The present invention relates to power tools and, more particularly, to a handle arrangement for power tools.
A power tool, such as a circular saw, generally includes a housing supporting a motor which rotatably drives a tool element, such as a saw blade. Typically, an operator's handle is integrally formed with the housing. In a circular saw, a shoe plate supports the saw on the surface of a workpiece.
In some circular saws, the housing is adjustable relative to the shoe plate to change the depth of cut of the saw blade. For example, the housing may pivot relative to the shoe plate about an axis adjacent the front of the shoe plate (front pivot depth adjustment) or about an axis adjacent the rear of the shoe plate (rear pivot depth adjustment). In another construction, the shoe plate is slidably lowered and raised relative to the housing (drop shoe depth adjustment). In each of these depth adjustment arrangements, when the depth of cut of the saw blade is adjusted, the position and/or orientation of the handle relative to the workpiece is also adjusted.
U.S. Pat. No. 4,516,324 discloses a modular housing system for a circular saw. The circular saw includes a single, one-piece housing having an interface portion which interchangeably mounts either a pivot adjust subassembly or a vertical (drop shoe) adjust subassembly for changing the depth of cut of the circular saw. The main handle can have either a “push handle” configuration or a “top handle” configuration. The selected handle component is slipped onto the one-piece field case and secured by fasteners.
One independent problem with a circular saw including an operator's handle that is integrally formed with the housing, is that, in some cutting operations, the operator may prefer a “push handle” to a “top handle” or vice versa. However, the operator cannot adjust the handle to the desired position relative to the housing.
Another independent problem with a circular saw with an integral handle is that, when the depth of cut of the saw blade is adjusted, the handle position and orientation also changes. The resulting handle position is often uncomfortable and is seldom the optimal position for operation of the circular saw.
For example, in a circular saw with a front pivot depth adjustment assembly, at full depth of cut, the handle is typically positioned as a “push handle”. At a minimum depth of cut, the handle position is changed to a “top handle” position. In a circular saw with a rear pivot depth adjustment assembly, at full depth of cut, the handle must be oriented above a typical “push handle” position because, when the saw is adjusted to a minimum depth of cut, the handle is lowered.
One independent problem with the handle arrangement disclosed in U.S. Pat. No. 4,516,324 is that the circular saw includes two separate handles. The handle component that is not in use must be stored and may be lost or damaged.
Another independent problem with the handle arrangement disclosed in U.S. Pat. No. 4,516,324 is that the saw includes a handle that is only a “push handle” or a “top handle” and that is not adjustable between these configurations. Additional fasteners are also required.
The present invention provides a handle arrangement for a power tool that alleviates the one or more of the above-described and other independent problems with the above-described handle arrangements. In some aspects, the invention provides a power tool, such as a circular saw, that generally includes a handle that is movable relative to the motor housing. Preferably, the handle is pivotable about the axis of the saw blade relative to the motor housing.
Also, in some aspects, the invention provides a locking assembly for locking the handle in a position relative to the housing. Preferably, the locking assembly provides a frictional engagement between the handle and the housing and includes a clamping member that releasably applies a clamping force to the housing to lock the handle in a position relative to the housing. Preferably, the locking assembly also provides a positive engagement between the handle and the housing and includes inter-engaging teeth formed on both the handle and the housing.
Further, in some aspects, the invention provides means for connecting the switch to the motor to accommodate movement of the switch with the handle and relative to the motor. Preferably, the connecting means are provided by a wiring arrangement.
In addition, in some aspects, the invention provides interaction between the switch and the locking assembly to prevent inadvertent operation of one when the other is operated. Specifically, the switch preferably cannot be operated when the locking assembly is unlocked, and the locking assembly cannot be unlocked when the switch is connecting the motor to the power source.
One independent advantage of the present invention is that the handle is movable relative to the housing of the power tool to allow the operator to position the handle as desired for a given cutting operation. As a result, the operator can adjust the handle to a position that is most comfortable and allows the greatest control of the circular saw during cutting operations.
Another independent advantage of the present invention is that, when the circular saw is adjusted to change the depth of cut of the saw blade, the operator can also adjust the handle to an optimum position for the given cutting operation.
Yet another independent advantage of the present invention is that the circular saw does not include additional components that must be substituted for one another to change the configuration of the handle or additional fasteners. This reduces the chance that such an additional component is lost or damaged and also eliminates the need to store additional components.
A further independent advantage of the present invention is that the handle is adjustable to substantially any position between a first position, such as a “push handle” position, and a second position, such as a “top handle” position.
Other independent features and independent advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings.
Before at least one embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of the construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
A power tool embodying aspects of the invention is illustrated in FIG. 1A. In the illustrated construction, the power tool is a circular saw 10 and includes a motor housing 14 supporting an electric motor 18 (shown schematically in FIG. 1A). The motor 18 is connectable to a power source and is operable to rotatably drive a tool element, such as a saw blade 22, about an axis 26 to cut a workpiece W.
The circular saw 10 also includes (see
In the illustrated construction, the circular saw 10 includes a front pivot depth adjustment assembly 46 to adjust the depth of cut of the saw blade 22. The depth adjustment assembly 46 includes a pivot member 50 defining the pivot axis 34 and pivotally connecting the shoe plate 30 to the housing 14. As shown in
In other constructions (not shown), the circular saw 10 may include, for example, a rear pivot depth adjustment assembly or a drop shoe depth adjustment assembly rather than the front pivot depth adjustment assembly 46. It should be understood that the present invention applies to a circular saw with any type of depth adjustment assembly.
The circular saw 10 also includes (see
In the illustrated construction, the handle member 70 has (see
The circular saw 10 also includes (see
The locking assembly 82 includes (see
The locking assembly 82 also includes (see
To movably connect the end 98 of the locking member 86 to the handle member 70, the locking assembly 82 also includes a threaded pin 126 which engages the through pin 100 connected to the end 98 of the locking member 86. The threaded pin 126 also extends through the tapped pin 114 supported in the cam-shaped portion 106 of the actuating member 102. The annular opening 118 accommodates pivoting movement of the actuating member 102 relative to the threaded pin 126.
To move the locking member 86 between the locked and unlocked positions, the actuating member 102 is pivoted, moving the threaded pin 126 and the end 98 of the locking member 86. As the actuating member 102 is moved from the locked position (shown in
To move the locking member 86 to the locked position, the actuating member 102 is moved from the unlocked position (shown in
In the unlocked position (shown in FIG. 5), the threaded pin 126 is adjustable to change the clamping force applied by the locking member 86 when the locking member 86 is in the locked position. With the actuating member 102 in the unlocked position, the exposed end 128 of the threaded pin 126 is accessible by the operator to threadably loosen or tighten the locking member 86. This adjustment of the locking member 86 may be necessary due to manufacturing tolerances or may become necessary due to wear of the movable handle arrangement 66.
The locking assembly 82 also includes (see
In the preferred embodiment, the locking assembly 82 provides both a frictional engagement, through the clamping force applied by locking member 86 to the support portion 72 of the housing 14, and a positive engagement, through the inter-engaging teeth 130. In other constructions (not shown), however, the locking assembly 82 may only provide either a frictional engagement or a positive engagement.
For example, the locking assembly 82 may include only the frictional engagement provided by a locking member, similar to the locking member 86, applying a clamping force to the support portion of the housing 14. Alternatively, the locking assembly 82 may provide only the positive engagement, such as by a locking projection that is engageable with a locking recess to fix the handle member 70 in a position relative to the housing 14. Such a positive engagement could be provided by a detent assembly between the handle member 70 and the support portion 72 of the housing 14 with locking recesses corresponding to respective positions of the handle member 70 relative to the housing 14.
The circular saw 10 also includes (see
The circular saw 10 also includes means for connecting the switch 150 to the motor 18. The connecting means accommodates movement of the switch 150 relative to the motor 18 so that, in any position of the handle member 70 relative to the housing 14, the switch 150 is operable to selectively connect the motor 18 to the power source.
In the illustrated construction, the connecting means includes a wiring arrangement 154 (see
In another construction (not shown), the connecting means may include a fixed first conductor mounted on the housing 14 and electrically connected to the motor 18. The first conductor extends along the path of movement of the handle member 70. In this construction, the connecting means also includes a movable second conductor fixed to the handle member 70 and electrically connected to the switch 150. The second conductor is movably connected to the first conductor and moves along the first conductor to thereby maintain the electrical connection between the switch 150 and the motor 18 at any position of the handle member 70 relative to the housing 14.
In yet another construction (not shown), the connecting means may include a remote transmitter and sensor combination to connect the switch 150 to the motor 18. In this construction, the transmitter is fixed to and moves with the handle member 70. The transmitter transmits a signal based on the condition of the switch 150, for example, an “ON” signal or an “OFF” signal. The sensor or receiver is mounted on the housing 14 and electrically connected to the motor 18. The sensor senses the transmitted signal and, if, for example, the “ON” signal is transmitted, connects the motor 18 to the power source. In this construction, the power source is directly connectable to the motor 18, rather than being connected through the switch 150.
A cover 166 is positioned over the motor 18 and the connecting means. In the illustrated construction, the cover 166 includes a channel 170 that accommodates movement of the wires 156 between the extreme pivoted positions (shown in solid and phantom lines in FIG. 3). The channel 170 also insures that the wiring arrangement 154 is protected and not damaged during movement of the handle member 70 relative to the housing 14.
The circular saw 10 also includes (see
The preventing means are provided by a locking plate 174 which interacts with both the locking assembly 82 and the switch assembly 142. The locking plate 174 includes an end 178 for engagement with the tab 122 of the actuating member 102. At the other end, the locking plate 174 includes a blocking portion 182 and an aperture 186. A depressable button 188 is connected to the locking plate 174. The button 188 includes an elongated portion to provide a debris barrier. A spring member 190 biases the locking plate 174 toward engagement with the actuating member 102 (in the direction of arrow B in FIGS. 4 and 5).
As shown in
During movement of the actuating member 102 to the locked position, the tab 122 engages the end 178 and moves the locking plate 174 in the direction opposite to arrow B. Alternatively, the operator depresses the button 188 to move the locking plate 174. Once the actuating member 102 is in the locked position, the end 178 engages in the recess formed on the tab 122.
As shown in
In order to move the actuating member 102 to the unlocked position, the locking plate 174 must be moved in the direction opposite to arrow B. To move the locking plate 174, the operator depresses the button 188, disengaging the end 178 from recess formed on the tab 122. In the illustrated construction, the actuating member 102 cannot be moved to the unlocked position without the operator depressing the button 188. This reduces the likelihood that the actuating member 102 can be accidentally moved to the unlocked position and that the locking assembly 82 can be accidentally released.
In another construction (not shown), the locking plate 174 does not include the button 188. An unlocking force applied by the operator to move the actuating member 102 to the unlocked position causes the tab 122 to move the locking plate 174 in the direction opposite to arrow B. In such a construction, the configuration of the tab 122 would ensure that the required unlocking force is much greater than a force that would be applied if, for example, the operator accidentally pulled on the actuating member 102. This construction also reduces the likelihood of the locking assembly 82 being accidentally unlocked.
In either construction, however, when the trigger 146 is depressed (as shown in solid lines in FIG. 4), the upper portion 194 of the trigger 146 engages the forward wall of the aperture 186, and the locking plate 174 is prevented from moving in the direction opposite to arrow B. Thus, the locking plate 174 provides a means for preventing the locking assembly 82 from being moved from the locked condition to the unlocked condition when the switch assembly 142 is in the operated condition.
With the trigger in the unoperated condition (as shown in phantom lines in FIG. 4), the upper portion 194 of the trigger 146 does not engage the forward wall of the aperture 186. The locking plate 174 can be moved in the direction opposite to arrow B, and the actuating member 102 can be moved to the unlocked position (shown in FIG. 5).
In other constructions (not shown), the preventing means may be provided by other mechanical interaction between the locking assembly 82 and the switch assembly 142. For example, the preventing means may be provided by direct interaction (not shown) between the trigger 146 and the actuating member 102 without an additional component such as the locking plate 174.
In yet other constructions, the preventing means may be provided by non-mechanical means, such as by additional electrical switches which must be operated to enable operation of the locking assembly 82 and/or the switch assembly 142. For example, the locking assembly 82 can include a switch (not shown) electrically connected to the switch 150. This additional switch would prevent the switch 150 from connecting the motor 18 to the power source when the locking assembly 82 is in the unlocked condition.
In the illustrated construction, the switch assembly 142 also includes (see
With the shuttle switch 198 in the centered position (shown in FIG. 8A), the upper portion 194 of the trigger 146 contacts the ribs 202, preventing the switch 150 from connecting the motor 18 to the power source. To operate the switch 150, the shuttle switch 198 must first be moved laterally (in the direction of arrow C in
Movement of the shuttle switch 198 to a lateral position (such as that shown in
In operation, the operator selects the desired position of the handle member 70 relative to the housing 14 and ensures that the locking assembly 82 is in the locked condition as shown in
When the operator wants to change the position of the handle member 70 relative to the housing 14, for example, when the depth of cut of the saw blade 22 is adjusted, the operator first moves the switch assembly 142 to the unoperated condition by releasing the trigger 146.
The operator can then move the locking assembly 82 to the unlocked condition. The button 188 is depressed, and the actuating member 102 is moved to the unlocked position (as shown in
As shown in
One or more independent features and independent advantages of the invention are set forth in the following claims.
This is a continuation of patent application Ser. No. 09/940,222, filed Aug. 27, 2001, now U.S. Pat. No. 6,588,112, which is a division of patent application Ser. No. 09/618,217, filed Jul. 18, 2000, now U.S. Pat. No. 6,301,790, issued Oct. 16, 2001, which is a continuation of patent application Ser. No. 09/134,626, filed Aug. 14, 1998, now U.S. Pat. No. 6,108,916, issued Aug. 29, 2000.
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Number | Date | Country | |
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20040003698 A1 | Jan 2004 | US |
Number | Date | Country | |
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Parent | 09618217 | Jul 2000 | US |
Child | 09940222 | US |
Number | Date | Country | |
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Parent | 09940222 | Aug 2001 | US |
Child | 10614528 | US | |
Parent | 09134626 | Aug 1998 | US |
Child | 09618217 | US |