The invention relates to a bench-type power tool, and in particular to a push-pull power tool.
Bench-top power tools come in a variety of different designs. In most cases, a bench-top power tool includes a frame or a housing which includes a top portion for supporting a workpiece (e.g., a piece of wood) and a shaping tool (e.g., a saw assembly) with a blade. The shaping tool is positioned above the top portion for shaping the workpiece (e.g., cutting the workpiece). The shaping tool is generally supported by a support member (e.g., a carriage).
Bench-top power tools may be divided into two categories. In a first category the shaping tool is not moveable (i.e., stationary) along an axial direction parallel to a length of the frame. An operator of the power tool moves the workpiece toward the shaping tool in order to shape the workpiece. In a second category, the shaping tool is moveable and the operator moves the shaping tool toward the workpiece. The support member, in the second category, is generally coupled to sliding members (e.g., tracks) to move the support member relative to the top portion.
Bench-type power tools with moveable shaping tools provide certain advantages. For example, the operator may fix the workpiece to the top portion with fixing members (e.g., clamps) which may result in an easier shaping operation in cases where the workpiece is large (e.g., a sheet of plywood). The operator can grasp a gripping member (e.g., a knob) that is connected to a rod that is coupled to the shaping tool and slide the shaping tool forward toward a front portion of the power tool, in order to shape the workpiece.
Most bench-top power tools are also designed to provide adjustability of the shaping tool with respect to the top portion, which in turn provides adjustability with respect to the workpiece. For example, the shaping tool may be adjustable to provide a bevel shaping angle. The adjustments are performed by adjustment controls (e.g., knobs or levers). The operator may desire to adjust the bevel angle of the shaping tool to a predetermined angle, or alternatively, adjust the bevel angle by visually inspecting the bevel angle of the shaping tool with respect to the workpiece.
The adjustment controls of the push-pull saws of the prior art are coupled to the shaping tool and slide with the shaping tool with respect to the top portion and the frame or the housing. As a result, the controls may be unreachable by the operator when the shaping tool is in a position that is far from the operator.
In the case where the operator desires to adjust the bevel angle to a predetermined angle, the bevel angle adjustment control may be completely under the bench when the shaping tool is remote from the operator. In such a situation the operator may inconveniently need to reach under the bench and make the desired adjustments. Alternatively, the operator may need to slide the shaping tool so that the adjustment controls are reachable. In either case, the operator may be inconvenienced.
In the case where the operator desires to visually change the bevel angle of the shaping tool with respect to the workpiece, the operator may be excessively inconvenienced. In this situation, the operator may be required to follow a cumbersome procedure. In particular, the operator may be required to push the shaping tool toward the back portion of the bench, place the workpiece on the top portion, and inspect the bevel angle of the blade with respect to the workpiece. If the angle is incorrect, the operator may be required to remove the workpiece, slide the shaping tool toward the front portion of the bench in order to be able to reach the bevel angle control, adjust the angle, and repeat the aforementioned angle-adjustment procedure.
Therefore, while adjusting the bevel angle of the shaping tool with the workpiece remaining on the top portion of the bench may be possible by the operator reaching the bevel angle control that may be located under the bench, such an adjustment is inconvenient for the operator. Therefore, there is a need to be able to adjust the bevel angle of a bench-type push-pull shaping tool in a convenient manner.
According to one embodiment of the present disclosure, there is provided a push-pull power tool. The push-pull power tool includes a table, a carriage configured to move along the table in a linear direction, a cutting assembly carried by the carriage, and a bevel adjustment arrangement configured to pivot the cutting assembly relative to the table, the bevel adjustment arrangement including an actuator, wherein the actuator is configured to remain substantially stationary in the linear direction when the carriage is moved a substantial distance in the linear direction
According to another embodiment of the present disclosure, there is provided a push-pull table saw. The push-pull table saw includes a table, a carriage configured to move along the table in a linear direction, a cutting assembly carried by the carriage, and a bevel adjustment arrangement configured to pivot the cutting assembly relative to the table, the bevel adjustment arrangement including an actuator, wherein the actuator is configured to remain substantially stationary in the linear direction when the carriage is moved a substantial distance in the linear direction, and a height control member coupled to the saw assembly and configured to move the blade parallel to a second axis along the height of the housing in response to movement of the height control member, wherein the bevel control member remains vertically stationary during movement of the blade parallel to the second axis
According to yet another embodiment of the present disclosure, there is provided a push-pull saw. The push-pull saw includes a carriage configured to movably support a saw assembly, a push-pull rod coupled to the carriage and operable to move the carriage in a linear path of movement in response to the push-pull rod being moved in the linear path, and a bevel control rod coupled to the carriage and operable to move the saw assembly in a bevel path defined within a plane substantially perpendicular to the linear path in response to rotation of the bevel control rod, wherein the bevel control rod remains axially stationary during movement of the push-pull rod and the carriage in the linear path.
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the invention is thereby intended. It is further understood that the present invention includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the invention as would normally occur to one of ordinary skill in the art to which this invention pertains.
While a push-pull table saw is depicted in the figures of the present disclosure, it should be understood that the present disclosure applies to other types of push-pull bench-type power tools. For example, the present disclosure can also apply to a push-pull router that is coupled to a bench. Therefore, where a power saw or a saw assembly is referenced, it should be appreciated that other power tools, such as a router, may be substituted for the power saw.
The table 102 includes a table top 104, a front portion 106, and a rear portion 108. The table 102 can be formed in a shape of an enclosed housing, or as shown in
The saw assembly 230 (
The height adjustment arrangement 129 includes the shaft 130 connected to an actuator in the form of a height adjustment control knob 132. The shaft 130 extends through an arcuate opening 138 formed in the front portion 106 on the front plate 107.
The height adjustment control knob 132 is connected to the shaft 130 and provides a push-pull function as well as a rotational function. Therefore, linear movement of the height adjustment control knob 132 from a position near the front plate 107 to a position remote from the table 102, results in a linear movement of the saw assembly 230 along a linear path from a position near the back portion 108 to a position near the front portion 106, respectively. As a result, linear movement of the height adjustment control knob 132 results in a linear movement of the blade 120 from a position near the back portion of the opening 110 to a position near the front portion of the opening 110.
In addition to linear movement of the height adjustment control knob 132, the knob 132 can also be rotated. The shaft 130 is coupled to the saw assembly 230 (
The bevel angle adjustment arrangement 133 includes a bevel angle adjustment knob 134 connected to a bevel control rod 137 and which extends through an optional bushing 136 affixed to the front plate 107. The bevel control rod 137 is a rod that can be fully or partially formed in the form of a splined shaft. The bushing 136 may be configured to provide a rotational locking feature for the splined shaft 137 utilizing a ratchet and a pawl arrangement known to one of ordinary skill in the art. The bevel control rod 137 extends the length of the table 102 to an optional complementary bushing (not shown) on the rear plate 109.
The bevel angle adjustment knob 134 is axially fixed with respect to the front plate 107, i.e., the bevel angle adjustment knob 134 does not move along a linear path parallel to the length of the table 102. However, the bevel angle adjustment knob 134 is rotationally moveable. As will be described in greater detail below, rotating the bevel angle adjustment knob 134 causes rotation of the bevel control rod 137 which causes rotation of the saw assembly 230 with respect to the table top 104 which provides a desired bevel angle for the blade 120. Therefore, the bevel control rod 137 that is coupled to a pivotable mount in the form of a carrier 220, to which the saw assembly 230 is mounted (
Since the shaft 130 and the height adjustment control knob 132 are coupled to the saw assembly 230, rotating the bevel angle adjustment knob 134 also causes movement of the height adjustment control knob 132 and the shaft 130 along an arcuate path with respect to the front plate 107 and defined by the arcuate opening 138. The arcuate opening 138 is, therefore, provided on the front plate 107 to provide sufficient space for the shaft 130 to move in response to rotation of the bevel angle adjustment knob 134.
The carriage 200 also includes a pivotable mount in a form of the carrier 220. The carrier includes side walls 222 and 224 and a bottom plate 226 for connecting the side walls 222 and 224 and for supporting the saw assembly 230 which is connected to the bottom plate 226.
A portion of the shaft 130 is shown in
The sliding bracket 202 slidably interfaces with the sliding members 246 and 248 by complementary sliding members 252 and 254, respectively. The sliding interfaces 246/252 and 248/254 are further described below in reference to
Since the side wall 222 and the bottom plate 226 are connected, rotating the bevel angle adjustment knob 134 causes rotation of the bevel control rod 137 which causes rotation of the side wall 222 which causes rotation of the bottom plate 226. Rotation of the bottom plate causes rotation of the saw assembly 230 which causes beveling of the saw blade 120. The ends of the arcuate opening 244 may be used to provide limits for how far the carrier 220 can rotate.
While the splined interface between the gears 250 and the splines of bevel control rod 137 provide the rotational movement for the carrier 220, the same splined interface can also provide a sliding interface. Once the desired rotational position has been reached (i.e., the bevel angle), the carriage 200 can be slidably moved from the position near the rear portion 108 to the position near the front portion 106, and vice versa. The complementary sliding members 246/252 and 248/254 provide the axial sliding interface of the sliding bracket 202 with respect to the table top 104.
As explained above, the shaft 130 is utilized to both slide the carriage 200 along the length of the table 102 as well as to adjust the height of the blade 120 with respect to the table top 104. The shaft 130 is coupled to the saw assembly 230. While pulling and pushing of the shaft 130 forces the saw assembly 230 and consequently the carriage 200 to slide, rotating the shaft 130 causes the blade 120 to raise and lower with respect to the table top 104. However, only the blade 120 moves up and down and not the saw assembly 230. In other words, the carrier 220 and the carriage 200 are stationary in the vertical direction.
In operation, the operator of the push-pull table saw 100 can push the height adjustment control knob 132 to move the carriage 200 including the carrier 220 to the position near the rear portion 108. The operator can then place a workpiece on the table top 104 and position the workpiece next to the blade 120. The operator can adjust the bevel angle of the blade 120 by rotating the bevel angle adjustment knob 134 and bevel control rod 137 by releasing the optional pawl from a splined portion of the bevel control rod 137. Regardless of the position of the carriage 200, the bevel angle adjustment knob 134 is advantageously disposed at the front portion of the push-pull table saw 110. Rotation of the bevel control rod 137 causes rotation of the carrier 220 with respect to the surface of the table top 104 which causes beveling of the saw blade 120 with respect to the table top 104. Once the desired bevel angel has been reached, the operator can turn on the saw assembly 230 by activating the power switch 114, and pulling the carriage 200 to the position near the front portion 106 in order to cut the workpiece at the desired bevel angle. Similarly, the operator can adjust the bevel angle of the blade 120 when the carriage 200 is at the position near the front portion of the push-pull saw 100.
While the embodiment of the push-pull table saw 100 described above uses a bevel control rod 137 that is partially or fully splined, another embodiment of a push-pull saw is described below.
The carriage 400 includes sidewalls 402 and 404 and an optional bottom member 406. An arcuate opening 444 is formed in the side wall 402 of the carriage 400 allowing for passage of the rod 330 and for arcuate movement of the rod 330. Similarly, opening 445 are formed in the side walls 402 and 404 allowing for passage of the keyed shaft 337. The keyed shaft 337 is coupled to the handle 334 and is configured to rotate in response to rotation of the handle 334. While the keyed shaft 337 is depicted to pass through openings 445 disposed on the side walls 402 and 404, bearing assemblies (not shown) mounted on the side walls 402 and 404 can also be provided to provide additional support for the keyed shaft 337. The keyed shaft 337 is depicted to extend beyond the carriage 400 on both sides of the carriage 400. The keyed shaft 337 can be configured to extend to the outside structures (not shown) such as the housing (not shown). Sliding members 446 and 448 are attached to the bottom side of the table top 304. The side walls 402 and 404 slidably interface with the sliding members 446 and 448 by complementary sliding members (not shown), similar to the sliding interfaces 246/252 and 248/254 depicted in
While the rod 330 is allowed to move with respect to the carriage 400 about an arcuate path defined by the arcuate opening 444, the rod 330 is axially fixed with respect to the carriage. Therefore, pulling and pushing of the knob 332 causes the carriage 400 to slidably engage with the sliding members 446 and 448 and thereby cause the carriage to move from left to right and vice versa with respect to
The push-pull table saw 300 also includes a carrier 420 for supporting the saw assembly (not shown). The carrier 420 is positioned within the carriage 400 and is axially fixed with respect to the carriage 400. The carrier 420 includes side walls 422 and 424 and a bottom support surface 426, configured to support the saw assembly (not shown). The carriage 420 includes a bearing assembly 410 (depicted in
The inner portion 425 includes gears 454 which interface with toothed arcs in the form of gears 456. Gears 456 are fixedly mounted or integrated with the side wall 422. Therefore, rotation of the keyed shaft 337, which as described above, causes rotation of the inner portion 425 of the bearing assembly 410, causes rotation of the side wall 422 which causes rotation of the carrier 420 within the carriage 400. These corresponding rotations are noted in
In operation, the operator of the push-pull table saw 300 adjusts the height adjustment-push pull mechanism 329 in order to achieve the desired height for the blade 320. The operator then rotates the knob 334 in order to rotate the keyed shaft 337. Rotation of the keyed shaft 337 rotates the inner portion 425 of the bearing assembly 410. Rotation of the inner portion 425 causes rotation of the gears 454 which rotate gears 456 of the side wall 422. The rotation of the side wall 422 causes rotation of the carrier 420 with respect to the carriage 400 thereby causing the beveling of the saw assembly (not shown) which causes beveling of the saw blade 320 with respect to the table top 304.
Once the correct height and bevel angle of the blade 320 are achieved, the operator pushes and pulls the height adjustment-push pull mechanism 329 in order to slide the carriage 400, the carrier 420 and therefore the saw assembly (not shown) and the blade 320 back and forth in order to make the desired cut of the workpiece. The bearing members 450 and 452 rotate on the keyed shaft 337 as the carriage 400 is pushed and pulled in response to the movement of the height adjustment-push pull mechanism 329.
While the geared interface between the gears 454 and 456 is depicted in
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications and further applications that come within the spirit of the invention are desired to be protected.