U.S. patent application number 10/189899 was filed with the patent office on 2002-12-26 for power tool with light emitting diode.
This patent application is currently assigned to Roto Zip Tool Corporation. Invention is credited to Adler, Scott, Bullis, Daniel, Gunseor, Larry, Kopras, Jason R., Kopras, Robert K., Rindy, Ryan, Seals, Douglas.
Application Number | 20020197123 10/189899 |
Document ID | / |
Family ID | 24013789 |
Filed Date | 2002-12-26 |
United States Patent
Application |
20020197123 |
Kind Code |
A1 |
Kopras, Robert K. ; et
al. |
December 26, 2002 |
Power tool with light emitting diode
Abstract
A hand-held power tool, such as a rotary cutting tool, allows
for improved operator control and visibility. The power tool
includes a housing and a motor provided in the housing. A cutting
accessory is coupled to the motor and is adapted to cut a workpiece
at a point of cut. At least one light emitting diode is coupled to
the housing and configured to direct light toward the point of
cut.
Inventors: |
Kopras, Robert K.; (Black
Earth, WI) ; Kopras, Jason R.; (Mount Horeb, WI)
; Adler, Scott; (Madison, WI) ; Seals,
Douglas; (Fitchburg, WI) ; Rindy, Ryan;
(Madison, WI) ; Gunseor, Larry; (New Glarus,
WI) ; Bullis, Daniel; (Madison, WI) |
Correspondence
Address: |
Marcus W. Sprow
Foley & Lardner
777 East Wisconsin Avenue
Milwaukee
WI
53202-5367
US
|
Assignee: |
Roto Zip Tool Corporation
|
Family ID: |
24013789 |
Appl. No.: |
10/189899 |
Filed: |
July 3, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10189899 |
Jul 3, 2002 |
|
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09506244 |
Feb 17, 2000 |
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6443675 |
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Current U.S.
Class: |
409/182 |
Current CPC
Class: |
B25F 5/026 20130101;
Y10T 409/306608 20150115; Y10S 16/24 20130101; Y10T 409/304088
20150115; Y10T 409/303976 20150115; Y10T 403/595 20150115; Y10T
16/444 20150115; Y10T 83/242 20150401; B25F 5/02 20130101; Y10S
16/12 20130101; Y10S 29/082 20130101; Y10T 408/21 20150115; B25F
5/008 20130101; Y10T 16/469 20150115; Y10T 409/308624 20150115;
Y10T 408/65 20150115; B27C 5/10 20130101; Y10T 83/828 20150401;
B25F 5/021 20130101; Y10T 83/2066 20150401; Y10S 29/083 20130101;
Y10T 83/68 20150401 |
Class at
Publication: |
409/182 |
International
Class: |
B23C 001/20 |
Claims
What is claimed is:
1. A hand-held cutting tool comprising: a housing; a motor provided
in the housing; a cutting accessory coupled to the motor, the
cutting accessory being adapted to cut a workpiece at a point of
cut; and at least one light emitting diode coupled to the housing
and configured to direct light toward the point of cut.
2. The hand-held cutting tool of claim 1, further comprising an
electrical cord coupled to the housing and adapted to provide
electrical power to the motor.
3. The hand-held cutting tool of claim 2, wherein the at least one
light emitting diode is turned on automatically when the motor is
in operation.
4. The hand-held cutting tool of claim 1, wherein the at least one
light emitting diode is a high-output light emitting diode.
5. The hand-held cutting tool of claim 1, further comprising two
light emitting diodes coupled to the housing.
6. The hand-held cutting tool of claim 5, wherein the housing has
an axis and the two light emitting diodes are arranged at an angle
to the axis.
7. The hand-held cutting tool of claim 5, wherein a first beam of
light is provided by a first light emitting diode and a second beam
of light is provided by a second light emitting diode, the first
and second beams of light intersecting at the point of cut when the
hand-held cutting tool is in operation.
8. The hand-held cutting tool of claim 7, further comprising a
depth guide attached to the housing to set a depth of cut of the
hand-held cutting tool.
9. The hand-held cutting tool of claim 1, wherein the at least one
light emitting diode illuminates at least a portion of the cutting
accessory.
10. The hand-held cutting tool of claim 1, wherein the at least one
light emitting diode is mounted in an aperture formed in the
housing.
11. The hand-held cutting tool of claim 1, wherein the housing
tapers along the length of the housing.
12. The hand-held cutting tool of claim 1, wherein the cutting
accessory is a tool bit having a cutting edge helically wrapped
around the tool bit.
13. The hand-held cutting tool of claim 1, further comprising a fan
coupled to the housing to direct air to the point of cut.
14. The hand-held cutting tool of claim 1, further comprising a
detachable handle coupled to the housing.
15. The hand-held cutting tool of claim 14, wherein the detachable
handle includes a trigger switch for activating the motor.
16. A cutting tool comprising: a housing enclosing a motor; cutting
means coupled to the motor and configured to form cuts in a
workpiece at a point of cut; and a plurality of light emitting
diodes provided on the cutting tool, each of the light emitting
diodes directing a beam of light away from the housing and toward
the point of cut.
17. The cutting tool of claim 16, wherein the plurality of light
emitting diodes are automatically turned on when the motor is
activated.
18. The cutting tool of claim 17, wherein each of the light
emitting diodes is a high-output light emitting diode.
19. The cutting tool of claim 16, wherein the plurality of light
emitting diodes are spaced equally about the cutting means.
20. The cutting tool of claim 19, wherein the plurality of light
emitting diodes are positioned at an angle to the cutting
means.
21. The cutting tool of claim 16, wherein light beams emitting from
each of the plurality of light emitting diodes overlap at a point
spaced away from the housing.
22. The cutting tool of claim 21, wherein the light beams
illuminate at least a portion of the cutting means.
23. The cutting tool of claim 22, wherein the light beams
illuminate at least a portion of the cutting means at the point of
cut.
24. The cutting tool of claim 23, wherein power for the cutting
tool is provided through an electrical cord coupled to the
motor.
25. The cutting tool of claim 23, further comprising an adjustable
depth guide for setting a depth of cut of the cutting means.
26. The cutting tool of claim 16, wherein each of the plurality of
light emitting diodes are provided in apertures formed in the first
end of the housing.
27. The cutting tool of claim 16, wherein the cutting means
comprises a rotary tool bit.
28. The cutting tool of claim 27, wherein the motor is configured
to rotate the rotary tool bit at a speed of at least 15,000
RPM.
29. The cutting tool of claim 16, further comprising at least one
air vent formed in the housing for directing a flow of air toward
the point of cut.
30. A hand-held power tool comprising: a housing having a motor
provided therein; a shaft extending from a first end of the housing
along an axis of the housing, the shaft being coupled to the motor;
a light emitting diode provided in the first end of the housing to
direct light away from the first end of the housing substantially
along the axis of the housing; and an electrical cord coupled to
the motor for providing power to the hand-held power tool.
31. The hand-held power tool of claim 30, further comprising means
for attaching at least one of a cutting tool bit and a cutting
accessory to the shaft.
32. The hand-held power tool of claim 31, further comprising at
least one of a cutting tool bit and a cutting accessory coupled to
the shaft.
33. The hand-held power tool of claim 30, wherein the light
emitting diode is a high output light emitting diode.
34. The hand-held power tool of claim 30, further comprising a
plurality of light emitting diodes provided in the first end of the
housing.
35. The hand-held power tool of claim 34, wherein the plurality of
light emitting diodes are arranged at an acute angle with respect
to the axis of the housing.
36. The hand-held power tool of claim 35, wherein beams of light
emitting from each of the plurality of light emitting diodes
overlap at a point spaced away from the housing along the axis.
37. The hand-held power tool of claim 36, wherein the point spaced
away from the housing corresponds to a point of cut in a
workpiece.
38. The hand-held power tool of claim 30, wherein the light
emitting diode is turned on automatically whenever the motor is
activated.
39. The hand-held power tool of claim 30, wherein the housing has a
first width at the first end and a second width at a second end,
the second width being greater than the first width.
40. The hand-held power tool of claim 30, further comprising a
detachable handle coupled to the housing.
41. The hand-held power tool of claim 30, further comprising an air
vent formed in the first end of the housing and means for directing
a flow of air from the air vent away from the housing along the
axis.
42. A power tool having an electrical cord for transmitting power
to the power tool, the power tool comprising: a housing; a motor
provided in the housing; a tool bit coupled to the motor; and a
plurality of high-output light emitting diodes coupled to the
housing and configured to illuminate at least a portion of the tool
bit at a point of cut; wherein the plurality of light emitting
diodes each emit light when the motor is activated.
43. The power tool of claim 42, wherein a beam of light is emitted
from each of the plurality of light emitting diodes, and wherein
the beams of light intersect at a point spaced away from the
housing.
44. The power tool of claim 43, wherein the plurality of light
emitting diodes are arranged at an acute angle to the tool bit to
illuminate at least a portion of the tool bit.
45. The power tool of claim 43, wherein the beams of light
intersect at a point of cut of the tool bit, wherein the point of
cut is determined by an adjustable depth guide coupled to the power
tool.
46. The power tool of claim 42, wherein the power tool comprises
two light emitting diodes coupled to the housing.
47. A hand-held power tool having an electrical cord for providing
power to the power tool, the power tool comprising: a housing; a
motor provided in the housing; a tool bit coupled to the motor, the
tool bit being adapted to cut a workpiece at a point of cut; a
depth guide provided on the housing for altering the depth of cut
of the tool bit into a workpiece between a first position and a
second position; a plurality of high-output light emitting diodes
coupled to the housing and configured to illuminate at least a
portion of the tool bit at a point of cut between the first and
second positions of the depth guide; wherein the plurality of light
emitting diodes each emit light when the motor is activated.
48. The hand-held power tool of claim 47, further comprising a
handle removably coupled to the housing.
49. The hand-held power tool of claim 48, wherein the handle
includes a trigger switch for activating the motor.
50. The hand-held power tool of claim 47, further comprising a fan
provided in the housing to direct a flow of air toward the point of
cut.
51. The hand-held power tool of claim 47, wherein the plurality of
light emitting diodes automatically emit light whenever the motor
is activated.
52. The hand-held power tool of claim 47, wherein the motor is
configured to rotate the tool bit at a speed of at least 15,000
RPM.
53. The hand-held power tool of claim 47, wherein the housing has a
first end and a second end, the first end having a larger width
than the second end.
54. The hand-held power tool of claim 47, further comprising a
multiple-position power switch coupled to the housing.
55. The hand-held power tool of claim 54, wherein the
multiple-position power switch is configured to toggle between at
least three operating conditions.
56. The hand-held power tool of claim 47, wherein the motor is a
variable speed motor.
57. The hand-held power tool of claim 47, wherein the depth guide
is configured to be detachable from the housing.
58. The hand-held power tool of claim 47, wherein the tool bit has
a cutting edge helically wrapped around the tool bit.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application is a division of application Ser. No.
09/506,244, filed Feb. 17, 2000 by Kopras et al., entitled
"Hand-Held Power Tool," the disclosure of which is expressly
incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] The invention relates generally to hand-held power tools.
More specifically, the invention relates to hand-held power tools
having at least one light emitting diode.
[0003] Hand-held power tools, such as hand-held power cutting
tools, generally include a housing and an electric motor contained
within the housing. The motor is configured to move a tool bit or
other cutting accessory at high speeds to form cuts in a workpiece
(e.g., a piece of wood, etc.). For example, a rotary cutting tool
is a hand-held power tool that includes an electric motor that
rotates a tool bit at high speeds. One type of tool bit that may be
used with a rotary cutting tool is a helical or spiral cutting tool
bit that includes a sharp cutting edge wrapped in a helix around
the axis of the bit.
[0004] Hand-held power cutting tools are used to remove material
from a workpiece, for example, by forming cuts in the workpiece. In
the above example of a rotary cutting tool having a rotating
helical cutting tool bit, the tool bit is moved through the
workpiece in a direction perpendicular to the axis of rotation of
the bit to remove material from the workpiece.
[0005] Precise control of a cut being made by a hand-held power
cutting tool requires that the user of the tool have good
visibility of the workpiece at the point of the cut. Such
visibility can be reduced by a build-up of cutting debris (e.g.,
sawdust) and poor lighting at the point of the cut. Some power
tools employ vacuum systems connected to the tool to remove cutting
debris. However, the use of such a vacuum system often makes use of
the tool more cumbersome. Proper lighting at the point of a cut can
be a problem, both in generally poorly lighted construction
environments and, more generally, in any environment where the
operator of the tool and the tool itself cast a shadow over the
workpiece.
[0006] There is thus a need for a hand-held power tool that allows
increased visibility at the point of a cut made in a workpiece.
There is also a need for a hand-held power tool that includes one
or more light emitting diodes for directing light away from the
housing of the hand-held power tool. There is also a need for a
hand-held power tool that includes one or more light emitting
diodes arranged at angles to the axis of the hand-held power tool
to provide an overlapping light beam at the point of cut in a
workpiece.
[0007] It would be desirable to provide a hand-held power tool that
provides one or more of these or other advantageous features. Other
features and advantages will be made apparent from the present
specification. The teachings disclosed extend to those embodiments
which fall within the scope of the appended claims, regardless of
whether they accomplish one or more of the above-mentioned
needs.
SUMMARY OF THE INVENTION
[0008] An exemplary embodiment relates to a hand-held cutting tool.
The hand-held cutting tool includes a housing and a motor provided
in the housing. A cutting accessory is coupled to the motor and is
adapted to cut a workpiece at a point of cut. The hand-held cutting
tool also includes at least one light emitting diode coupled to the
housing at the first end and configured to direct light toward the
point of cut.
[0009] Another exemplary embodiment relates to a cutting tool. The
cutting tool includes a housing enclosing a motor and cutting means
coupled to the motor and configured to form cuts in a workpiece at
a point of cut. A plurality of light emitting diodes are provided
on the cutting tool, each of the light emitting diodes directing a
beam of light away from the housing and toward the point of
cut.
[0010] Another exemplary embodiment relates to a hand-held power
tool. The hand-held power tool includes a housing having a motor
provided therein and a shaft extending from a first end of the
housing along an axis of the housing. The shaft is coupled to the
motor. A light emitting diode is provided in the first end of the
housing to direct light away from the first end of the housing
substantially along the axis of the housing. An electrical cord is
coupled to the motor for providing power to the hand-held power
tool.
[0011] Another exemplary embodiment relates to a power tool having
an electrical cord for transmitting power to the power tool. The
power tool includes a housing, a motor provided in the housing, and
a tool bit coupled to the motor. The power tool also includes a
plurality of high-output light emitting diodes coupled to the
housing and configured to illuminate at least a portion of the tool
bit at a point of cut, wherein the plurality of light emitting
diodes each emit light when the motor is activated.
[0012] Another exemplary embodiment relates to a hand-held power
tool having an electrical cord for providing power to the power
tool. The hand-held power tool includes a housing, a motor provided
in the housing, and a tool bit coupled to the motor. The tool bit
is adapted to cut a workpiece at a point of cut. The hand-held
power tool also includes a depth guide provided on the housing for
altering the depth of cut of the tool bit into a workpiece between
a first position and a second position. The hand-held power tool
further includes a plurality of high-output light emitting diodes
coupled to the housing and configured to illuminate at least a
portion of the tool bit at a point of cut between the first and
second positions of the depth guide, wherein the plurality of light
emitting diodes each emit light when the motor is activated.
[0013] Alternative exemplary embodiments relate to other features
and combinations of features as may be generally recited in the
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The invention will become more fully understood from the
following detailed description, taken in conjunction with the
accompanying drawings, wherein like reference numerals refer to
like elements, in which:
[0015] FIG. 1 is a perspective view of a hand-held power tool in
accordance with an exemplary embodiment;
[0016] FIG. 2 is a perspective view of the hand-held power tool
shown in FIG. 1, showing a detachable handle and adjustable depth
guide assembly;
[0017] FIG. 3 is a partial side view of the hand-held power tool
shown in FIG. 1, as taken along the line 3-3 in FIG. 2, showing
apertures formed in the hand-held power tool housing;
[0018] FIG. 4 is a front view, in partial cross-section, of a
detachable handle for the hand-held power tool shown in FIG. 1, as
taken along the line 4-4 in FIG. 2, showing a lever mechanism of a
moveable mounting mechanism in a closed position;
[0019] FIG. 5 is a front view, in partial cross-section, of a
detachable handle for the hand-held power tool shown in FIG. 1, as
taken along the line 4-4 in FIG. 2, showing a lever mechanism of a
moveable mounting mechanism in an open position;
[0020] FIG. 6 is a cross-sectional view of a detachable handle
coupled to the hand-held power tool, as taken along line 6-6 in
FIG. 1;
[0021] FIGS. 7, 8, and 9 are top views of the housing of the
hand-held power tool shown in FIG. 1, showing a multiple-position
on/off power in a first "off" position, a second trigger switch
enabled position, and a third "on" position, respectively;
[0022] FIG. 10 is a bottom end view of the hand-held power tool
shown in FIG. 1, showing an end of the hand-held power tool from
which a shaft emerges, with LEDs and air vents provided in the
end;
[0023] FIG. 11 is a cross-sectional view of a portion of the
housing of the hand-held power tool shown in FIG. 1, showing the
LEDs mounted at angles for directing crossing beams of light away
from the housing; and
[0024] FIG. 12 is an exploded perspective view of the bottom
portion of the housing illustrated in FIG. 11, showing a moveable
air vent cover.
DETAILED DESCRIPTION OF EXEMPLARY AND PREFERRED EMBODIMENTS
[0025] A hand-held rotary power or cutting tool 20 including
features for improving the ability of an operator to operate and
control the tool is shown generally in FIGS. 1 and 2. It should be
understood that, although the present invention will be described
in detail herein with reference to the exemplary embodiment of a
rotary cutting tool 20, the present invention may be applied to,
and find utility in, other types of hand-held power tools as
well.
[0026] The rotary cutting tool 20 includes a motor housing 22 to
which a detachable handle 24 is attached. The motor housing 22 is
preferably made of an electrically insulating material, such as
hard plastic. The motor housing 22 is generally cylindrical in
shape, and may include raised gripping surfaces 26 formed thereon
that allow a firm grip on the rotary cutting tool 20 to be
maintained when the rotary cutting tool 20 is grasped around the
motor housing 22. The motor housing 22 may be formed as two or more
molded pieces which are joined together to form the housing 22 in a
conventional manner, such as using fasteners, an adhesive, welding,
or a combination thereof.
[0027] An electric motor (not visible in FIGS. 1 and 2) is enclosed
within the motor housing 22. The motor receives electrical power
through an electrical cord 28 (only a portion of which is shown in
FIGS. 1 and 2). The electrical cord 28 may preferably include a
rubber cover that stays flexible in cold operating environments. A
thick rubber connecting sleeve 30 is preferably provided where the
electrical cord 28 is joined to the motor housing 22. This
connecting sleeve 30 provides strain relief at the end of the
electrical cord 28 to prevent crimping, cracking, and excessive
wear of the cord 28 where it is joined to the rotary cutting tool
20.
[0028] The connecting sleeve 30 is preferably made of a thicker or
less pliable material than the rubber coating covering the
electrical cord 28. As illustrated in FIGS. 1, 2, and 10, the
connecting sleeve 30 preferably extends from a side of the motor
housing 22 displaced radially from the position of the detachable
handle 24 on the motor housing 22 by approximately 90.degree.. The
connecting sleeve 30 is bent or shaped to turn from the position
where it is attached to the motor housing 22 in the direction of
the position of the detachable handle 24 on the motor housing 22.
Thus, the end of the electrical cord 28 which is connected by the
connecting sleeve 30 to the tool 20 is positioned by the connecting
sleeve 30 on the tool 20 such that the electrical cord 28 extends
from the motor housing 22 in a direction toward an operator of the
rotary cutting tool 20 holding the tool 20 by the detachable handle
24, but is displaced from the position of the handle 24. This
positioning of the electrical cord 28 helps assure that the
electrical cord 18 will not interfere with operation of the rotary
cutting tool 22 as the tool 22 is used, e.g., to cut a
workpiece.
[0029] The electric motor is turned on and off by a power on/off
switch 32 mounted on the motor housing 22. As will be discussed in
more detail below, the power on/off switch 32 is preferably a
multiple-position on/off switch. The electric motor may also be
turned on and off by a trigger switch 34 mounted on the detachable
handle 24. As will also be discussed in more detail below,
operation of the trigger switch 34 mounted in the detachable handle
24 to turn the electric motor on and off may be enabled by
operation of the multiple position on/off power switch 32.
[0030] The electric motor is preferably capable of operation at a
variety of speeds. A motor speed control button or switch 36 is
provided on the motor housing 22 for controlling the operating
speed of the tool motor. The motor speed control button 36 may be
implemented as a push button switch which changes the speed of the
motor each time the button 36 is depressed. Motor speed indicators,
such as indicator LEDs 38, may be mounted on the motor housing 22
near the motor speed control switch 36 to indicate to an operator
of the tool 20 the operating speed of the tool motor. The motor
speed control switch 36 and motor speed indicators 38 may be
covered (e.g., by a thin and flexible piece of plastic 40 attached
to the motor housing 22 in a conventional manner) to prevent dust
or other debris from entering the motor housing 22 and damaging or
affecting operation of the button 36, indicators 38, or other
components within the motor housing 22.
[0031] In an exemplary embodiment, the rotary cutting tool 20
includes an electric motor capable of being operated at four
speeds. When the motor is first turned on (e.g., using the
multiple-position on/off switch 32 or the trigger switch 34), the
motor begins operation at an initial preselected speed (e.g., a
no-load rotation speed of 15,000 RPM). Each the time the motor
speed control button 36 is actuated with the motor on and running,
the motor speed changes. For example, the motor speed may change
from the initial 15,000 RPM to 20,000 RPM the first time the button
36 is actuated, from 20,000 RPM to 25,000 RPM the second time the
button 36 is actuated, and from 25,000 RPM to 30,000 RPM the third
time the button is actuated. When the motor speed control button 36
is actuated the fourth time with the motor on and running, the
motor speed preferably decreases by one step, e.g., back to 25,000
RPM. In alternative embodiments, more or fewer than four motor
speeds may be provided, different motor speeds may be provided, and
different increments between available motor speeds may be provided
in accordance with alternative embodiments. Also, the motor speed
may be controlled to return to its initial operating speed upon the
next actuation of the speed control button after either the highest
or lowest operating speed is reached.
[0032] Appropriate ones of the motor speed indicator LEDs 38 are
illuminated each time the motor speed control button 36 is actuated
to indicate the operating speed of the motor. In alternative
embodiments, the speed of the motor may be controlled in a
different manner in response to actuation of the motor speed
control button 36. For example, the tool motor may start operation
at a relatively high initial operating speed, with the speed of the
motor reduced each time the motor speed control button 36 is
actuated, or may start at a relatively low initial operating speed,
with the speed of the motor increased each time the motor speed
control button 36 is actuated. Preferably, a microprocessor or
similar digital device is employed as a motor controller, mounted
in the motor housing 22, to control the ramp up and ramp down of
the speed of the cutting tool motor each time the motor speed
control button 36 is actuated, and to control the motor speed
indicator LEDs.
[0033] The motor controller may preferably be programmed to soft
start the motor when the on/off switch 32 is actuated to turn the
motor on initially. That is, the motor controller may control the
motor to increase the motor speed gradually to the initial
operating speed when the motor is first turned on via the on/off
switch 32. Note, however, that this soft start of the motor is
preferably not employed when operation of the motor is started by
actuation of the trigger switch 34, as will be described in more
detail below.
[0034] The electric motor of the rotary cutting tool 20 drives a
motor shaft. A fan, located within the motor housing 22, is
preferably attached to the motor shaft. When the motor is turned
on, the fan is rotated at a high speed to draw air through the
motor housing 22 and across the electric motor to cool the motor.
For this purpose, intake air vents 41 and exhaust air vents are
preferably provided in the motor housing 22. Exhaust air vents are
preferably formed in the end 42 (see FIG. 10) and on the side 44 of
the housing 22, at the end of the housing 22 opposite the intake
air vents 41. Cool air is drawn by the motor fan into the motor
housing 22 through the air intake vents 41 to cool the electric
motor, with warm air exhausted from the motor housing 22 through
the exhaust air vents 42 and 44. As will be discussed in more
detail below, the flow of air out of the exhaust air vents 42 and
44 may be directed and controlled to remove, or to prevent the
removal of, cutting debris from the point of a cut being made using
the rotary cutting tool 20.
[0035] An end of the motor shaft extends from one end of the motor
housing 22 along the axis thereof. Attached to the end of the motor
shaft is a mechanical structure 46 for securing, e.g., a helical
cutting tool bit or other accessory to the motor shaft. A helical
or spiral cutting tool bit has a cutting edge wrapped around the
axis of the bit in a helix. This cutting edge is designed such that
the tool bit, when rotated at high speed, will cut through a
workpiece in a direction perpendicular to the axis of the bit. In
this cutting process, significant force is applied to the cutting
tool bit perpendicular to the axis thereof. Thus, although a
conventional drill-type chuck may be used for the structure 46 that
mechanically connects the bit to the motor shaft, the preferred
structure for securing the bit to the shaft is a collet-type system
46. As shown in FIG. 10, the collet bit attachment structure 46
includes a collet nut 48 and a collet 50 centered axially within a
central aperture of the collet nut 48. The collet nut 48 is mounted
on a threaded end of the motor shaft. To secure a bit to the motor
shaft, a shank of the bit is inserted into a central aperture 51 of
the collet 50. The collet nut 48 is then tightened, first by hand
and then with a wrench 52, until the bit is held securely. As the
collet nut 48 is tightened down on the threaded end of the shaft,
the collet 50 is compressed within the collet nut 48 between a
partially closed end of the collet nut 48 and the shaft. The collet
50 is slotted and has tapered ends such that when the collet 50 is
compressed between the collet nut 48 and the shaft, the collet is
compressed radially, causing the central aperture 51 of the collet
50 to close tightly around the shank of the tool bit. To remove the
bit from the motor shaft, the collet nut 48 is loosened, using the
wrench 52, until the bit can be removed easily from the central
aperture 51 of the collet 50.
[0036] A shaft lock 54 (FIG. 10) is used to prevent rotation of the
motor shaft when the collet nut 48 is being loosened and tightened.
The shaft lock 54 includes a shaft lock pin which extends through
the motor housing 22. When the shaft lock 54 is depressed, the
shaft lock pin engages the motor shaft, preventing rotation of the
shaft, and allowing the collet nut 48 to be loosened and tightened.
When the shaft lock 54 is released, a spring (not shown) attached
to the shaft lock 54 causes the shaft lock pin to become disengaged
from the motor shaft, allowing free rotation thereof.
[0037] To set the depth of cut to be made by the rotary cutting
tool 20, an adjustable depth guide assembly 56 may be provided. The
depth guide assembly 56 includes a depth guide 58, a locking
mechanism 60, and a depth guide bracket 62. The depth guide bracket
62 is attached to the rotary cutting tool housing 22 around the
location where the motor shaft emerges from the housing 22.
[0038] Preferably, the depth guide bracket 62 may be made
detachable from the housing 22. The depth guide bracket 62 may be
attached to the housing 22 in any conventional manner. For example,
the depth guide bracket 62 may be formed to have a split collar
structure and a cam closing mechanism 69 which is operated to close
the collar tight around the end of the tool housing 22 to attach
the bracket 62 thereto, and which may be operated to loosen the
collar to remove the bracket 62 from the housing 22. The depth
guide bracket 62 includes an extension 64 extending in an axial
direction therefrom. The depth guide 58 includes a corresponding
extension 66 extending in an axial direction therefrom and which is
aligned and coupled with the extension portion 64 of the depth
guide bracket 62. The two extending portions 64 and 66 may be
formed such that one of the extending portions 64 includes a tongue
which may be extended into a groove formed in the other extending
portion 66 to join the depth guide 58 and depth guide bracket 62
together while keeping the axially extending portion 66 of the
depth guide 58 aligned on the same axis with the axially extending
portion 64 of the depth guide bracket 62.
[0039] The depth of cut may be set by moving the depth guide 58 in
an axial direction, by sliding the axially extending portion 66
thereof along the axially extending portion 64 of the depth guide
bracket 62. The locking mechanism 60 is then engaged to lock the
extending portions 64 and 66 together to securely fix the depth
guide 58 in place. The locking mechanism 60 may be implemented as a
cam lever 60, as shown, mounted on the extending portion 66 of the
depth guide 58 and coupled to the extending portion 64 of the depth
guide bracket 62 to lock the two extending portions 64 and 66
together tightly when the cam lever 60 is engaged. Alternatively,
the locking mechanism may be implemented using a threaded nut or a
screw for locking the extending portions 64 and 66 together
tightly. When locked into position, the depth guide 58 provides a
depth guide surface 68 which lies in a plane perpendicular to the
axis of the rotary cutting tool 20. The main components which form
the depth guide 56 may be molded of hard plastic, or alternatively
may be made of any other suitable material.
[0040] The detachable handle 24 is preferably detachably attachable
to the motor housing 22 of the rotary cutting tool 20. The handle
24 includes a gripping surface 70, which may be contoured in shape
so that the handle 24 may be grasped comfortably in the hand by an
operator of the rotary cutting tool 20. The handle gripping surface
70 is aligned substantially parallel with the axis of the rotary
cutting tool housing 22. It should be understood that the term
"substantially parallel" as used in this context throughout this
specification means "more parallel than not." Therefore, the angle
of the handle gripping surface 70 with respect to the axis of the
rotary cutting tool 20 may be varied from exactly parallel by
several degrees. The handle gripping surface 70 may be made of a
semi-rigid plastic material or any other suitable material.
[0041] The handle 24 allows the rotary cutting tool 20 to be
grasped more firmly and comfortably with both hands, to provide
greater control of the tool 20 during operation, and thereby
provides for more accurate cuts with less operator fatigue. The
handle 24 also allows the rotary cutting tool 20 to be grasped more
firmly during motor start-up, during which the reaction torque of
the tool motor may cause the tool 20 to twist. Thus, the handle 24
also facilitates safe use of the tool 20. It may be desirable,
however, that the handle 24 be detached for some applications. For
example, for making cuts in close quarters or obstructed areas, the
handle 24 may become an obstruction, and actually interfere with
the making of accurate cuts. Thus, it is desirable to provide both
for securely attaching the handle 24 to the rotary cutting tool 20
when needed and for easily detaching the handle 24 from the tool 20
when its use would interfere with operation of the tool 20.
[0042] A preferred structure for detachably attaching the handle 24
to the rotary cutting tool 20 is described in detail with reference
to FIGS. 3-6. This structure provides for quick and easy release of
the detachable handle 24 from the tool housing 22 and quick and
secure attachment of the detachable handle 24 thereto. As shown in
FIG. 3, the motor housing 22 preferably includes first 72 and
second 78 fixed mounting structures formed therein for attaching
the detachable handle 24 to the housing 22. For example, a first
aperture 72 is formed on a side of the housing 22 to which the
handle 24 is to be attached near an end of the housing 22 opposite
the end of the tool 20 from which the motor shaft extends. As
illustrated in FIG. 3, the first handle mounting aperture 72
preferably includes a slot aperture 74 formed therein. The slot
aperture 74 may be formed in a metallic plate or insert 76 (FIG. 6)
mounted within the housing 22 in a conventional manner behind the
first housing aperture 72. A sidewall of the insert 76 may be
threaded to form a threaded aperture wall 77 within the first
aperture 72. One or more second mounting apertures 78 are formed in
the side of the motor housing 22 near the end of the motor housing
22 from which the motor shaft emerges from the housing. In the
preferred embodiment shown in the FIGURES, two such second mounting
apertures 78 are formed in the motor housing 22. The first mounting
aperture 72 and the second mounting apertures 78 are preferably
positioned on the motor housing 22 with respect to each other such
that when the detachable handle 24 is attached to the housing 22 in
the manner to be described below, the handle gripping surface 70 is
aligned substantially parallel with the axis of the rotary cutting
tool housing 22.
[0043] The detachable handle 24 is attached to the housing 22 by a
fixed handle mounting structure 80 formed on a first end of the
handle, to be coupled to the second fixed mounting structure 78
formed in the housing 22, and a moveable mounting mechanism 82,
mounted in a second end of the handle 24, to be coupled to the
first fixed mounting structure 72 formed in the housing 22. For
example, fixed extending handle tabs 80 may be formed at one end of
the handle 24 for insertion into the corresponding second housing
apertures 78, and a rotatable rod 82 may be mounted extending from
the other end of the detachable handle 24 for insertion into the
aperture slot 74 formed in the first housing aperture 72.
[0044] The extending handle tabs 80 may be integrally formed as
part of the handle 24, or may be attached thereto in a conventional
manner (e.g., using an adhesive, etc.). Alternatively, the tabs 80
may be implemented as a separate metal part attached to the handle
24. The tabs 80 preferably extend from one end of the handle and
turn downward to form a hook-like configuration. The tabs 80 are
preferably spaced apart on the end of the handle 24 such that the
spacing between the tabs 80 corresponds to the spacing between the
second apertures 78 formed in the housing 22. The hook shape of the
tabs 80 allows the tabs 80 to be inserted into the apertures 78 in
a manner such that the tabs 80 are hooked within the apertures 78
within and behind a portion of the housing 22. In other words, when
the handle 24 is positioned on the housing 22 with the tabs 80
positioned properly in the apertures 78, the end of the handle with
the tabs 80 extending therefrom cannot be removed in a radial
direction from the housing 22, because the tabs 80 are hooked
within the housing 22.
[0045] The rotatable rod 82 extends from the other end of the
handle 24 (i.e., the end of the handle 24 opposite the end of the
handle 24 having the extending tabs 80 extending therefrom). The
rotatable rod 82 is positioned on the handle 24 such that the
rotatable rod 82 may be inserted into the first aperture 72 formed
in the housing 22, to position the handle 24 on the housing 22 when
the extending handle tabs 80 are positioned in the housing
apertures 78. The rotatable rod 82 preferably includes a radially
extending and flattened portion 84 formed at a distal end thereof.
A second radially extending portion 86 is preferably formed on the
rotatable rod 82 proximal to the distal radially extending portion
84. The rotatable rod 82 is attached to a lever mechanism 88, which
extends, at least in part, outside of the detachable handle 24. The
portion of the lever 88 extending from the removable handle 24
preferably includes an extending tab 90. The extending tab 90 is
positioned on the lever 88, and the lever 88 is positioned on the
detachable handle 24, such that the lever 88 may be operated easily
by, e.g., an operator's thumb positioned adjacent to the tab 90
when the handle 24 is grasped in a normal manner by the operator
for use of the rotary cutting tool 20 to which the handle 24 is
attached.
[0046] The lever mechanism 88 and rotatable rod 82 are mounted in
the end of the detachable handle 24 in a conventional manner such
that the rotatable rod 82 is rotatable therein by operation of the
lever 88. When the lever mechanism 88 is rotated into an "open"
position, as illustrated in FIG. 5, the radially extending and
flattened distal portion 84 of the rotatable rod 82 is oriented
such that the distal end 84 of the rod 82 may be inserted into the
slot 74 formed in the first aperture 72 in the tool housing 22. The
lever mechanism 88 is put into this "open" position for mounting
the handle to, and removing the handle 24 from, the housing 22.
When the lever mechanism 88 is rotated into a "closed" position, as
illustrated in FIG. 4, the radially extending and flattened distal
end 84 of the rotatable rod 82 is rotated into a position
perpendicular to the orientation of the slot 74 formed in the first
aperture 72 in the housing 22. In this position, the distal end 84
of the rotatable rod 82 cannot be inserted into the aperture 72, or
removed therefrom, if the rod 82 has been positioned in the
aperture 72. Thus, the lever mechanism 88 is operated to rotate the
rotatable rod 82 into the "closed" position when the handle 24 is
placed in the proper position on the housing 22, to secure the
detachable handle 24 to the housing.
[0047] The detachable handle 24 is further securely attached to the
housing 22 by interaction of the second radially extending portion
86 of the rotatable rod 82 with the threaded wall 77 of the first
aperture 72 formed in the housing 22. The rotatable rod 82 is
extended into the aperture 72 such that the second radially
extending portion 86 thereof is positioned adjacent to the threaded
wall 77 of the aperture 72. As the lever 88 is operated from the
open position (FIG. 5) to the closed position (FIG. 4) to rotate
the rotatable rod 82, the second radially extending portion 86 is
rotated along the threading formed on the wall 77 of the aperture
72 to pull the rotatable rod 82 inward, thereby pulling the end of
the handle 24 in which the rotatable rod 82 is mounted tightly
against the housing 22. With the end of the handle 24 having the
rotatable rod 82 extending therefrom pulled tightly against the
housing 22, the handle 24 is secured tightly to the housing 22.
That is, movement of the handle 24 with respect to the housing 22
is prevented.
[0048] The following method may, therefore, be employed to easily,
quickly, and securely attach the detachable handle 24 to the tool
housing 22, and to easily and quickly remove the handle 24 from the
housing 22. The handle 24 is positioned such that the tabs 80
extending from one end of the handle 24 are aligned with the tab
apertures 78 formed in the housing 22. The handle 24 is tilted
backward slightly, and the ends of the hooked tabs 80 are extended
into the apertures 78 such that the ends of the tabs 80 are engaged
within the housing 22. With the tabs 80 hooked in the second
apertures 78, the other end of the handle 24 is brought forward
toward the first aperture 72 formed in the housing 22. With the
lever 88 rotated into the open position (FIG. 5), the radially
extending and flattened distal end 84 of the rotatable rod 82 is
extended through the slot 74 formed in the aperture 72. With the
distal end of the rotatable rod 82 extended into the slot 74, the
second radially extending portion 86 of the rotatable rod 82 is
engaged with the threads formed in the wall 77 of the first
aperture 72. The lever 88 is then rotated from the open position
(FIG. 5) to the closed position (FIG. 4). This rotates the
rotatable rod 82 such that the radially extending and flattened
distal end 84 of the rod 82 is rotated into an orientation
perpendicular to the slot 74 formed in the aperture 72. This
prevents the distal end 84 of the rod 82 from being removed from
the aperture 72. The rotation of the lever 88 also causes the
second radially extending portion 86 of the rod 82 to rotate in the
threads formed in the wall 77 of the aperture 72, thereby pulling
the end of the handle 24 tightly against the housing 22. In this
manner, the detachable handle 24 is easily, quickly, and very
securely attached to the housing 22, using a single hand, and
without need for any special tools.
[0049] To remove the detachable handle 24 from the housing 22, the
lever 88 is rotated from the closed position (FIG. 4) to the open
position (FIG. 5). As the lever 88 is rotated, the second radially
extending portion 86 of the rotatable rod 82 is rotated in the
threads formed in the wall 77 of the first housing aperture 72 in a
loosening direction, thereby causing the end of the handle 24 to
move slightly away from the housing 22. The rotation of the rod 22
also causes the radially extending and flattened distal end 84 of
the rod 82 to be aligned with the slot 74 formed in the rod
aperture 72, such that the rod 82 is removable from the aperture 72
by pulling the end of the handle 24 away from the tool housing 22.
With the end of the handle having the rotatable rod 82 mounted
therein removed from the housing 22, the handle 24 may be lifted
away from the housing 22 to remove the tabs 80 from the second
apertures 78 formed in the housing 22. In this manner, the
detachable handle 24 is easily and quickly removed from the housing
22 using a single hand, and without need for any special tools.
[0050] The detachable handle 24 is preferably made of an
electrically insulating material, such as hard plastic. The handle
24 may be formed of such a material in two complementary and
symmetric halves by a conventional molding process. The two halves
are then joined together to form the complete handle 24. The two
handle halves may be joined together in a conventional manner, for
example, using an adhesive. The two handle halves are also
preferably screwed together, using screws or another type of
fastener. For this purpose, screw holes 91 may be formed in the
handle halves.
[0051] As illustrated in FIG. 6, the handle 24 is substantially
hollow, but includes molded internal structural elements 92 which
provide strength and rigidity to the handle 24. The internal
structural elements 92 of the handle 24 give the handle 24 the
strength and rigidity of a solid handle, without requiring the
amount of material required to form a solid handle, and with the
light weight of a substantially hollow handle. Minimizing the
weight of the handle 24 in this manner helps to minimize the
fatigue experienced by an operator using the tool 20 with the
handle 24 in place.
[0052] The structural elements 92 of the detachable handle 24 not
only provide strength and rigidity to the handle 24, but also form
hollow compartments or chambers 96 within the handle 24.
Compartments formed by the structural elements 92 of the handle 24
may be positioned so as to be employed for convenient storage
locations. For example, as illustrated in FIG. 6, a collet 97 and
the wrench 52 for tightening the collet nut 48 may be stored
conveniently in compartments 96A and 96B, respectively, formed
inside the handle 24. A third compartment 96C may be provided for
storage of, for example, extra cutting tool bits.
[0053] Storage compartments 96A and 96C are accessed via an
aperture in the handle 24. To prevent objects stored in the
compartments 96A and 96C from sliding out during use of the tool
20, a compartment door 98 may preferably be provided to cover the
compartment aperture. The door 98 may preferably be a hinged door,
which is attached via a hinge structure 99 to the detachable handle
24. The hinged door 98 may be opened about the hinge 99 structure
to access the compartments 96A and 96C within the detachable handle
24. Ridges 100, or other gripping surfaces, may be formed on the
hinged door 99 to facilitate grasping of the door 98 to open and
close the door 98. Conventional latching tabs 102 may preferably be
formed, e.g., on the inside of the door 98, to engage the inside of
the detachable handle 24 to maintain the door 98 in a closed
position when a tool 20 to which the handle 24 is attached is in
operation.
[0054] The other accessible handle compartment 96B preferably may
be specifically designed to hold the wrench 52 within the handle 24
when it is not in use. An aperture in the handle 24 provides access
to the wrench compartment 96B. The size of the compartment 96B is
such that the wrench 52 is held snugly therein to prevent it from
sliding out during operation of the tool 20. As illustrated in
FIGS. 1 and 2, a portion 104 of the handle 24 around the aperture
to the wrench compartment 96B is reduced in width such that, when
the wrench 52 is placed in the compartment 96B, the head of the
wrench extends slightly from this portion 104 of the sides of the
handle 24. This permits the head of the wrench 52 to be grasped to
pull the wrench 52 from the compartment 96B.
[0055] The compartments 96 in the power tool handle 24 allow power
tool accessories, such as extra cutting tool bits or collets 97, to
be kept conveniently at hand, and separate from other tools and
accessories. It should be noted that various storage compartments
of different sizes and shapes than those described may be
incorporated into the handle 24. Also, various types of doors or
other covers may be used to close off or access the compartments
96. Moreover, it is clear that a user may store other items within
the storage compartments 96. In the embodiment described herein,
however, one compartment 96B is specifically designed to hold the
wrench 54.
[0056] As discussed above, the detachable handle 24 includes a
trigger switch 34 mounted therein for turning the motor on and off
when the detachable handle 24 is attached to the housing 22. The
trigger switch 34 is preferably mounted adjacent to the gripping
surface 70 of the detachable handle 24 on a side of the handle 24
facing the housing 22 when the detachable handle 24 is attached to
the housing 22. The trigger switch 34 is preferably positioned on
the detachable handle 24 such that the trigger switch 34 is
operable by the little finger (pinkie) and ring finger of the hand
of an operator when an operator is grasping the handle 24 for use
of the tool 20 to which the handle is attached. The trigger switch
34 is thus preferably positioned at a lower end of the side of the
detachable handle 24 facing the tool housing 22. This positioning
of the trigger switch 34 on the detachable handle 24 allows the
operator's stronger middle finger, index finger, and thumb to be
used solely for holding and controlling the tool 20 to which the
handle 24 is attached. The grip of these stronger fingers on the
handle 24 need not be loosened to turn the tool on and off, as the
trigger switch 34 provides for on/off operation of the tool 20
using two weaker fingers. Furthermore, the stronger fingers of the
hand are less likely to become fatigued due to continuous holding
of a trigger switch in an on position during operation of the tool.
For example, there is a tendency to grasp a tool handle too
strongly, and in a very fatiguing manner, when the same fingers are
used for activating a trigger switch as are used for holding and
controlling the tool itself.
[0057] The operator of a hand-held power tool 20 may activate the
tool motor by actuating the trigger switch 34 mounted in the
detachable handle 24. The actuation of the trigger switch 34
mounted in the detachable handle must be communicated to a motor
controller 108 mounted in the motor housing 22. The motor
controller 108 may be implemented as any circuit for controlling
activation of the tool motor. Thus, the motor controller 108 may be
implemented using a programmable device, such as a microprocessor,
using discrete analog or digital components, or even using a simple
wiring scheme. Preferably, the mechanism for coupling the trigger
switch 34 in the detachable handle 24 to the motor controller 108
in the motor housing 20 does not interfere with the easy, quick,
and secure attachment of the detachable handle 24 to the housing
22, or with the quick and easy removal of the handle 24
therefrom.
[0058] In accordance with an exemplary embodiment, the trigger
switch 34 is coupled to the motor controller 108 without a direct
mechanical connection between the trigger switch 34 and the motor
controller 108 in the motor housing 22. This also allows for
coupling the trigger switch 34 to the motor controller 108 without
providing an additional aperture in the housing 22, through which
potentially damaging debris may enter the motor housing 22 when the
detachable handle 24 is not attached thereto. In a preferred
embodiment, the trigger switch 34 is coupled to the motor
controller 108 using a magnet 116 mounted on a moveable arm 112
which is mounted in the detachable handle 24. The moveable arm 102,
and hence the magnet 116, is moved in response to actuation of the
trigger switch 34. A magnetic field sensor 120 (e.g., a Hall effect
sensor) is mounted in the tool housing 22 and coupled to the motor
controller 108 for detecting movement of the magnet 116 when the
trigger switch 34 is actuated to move the moveable arm 112.
[0059] The trigger switch 34 may be mounted in the detachable
handle 24 so as to be rotatable about a pivot point 110. For
example, as illustrated in FIG. 6, the trigger switch 34 may be
mounted in the detachable handle 24 so as to be rotatable about a
point 110 located near a bottom end of the trigger switch within
the detachable handle 24. At the opposite end of the trigger
switch, within the detachable handle 24, the end of the trigger
switch 34 is placed in contact with a first end of the moveable arm
112. The moveable arm 112 is preferably mounted in the detachable
handle 24 so as to be rotatable about a pivot point 114 located
near the center of the moveable arm 112. The magnet 116 is mounted
in or attached to the end of the moveable arm 112 in a conventional
manner.
[0060] A compression spring 118 may be mounted in the detachable
handle so as to press against the end of the moveable arm 112 where
the moveable arm 112 contacts the trigger switch 34. Thus, the
compression spring 118 biases the moveable arm 112 against the end
of the trigger switch 34, thereby also biasing the trigger switch
34 into an "off" position. In this position, as illustrated in FIG.
6, the magnet 116 mounted in the moveable arm 112 is positioned at
a spaced apart distance from the housing 22 of the tool 20 (when
the detachable handle 24 is attached to the housing 22). When the
trigger switch 34 is actuated, the switch 34 is rotated about pivot
point 110. The end of the trigger switch 34 in contact with the
moveable arm 112 presses the end of the moveable arm 112 against
the biasing action of the compression spring 118, which compresses
the compression spring 118 and rotates the moveable arm 112 about
pivot point 114. This moves the magnet 116 into closer proximity to
the tool housing 22 (when the detachable handle 24 is attached to
the housing 22).
[0061] The magnetic field sensor 120, such as a Hall effect sensor,
is mounted within the tool housing 22 opposite the position of the
magnet 116 when the trigger switch 34 is actuated. The magnetic
field sensor 120 may be any conventional sensor adapted to detect
when the magnet 116 is moved forward into a position adjacent to
the housing 22, i.e., when the magnet 116 is moved into the "on"
position by an operator actuating the trigger switch 34. The
magnetic field sensor 120 is coupled to the motor controller 108 in
a conventional manner, so as to provide a signal to the motor
controller 108 to turn the tool motor on when the magnet 116 is
moved into the "on" position. The housing 22 is preferably made of
a dielectric material, such that the magnetic field sensor 120 may
be mounted within the housing 22, and operation thereof in
combination with the magnet 116 to turn the tool motor on will not
be affected by the presence of a portion of the housing 22 between
the magnet 116 and magnetic field sensor 120. Thus, there is no
need to form an additional aperture in the housing 22 to couple the
trigger switch 34 to the motor controller 108.
[0062] When the trigger switch 34 is released, the compression
spring 118 operates to rotate the trigger switch 34 and moveable
arm 112 about pivot points 110 and 114, respectively, back into the
"off" position. In this position, the magnet 116 is moved back away
from the housing 22 a sufficient distance such that the magnetic
field sensor 120 no longer detects the presence of the magnet 116.
When the presence of the magnet is no longer detected by the sensor
120, it provides a signal (or ceases providing a signal) to the
motor controller 108 to turn off the tool motor. Thus, the
preferred mechanism for coupling the trigger switch 34 to the motor
controller 108 does not employ a direct mechanical connection
between trigger switch 34 and the motor controller 108. The
mechanism for coupling the trigger switch 34 in the detachable
handle 24 to the motor controller 108 in the motor housing 22
therefor does not interfere with the easy and quick attachment of
the detachable handle 24 to, and removal of the detachable handle
24 from, the motor housing 22.
[0063] As discussed above, the hand-held power tool 20 preferably
includes a multiple-position on/off power switch 32 mounted in the
tool housing 22. The multiple-position on/off power switch 32 is
preferably employed to both turn the tool motor on and off and to
enable operation of the trigger switch 34 to turn the tool motor on
and off. For example, in a first operating position of the
multiple-position on/off switch 32, as illustrated in FIG. 7, the
motor is turned off, and operation of the motor by the trigger
switch 34 is disabled. Thus, with the multiple-position on/off
switch in this first position, the motor cannot be turned on by
actuating the trigger switch 34 mounted in the detachable handle 24
attached to the tool 20. In a second operating position of the
multiple-position on/off switch 32, as illustrated in FIG. 8, the
motor remains off, but the trigger switch 34 is enabled to turn the
tool 20 on and off. Thus, when the multiple position on/off switch
32 is in this second position, the motor may be activated by
actuating the trigger switch 34 mounted in the detachable handle 24
attached to the tool 20. The motor 20 is turned off by releasing
the trigger switch 34. In a third operating position of the
multiple position on/off switch, as illustrated in FIG. 9, the
motor is turned on. In this position, as in the first position, the
trigger switch 34 is also disabled. In other words, when the
multiple position on/off switch 32 is in the third position, the
motor is turned on, and may not be turned off by either actuating
or releasing the trigger switch 34.
[0064] In an exemplary embodiment, the hand-held power tool
provides for improved visibility of a workpiece at the point of a
cut being made by the tool 20. In accordance with an exemplary
embodiment, improved visibility under poor lighting conditions is
provided by one or more high-output light emitting diodes (LEDs)
130 mounted in the tool housing 22 at the end thereof from which a
motor shaft extends and to which a tool bit or other accessory is
attached. The LEDs 130 mounted in the housing 22 are preferably
turned on whenever the cutting tool motor is in operation.
[0065] As illustrated in FIGS. 10-12, one or more high-output LEDs
130 may be mounted, in a conventional manner, in LED apertures 132
(e.g., pockets, receptacles, etc.) formed in the end of the housing
22. The LEDs 130 may be implemented using commercially available
high-output LEDs. Preferably, two or more LEDs 130 are mounted in
the housing 22. The two or more LEDs 130 are preferably mounted in
the housing 22 so as to be spaced apart around the mounting
structure 46 for mounting, e.g., a tool bit to the cutting tool
motor shaft. For example, two high-output LEDs 130 may be
positioned on opposite sides of the motor shaft.
[0066] As illustrated in FIG. 11, the LEDs 130 are preferably
mounted at angles within the housing 22. This may be achieved by
forming the LED apertures 132 in the housing 22 at the desired
angles with respect to the axis of the motor housing 22. The angles
at which the LEDs 130 are mounted in the housing 22 are preferably
selected such that the beams of light 134 emitted by the LEDs 130
form an overlap or intersecting area 136 at the point of a cut when
the tool 20 is in operation. For example, the angles with which the
LEDs 130 are mounted in the housing 22 may be selected so that the
beam overlap area 136 corresponds to the location where a tool bit
enters a workpiece being cut thereby.
[0067] It should be understood that, although two LEDs 130 are
illustrated in the exemplary embodiment shown in FIGS. 10-12, more
than two LEDs may be mounted in the end of the motor housing 22 to
illuminate a workpiece at the point of a cut, with the plurality of
LEDs mounted in the housing 22 at angles to form an overlap area of
light beams at the point of the cut.
[0068] As a workpiece, such as a piece of wood, is cut using the
tool 20, cutting debris (e.g., sawdust) may deposit and build up on
the workpiece surface at or near the point of cut made by the tool
20. This debris can interfere with the visibility of the operator
trying to control the tool 20 to make a precise cut of a desired
shape. For example, the debris may obscure a cut line marked on the
workpiece by the operator. A tool 20 in accordance with an
exemplary embodiment preferably includes one or more air vents 42
formed in the bottom of the housing 22 to direct a flow of air onto
a workpiece being cut to blow debris therefrom, thus enhancing
visibility at the point of a cut. In an exemplary embodiment, the
air vents 42 are formed in the housing 22 at the end of the housing
22 adjacent to the point where the motor shaft emerges from the
housing 22, i.e., at the end of the shaft where a tool bit or other
attachment is attached to the motor shaft.
[0069] In an exemplary embodiment, a fan may be provided within the
housing 22. Preferably, the housing is attached or coupled to the
motor shaft. When the motor is turned on, the fan is rotated at a
high speed to draw air through the housing 22 and across the motor
to thereby cool the motor. Air drawn through the housing by the fan
is directed through the air vents onto the workpiece surface at the
point of the cut, thereby blowing debris away from the point of the
cut.
[0070] For some workpiece materials, it is desirable to not blow
cutting debris away from the point of the cut. For example, a
workpiece such as gypsum board drywall produces fine powdery
cutting debris as a cut is made. It may be undesirable to blow this
material into the air. Therefore, in accordance with an exemplary
embodiment, a moveable air vent cover 140 is provided that allows
the air vents 42 to be opened and closed. The air vent cover 42 may
be positioned to either allow or prevent air flow from air vents 42
as desired. Preferably, the air vent cover 140 is mounted in the
power tool housing for rotational movement therein.
[0071] A preferred and exemplary embodiment of a movable air vent
cover 140 which may be employed is illustrated in FIG. 12. The
exemplary air vent cover 140 is implemented as a substantially flat
ring 140 which is mounted within the housing 22 adjacent to the air
vents 42. The air vent cover 140 may be implemented as a complete
or partially broken ring, as illustrated in FIG. 12. The air vent
cover 140 is mounted for rotational movement within the housing 22
in a conventional manner.
[0072] A tab, lever, handle, or other structure 142 is preferably
formed to extend radially from the air vent cover 140. The tab 142
is preferably formed to extend outward through a slot 144 formed in
the sidewall of the housing 22 when the air vent cover 140 is
positioned in the housing 22. Thus, an operator of the tool 20 is
able to rotate the air vent cover 140 within the housing 22 by
means of the tab 142 extending therefrom. The air vent cover 140
may be rotated between a first position allowing air flow through
the air vents to be directed toward a workpiece and a second
position blocking air flow toward the workpiece. Thus, an operator
may direct a flow of air toward a workpiece to blow cutting debris
therefrom and enhance visibility of the workpiece surface at the
point of the cut or may block such air flow as desired.
[0073] The air vent cover 140 has one or more air vent apertures
146 formed therein. When the air vent cover 140 is rotated into the
correct position, the air vent apertures 146 formed in the air vent
cover 140 are aligned with the air vents 42, thereby allowing air
flow through the motor housing 22 to exit through the air vents 42
to clear cutting debris away from the point of a cut. By rotating
the air vent cover 140 using the tab 142, the air vent apertures
146 may be moved out of alignment with the air vents 42 such that
the air vent cover 140 blocks the flow of air through the housing
22 from exiting through the air vents 42. Thus, by rotating the air
vent cover 140 using the tab 142, the air vents 42 may be opened
and closed to provide a flow of air to remove cutting debris away
from a workpiece or to prevent such a flow of air.
[0074] The moveable air vent cover may also be formed to open vents
44 formed in the housing directed radially outward from the sides
of the housing when the air vents directed toward the workpiece are
closed. Air drawn through the motor housing to cool the motor may
thereby be redirected in a direction radial to the tool, using the
moveable air vent cover, so as to not disturb cutting debris from a
workpiece being cut. When the flow of air through the air vents 42
is blocked by the air vent cover 140 (e.g., the apertures 42 formed
in the air vent cover 140 are moved out of alignment with the air
vents 42), the flow of cooling air flowing through the tool housing
22 exits the housing 22 through exhaust air vents 44 formed in the
side of the housing 22, in a direction away from the workpiece
being cut.
[0075] To increase the flow of air out of the air vents 42, at
least a portion of the exhaust air vents 44 are blocked when the
air vent cover 140 is positioned such that air vent apertures 146
are aligned with the air vents 42. One or more axially or
vertically extending portions 148 may be formed on the air vent
cover 140 for this purpose. As illustrated in FIG. 12, the axially
extending portions 148 may be formed along the outer edge of the
air vent cover 140. The axially extending portions 148 extend to a
sufficient height, and are positioned on the air vent cover 140,
such that the axially extending portions 148 may be positioned to
block a flow of air through at least some of the air exhaust vents
44 when the air vent cover 140 is rotated into a position such that
the air vent apertures 146 are aligned with the air vents 42. When
the air vent cover 140 is rotated into a position such that the air
vents 42 are covered by the air vent cover 140, the axially
extending portions 148 move away from and no longer block the air
exhaust vents 44, to allow increased flow of air therethrough. In
this manner, air flow is redirected from the air exhaust vents 44
through the air vents 42 when the air vents 42 are opened to
increase the flow of air through the air vents 42 and to remove
cutting debris from a workpiece being cut.
[0076] The present invention provides a hand-held power tool that
allows for increased control and visibility. Though described in
detail herein with respect to a particular type of hand-held power
cutting tool, it should be noted that the present invention is not
limited in application to any particular tool design. The features
of the present invention may be used with other types of hand-held
power tools.
[0077] Although only a few embodiments of the present inventions
have been described in detail in this disclosure, those skilled in
the art who review this disclosure will readily appreciate that
many modifications are possible (e.g., variations in sizes,
dimensions, structures, shapes and proportions of the various
elements, values of parameters, mounting arrangements, use of
materials, colors, orientations, protocols, etc.) without
materially departing from the novel teachings and advantages of the
subject matter recited in the claims. Accordingly, all such
modifications are intended to be included within the scope of the
present invention as defined in the appended claims. The order or
sequence of any process or method steps may be varied or
re-sequenced according to alternative embodiments. In the claims,
any means-plus-function clause is intended to cover the structures
described herein as performing the recited function and not only
structural equivalents but also equivalent structures. Other
substitutions, modifications, changes and omissions may be made in
the design, operating conditions and arrangement of the preferred
and other exemplary embodiments without departing from the spirit
of the present inventions as expressed in the appended claims.
* * * * *