Vertical saw and driving assembly for vertical saw

Abstract

The utility model discloses a vertical saw and a driving assembly for the vertical saw. The vertical saw comprises a shell, a vertical saw blade and a driving assembly, a handle extending laterally from the housing in the direction of a handle axis; a battery selectively coupled to the handle; a foot plate configured to contact a workpiece during a cutting operation; the driving assembly is powered by the battery and comprises a motor, a transmission device driven by the motor, and an output main shaft driven by the transmission device and connected to the saw blade. The vertical saw further includes a standstill yoke mechanism for converting rotational motion of the transmission into reciprocating motion of the output spindle and the saw blade substantially along a vertical axis perpendicular to the handle axis, where the standstill yoke mechanism includes a sleeve eccentrically mounted to a driven gear of the transmission. The sleeve includes a spherical bearing surface that is received within a laterally extending slot of the output spindle for sliding movement with the output spindle.

Description

[0001] Cross - reference to related applications

[0002] This application claims priority to the previously filed U.S. Provisional Patent Application No. 63 / 512,524, filed on July 7, 2023, the entire content of which is incorporated herein by reference. Technical field

[0003] The present utility model relates to a power tool, and more particularly to a jigsaw. Background art

[0004] Various different power tools (such as jigsaws) typically include a mechanism in the drive train that converts rotational movement into reciprocating movement. In some instances, the mechanism is a scotch yoke mechanism that converts the rotational movement of an electric motor into the reciprocating movement of a saw blade. Summary of the utility model

[0005] In one aspect, the present utility model provides a jigsaw, which includes: a housing; a handle that extends substantially laterally from the housing along the handle axis; a battery selectively coupled to the handle; a foot plate coupled to the housing and configured to contact a workpiece during a cutting operation; a drive assembly powered by the battery and including an electric motor, a transmission driven by the electric motor, and an output spindle driven by the transmission and coupled to a saw blade; and a scotch yoke mechanism for converting the rotational movement of the transmission into the reciprocating movement of the output spindle and the saw blade generally along a vertical axis perpendicular to the handle axis, wherein the scotch yoke mechanism includes a sleeve eccentrically mounted to a driven gear of the transmission, the sleeve includes a spherical bearing surface received in a laterally extending groove of the output spindle to slide together with the output spindle.

[0006] In some embodiments, the bearing surface has a convex cross - sectional shape in a plane containing the central axis of the sleeve.

[0007] In some embodiments, the convex cross - sectional shape of the bearing surface has a radius of curvature of up to 30 millimeters.

[0008] In some embodiments, during an orbital cutting mode, the output spindle swings forward and backward up to two degrees relative to the vertical axis.

[0009] In another aspect, the present utility model provides a drive assembly for a jigsaw, the jigsaw being configured to cut a workpiece during a cutting operation, the jigsaw comprising: a motor that rotates about a first axis; an output spindle that is driven by the motor along a second axis and is coupled to a saw blade; and a stop yoke mechanism for converting the rotational movement of the motor into a reciprocating movement of the output spindle and the saw blade generally along a second axis perpendicular to the first axis, wherein the stop yoke mechanism includes a sleeve that rotates orbitally about the first axis, the sleeve including a spherical bearing surface that is received within a laterally extending groove of the output spindle to slide move therewith along with the output spindle.

[0010] In some embodiments, the bearing surface has a convex cross-sectional shape in a plane containing the central axis of the sleeve.

[0011] In some embodiments, the convex cross-sectional shape of the bearing surface has a radius of curvature of up to 30 millimeters.

[0012] In some embodiments, during an orbital cutting mode, the output spindle swings forward and backward relative to the second axis by up to two degrees.

[0013] In another aspect, the present utility model provides a drive assembly for a jigsaw, the jigsaw being configured to cut a workpiece during a cutting operation, the jigsaw comprising: a motor; an output spindle that is coupled to a saw blade and is driven by the motor along an axis generally perpendicular to the workpiece; and a stop yoke mechanism that is disposed between the motor and the output spindle and is configured to convert the rotational movement of the motor into a reciprocating movement of the output spindle and the saw blade, wherein the stop yoke mechanism includes a sleeve that has a spherical bearing surface that is received within a laterally extending groove of the output spindle to slide move therewith along with the output spindle.

[0014] In some embodiments, the bearing surface has a convex cross-sectional shape in a plane containing the central axis of the sleeve.

[0015] In some embodiments, the convex cross-sectional shape of the bearing surface has a radius of curvature of up to 30 millimeters.

[0016] In some embodiments, during an orbital cutting mode, the output spindle swings forward and backward relative to the axis by up to two degrees.

[0017] Other features and aspects of the present utility model will become apparent by considering the following detailed description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a perspective view of a jigsaw according to an embodiment of the present utility model.

[0019] Figure 2 is Figure 1 a partial exploded perspective view of a jigsaw

[0020] Figure 3 is Figure 1 a perspective view of a drive assembly of the jigsaw, showing a motor, a transmission, an output main shaft, and an anti-rotation yoke mechanism disposed between the transmission and the output main shaft.

[0021] Figure 4 is Figure 2 a cross-sectional view of the jigsaw taken along line 4-4 of

[0022] Figure 5 is Figure 1 a perspective view of a part of the drive assembly of the jigsaw, showing the anti-rotation yoke mechanism and a counterweight for balancing the movement of the output main shaft.

[0023] Figure 6 is

[0024] Before explaining in detail any embodiments of the present invention, it should be understood that the application of the present invention is not limited to the details of the component construction and arrangement set forth in the following description or shown in the following drawings. The present invention is capable of having other embodiments and of being practiced or carried out in various ways. Further, it should be understood that the terminology and phrases used herein are for the purpose of description and should not be regarded as limiting. Detailed Description of the Invention

[0025] Figure 1 shows a power tool, such as a jigsaw 10, which includes: a housing 14; a handle 18 that extends from the housing 14 in a generally transverse direction; a battery 22 that is selectively coupled to the handle 18; a foot plate 26 that is pivotally coupled to the housing 14 and is configured to contact a workpiece during a cutting operation; and a saw blade 30 that projects from the lower surfaces of the housing 14 and the foot plate 26. The jigsaw 10 includes a drive assembly 34 ( Figure 2 ), which is powered by the battery 22 and is operable to cause the saw blade 30 to reciprocate to cut the workpiece. The jigsaw 10 defines a handle axis 38 that extends in the direction of the handle 18. Moreover, the saw blade 30 generally reciprocates within a blade plane 40 during a cutting operation.

[0026] Refer to Figure 1 and Figure 2, the handle 18 receives the battery 22 along the handle axis 38 and supports the controller 46. The controller 46 is disposed between the battery 22 and the drive assembly 34 in the direction along the handle axis 38. The jigsaw 10 further includes gripping surfaces 42a, 42b which are respectively disposed on the housing 14 and the handle 18 and can be tightly grasped by the user to operate and manipulate the jigsaw 10 relative to the workpiece. In addition to the housing 14 and the handle 18, the gripping surfaces 42a, 42b are also made of non-conductive material (e.g., plastic with or without elastomeric overmolding). If the user accidentally cuts a wire during a cutting operation, such non-conductive material will electrically insulate the user, thereby suppressing or at least reducing the electric shock.

[0027] Continuing to refer to Figure 1 and Figure 2 , the jigsaw 10 further includes an enabling switch 54 which is in electrical communication with the controller 46 to selectively supply power to the drive assembly 34. Specifically, the enabling switch 54 provides an input to the controller 46 which in turn directs current from the battery 22 to the drive assembly 34. The enabling switch 54 is disposed adjacent to the handle 18 and is slidable along a switch axis 56 between an enabled state and a disabled state, in which enabled state the battery 22 supplies current to the drive assembly 34 and in which disabled state the drive assembly 34 is deactivated. The switch axis 56 is parallel to the handle axis 38 of the jigsaw 10 ( Figure 1 ). The enabling switch 54 is coupled to a linkage 58 which is disposed inside the housing 14 and is movable together with the enabling switch 54. The linkage 58 is parallel to the handle axis 38 and is configured to interact with a limit switch 60 ( Figure 2 ), which is in electrical communication with the controller 46 and closes a circuit to enable the motor 66 when depressed via the linkage 58. Thus, the linkage 58 slides in a direction parallel to the handle axis 38 to engage and disengage the limit switch 60 during the enabled state and the disabled state respectively.

[0028] A mode selector switch 62 ( Figure 1 ) is disposed on the housing 14 and allows the user to switch the jigsaw 10 between a track cutting mode and a straight cutting mode. Figure 3 and Figure 4 show a support arm 63 which supports the saw blade 30 during the track cutting mode and the straight cutting mode. Specifically, at the distal end of the support arm 63 is a wheel 64 which engages the saw blade 30 and reduces friction when the saw blade 30 reciprocates relative to the support arm 63. Thus, during the return (i.e., cutting) stroke of the saw blade 30, the support arm 63 and the wheel 64 jointly and selectively apply a track motion to the saw blade 30.

[0029] Refer to Figure 3 and Figure 4, the drive assembly 34 of the jigsaw 10 is disposed within the housing 14 and the handle 18. The drive assembly 34 includes: a motor 66; a transmission 70 driven by the motor 66; an output spindle 72 to which the saw blade 30 is removably secured; and an anti-rotation yoke mechanism 74 that converts the rotational motion of the transmission 70 into a reciprocating motion of the output spindle 72, as described in further detail below. A frame 76 is disposed within the housing 14 and supports the motor 66 and the transmission 70 within the housing 14. Like the housing 14 and the handle 18, the frame 76 is constructed of a non-conductive material (e.g., plastic). Such non-conductive material electrically insulates the user if the user accidentally cuts a wire during a cutting operation, thereby inhibiting or at least reducing the risk of electric shock. As Figure 4 shown, the frame 76 includes a first aperture 78 and a second aperture 82 that respectively support the motor 66 and the transmission 70. Specifically, the first aperture 78 receives and supports the drive shaft 84 of the motor 66, which in turn supports a helical drive gear 86. The second aperture 82 receives and supports the driven shaft 88 of a helical driven gear 90 of the transmission 70. The helical drive gear 86 meshes with and drives the helical driven gear 90 of the transmission 70. Since the rotational motion of the transmission 70 is converted into a reciprocating motion of the output spindle 72 via the anti-rotation yoke mechanism 74, the saw blade 30 is also driven in a reciprocating manner along a vertical axis 94 during a straight cutting mode. The vertical axis 94 is perpendicular to the handle axis 38.

[0030] Reference Figure 5, the anti-rotation yoke mechanism 74 is configured in a manner that extends the life of the drive assembly 34. As described above, the anti-rotation yoke mechanism 74 converts the rotational motion of the transmission 70 into the reciprocating motion of the output spindle 72. The anti-rotation yoke mechanism 74 includes a counterweight 98 and a slider portion 102 of the output spindle 72. During the straight cutting mode, the counterweight 98 and the output spindle 72 reciprocate in opposite directions parallel to and along the vertical axis 94, respectively. Through the opposite reciprocating motions, the counterweight 98 effectively dampens the mass and acceleration of the saw blade 30 and the output spindle 72 to prevent the jigsaw 10 from jumping relative to the workpiece. The saw blade 30, the output spindle 72, and the slider portion 102 reciprocate together substantially along the vertical axis 94 during the straight cutting mode. The anti-rotation yoke mechanism 74 further includes a cam 106 and a sleeve 110 that are disposed radially opposite each other on the helical driven gear 90. Specifically, the cam 106 is eccentrically mounted to the driven shaft 88 of the driven gear 90, and the sleeve 110 is disposed on the driven gear 90 radially opposite the cam 106. The counterweight 98 is driven by the cam 106, and the slider portion 102 and thus the output spindle 72 are driven by the sleeve. Specifically, the cam 106 is received within the elongated slot 114 of the counterweight 98 such that the rotation (i.e., orbit) movement of the cam 106 causes the reciprocating movement of the counterweight 98. Similarly, the sleeve 110 is received within the laterally extending slot 118 of the slider portion 102 such that the rotation (i.e., orbit) movement of the sleeve 110 causes the reciprocating movement of the slider portion 102 and the output spindle 72.

[0031] Reference Figure 6 , the sleeve 110 includes a support surface 122 that engages the laterally extending slot 118. The shape of the support surface 122 is convex or spherical rather than cylindrical, such that the support surface 122 bulges radially outward. Specifically, the apex 126 of the support surface 122 has a first diameter D1 that is greater than the second diameter D2 of the first end 130 and the second end 134 of the support surface 122, thereby creating a convex or spherical shape. In other words, the sleeve 110 has a convex cross-sectional shape in a plane containing the central axis 136 of the sleeve 110 (as Figure 6As shown, the support surface 122 has a rounded corner. The radius of curvature R of the support surface 122 is approximately 25 millimeters to 35 millimeters. Specifically, the radius of curvature R of the support surface 122 is 30 millimeters. The convex shape of the support surface 122 helps the slider portion 102 of the output spindle 72 to swing (i.e., oscillate) from the vertical axis 94. When the jigsaw 10 is operated in the orbital cutting mode, the output spindle 72 swings forward and backward by an angle 138 with respect to the vertical axis 94, which is facilitated by the support arm 63 contacting the saw blade 30. The angle 138 is approximately one degree to four degrees. Specifically, the angle 138 is two degrees. More specifically, the angle 138 is 1.8 degrees. The laterally extending groove 118 also includes a chamfered edge 142 such that the slider portion 102 avoids edge contact with the spherical support surface 122. The chamfered edge 142 has a width dimension W of approximately 0.1 millimeter to 0.3 millimeter. Specifically, the width dimension W of the chamfered edge 142 is 0.2 millimeter. In a typical jigsaw, the support surface of the sleeve is cylindrical, so the forward and backward swinging of the slider portion 102 causes edge contact between the slider portion 102 and the sleeve 110, resulting in excessive wear between the two components.

[0032] The jigsaw 10 further includes a quick disconnect mechanism or blade ejection mechanism 146 disposed on the housing 14. The blade ejection mechanism 146 is pivotable about the output spindle 72 and is configured to selectively lock the saw blade 30 to the output spindle 72. Specifically, the blade ejection mechanism 146 can pivot from a locked position in which the saw blade 30 is inhibited from being removed from the output spindle 72 to an unlocked position in which the saw blade 30 is permitted to be removed from the output spindle 72. Figure 1 The blade ejection mechanism 146 is shown biased towards the locked position.

[0033] During operation, the user can grip the gripping surfaces 42a, 42b of the housing 14 and the handle 18 to manipulate the jigsaw 10 relative to the workpiece. The user can rest the jigsaw 10 on the workpiece via the footplate 26 and align the saw blade 30 with the desired cut. The saw blade 30 reciprocates within the blade plane 40 in response to the user sliding the enable switch 54 to the enabled state. Once the motor 66 is enabled, the motor 66 drives the transmission 70 in rotational movement, which in turn drives the counterweight 98 and the output spindle 72 in reciprocating movement. The slider portion 102 converts the rotational movement of the transmission 70 into the reciprocating movement of the output spindle 72. The sleeve 110 translates through the laterally extending slot 118 of the slider portion 102, thereby driving the output spindle 72 and the saw blade 30 along the vertical axis 94 in a straight cutting mode. When the jigsaw 10 is in the orbital cutting mode, the output spindle 72 and thus the slider portion 102 swing approximately two degrees relative to the vertical axis 94 in response to the support arm 63 applying an orbital movement to the saw blade 30. When the slider portion 102 swings relative to the vertical axis 94, the spherical or convex shape of the support surface 122 minimizes the mechanical interference between the sleeve 110 and the laterally extending slot 118. Thus, there is less wear and tear on the sleeve 110 and the slider portion 102. The chamfered edge 142 also extends the life of the drive assembly 34 to avoid edge contact with the support surface 122 when the slider portion 102 swings relative to the vertical axis 94.

[0034] Although the present disclosure has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more of the independent aspects of the disclosed subject matter. The various features and advantages of the present disclosure are set forth in the following claims.

Claims

1. A jigsaw, comprising: A housing; A handle that extends laterally from the housing in the direction of the handle axis; A battery selectively coupled to the handle; A foot plate coupled to the housing and configured to contact a workpiece during a cutting operation; A drive assembly powered by the battery and including a motor, a transmission driven by the motor, and an output spindle driven by the transmission and coupled to a saw blade; And A stop yoke mechanism for converting the rotational motion of the transmission into a reciprocating motion of the output spindle and the saw blade generally along a vertical axis perpendicular to the handle axis, Characterized in that the stop yoke mechanism includes a sleeve eccentrically mounted to a driven gear of the transmission, the sleeve including a spherical bearing surface received in a laterally extending groove of the output spindle to slide with the output spindle.

2. The jigsaw according to claim 1, wherein, The bearing surface has a convex cross-sectional shape in a plane containing the central axis of the sleeve.

3. The jigsaw according to claim 2, wherein, The convex cross-sectional shape of the bearing surface has a radius of curvature of up to 30 mm.

4. The jigsaw according to claim 1, characterized in that, The bearing surface includes a vertex with a diameter greater than the diameters of the first and second ends of the bearing surface.

5. The jigsaw according to claim 1, wherein, During orbital cutting mode, the output spindle swings forward and backward relative to the vertical axis by up to two degrees.

6. The jigsaw according to claim 5, characterized in that, The laterally extending groove includes a chamfered edge to avoid edge contact with the sleeve when the output spindle swings relative to the vertical axis.

7. The jigsaw according to claim 6, characterized in that, The chamfered edge has a width dimension of approximately 0.2 mm.

8. A drive assembly for a jigsaw configured to cut a workpiece during a cutting operation, the jigsaw comprising: A motor that rotates about a first axis; An output spindle driven by the motor along a second axis and coupled to a saw blade; And A stop yoke mechanism for converting the rotational motion of the motor into a reciprocating motion of the output spindle and the saw blade generally along a second axis perpendicular to the first axis, Characterized in that the stop yoke mechanism includes a sleeve that rotates orbitally about the first axis, the sleeve including a spherical bearing surface received in a laterally extending groove of the output spindle to slide with the output spindle.

9. The drive assembly according to claim 8, characterized in that, The bearing surface has a convex cross-sectional shape in a plane containing the central axis of the sleeve.

10. The drive assembly according to claim 9, characterized in that, The convex cross-sectional shape of the bearing surface has a radius of curvature of up to 30 mm.

11. The drive assembly according to claim 8, characterized in that, The bearing surface includes a vertex with a diameter greater than the diameters of the first and second ends of the bearing surface.

12. The drive assembly according to claim 8, wherein During orbital cutting mode, the output spindle swings forward and backward relative to the second axis by up to two degrees.

13. The drive assembly according to claim 12, characterized in that, The laterally extending groove includes a chamfered edge to avoid edge contact with the sleeve when the output spindle swings relative to the second axis.

14. The drive assembly according to claim 13, characterized in that, The chamfered edge has a width dimension of approximately 0.2 mm.

15. A drive assembly for a jigsaw configured to cut a workpiece during a cutting operation, the jigsaw comprising: A motor; An output spindle coupled to a saw blade and driven by the motor along an axis generally perpendicular to the workpiece; And A rotation-stopping yoke mechanism is provided between the motor and the output main shaft and is configured to convert the rotational movement of the motor into the reciprocating movement of the output main shaft and the saw blade. It is characterized in that the rotation-stopping yoke mechanism includes a sleeve having a spherical bearing surface that is received in a laterally extending groove of the output main shaft to slide together with the output main shaft.

16. The drive assembly according to claim 15, characterized in that, The bearing surface has a convex cross-sectional shape in a plane containing the central axis of the sleeve.

17. The drive assembly according to claim 16, wherein The convex cross-sectional shape of the bearing surface has a radius of curvature of up to 30 mm.

18. The drive assembly according to claim 15, characterized in that, The bearing surface includes a vertex with a diameter greater than the diameters of the first and second ends of the bearing surface.

19. The drive assembly according to claim 15, characterized in that, During the orbital cutting mode, the output main shaft swings forward and backward relative to the axis by up to two degrees.

20. The drive assembly according to claim 19, characterized in that, The laterally extending groove includes a chamfered edge to avoid edge contact with the sleeve when the output main shaft swings relative to the axis, wherein the chamfered edge has a width dimension of approximately 0.2 mm.

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