeat the steps noted above depending upon the voltage of
the battery cells forming battery 16. For the exemplary steps
defined in battery state of charge flow diagram 113, the voltage
lookup table 142 of FIG. 9B, which can be saved for example in the
memory device/function provided with microcontroller 42 shown and
described in reference to FIG. 2, can be accessed for determining
the number of LEDs which will be illuminated based on multiple
ranges of battery voltages that are measured. It is noted the
values identified in voltage lookup table 142 can vary depending
upon the voltage and number of cells provided by battery 16.
[0062] Additional modes of operation for drill driver 10 can be
displayed on display port 80 as follows. For example, either
forward or reverse direction of operation for chuck 20 can be
indicated as follows. When the forward operating mode is selected,
first, fifth, and sixth LEDs 102, 110, 112 will be illuminated.
When a reverse or counterclockwise rotation of chuck 20 is
selected, fourth, fifth, and sixth LEDs 108, 110, 112 will be
illuminated. The color selected for indication of rotational
direction can vary from the color selected for the battery status
check. For example, the color indicated by the LEDs during
indication of the rotational direction can be blue or a combination
color of blue/green. Similar to the indication provided for the
battery status check, a live torque reading selected during
rotation of rotary member 36 will illuminate either one or multiple
successive ones of the LEDs depending upon the torque level
selected. For example, at a minimum torque level only first LED 102
will be illuminated. At a maximum torque level all six of the LEDs
102-112 will be illuminated. Individual ones of the LEDs will
successively illuminate as rotary member 36 is axially rotated
between the minimum and the maximum torque command settings.
Oppositely, the number of LEDs illuminated will reduce successively
as rotary member 36 is oppositely rotated, indicating a change in
torque setting from the maximum toward the minimum torque command
setting. When there are more settings than the number of LEDs
available, combination colored LEDs can be illuminated such as
blue/green. The LEDs of display port 80 will also perform
additional functions related to operation of chuck 20, which will
be described in greater detail with reference to clutch operating
modes to be further described herein.
[0063] In another aspect of this disclosure, the drill driver 10 is
configured to operate in different modes. For example, the drill
driver 10 may provide an input component (e.g., rotary member 36)
that enables the tool operator to select a clutch setting for an
electronic clutch. In one embodiment, the operator selects between
a drill mode and a drive mode. In a drill mode, the amount of
torque applied to the output spindle is ignored and transmission of
torque is not interrupted by the controller 42 during tool
operation; whereas, in a drive mode, torque applied to the output
spindle is monitored by the controller 42 during tool operation.
The controller 42 may in turn interrupt transmission of torque to
the output spindle under certain tool conditions. For example, the
controller may determine when a fastener being driven by the tool
reaches a desired stopping position (e.g. flush with the workpiece)
and terminate operation of the tool in response thereto without
user intervention. It is readily understood that the selected
clutch setting can be implemented by the controller 42 with or
without the use of a mechanical clutch. That is, in some
embodiments, the drill driver 10 does not include a mechanical
clutch.
[0064] Referring to FIG. 11A, drill driver 10 can include
individual switches for operator selection between either a drill
mode or a drive mode. A drill selector switch 170 is depressed when
drill operating mode is desired. Conversely, a drive selector
switch 172 is depressed when drive operating mode is desired. The
drill and drive operating modes are both operable with drill driver
10 regardless of the rotating direction of chuck 20. For example,
operation in both the drill mode and drive mode are possible in a
clockwise or forward rotational direction 174 and also in a counter
clockwise or reverse rotational direction 176 of chuck 20. It is
further noted that the selected one of either drill selector switch
170 or drive selector switch 172 may illuminate upon depression by
the user. This provides further visual indication of the mode
selected by the user.
[0065] Drill selector switch 170 and drive selector switch 172 may
be actuated in different sequences to activate other tool operating
modes. For example, the drive selector switch 172 may be pushed and
held for a fixed period of time (e.g., 0.15 sec) to activate a high
torque drive mode; whereas, pushing the driver selector switch 172
twice in the fixed period of time may activate a low torque drive
mode. To indicate the different drive modes, the driver selector
switch 172 may be lit steady when in the high torque drive mode and
blinking when in the low torque drive mode. These two sequences are
merely illustrative and other combinations of sequences are
envisioned to activate these or other tool operating modes.
[0066] FIG. 11B depicts an alternative display interface 1100 for
selecting between a drill mode and a drive mode. In this
embodiment, the buttons for selecting the operating mode are
integrated into the top surface of the drill driver housing. A
drill icon 1102 is used to represent the drill mode; whereas, a
screw icon 1104 is used to represent the drive mode although other
types of indicia may be used to represent either of these two
operating modes. Once selected by the tool operator, the mode is
activated (i.e., a signal is sent from the button to the
controller) and an LED behind the button is lit to indicate which
operating mode has been selected. The LED lights the icon which
remains lit until the operating mode is changed, the tool becomes
inactive or is otherwise powered down. The display interface may
also include LEDs 1106 for indicating the state of charge of the
battery in a similar manner as described above.
[0067] An exemplary construct for the display interface is further
illustrated in FIG. 11C. The display interface module is comprised
of a plastic carrier 1112, a flexible circuit board 1113, and a
translucent rubber pad 1114. The carrier 1112 serves to hold the
assembly together and attaches to the top of the housing. The
circuit board 1113 supports the switches and LEDs and is sandwiched
between the rubber pad 1114 and the carrier 1112. The rubber pad is
painted black and laser etched to form the icon shapes thereon.
[0068] Referring to FIGS. 12A and 12B and again to FIG. 11, a
drill/drive mode flow diagram 177 defines steps taken by the
control circuit of drill driver 10 distinguishing between a drill
mode 180 and a drive mode 182. In an initial check mode step 178,
the status of drill selector switch 170 and/or drive selector
switch 172 is checked to determine which input is received by the
user. If the check mode step 178 indicates that drill mode 180 is
selected, a trigger actuation first function 184 is initiated when
trigger 28 is depressed. Following trigger actuation first function
184, a motor start step 186 is performed, thereby initiating
operation of motor 34. During operation of the motor 34, an
over-current check step is performed to determine if motor 34 is
operating above a predetermined maximum current setting. If the
over-current indication is present from motor over-current check
188, an over current flag 190 is initiated followed by a stop motor
step 192 where electrical power to motor 34 is isolated. A drill
drive mode return step 194 is then performed wherein continued
operation of motor 34 is permitted after the user releases trigger
28. Returning to the motor over-current check 188, if an
over-current condition is not sensed during the motor over-current
check 188, continued operation of motor 34 is permitted.
[0069] With continuing reference to drill/drive mode flow diagram
177, when driver selector switch 172 is depressed by the user and
drive mode 182 is entered, a check is performed to determine if an
auto seating flag 196 is indicated. If the auto seating flag 196 is
not present, the following step determines if a timed operating
system flag 198 is present. If the timed operating system flag 198
is present, in a next duty cycle setting step 200 a timed operating
duty cycle is set. Following step 200, motor 34 is turned on for a
predetermined time period such as 200 ms (milliseconds) in a timed
operating step 202. Following timed operating step 202, in a
seating/timed operating flag indication step 204, the control
system identifies if both an auto seating flag and a timed
operating flag are indicated. If both the auto seating flag and
timed operating flag indication step 204 are indicated, operation
of motor 34 is stopped in a stop motor running step 206.
[0070] Returning to timed operating system flag 198, if the flag is
not present, a trigger activation second function 208 is performed
which initiates operation of motor 34 in a timed turn on motor
start 210. Following this and similar to motor over-current check
188, a motor over-current check 212 is performed. If an
over-current condition is not indicated, a first routine 214
algorithm is actuated followed by a selection "on" check 216. If
the selection "on" check 216 is negative, a second torque routine
218 algorithm is run, following which if a positive indication is
present, returns to the seating/timed operating flag indication;
and if negative, returns to the return step 194. If the selection
"on" check performed at step 216 is positive, a third routine 220
algorithm is run which if positive thereafter returns to
seating/timed operating flag indication step 204 and, if negative,
returns to return step 194.
[0071] In some embodiments, the drive mode may divided into an
automated drive mode and one or more user-defined drive modes,
where each of the user-defined drive modes specify a different
value of torque at which to interrupt transmission of torque to the
output spindle. In the automated drive mode, the controller
monitors the current being delivered to the motor and interrupts
torque to the output spindle in response to the rate of change of
current measures. Various techniques for monitoring and
interrupting torque in an automated manner are known in the art,
including techniques to setting a fastener in a workpiece, and fall
within the broader aspects of the disclosure. An improved technique
for detecting when a fastener reaches a desired stopping position
is further described below. In such embodiments, it is readily
understood that the input component may be configured for selection
amongst a drill mode, an automated drive mode and one or more
user-defined drive modes.
[0072] Referring to FIG. 10 and again to FIGS. 1 and 2, a current
versus time graph 144 defines a typical motor current draw during
operation to install a fastener using drill driver 10. Initially,
an inrush current 146 briefly peaks prior to the current draw
continuing at a low rate of change (LROC) current 148. LROC current
148 corresponds to a body of a fastener such as a screw penetrating
a material such as wood at a constant speed. At the time when a
head of the fastener contacts and begins to enter the wood, the
current draw changes to a high rate of change (HROC) current 150
for a brief period of time until a current plateau 152 is reached,
defining when the fastener head is fully embedded into the wood. As
is known, the level of current draw is proportional to the torque
created by motor 34.
[0073] In a selected one of the user-defined drive modes, the
controller sets a value of a maximum current threshold in
accordance with the selected one of the user-defined drive modes
and interrupts torque to the output spindle in response to the
current measures exceeding the maximum current threshold. For
example, the user selects one of the user-defined drives modes as
the desired clutch setting using, for example rotary member 36.
Current levels 154 designated as "a", "b", "c", "d", "e", "f"
correlate to the plurality of predefined torque levels designated
as "1", "2", "3", "4", "5", "6", respectively. During tool
operation, the controller 42 will act to terminate rotation of the
chuck when the current monitored by the controller 42 exceeds the
current level associated with the selected user-defined drive mode
(i.e., torque setting). The advantage of providing both types of
drive modes (i.e., control techniques) within drill driver 10
includes the use of current level increments 154 which, based on
prior operator experience, may indicate an acceptable predetermined
torque setting for operation of chuck 20 in a specific material.
Where the user may not be familiar with the amount of fastener
headset in a particular material and/or with respect to a
particular sized fastener, the automatic analysis system can be
selected, providing for acceptable setting of the fastener which
may occur in-between individual ones of the current level
increments 154.
[0074] FIG. 24 illustrates an improved technique for controlling
operation of the drill driver when driving a fastener. Briefly, the
current delivered to the electric motor is sampled periodically at
502 by the controller of the drill driver. The current measures
most recently sampled by the controller are stored at 504 in a
memory of the drill driver. From the most recently sampled current
measures, a slope for the current measures is determined at 506 by
way of linear regression. Linear regression is used because it has
a better frequency response making it more immune to noise as
compared to conventional computation methods. When a fastener being
driven by the drill driver reaches a desired stopping position,
torque transmitted to the output shaft is interrupted at 508 by the
controller. The desired stopping position is determined based in
part on the slope of the current measures as will be further
described below.
[0075] FIGS. 25 and 26 further illustrating an automated technique
for setting a fastener in a workpiece. Current delivered to the
electric motor is sampled periodically by the controller of the
drill driver. In an example embodiment, the controller can ignore
current samples captured during an inrush current period (e.g., 180
ms after trigger pull). Whenever there is a change in the trigger
position (i.e., change in PWM duty cycle), the controller will stop
sampling the current until the inrush current period has lapsed. In
some embodiments, the automated technique is implemented by the
controller regardless of the position of the trigger switch. In
other embodiments, the automated technique is only implemented by
the controller when the trigger position exceeds a predefined
position threshold (e.g., 90%). Below this position threshold, the
tool operates at lower speeds, thereby enabling the tool operator
to set the fastener to the desired position without the need for
the automated technique.
[0076] Current measures may be digitally filtered before computing
the current change rate. In an example embodiment, current is
sampled in 15 milliseconds intervals. During each interval, the
controller will acquire ten current measures as indicated at 560
and compute an average from the ten measures although more or less
measures may be acquired during each interval. The average for a
given interval may be considered one current sample and stored in
an array of current samples indicated at 562 in FIG. 26, where the
array of current samples stores a fixed number (e.g., four) of the
most recently computed values. The controller will then compute an
average from the current samples in the array of current samples.
The average for the values in the array of current samples is in
turn stored in a second array as indicated at 564 in FIG. 26, where
the second array also stores a fixed number (e.g., five) of the
most recently computed averages. These averaged current measures
can then be used to determine the rate of current change. Other
techniques for digitally filtering the current measures are also
contemplated by this disclosure.
[0077] With continued reference to FIG. 25, the slope of the
current is determined at 524 from the digitally filtered current
measures. In an example embodiment, a linear regression analysis is
used to compute the slope. In a scatter plot, the best fit line of
the scatter data is defined by the equation y=a+bx, where the slope
of the best fit line can be defined as
b = xy - ( x y ) / n x 2 - ( x ) 2 / n , ##EQU00001##
where n is the number of data points. The intercept will be ignored
in this disclosure. For illustration purposes, assume data scatter
plot with current values for y of [506,670,700,820,890]
corresponding to sample values of [1, 2, 3, 4, 5], such that n=5.
Using linear regression, the slope b of the best fit line is equal
to 91.8. While a simple linear regression technique has been
explained, other linear regression techniques are also contemplated
by this disclosure.
[0078] Slope of the current measures may be used as the primary
indicator for when the fastener has been set at a proper depth in
the workpiece. Particularly, by using the slope of the current, the
tool is able to determine when the tool is in the HROC (of current)
area shown in the graph of FIG. 10. In the example embodiment, a
slope counter is maintained by the controller. The current slope is
compared at 524 to a minimum slope threshold. For example, the
minimum slope threshold may be set to a value of 40. This value may
be set such that slope values exceeding the minimum slope threshold
are indicative of the HROC 150 range shown in FIG. 10. The slope
threshold value may be derived empirically for different tools and
may be adjusted according to the sampling time, motor attributes
and other system parameters. In embodiments where the automated
technique is implemented by the controller only when the trigger
position exceeds a predefined position threshold, minor variations
in trigger position (e.g., 10% from a baseline position) can be
ignored once the current slope exceeds the minimum slope threshold
and until such time as the fastener has been set and the torque to
the output spindle is interrupted.
[0079] The slope counter is adjusted in accordance with the
comparison of the current slope to the minimum slope threshold. The
slope counter is incremented by one when the computed slope exceeds
the minimum slope threshold as indicated at 536. Conversely, the
slope counter is decremented by one when the computed slope is less
than or equals the minimum slope threshold as indicated at 532.
When the slope is less than or equal to the minimum slope
threshold, the value of the current slope is also set to zero as
indicated at 528. In the event the slope counter is equal to zero,
the slope counter is not decremented further and the slope counter
remains at zero as indicated at 534. Following each adjustment, the
value of the slope counter is stored in an array of slope counts as
indicated at 566 in FIG. 26, where the array of slope counts stores
a fixed number (e.g., five) of the most recent slope count
values.
[0080] Next, the slope counts are evaluated at 546 in relation to a
fastener criteria. The fastener criteria at step 546 includes both
a setting criteria, which is indicative of a desired stopping
position for the fastener being driven by the tool, and a default
criteria. The setting criteria and default criteria may be used
together, as shown in 546 of FIG. 25, or only one of the criteria
may be used. The setting criteria will be described first. In the
setting criteria a fastener is assumed to have reached a desired
stopping position when the slope counts increase over a series of
values stored in the array of slope counts, where the series of
values may be less than or equal to the total number of values
stored in the entire array. In this example, each slope count value
in the array is compared to an adjacent slope count value starting
with the oldest value. The setting criteria is met when each value
in the array is less than the adjacent value as compared from
oldest value to the most recent value. For example, if the array is
designed to hold five slope count values (SC1 through SC5), the
setting criteria may be met when the consecutive count values are
each increasing--i.e., SC1<SC2<SC3<SC4<SC5. In other
words, the setting criteria is satisfied when the controller
detects five successive computer slope values greater than the
predetermined minimum slope threshold.
[0081] As noted above, the setting criteria may not use the entire
array of values. For example, the array may be designed to hold
five slope count values, but the setting criteria may be set such
that an increase of counts over a series of four values (e.g.
SC2<SC3<SC4<SC5) is sufficient. Other variations regarding
the particular number of counts required are also contemplated.
[0082] The fastening criteria evaluated at step 546 may also
include a default criteria. In some instances, the setting criteria
described above with respect to FIGS. 25 and 26 may fail to trigger
due to, for example, an anomaly reading or variations in a
workpiece which result in the controller failing to detect the
occurrence of the above-described setting criteria. In that case,
there may be an additional criteria serving as a default criteria.
In the default criteria, a fastener is assumed to have reached, or
passed, a desired stopping position when the slope count peaks
within a series of values stored in the array. In other words, if
after detecting successive slope values that exceed the minimum
slope threshold, the controller now detects successive slope values
less than the minimum slope threshold, it is apparent the
above-described setting criteria will not be met.
[0083] As with the setting criteria, the series of values may be
less than or equal to the number of values stored in the entire
array. In this example, slope count values in the array are again
compared to each other. The default criteria is met when the slope
count values in the array increase from the oldest value to an
intermediate peak value and then decrease from the intermediate
peak value to the most recent value. For example, the default
criteria may be met if SC1<SC2<SC3>SC4>SC5. Of course,
other particular default criteria may be used. For example, the
default criteria may require more successive increases or more
successive declines than that provided in the example above (e.g.,
SC1<SC2<SC3<SC4>SC5>SC6>SC7; or
SC1<SC2>SC3>SC4; etc.). In this embodiment shown in FIG.
25, the setting criteria and default criteria are used together.
However, in an alternative embodiment, each may be used alone.
Other types of setting and default criteria are also contemplated
by this disclosure.
[0084] Torque transmitted to the output spindle is interrupted at
548 when the slope counts meet the setting criteria or default
criteria; otherwise, tool operation continues as indicated at 550.
Torque may be interrupted in one or more different ways including
but not limited to interrupting power to the motor, reducing power
to the motor, actively braking the motor or actuating a mechanical
clutch interposed between the motor and the output spindle. In one
example embodiment, the torque is interrupted by braking the motor,
thereby setting the fastener at the desired position. To simulate
the electronic clutching function, the user may be subsequently
provided with haptic feedback. By driving the motor back and forth
quickly between clockwise and counter-clockwise, the motor can be
used to generate a vibration of the housing which is perceptible to
the tool operator. The magnitude of a vibration is dictated by a
ratio of on time to off time; whereas, the frequency of a vibration
is dictated by the time span between vibrations. The duty cycle of
the signal delivered to the motor is set (e.g., 10%) so that the
signal does not cause the chuck to rotate. Operation of the tool is
terminated after providing haptic feedback for a short period of
time. It is to be understood that only the relevant steps of the
technique are discussed in relation to FIG. 25, but that other
software-implemented instructions may be needed to implement the
technique within the overall operation of the tool.
[0085] FIG. 27 illustrates an additional technique for controlling
operation of the drill driver when driving a fastener. Current
delivered to the electric motor can be sampled and filtered at 582
by the controller in the same manner as described above in relation
to FIG. 25. Likewise, the slope of the current samples can be
determined at 584 in the manner described above.
[0086] In this technique, motor speed is used as a secondary check
on whether to interrupt transmission of torque to the output
spindle but only when the current slope exceeds a minimum slope
threshold. Accordingly, the current slope is compared at 586 to a
minimum slope threshold (e.g., with a value of 40). The secondary
check proceeds at 588 when the current slope exceeds the minimum
slope threshold; otherwise, processing continues with subsequent
current sample as indicated at 582.
[0087] To perform the secondary check, motor speed is captured at
588. In one example embodiment, motor speed may be captured by a
Hall effect sensor disposed adjacent to or integrated with the
electric motor. Output from the sensor is provided to the
controller. Other types of speed sensors are also contemplated by
this disclosure.
[0088] In the example embodiment, the controller maintains a
variable or flag (i.e., Ref_RPM_Capture) to track when the current
slope exceeds the minimum slope threshold. The flag is initially
set to false and thereafter remains false while the present slope
is less than the minimum slope threshold. At the first occurrence
of the current slope exceeding the minimum slope threshold, the
flag is false and the controller will set a reference motor speed
equal to the present motor speed at 592. The reference motor speed
is used to evaluate the magnitude of decrease in motor speed. In
addition, the flag is set to true at 593 and will remain set to
true until the current slope is less than the minimum slope
threshold. For subsequent and consecutive occurrences of the
current slope exceeding the minimum slope threshold, the flag
remains set to true and reference speed is not reset. In this way,
the flag (when set to true) indicates that preceding slope values
have exceeded the minimum slope threshold.
[0089] Next, the present speed is compared at 594 to the reference
speed. When the motor is slowing down (i.e., the reference speed
exceeds the present speed), a further determination is made as to
the size of the decrease. More specifically, a difference is
computed at 595 between the reference speed and the present motor
speed. A difference threshold is also set at 596 to be a predefined
percentage (e.g., 5%) of the reference speed. The predefined
percentage can be derived empirically and may vary for different
tool types. The difference is then compared at 597 to the
difference threshold. Processing of subsequent current sample
continues until the difference between the reference speed and the
present speed exceeds the difference threshold as indicated at 597.
Once the difference between the reference speed and the present
speed exceeds the difference threshold (and while the motor speed
is decreasing), transmission of torque to the output spindle is
interrupted at 598. It is to be understood that only the relevant
steps of the technique are discussed in relation to FIG. 25, but
that other software-implemented instructions may be needed to
implement the technique within the overall operation of the tool.
Furthermore, the secondary check described above in relation to
FIG. 27 is intended to work cooperatively (e.g., in parallel with)
the technique described in FIGS. 25 and 26. It is also envisioned
that this technique may be implemented independent from the
technique described in FIGS. 25 and 26 as a method for
automatically setting a fastener in a workpiece.
[0090] Referring to FIG. 13 and again to FIGS. 1-6, when the user
places the drill driver 10 in a clutch mode by manual rotation or
operation of the rotary member 36 of rotary potentiometer/switch
assembly 32, and positions a tool such as a setting tool 222 in
clutch jaws 22 of chuck 20, a first fastener 224 can be driven into
first and second components 226, 227 to join the first and second
components 226, 227. Subsequent operation of trigger 28 permits
installation of first fastener 224 to a desired depth or degree of
head seating for a fastener head 228 in relation to a component
surface 230 of first component 226. Because different screws have
different characteristics, the drill driver 10 may enable the user
to rough tune the fastener setting algorithm. For example, the
current change rate threshold for a shorter screw may be lower than
for a longer screw. To accommodate such differences, the drill
driver 10 may provide two or more different user-actuated buttons
that allow the user to tune the fastener setting algorithm.
Continuing with the example above, one button may be provided to a
shorter screw and one button may be provided for a longer screw.
The current change rate threshold may be adjusted depending upon
which button is actuated by the tool operator before an
installation operation. It is readily understood that other
parameters of the fastener setting algorithm or the tool (e.g.,
motor speed) may be adjusted in accordance with button actuation.
Moreover, more or less buttons may be provided to accommodate
different fastener characteristics or installation conditions.
[0091] After completing installation of first fastener 224 such
that fastener head 228 contacts component surface 230, it is often
desirable to install a second or more fasteners to couple the first
and second components 226, 227. Referring to FIG. 14 and again to
FIGS. 12 and 13, drill driver 10 can further include a control
feature zone 232 positioned, for example, at an upper facing
surface of motor housing 30. Control feature zone 232 can include a
plus (+) button 234 and a minus (-) button 236, as well as a memory
store button 238. After completing installation of first fastener
224, the user can press the memory store button 238 to record an
amperage draw that was required to seat first fastener 224.
[0092] Referring to FIG. 15 and again to FIGS. 1-2 and 12-14, to
install a second or subsequent fastener 224', the user again
presses the memory store button 238 and actuates trigger 28 to
begin installation of second fastener 224'. The electronic control
circuit of PCB 40 senses when the current draw that equals the
current draw stored in the memory feature of microcontroller 42 is
again reached during the installation of fastener 224' and provides
feedback to the user that fastener 224' has seated in a similar
manner as first fastener 224. As previously noted, the current draw
for installation of each of the fasteners 224, 224' can be equated
to a torque force required to drive the fastener. After the control
circuit identifies that fastener 224, 224' is nearly seated based
on the torque level sensed, the control circuit can vary the
feedback to allow the user better control in stopping installation
of fastener 224' at the appropriate time and/or depth.
[0093] The feedback provided to the user can be manipulated as
follows. First, the output of motor 34 can be stopped. Second, the
speed of motor 34 can be reduced. For example, the speed of motor
34 can be reduced from approximately 600 rpm to approximately 200
rpm. This reduction in operating speed provides the user with
visible feedback on the rate at which the fastener is being
installed and provides additional time for the user to respond to
how far fastener 224' is being set into the first and second
components 226, 227. Third, operation of motor 34 can be ratcheted,
for example by pulsing motor 34 on and off to provide discreet,
small rotations of the fastener 224'. This acts to slow down the
average rotation speed of chuck 20, providing the user more control
in setting the depth of penetration of fastener 224'. This could
also function as an indication to the user that fastener
installation is nearly complete and that the drill driver 10 has
changed operating mode. In addition, ratcheting of motor 34 also
provides a sensation to the user similar to a mechanical clutch
operation. Fourth, the varied output of motor 34 from the above
second and third operations can continue indefinitely or could
continue for a fixed period of time and then stop. For example, the
varied output of motor 34 can continue until the user releases
trigger 28.
[0094] With continuing reference to FIG. 14, in addition to the
memory storage feature provided by memory store button 238, the
user can use either the plus button 234 or the minus button 236 to
fine tune a current draw limit in response to slight variations in
either the fastener and/or the first or second component 226, 227.
For example, if the user identifies that the amperage draw saved
using memory store button 238 after installation of the first
fastener 224 does not seat the fastener head 228 of second fastener
224' to an acceptable degree, the user can press the plus button
234 to incrementally increase a cutout level of current load
provided to motor 34. Similarly, but to an opposite extent, the
minus button 236 can be depressed to incrementally decrease the
cutout level of current load. The features provided by plus button
234, minus button 236, and memory store button 238 are available in
either drill or drive mode. These features allow the user to fine
tune the operation of drill driver 10 over a wide variety of
materials, such as wood, plywood, particle board, plastics, metal,
and the like, for which universal limits cannot be established.
[0095] Referring again to FIGS. 12 and 14 as well as to FIGS. 1 and
2, in the event that operation of motor 34 stops before fastener
head 228 is completely engaged or parallel with respect to
component surface 230, a timed operation mode is available to
complete the installation of fastener 224 which provides an
automatic period of operating time for motor 34, thereby
eliminating the need for the user to estimate the time or degree of
rotation of chuck 20 to achieve full setting of fastener 224. When
operation of motor 34 ceases and the user releases trigger 28, if
the user visually recognizes that additional displacement of
fastener 224 is required, and if the user subsequently depresses
trigger 28 within a predetermined time period after the motor 34
has ceased operation, a timed operation mode is automatically
engaged. The predetermined time period for initiation of the timed
operation mode can be varied, but can be set, for example, at a
period of time of approximately one second. Therefore, if the user
recognizes that additional driving force is required to seat
fastener 224' and again depresses trigger 28 within approximately
one second of the stop of motor 34, motor 34 is again energized to
rotate chuck 20 for a period of time approximating 200 ms of chuck
20 rotation. If the first operation in timed operation mode is not
sufficient to fully seat fastener 224, and the user releases
trigger 28 and again depresses trigger 28 within approximately one
second, a second or subsequent timed operation mode operation of
approximately 200 ms will occur. The number of timed operation mode
operations is not limited; therefore, the user can continue in this
mode provided that trigger 28 is depressed within the minimum time
period required. The timed operation mode will time-out if the user
does not again depress trigger 28 within the predetermined time
period, such as the exemplary one second time period described
above. Following the time-out of the timed operation mode
operation, the drill driver 10 will return to normal or the
previous operating mode based on the parameters previously set by
the user.
[0096] Referring to FIG. 16 and again to FIGS. 12, 14, and 1-2, a
timed operation mode flowchart identifies the various steps of
operation of the electronic control circuit of drill driver 10
providing for timed operation mode control. Initially, with drill
driver 10 in drive mode, when the user releases trigger 28 the
control circuit searches for a timed operation flag 242. If the
timed operation flag 242 is present, indicating that the user has
re-depressed trigger 28 within a predetermined time period (for
example 1 second), a timed operation duty cycle set step 244 is
performed which subsequently directs, via a motor turn on step 246,
motor 34 to energize for a predetermined time period (for example
200 ms) of chuck 20 rotation. As motor 34 operates in the timed
operation mode, following indication by a counter that timed
operation has been completed, in a stop motor step 248 motor 34 is
de-energized. After motor 34 is de-energized, an increase switch
hold counter step 250 initiates, which will allow further operation
in the timed operation mode if trigger 28 is again depressed within
the predetermined time period. In a switch check step 252, a check
is performed to identify if an analog digital converter (ADC)
switch controlled by trigger 28 is still closed while an additional
increase switch hold counter step 250 is performed. If the switch
check step 252 indicates that the trigger 28 has been released, a
first comparison step 254 is performed wherein a switch hold
counter is compared to a normal hold counter to determine if the
switch hold counter is less than the normal hold counter. If the
switch hold counter in first comparison step 254 is not less than
the normal hold counter, a subsequent second comparison step 256 is
performed wherein it is determined if the switch hold counter is
greater than the normal hold counter. If, as a result of the second
comparison step, the switch hold counter is not determined to be
greater than the normal hold counter, the timed operation mode is
ended. Returning to the timed operation flag 242 initially queried
at the start of the timed operation mode, if timed operation flag
242 is not present, the timed operation mode cannot be
initiated.
[0097] Returning to the first comparison step 254, if the switch
hold counter is less than the normal hold counter, a decrease
counter step 258 is performed wherein the timed operation time
delay counter is decreased. Returning to the second comparison step
256, if the switch hold counter is greater than the normal hold
counter, an increase counter step 260 is performed wherein the
timed operation time delay counter is increased. Following either
the decrease counter step 258 or the increase counter step 260, the
timed operation mode is timed-out.
[0098] Referring to FIG. 17 and again to FIG. 16, a voltage versus
time graph 262 identifies the current draw at various voltages over
time provided for operation of motor 34 in the timed operation
mode.
[0099] If drill driver 10 is preset to operate in an automatic
operating mode, the timed operation mode can be automatically
induced when the electronic control system identifies that motor 34
has stopped rotation, for example due to either the maximum current
or torque setting being reached, while the user continues to
depress trigger 28. After the determination that motor 34 has
stopped for a predetermined period of time while trigger 28 is
still depressed, the timed operation mode automatically begins and
will rotate motor 34 and chuck 20 for approximately 200 ms. The
predetermined time period for automatic initiation of the timed
operation mode can also be for example one second, or set to any
other desired time period.
[0100] If drill driver 10 is set to operate in the manual mode and
the rotary potentiometer/switch assembly 32 is used to predetermine
or preset an operating torque via a torque command for chuck 20,
motor 34 will stop when the predetermined torque setting is
reached. If the user releases trigger 28 at this time, and then
re-depresses trigger 28 within a predetermined period of time, a
last saved high current level required to fully seat a fastener,
saved for example in the EEPROM or memory device/function of
microcontroller 42, will be automatically reapplied, thereby
further rotating chuck 20 until the high current level last saved
in memory is achieved. This permits a combination of a manual and
an automatic operation of drill driver 10 such that the
predetermined or preset torque limits manually entered by the user
can be supplemented automatically by a current level saved in the
memory corresponding to a fully set fastener position.
[0101] Referring to FIG. 18 and again to FIGS. 1 and 2, information
stored in any of the various memory devices/functions of drill
driver 10 can be supplemented by additional information from one or
more offsite locations, to increase the number of operations
performed by drill driver 10, or to change tool performance for
particular tasks. For example, where electronic clutch settings for
multiple different fasteners are available for multiple different
material combinations, the user can download additional data for
these clutch settings which will automatically be saved for use for
operation of drill driver 10. To receive new data, a receiver 264
provided in drill driver 10 is connected to a programmable
controller 266. According to one aspect, an application library 268
that is remote from drill driver 10 contains data to transfer to
drill driver 10. Data stored at application library 268 can be
transferred upon query by the user via a wireless signal path 270
to a user interface device 272. Predetermined password or
authorization codes can be sent to the user to authorize entry into
application library 268. User interface device 272 can be one of
multiple devices, including computers or portable cell phones such
as a smartphone. The data received wirelessly by the user interface
device 272 and temporarily stored therein can be subsequently
transferred by the user via a wireless signal path 274 to drill
driver 10. The data received via the wireless signal path 274 from
user interface device 272 is received at receiver 264 and stored by
programmable controller 266 or other memory devices/functions of
drill driver 10. This operation increases or supplements the
database of data saved by drill driver 10 such that new information
that may become available during the lifetime of drill driver 10
can be used.
[0102] Referring to FIG. 19, an initialization flow diagram 276
identifies the various steps taken by the electronic control system
of drill driver 10 upon initial startup of the unit. In an
initialization step 278, variables and hardware required during
startup of the unit are initialized. In a following read EEPROM
step 280, the data saved in the EEPROM of microcontroller 42 is
read to determine the last mode of operation and thereby used to
initialize the mode selection for initial operation of drill driver
10. In a check status step 282, it is determined whether any of a
power off timeout has occurred, whether an under-voltage cutoff has
occurred, whether a high temperature cutoff has occurred, or if an
over-current flag is indicated. If none of the conditions
identified by check status step 282 are present, a subsequent read
trigger step 284 is performed wherein the analog-digital converter
(ADC) for trigger 28 is read to determine if the ADC signal is
greater than a predetermined start limit. If the start limit is not
exceeded, as determined in read trigger step 284, a stop motor
running operation 286 is performed. If the limits read for the
trigger ADC signal in read trigger step 284 are greater than the
predetermined start limits, a select mode step 288 operates to
return to the check status step 282.
[0103] Following the stop motor running operation 286, a first
check button step 290 is performed wherein it is determined if a
forward operational selection button or switch is actuated. If the
first check button step 290 is positive, a set forward mode step
292 is performed. If the first check button step 290 is negative, a
second check button step 294 is performed, wherein it is determined
if a reverse operational selection button or switch has been
actuated. If the second check button step 294 is positive, a set
reverse mode step 296 is performed. If the second check button step
294 is negative, a third check button step 298 is performed wherein
a determination is made if the drive mode button or drive mode
selector is actuated. If the third check button step 298 is
positive, a set drive mode step 300 is performed. If the third
check button step 298 is negative, a fourth check button step 302
is performed wherein it is determined if the drill mode button or
drill mode selector is actuated. If the result of the fourth check
button step 302 is positive, a set drill mode step 304 is
performed. If the fourth check button step 302 is negative, a clear
flag step 306 is performed wherein an auto seating flag is set to
zero.
[0104] Returning to the check status step 282, if any of the items
checked are indicated, a stop motor step 308 is performed to stop
operation of motor 34. Following the stop motor step 308, a saved
step 310 is performed wherein last data received, such as a maximum
operating torque or operating current, is saved to the EEPROM of
microcontroller 42. Following saved step 310, a power off step 312
is performed turning off operating power to drill driver 10 and
enter sleep mode step 314 is performed following the power off step
312 to save electrical battery energy of drill driver 10.
[0105] Referring to FIG. 20 and again to FIGS. 1-2 and 12, a
diagram 316 of the electronic control circuit of the present
disclosure is provided. The battery 16 voltage is normally isolated
when a trigger switch 318 is open. When trigger switch 318 is
closed, for example by depressing trigger 28, a DC/DC 10-volt
supply 320 is energized by battery 16. The DC/DC 10-volt supply 320
is a 10-volt DC regulator that supplies power to the LED display
screen 100 and to an "H" bridge driver which will be further
described herein. Also connected to DC/DC 10-volt supply 320 is a
3-volt supply 322. Three-volt supply 322 provides 3-volt power for
operation of electronics logic. The LED display screen 100, as
previously described herein, provides multiple LEDs including first
through sixth LEDs 102-112. A mode select module 324 receives input
from operation of either drill selector switch 170 or driver
selector switch 172. The LED display screen 100, 3-volt supply 322,
mode select module 324, and rotary potentiometer/switch assembly 32
are each connected to a microcontroller 42. Microcontroller 42
controls all peripheral features and interfaces, sets the direction
of operation and the pulse-width module setting for "H" bridge
control, and further processes all analog input signals for drill
driver 10. An "H" bridge driver 328 is also connected to
microcontroller 42. "H" bridge driver 328 is a motor controller for
a four MOSFET (metal-oxide-silicon field-effect transistor) bridge
and controls forward, reverse, and breaking functions of motor 34.
An "H" bridge 330 is a group of four MOSFETs connected in an "H"
configuration that drive motor 34 in both forward and reverse
directions. A current amplifier 332 senses the current draw across
a shunt resistor and amplifies the current signal for the
microcontroller 42.
[0106] Referring to FIG. 21, a motor control mode flow diagram 334
identifies the various operational steps performed during motor
control mode operation. A read trigger position step 336 is
initially performed to identify an "on" or "off" position of
trigger 28. Following the read trigger position step 336, a trigger
release check 338 is performed to identify when trigger 28 is
released following depression. If trigger 28 has been released, a
stop motor step 340 is performed, stopping operation of motor 34. A
subsequent return step 342 is performed to return to the motor
control mode. If the trigger 28 has not been released, as
determined by trigger release step 338, a setting step 344 is
performed wherein the pulse-width modulation is set and an FET
(field effect transistor) drive is enabled. Following the setting
step 344, a check step 346 is performed to determine if a battery
under-voltage trip has occurred. If a battery under-voltage trip
has occurred, the stop motor step 340 is performed. If no battery
under-voltage trip has occurred during check step 346, a subsequent
battery over-temperature check 348 is performed to determine if an
over-temperature condition of battery pack 16 has occurred. If a
battery over-temperature condition has occurred, the stop motor
step 340 is performed. If there is no indication of a battery
over-temperature condition, a monitoring step 350 is performed
wherein the motor back EMF (electromagnetic field) and load current
are monitored during the time period of operation in motor control
mode.
[0107] Referring to FIG. 22A and again to FIGS. 1-6 and 8, as the
user rotates rotary member 36 to adjust or set a clutch torque
setting, individual ones of the first through sixth LEDs 102-112
may be illuminated. This provides visual indication to the user of
the relative increase or decrease in torque setting. Initially,
upon rotation in any direction of rotary member 36, in a step 352
all of the green or blue LEDs that are currently illuminated are
turned off. Following this, a read torque select input step 354 is
performed wherein the electrical signal generated by rotation of
rotary member 36 is read which corresponds to a selected torque
input.
[0108] According to several aspects, axial rotation of rotary
member 36 provides twelve individual torque settings. In a first
torque select step 356, a determination is made if the selected
torque input corresponds to torque setting 12. If step 356 is
affirmative, in a setting torque step 358, a torque level of 20
amps is set. At this time, in a step 360, green LED represented by
sixth LED 112 is illuminated. If the result of step 356 is
negative, in a following step 362, a determination is made if the
selected torque input corresponds to torque setting 11. If
affirmative, in a step 364, a torque of 18.5 amp level is set. At
this same time, the color of sixth LED 112 is changed from green to
blue in a step 366. If the response from step 362 is negative in a
step 368, a determination is made if the selected torque input
corresponds to torque setting 10. If the answer is affirmative, in
a step 370, a torque level of 17 amps is set. At this time, the
fifth LED 110 is illuminated using a green color in a step 372. If
the response to step 368 is negative, in a step 374, a
determination is made if the selected torque input corresponds to
torque setting 9. If the response is affirmative, in a step 376, a
torque of 15.5 amp level is set. At this time, fifth LED 110 is
changed from green to blue in a step 378. If the response from step
374 is negative, in a step 380, a determination is made if the
selected torque input corresponds to torque setting 8. If
affirmative, in a step 382, a torque level of 14 amps is set. At
this time, the fourth LED 108 is illuminated using a green color in
a step 384. If the response from step 380 is negative, in a step
386, a determination is made if the selected torque input
corresponds to torque setting 7. If affirmative, in a step 388, a
torque of 12.5 amp level is set. At this time, the fourth LED 108
is changed from green to a blue color in a step 390. If the
response to step 386 is negative, in a step 392, a determination is
made if the selected torque input corresponds to torque setting 6.
If affirmative, in a step 394, a torque of 11 amp level is set. At
this time, the third LED 106 is illuminated using a green color in
a step 396. If the response from step 392 is negative, in a step
398, a determination is made if the selected torque input
corresponds to torque setting 5. If affirmative, in a step 400, a
torque of 9.5 amp level is set. At this time, the third LED 106 is
changed from a green to a blue color in a step 402. If the response
to step 398 is negative, in a step 404, a determination is made if
the selected torque input corresponds to torque setting 4. If
affirmative, in a step 406, a torque of 8 amp level is set. At this
time, the second LED 104 is illuminated using a green color in a
step 408. If the response to step 404 is negative, in a step 410, a
determination is made if the selected torque input corresponds to
torque setting 3. If affirmative, in a step 412, a torque of 6.5
amp level is set. At this time, the second LED 104 is changed from
a green to a blue color in a step 414. If the response to step 410
is negative, in a step 416, a determination is made if the selected
torque input corresponds to torque setting 2. If affirmative, in a
step 418, a torque of 5 amp level is set. At this time, the first
LED 102 is illuminated using a green color in a step 420. If the
response to step 416 is negative, in a step 422, a determination is
made if the selected torque input corresponds to torque setting 1.
If affirmative, in a step 424, a torque of 3.5 amp level is set. At
this time, the first LED 102 is changed in color from green to blue
in a step 426. It is noted that the sequencing identified in clutch
torque flow diagram 351 corresponds to a decreasing torque value
manually set by the user. The sequence is reversed if the user is
selecting torque values that increase in value.
[0109] Referring to FIG. 22B, a lookup table 428 provides saved
values corresponding to the selected torque input level. A torque
level in amps corresponding to the torque input level is also
provided, as well as the corresponding color and illuminated LED
for the LED display.
[0110] Referring to FIG. 23 and again to FIGS. 1-6 and 8, when the
user manually displaces the rotary potentiometer/switch assembly 32
by pushing in either a right-to-left or left-to-right direction
against rotary member 36, a drill driver 10 clutch rotation
direction is selected or changed. As previously noted, opposite
displacements of rotary potentiometer/switch assembly 32 provide
either a forward or a reverse clutch rotational direction. A
forward/reverse LED display flow diagram 430 identifies the
corresponding LED display that is presented upon selecting either
the forward direction in a forward step 434 or the reverse
direction in a reverse step 436. These steps follow an initial
inquiry in a forward/reverse step 432 initiated by motion of the
rotary member 36. If the forward rotational direction is selected,
following forward step 434 and in sequential order, each of the
first through sixth LEDs 102-112 are illuminated. Initially, in a
step 438, the first LED 102 is illuminated using a blue color.
Following a 60 millisecond delay step 440, first LED 102 is turned
off and second LED 104 is turned on in a blue color in a step 442.
Following a 60 millisecond delay step 444, second LED 104 is turned
off and third LED 106 is turned on in a blue color in a step 446.
Following another delay of 60 ms in a step 448, third LED 106 is
turned off and fourth LED 108 is turned on in a blue color in a
step 450. Following a delay of 60 ms in a step 452, fourth LED 108
is turned off and fifth LED 110 is turned on in a blue color in a
step 454. Following an additional 60 ms delay step 456, the fifth
LED 110 is turned off and the sixth LED 112 is turned on in a blue
color in a step 458. Following a final delay of 60 ms in a step
460, the sixth LED 112 is turned off in a step 462. Based on the
sequence of operation of first through sixth LEDs 102-112 in the
forward operating mode, the LEDs will appear to rapidly illuminate
in a clockwise direction.
[0111] An opposite operation starting with illumination of sixth
LED 112 and continuing to first LED 102 occurs if the reverse step
436 is actuated. Following reverse step 436, sixth LED 112 is
illuminated in a blue color in a step 464. Following a delay of 60
ms in a step 466, the sixth LED 112 is turned off and the fifth LED
110 is turned on in a blue color in a step 468. Following a delay
of 60 ms in a step 470, the fifth LED 110 is turned off and the
fourth LED 108 is turned on in a blue color in a step 472.
Following a delay of 60 ms in a step 474, the fourth LED 108 is
turned off and the third LED 106 is turned on in a blue color in a
step 476. Following an additional delay of 60 ms in a step 478, the
third LED 106 is turned off and the second LED 104 is turned on in
a blue color in a step 480. Following a delay of 60 ms in a step
482, the second LED 104 is turned off and the first LED 102 is
turned on in a blue color in a step 484. Finally, following a delay
of 60 ms in a step 486, the first LED 102 is turned off in a step
488. Based on the sequence of operation of sixth through first LEDs
112-102 in the reverse operating mode, the LEDs will appear to
rapidly illuminate in a counter-clockwise direction.
[0112] One of the drawback of the LED-based display described above
is that the clutch setting is not quantified for the tool operator.
An alternative display 600 for a drill driver 10 having an
electronic clutch is shown in FIG. 28. In this alternative
embodiment, a number corresponding to the clutch setting is
displayed on the display 600. For example, the numeric value may
range from one to six as described above in relation to FIG. 10. In
one embodiment, the display 600 may be implemented using a simple
dot matrix display although other types of displays are also
contemplated by this disclosure. The clutch setting can be set, for
example, using the rotary member 36. Other types on mechanisms fall
for selecting a clutch setting also within the broader aspects of
this feature. In some embodiments, a light sensor 602 may also be
integrated into the housing of the drill driver 10. The signal from
the light sensor is received by the controller and can be used to
adjust the brightness of the display, thereby improving the
visibility of the display in different light conditions.
[0113] For drill drivers having multi-speed transmissions, the
maximum clutch torque setting for the mechanical clutch is dictated
by the maximum torque that can be achieved in a high speed (low
torque) setting. Setting the maximum torque setting for the clutch
in this manner prevents the tool from stalling regardless of the
speed and clutch settings but creates a difference in the maximum
torque setting between low speed and high speed modes. In an
electronic clutch, different ranges of clutch settings can be
assigned to each of the different speed settings. For example, in a
high speed (low torque) setting, the clutch settings may range
between eight settings (i.e., 1-8); whereas, in the low speed (high
torque) setting, the clutch setting may range between twelve
settings (i.e., 1-12), where for clutch setting correlates to a
different user selectable predefined maximum torque level as noted
above. To support this arrangement, the clutch settings are display
by the controller on the display 600 using different scales. When
the tool is in the low speed setting, all twelve clutch settings
can be selected by the user and thus may be displayed on the
display. When the tool is in the high speed setting, only the first
eight settings (i.e., 1-8) are selected by the user and thus may be
display on the display. In some embodiments, the clutch setting
mechanism (e.g., rotary member 36) enables the user to pick from
the full range of settings (e.g., 12 different settings). In the
case the tool is in the high speed setting, values for the first
eight setting are displayed as well as the value for the eight
setting being displayed for the four additional setting available
on the clutch setting mechanism. That is, values for the twelve
selectable setting of the rotary member are displayed as 1, 2, 3,
4, 5, 6, 7, 8, 8, 8, 8, 8, respectively. While reference is made to
a drill driver with two speed transmission, it is readily
understood that this concept may be extended to three or more speed
transmissions as well.
[0114] Example embodiments are provided so that this disclosure
will be thorough, and will fully convey the scope to those who are
skilled in the art. Numerous specific details are set forth such as
examples of specific components, devices, and methods, to provide a
thorough understanding of embodiments of the present disclosure. It
will be apparent to those skilled in the art that specific details
need not be employed, that example embodiments may be embodied in
many different forms and that neither should be construed to limit
the scope of the disclosure. In some example embodiments,
well-known processes, well-known device structures, and well-known
technologies are not described in detail.
[0115] The terminology used herein is for the purpose of describing
particular example embodiments only and is not intended to be
limiting. As used herein, the singular forms "a," "an," and "the"
may be intended to include the plural forms as well, unless the
context clearly indicates otherwise. The terms "comprises,"
"comprising," "including," and "having," are inclusive and
therefore specify the presence of stated features, integers, steps,
operations, elements, and/or components, but do not preclude the
presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof. The
method steps, processes, and operations described herein are not to
be construed as necessarily requiring their performance in the
particular order discussed or illustrated, unless specifically
identified as an order of performance. It is also to be understood
that additional or alternative steps may be employed.
[0116] The foregoing description of the embodiments has been
provided for purposes of illustration and description. It is not
intended to be exhaustive or to limit the disclosure. Individual
elements or features of a particular embodiment are generally not
limited to that particular embodiment, but, where applicable, are
interchangeable and can be used in a selected embodiment, even if
not specifically shown or described. The same may also be varied in
many ways. Such variations are not to be regarded as a departure
from the disclosure, and all such modifications are intended to be
included within the scope of the disclosure.
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