U.S. patent application number 10/654548 was filed with the patent office on 2005-03-03 for method for driving electric percussion tool.
Invention is credited to Yiu, Chih Hao.
Application Number | 20050045352 10/654548 |
Document ID | / |
Family ID | 34621277 |
Filed Date | 2005-03-03 |
United States Patent
Application |
20050045352 |
Kind Code |
A1 |
Yiu, Chih Hao |
March 3, 2005 |
METHOD FOR DRIVING ELECTRIC PERCUSSION TOOL
Abstract
A method for driving an electric percussion tool which includes
a solenoid, a plunger core partially engaged in one end of the
solenoid, and a spring disposed out of the solenoid and closer to
the other end of the solenoid and distal to the plunger core. The
solenoid is energized to draw the plunger core from one end to the
middle of the solenoid, and selectively de-energized to allow the
plunger core to force against the spring member. The solenoid is
energized and de-energized again to move the plunger core toward
the middle portion and then to move in the driving direction in
addition to the spring biasing force applied by the spring
member.
Inventors: |
Yiu, Chih Hao; (Taichung,
TW) |
Correspondence
Address: |
Charles E. Baxley, ESQ>
90 John Street-3rd Floor
New York
NY
10038
US
|
Family ID: |
34621277 |
Appl. No.: |
10/654548 |
Filed: |
September 1, 2003 |
Current U.S.
Class: |
173/1 |
Current CPC
Class: |
B25C 1/06 20130101; B25D
11/064 20130101; B25C 5/15 20130101 |
Class at
Publication: |
173/001 |
International
Class: |
B21J 001/00 |
Claims
1. (canceled).
2. A method for driving an electric percussion tool, said electric
percussion tool including a solenoid having a first end and a
second end and a middle portion, a plunger core partially engaged
in said first end of said solenoid, and a spring member, said
method comprising: energizing said solenoid to draw said plunger
core from said first end of said solenoid toward said middle
portion of said solenoid, de-energizing said solenoid, to allow
said plunger core to move from said middle portion of said solenoid
toward said second end of said solenoid with a moment of inertia of
said plunger core, applying a spring biasing force of said spring
member against said plunger core to force said plunger core to move
partially into said second end of said solenoid, and energizing
said solenoid again to draw said plunger core from said second end
of said solenoid toward said middle portion of said solenoid, and
to allow said plunger core to move from said middle portion of said
solenoid toward said first end of said solenoid with a moment of
inertia of said plunger core.
3. The method for driving electric percussion tools as claimed in
claim 2 further comprising de-energizing said solenoid again, to
allow said plunger core to move from said middle portion of said
solenoid toward said first end of said solenoid with a moment of
inertia of said plunger core.
4. The method for driving electric percussion tools as claimed in
claim 2 further comprising spacing said spring member away from
said solenoid to allow said plunger core to move outwardly beyond
said second end of said solenoid when said plunger core is forced
against said spring member.
5. The method for driving electric percussion tools as claimed in
claim 4, wherein said solenoid is energized again to draw said
plunger core from said second end of said solenoid toward said
middle portion of said solenoid when said plunger core is forced to
move partially into said second end of said solenoid by said spring
member.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method for driving tools,
and more particularly to a method for driving electric hammer or
impact or percussion tools
[0003] 2. Description of the Prior Art
[0004] Various kinds of typical electric percussion tools, impact
beating tools, or the like have been developed and provided for
hammering or stapling or nailing purposes, and comprise a plunger
core slidably received in a coil or solenoid, which may actuate or
force the plunger core to move and thus to hammer or impact onto
objects.
[0005] For example, U.S. Pat. No. 3,308,892 to Palmer, and U.S.
Pat. No. 4,215,297 to Jacquemet disclose two of the typical
electric percussion tools, impact beating tools, or the like and
comprise a single plunger core slidably received in a single
solenoid, and a spring member for recovering the plunger core back
to the original position, or away from the middle portion of the
solenoid.
[0006] In operation, the plunger core may be forced to move toward
the middle portion of the solenoid every time when the solenoid is
energized. The spring member is provided for recovering or moving
the plunger core away from the middle portion of the solenoid after
every striking or hammering operation, for allowing the solenoid to
actuate or move the plunger core next time.
[0007] However, the striking or hammering forces of the plunger
core is small or less, such that the plunger core has to be forced
or actuated many times, in order to conduct the striking or
hammering operation many times.
[0008] In order to improve the small striking or hammering
problems, another typical electric percussion tool has been
developed to provide a ram propelled device to produce high impact
forces against the work pieces. U.S. Pat. No. 3,811,313 to Schut
discloses one of the typical impact devices. However, a complicated
configuration and a number of members or elements are required to
be provided to form the electromagnetic high energy pulse coil and
the ram propelled device.
[0009] U.S. Pat. No. 3,054,464 to Ondeck, and U.S. Pat. No.
5,760,552 to Chen, et al., and U.S. Pat. No. 6,364,193 to Tsai
disclose the other typical electric percussion tools, impact
beating tools, or the like and comprise a plunger core slidably
received in two or more solenoids which may be actuated in series
to actuate the plunger core to impact onto the objects.
[0010] However, a large space is required to receive the two or
more solenoids, such that the volume of the tools may be greatly
increased.
[0011] U.S. patent application No. US2002/0014344A1 to Geiger et
al. discloses a further typical electric percussion tool which
includes two coils or solenoids having an axis disposed or extended
transverse to the oscillation axis of a working tool. Similarly, a
complicated configuration and a number of members or elements are
required to be provided to form and to arrange the electro-magnetic
hammer and a yoke thereof.
[0012] In all of the typical electric percussion tools, the spring
members are all provided for recovering the plunger core only, and
may not be used to force the plunger core while conducting the
striking or hammering operations.
[0013] The present invention has arisen to mitigate and/or obviate
the afore-described disadvantages of the conventional methods for
driving electric percussion tools.
SUMMARY OF THE INVENTION
[0014] The primary objective of the present invention is to provide
a method for driving electric percussion tool and for allowing the
spring member to apply a moving or driving force against the
plunger core, in addition to a solenoid, while conducting the
striking or hammering operations.
[0015] In accordance with one aspect of the invention, there is
provided a method for driving an electric percussion tool,
comprising actuating a solenoid to act onto a plunger core, and
actuating a spring member to apply a spring biasing force onto the
plunger core in addition to the solenoid.
[0016] In accordance with the other aspect of the invention, there
is provided a method for driving an electric percussion tool, the
electric percussion tool including a solenoid having a first end
and a second end and a middle portion, a plunger core partially
engaged in the first end of the solenoid, and a spring disposed out
of the solenoid and closer to the second end of the solenoid, and
distal to the first end of the solenoid and the plunger core. The
method comprises energizing the solenoid to draw the plunger core
from the first end of the solenoid toward the middle portion of the
solenoid, de-energizing the solenoid, to allow the plunger core to
move from the middle portion of the solenoid toward the second end
of the solenoid with a moment of inertia of the plunger core, and
to allow the plunger core to move and force against the spring
member, energizing the solenoid again to draw the plunger core from
the second end of the solenoid toward the middle portion of the
solenoid, and de-energizing the solenoid again, to allow the
plunger core to move from the middle portion of the solenoid toward
the first end of the solenoid with a moment of inertia of the
plunger core.
[0017] The spring member may apply a spring biasing force against
the plunger core to force the plunger core to move from the second
end of the solenoid toward the first end of the solenoid, in
addition to the solenoid, and thus to allow the plunger core to be
forced or actuated by both the electromagnetic action of the
solenoid and the spring biasing force of the spring member.
[0018] The spring member is preferably spaced away from the
solenoid to allow the plunger core to move outwardly beyond the
second end of the solenoid when the plunger core is forced against
the spring member.
[0019] The solenoid is energized again to draw the plunger core
from the second end of the solenoid toward the middle portion of
the solenoid when the plunger core is forced to move partially into
the second end of the solenoid by the spring member.
[0020] Further objectives and advantages of the present invention
will become apparent from a careful reading of the detailed
description provided hereinbelow, with appropriate reference to the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a cross sectional schematic view of an electric
percussion tool to be operated or actuated with a method in
accordance with the present invention;
[0022] FIG. 2 is a plan schematic view illustrating an actuating
electric circuit for driving or actuating or operating the electric
percussion tool;
[0023] FIG. 3 is a plan schematic view similar to FIG. 2,
illustrating another electric circuit for driving or actuating or
operating the electric percussion tool;
[0024] FIG. 4 is a schematic view illustrating the driving signals
for actuating the solenoid of the electric percussion tool;
[0025] FIG. 5 is a schematic view illustrating the procedures for
driving or actuating or operating the electric percussion tool;
and
[0026] FIG. 6 is a schematic view similar to FIG. 5, illustrating
the procedures for driving or actuating or operating the electric
percussion tool with different actuating signals.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] Referring to the drawings, and initially to FIG. 1 an
electric percussion tool to be driven or operated by a method in
accordance with the present invention comprises a housing 10
including a chamber 11 formed therein, and including an opening 12
formed in one end thereof and defined by an end wall 13 and
communicating with the chamber 11 thereof.
[0028] A spring member 14 is disposed in the chamber 11 of the
housing 10 and disposed in the other end of the housing 10 or
arranged or disposed distal to the opening 12 of the housing 10. A
plate 15 is attached to an inner end or a free end of the spring
member 14 and movable along the chamber 11 of the housing 10, and
includes a cavity 17 formed therein.
[0029] A coil or solenoid 20 is disposed in the middle portion of
the chamber 11 of the housing 10, and a plunger core 21 is slidably
received in the solenoid 20. The plunger core 21 is arranged to be
partially movable out of one end 22 of the solenoid 20, but may not
be completely or fully moved out of the one end 22 of the solenoid
20. The spring member 14 is disposed out of the solenoid 20 and
distal to the plunger core 21.
[0030] The plunger core 21 is arranged to be completely or fully
movable out of the other end 23 of the solenoid 20 (FIGS. 4, 5),
when required. The plunger core 21 includes a projection 24
extended from one end thereof to engage into the cavity 17 of the
plate 15, for allowing the plunger core 21 to suitably force
against the spring member 14.
[0031] It is preferable that the housing 10 further includes a
barrel 18 engaged in the chamber 11 thereof, and disposed around
the spring member 14, and includes an inner diameter no greater
than that of the solenoid 20, for suitably guiding the plate 15 and
the plunger core 21 to slide along the chamber 11 of the housing 10
or along an oscillation axis 50 of the housing 10 or of the
percussion tool, and to prevent the plunger core 21 from tilting
relative to the housing 10.
[0032] The barrel 18 is preferably made of non-conductive or
non-electromagnetic materials, for preventing the barrel 18 to
interfere the energizing or the operation of the solenoid 20 and
the plunger core 21. The plunger core 21 includes a shank 25
extended therefrom and extendible out through the opening 12 of the
housing 10, for hitting or hammering or impacting onto objects.
[0033] It is to be noted that the electric percussion tool as shown
in FIG. 1 is simplified for illustration purposes. The examples of
the electric percussion tools have been disclosed and described in
the cited arts, which may thus be taken as references for the
present invention. The electric percussion tool may be used for
nailing or stapling or hammering purposes.
[0034] Referring next to FIG. 2, illustrated is one example of an
actuating electric circuit 30 for driving or actuating or operating
the electric percussion tool as shown in FIG. 1. The actuating
electric circuit 30 includes a microprocessor unit (MPU) 31 for
programming or processing purposes, and/or for controlling the
operation of the electric percussion tool.
[0035] The actuating electric circuit 30 includes a power circuit
32 having one or more diodes 33 and one or more capacitors 34 for
providing stabilized electric power to energize the MPU 31 or the
other electric parts or elements which will be described
hereinafter. The actuating electric circuit 30 further includes an
actuating device 35 having a photodiode 36 coupled to the MPU 31,
for being actuated or operated by the MPU 31.
[0036] The actuating device 35 includes an actuating member 37,
such as a triode AC switch or triggering bi-directional thyristor
(TRIAC) 37 coupled to the solenoid 20, and arranged to be actuated
or operated by the MPU 31 via the photodiode 36, in order to
actuate or to energize the solenoid 20, and in order to actuate the
plunger core 21 to move relative to the solenoid 20.
[0037] As shown in FIG. 3, alternatively, a transistor 38 and a
bridge rectifier circuit 39 may further be provided and coupled to
the solenoid 20, instead of the TRIAC 37, and also arranged to be
actuated or operated by the MPU 31 via the photodiode 36, in order
to actuate or to energize the solenoid 20 and to actuate the
plunger core 21 to move relative to the solenoid 20.
[0038] Referring next to FIG. 4, illustrated is one example of the
pulse triggering signals 40, 42 for triggering the TRIAC 37 to
actuate or to energize the solenoid 20 of the electric percussion
tool. For example, during a time period 0-t1, one or more pulse
triggering signals 40 may be generated by the MPU 31 via the
photodiode 36, in order to turn on or to actuate the TRIAC 37 to
supply sinuous driving signals 41 to actuate the solenoid 20 to
move the plunger core 21 relative to the solenoid 20.
[0039] Similarly, during the other time period t2-t3, one or more
pulse triggering signals 42 may be generated by the MPU 31 via the
photodiode 36, in order to actuate the TRIAC 37 to supply sinuous
driving signals 43 to actuate the solenoid 20 to move the plunger
core 21 relative to the solenoid 20. In another time period t1-t2,
no sinuous driving signals will be supplied to actuate the solenoid
20 when no pulse triggering signals have been generated and
supplied by the MPU 31 and the photodiode 36.
[0040] It is to be noted that the sinuous driving signals 41, 43
having either positive or negative voltage may all be used to
actuate or to operate the solenoid 20 to move the plunger core 21
relative to the solenoid 20. In addition, whenever the solenoid 20
is energized or actuated by either positive or negative voltage of
the sinuous driving signals 41, 43, the plunger core 21 may all be
forced to move toward the middle portion of or within the solenoid
20, which will be described in further details hereinafter.
[0041] Referring next to FIG. 5, illustrated is one example of a
method or the procedures in accordance with the present invention
for driving or actuating or operating the electric percussion tool.
At the beginning, or at the time "0", the plunger core 21 is
arranged to be partially extended out of the one end 22 of the
solenoid 20, but not completely or fully moved out of the one end
22 of the solenoid 20, as shown in the position indicated by
"51".
[0042] A positive voltage pulse signal 44 or a sinuous driving
signal 41 will then be supplied by the actuating device 35, and
controlled by the MPU 31, to energize or to actuate the solenoid 20
to force or to move or to draw the plunger core 21 along the
oscillation axis 50 of the housing 10 (FIG. 1) or of the percussion
tool, and in the direction toward the middle portion or the other
end 23 of the solenoid 20, until the plunger core 21 is moved to
the middle portion of the solenoid 20, as shown in the position
indicated by "52", at the time t1.
[0043] When the plunger core 21 is moved to the middle portion of
the solenoid 20 at position "52", the TRIAC 37 may be stopped or
turned off or switched off automatically, such that no actuating
signals will be sent to the solenoid 20 at this moment, and such
that the solenoid 20 will be switched off or disabled at this
moment.
[0044] At this time, the plunger core 21 has a tendency or has a
moment of inertia to move away from the middle portion of the
solenoid 20, and to move toward the other end 23 of the solenoid
20, and to move or force against the spring member 14. It is
preferable that the spring member 14 is arranged to allow the
plunger core 21 to move outwardly beyond the other end 23 of the
solenoid 20, as shown in the position indicated by "53".
[0045] For example, the spring member 14 may be disposed on the
other end of the housing 10 and coupled to the plunger core 21 to
apply a pulling force against the plunger core 21, and to allow the
plunger core 21 to move outwardly beyond the other end 23 of the
solenoid 20. At this moment or at this position, the plunger core
21 is moved outwardly beyond the solenoid 20 and may not be
actuated by the solenoid 20.
[0046] The spring member 14 may then force or bias the plunger core
21 to move toward the solenoid 20, until the plunger core 21 is
partially moved into the other end 23 of the solenoid 20, as shown
in the position indicated by "54", at the time t3. At this moment
or at this position, the plunger core 21 may be actuated by the
solenoid 20 again.
[0047] Before the plunger core 21 is partially moved into the other
end 23 of the solenoid 20 at the time t3, it is preferable that the
plunger core 21 is arranged to just reach the other end 23 of the
solenoid 20, but not entering or moving into the other end 23 of
the solenoid 20 yet, at time "t2", where the negative signal
portion 45 of the sinuous driving signal ends.
[0048] However, alternatively, the spring member 14 may also be
arranged to allow the plunger core 21 to be partially received
within the other end 23 of the solenoid 20 only, and to prevent the
plunger core 21 from been completely moved out beyond the other end
23 of the solenoid 20.
[0049] Once or when the plunger core 21 is partially moved into the
other end 23 of the solenoid 20 at position "54", the solenoid 20
is energized or actuated again by the positive voltage pulse signal
46 or the sinuous driving signal 43 that may be supplied to the
solenoid 20 by the TRIAC 37 of the actuating device 35 and
controlled by the MPU 31.
[0050] At this moment, the plunger core 21 may be actuated or drawn
by the solenoid 20 to move along the oscillation axis 50 of the
housing 10 (FIG. 1) or of the percussion tool, and in the driving
or acting direction toward the middle portion or the one end 22 of
the solenoid 20, until the plunger core 21 is moved to the middle
portion of the solenoid 20, as shown in the position indicated by
"55", at the time t4.
[0051] When the plunger core 21 is moved to the middle portion of
the solenoid 20 at position "55", the TRIAC 37 may be stopped or
turned off or switched off automatically, such that no actuating
signals will be sent to the solenoid 20 at this moment, and such
that the solenoid 20 will be switched off or disabled at this
moment.
[0052] At this time, the plunger core 21 that has been actuated by
the solenoid 20 has a tendency or has a moment of inertia to move
away from the middle portion of the solenoid 20, and to move in the
driving or acting direction and toward the one end 22 of the
solenoid 20. Simultaneously, or at this moment or at this position,
the plunger core 21 may also be forced to move in the driving or
acting direction toward the one end 22 of the solenoid 20, from the
other end 23 of the solenoid 20, by the spring member 14, in
addition to the electromagnetic action by the solenoid 20, such
that the shank 25 of the plunger core 21 may be forced to impact or
to hit or to hammer onto the objects by both the electromagnetic
action of the solenoid 20 and the spring biasing force of the
spring member 14.
[0053] Referring next to FIG. 6, the solenoid 20 may be actuated by
one or more positive and/or negative voltage portions of the
sinuous driving signals 41, 43, in order to draw the plunger core
21, from either end of the solenoid 20 (position 51 or 54), to the
middle portion of the solenoid 20 (position 52 or 55).
[0054] It is to be noted that the electric percussion tool includes
a single solenoid 20 to drive or actuate the plunger core 21, and
the spring member 14 may be arranged to be compressed by the
plunger core 21 and to accumulate a spring biasing force to force
the plunger core 21 to move in the driving or acting direction
toward the one end 22 of the solenoid 20 in addition to the
electromagnetic action by the solenoid 20.
[0055] The spring member 14 may also be arranged to be compressed
or extended by the plunger core 21 either when the plunger core 21
moves from the one end 22 of the solenoid 20 toward the middle
portion of the solenoid 20, and/or from the middle portion toward
the other end 23 of the solenoid 20, and/or when the plunger core
21 moves out of the other end 23 of the solenoid 20. Similarly, the
spring member 14 may also be arranged to be pulled by the plunger
core 21 to accumulate the spring biasing force against the plunger
core 21.
[0056] The prior electric percussion tools fail to provide a single
solenoid 20 and a spring member 14 to act simultaneously onto the
plunger core 21 and to apply both the electromagnetic action of the
solenoid 20 and the spring biasing force of the spring member 14 to
force the shank 25 of the plunger core 21 to impact or to hit or to
hammer onto the objects.
[0057] However, two or more solenoids 20 may also be provided to
act or actuate the plunger core 21, and to draw the plunger core
21, from either end of the solenoids 20 to the middle portion of
the solenoids 20. The spring member 14 may also be used to be
compressed by the plunger core 21 and to accumulate the spring
biasing force to force the plunger core 21 to move in the driving
or acting direction toward the one end of the solenoids 20 in
addition to the electromagnetic action by the two or more solenoids
20. Alternatively, the spring member 14 may be disposed and
arranged to be coupled to the plunger core 21 and to apply a
pulling force against the plunger core 21.
[0058] Accordingly, the method for driving electric percussion
tools may be used for allowing the spring member to apply a moving
or driving force against the plunger core, in addition to a
solenoid, while conducting the striking or hammering
operations.
[0059] Although this invention has been described with a certain
degree of particularity, it is to be understood that the present
disclosure has been made by way of example only and that numerous
changes in the detailed construction and the combination and
arrangement of parts may be resorted to without departing from the
spirit and scope of the invention as hereinafter claimed.
* * * * *