Cutting saw

Abstract

A dicing saw includes a saw housing having a support arm projecting outwardly from a front end of the housing. A blade drive assembly disposed in the support arm includes a gear set and is configured to transmit rotational motion of the motor to the cutting blade. A lock handle is pivotally mounted on an outer surface of the support arm and is configured to actuate the lock pin. In the folded position, the lock handle is configured to disengage the locking pin from the drive gear, whereby the blade drive assembly freely drives the cutting blade. In the deployed position, the lock handle is configured to engage the locking pin with the drive gear to prevent rotation of the cutting blade. The deployed lock handle acts as a manual grip that allows a user to stabilize the saw when attaching and detaching the cutting blade.

Description

Background Art

[0001] A cut-off saw is a handheld power tool that employs a circular blade mounted on a support arm that protrudes from the front of the saw housing. Cut-off saws have no lower blade guard and typically drive a cutting blade having a diameter ranging from 8 to 14 inches. This type of saw is designed to be a general solution for cutting a variety of heavy materials, including reinforced concrete, other masonry materials, and metals including iron and black pipe. In some of these types of saws, mounting or replacing the saw blade to the support arm can be challenging because doing so requires preventing the drive shaft from rotating with one hand while mounting and securing the blade to the support arm with the other hand. It would be desirable to have a cut-off saw in which attachment and detachment of the blade from the saw is simplified. Summary of the invention

[0002] A cutting saw includes a saw housing, a brushless electric motor disposed within the saw housing, and a battery pack coupled to the saw housing, the battery pack providing power to the motor and a printed circuit board assembly (PCBA). The cutting saw also includes a blade drive assembly disposed in a support arm protruding from a front end of the saw housing. The blade drive assembly couples a cutting blade to the cutting saw and transmits a rotational output of the motor to the cutting blade. The saw housing includes a rear handle extending from a rear end of the saw housing. In addition, an auxiliary handle covers an upper side of the saw housing. The battery pack is disposed in a battery compartment defined by the saw housing. The battery compartment is located between the motor and the rear handle, and the battery pack is accessible via a battery cover detachably coupled to the saw housing.

[0003] The support arm of the saw housing surrounds the blade drive assembly. The blade drive assembly is a beltless direct drive system that includes several subassemblies that cooperate to transmit the rotational output of the electric motor to the cutting blade. For example, the intermediate drive subassembly is mechanically connected to the electric motor and transmits the rotational motion of the motor to the gear set subassembly. The gear set subassembly connects the intermediate drive assembly to the blade connection assembly and reduces the rotational speed of the motor output shaft. The fourth subassembly is a spindle lock assembly that is operable to selectively engage with the gear set to prevent the gear set from moving during attachment and detachment of the cutting blade. The spindle lock assembly includes a cam lock handle that is movable between a folded position and a deployed position, in which the gear set is unlocked and can rotate freely, and in the deployed position, the gear set is locked and prevented from moving. In the deployed position, the lock handle serves as a user handle.

[0004] In some aspects, a saw includes a saw housing. The saw housing has a front end, a rear end opposite the front end, and a hollow support arm protruding outward from the front end. The support arm includes a proximal end adjacent to the front end and a distal end opposite the proximal end. The saw includes an electric motor disposed in the saw housing. The electric motor has an output shaft rotatable about an output shaft axis. The saw includes a battery pack disposed in the saw housing. The battery pack is configured to power the electric motor. In addition, the saw includes a blade drive assembly disposed in the support arm. The blade drive assembly is configured to detachably connect a cutting blade to the distal end of the support arm, and when the cutting blade is connected to the saw, the rotational motion of the output shaft is transmitted to the cutting blade. The blade drive assembly includes a spindle, which is connected to the output shaft and is rotatable about the spindle axis. The spindle has a spindle first end supported by the support arm for rotation, and a spindle second end protruding outward from the support arm. The blade drive assembly includes a transmission device that connects the output shaft to the spindle and a blade connection subassembly disposed on the second end of the spindle. The blade connection subassembly is configured to detachably fix the cutting blade to the second end of the spindle. The blade drive assembly includes a locking handle covering the outer surface of the support arm. The locking handle includes a first end of the handle, a second end of the handle opposite to the first end of the handle, and a longitudinal axis of the handle extending between the first end of the handle and the second end of the handle. The locking handle is connected to the support arm via a pivot pin, and the pivot pin is arranged to be closer to the second end of the handle than the first end of the handle. In addition, the blade drive assembly includes a locking pin arranged in an opening of the support arm. The locking pin can translate relative to the support arm in the opening. The locking pin includes a first end of the pin directly contacting the locking handle and a second end of the pin facing the rotatable element of the transmission device. The locking handle can rotate around the pivot pin relative to the support arm between a first position and a second position, in which the longitudinal axis of the handle is at a first angle relative to the outer surface of the support arm, and in which the longitudinal axis of the handle is at a second angle relative to the outer surface of the support arm. The second angle is greater than the first angle. When the locking handle rotates around the pivot pin, the locking pin is driven by the locking handle to translate relative to the support arm. When the lock handle is in the first position, the pin second end is spaced from the rotatable element of the transmission so that the rotatable element of the transmission rotates freely, and when the lock handle is in the second position, the pin second end is engaged with the rotatable element of the transmission so that the rotatable element of the transmission is prevented from rotating.

[0005] In some embodiments, the saw includes a spring that surrounds the locking pin and biases the locking pin against the locking handle.

[0006] In some embodiments, the lock handle second end defines a curved cam surface.

[0007] In some embodiments, the locking pin is biased against the lock handle via a resilient member such that the first end of the locking pin directly contacts the cam surface.

[0008] In some embodiments, the cam surface is shaped such that when the lock handle is in the first position, the pin second end is spaced from the rotatable element of the transmission, and when the lock handle is in the second position, the pin second end is engaged with the rotatable element of the transmission.

[0009] In some embodiments, the locking pin is movable along a locking pin axis that is perpendicular to the axis of rotation of the pivot pin.

[0010] In some embodiments, a curved ridge protrudes from an outer surface of the support arm, the ridge partially surrounding the lock handle.

[0011] In some embodiments, when the locking handle is in the first position, a surface of the locking handle facing away from the support arm is recessed relative to the ridge.

[0012] In some embodiments, the main shaft axis is perpendicular to the output shaft axis. The transmission includes a gear set connecting the output shaft to the main shaft. The gear set includes a rotatable element of the transmission, the rotatable element being in the form of a driven gear fixed relative to the main shaft and rotatable about the main shaft axis. The driven gear includes a gear surface perpendicular to the main shaft axis. The gear surface defines a recess, and when the lock handle is in the second position, the second end of the pin is disposed in the recess so that the driven gear is prevented from rotating about the main shaft axis.

[0013] In some embodiments, the pivot pin extends in a direction perpendicular to the output shaft axis and the main shaft axis.

[0014] In some embodiments, the saw houses a main handle and an auxiliary handle. The main handle protrudes from the rear end, and the auxiliary handle includes an auxiliary handle first end coupled to a first side of the saw housing, an auxiliary handle second end coupled to a second side of the saw housing, and an auxiliary handle middle portion disposed between the auxiliary handle first end and the auxiliary handle second end. The auxiliary handle middle portion covers a third side of the saw housing.

[0015] In some embodiments, the transmission device includes an intermediate shaft disposed in the support arm, the intermediate shaft being rotatable about the output shaft axis and connecting the output shaft to the gear set.

[0016] In some aspects, a saw includes a saw housing. The saw housing has a front end, a rear end opposite the front end, and a protruding handle. The saw includes an electric motor disposed in the saw housing, the electric motor having an output shaft. The saw includes a battery pack disposed in the saw housing, the battery pack being configured to supply power to the electric motor. In addition, the saw includes a blade drive assembly configured to detachably connect a cutting blade to the saw and to transmit a rotational movement of the output shaft to the cutting blade when the cutting blade is connected to the saw. The blade drive assembly includes a spindle, which is driven via a transmission connected to the output shaft to rotate about a spindle axis. When the cutting blade is connected to the saw, the spindle transmits the rotation of the output shaft to the cutting blade. The blade drive assembly includes a lock handle disposed on an outer surface of the saw housing. The lock handle can pivot relative to the saw housing between a first folded position and a second unfolded position. In addition, the blade drive assembly includes a locking pin, which is supported in the saw housing and in direct contact with the lock handle. The locking pin is configured to translate relative to the saw housing based on the handle position. When the lock handle is in the first folded position, the lock handle is oriented substantially parallel to the outer surface of the saw housing and minimally protrudes relative to the outer surface of the saw housing, and the locking pin is disengaged from the gear, whereby the blade drive assembly is configured to allow the spindle to freely rotate about the spindle axis. Additionally, when the lock handle is in the second deployed position, the lock handle is oriented substantially perpendicular to the outer surface of the saw housing and maximally protrudes relative to the outer surface of the saw housing, whereby the lock handle serves as a manual grip that allows a user to stabilize the saw when attaching and detaching a cutting blade, and the locking pin is engaged with the transmission, whereby the blade drive assembly is configured to prevent the spindle from rotating about the spindle axis.

[0017] In some embodiments, when the locking handle is in the first position, a ridge protruding from the outer surface of the saw housing partially surrounds the locking handle.

[0018] In some embodiments, when the locking handle is in the first position, a surface of the locking handle facing away from the support arm is recessed relative to the ridge.

[0019] In some embodiments, the saw includes a spring that surrounds the locking pin and biases the locking pin against the locking handle.

[0020] In some embodiments, the lock handle second end defines a curved cam surface.

[0021] In some embodiments, the locking pin is biased against the lock handle via a resilient member such that the first end of the locking pin directly contacts the cam surface.

[0022] In some embodiments, the cam surface is shaped and sized such that the pin second end is spaced from the driven gear when the lock handle is in the first position and engages the recessed portion of the gear when the lock handle is in the second position. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a perspective view of a first side of a chop saw.

[0024] Figure 2 is a perspective view of a second side of the chop saw.

[0025] Figure 3 is a cross-sectional view of a chop saw as viewed along a support arm of the chop saw.

[0026] Figure 4 It is a cross-sectional view of the cutting saw seen along the longitudinal center line of the cutting saw.

[0027] Figure 5 is a side view of a chop saw.

[0028] Figure 6 is along Figure 5 A cross-sectional view of the cutting saw as seen at line 6--6.

[0029] Figure 7 yes Figure 6 An enlarged view of the portion of the cutting saw enclosed by a dotted line.

[0030] Figure 8 is an exploded view of the blade connection assembly.

[0031] Fig. 9 is a perspective view of a schematic illustration of a driven gear of a gear set.

[0032] Fig.10 is a cross-sectional view of the distal end of the support arm.

[0033] Fig.11 is a side perspective view of the distal end of the support arm with the lock handle omitted.

[0034] Fig.12 is a top perspective view of the lock handle of the spindle lock assembly.

[0035] Fig.13 is a bottom perspective view of the lock handle.

[0036] Fig.14 is a top perspective view of the spindle lock assembly shown in isolation with reference to the driven gear and the spindle.

[0037] Fig.15 is a bottom perspective view of the spindle lock assembly in isolation. DETAILED DESCRIPTION

[0038] refer to Figure 1-5, the cutting saw 1 is a handheld power tool that is configured to support a cutting blade 90 and drive it to rotate. The cutting blade 90 is circular and may be a segmented blade, a grinding disk, or any other rotatable element capable of removing material from a workpiece. In some embodiments, the cutting blade 90 may have an outer diameter in the range of 8 to 14 inches. For example, the cutting blade 90 may have a diameter of 9 inches. The cutting saw 1 includes a saw housing 2 that surrounds an electric motor 101 configured to drive the cutting blade 90, a battery pack 116 configured to power the electric motor 101, a printed circuit board assembly (PCBA) 112 that supports control electronics including a controller (not shown), and other saw components as will be described in detail below. The saw housing 2 includes a main handle 22 that protrudes from the rear end 4 of the saw housing 2, and a support arm 10 that protrudes from the front end 3 of the saw housing 2 in a direction opposite to the main handle 22.

[0039] The blade drive assembly 200 is housed within the hollow support arm 10. The blade drive assembly 200 is configured to detachably connect the cutting blade 90 to the support arm distal end 12, and when the cutting blade 90 is connected to the cutting saw 1, the rotational movement of the output shaft 102 of the electric motor 101 is transmitted to the cutting blade 90. The blade drive assembly 200 includes a blade lock handle 284, which is configured to lock the blade drive assembly 200 so that the cutting blade 90 can be connected to or removed from the cutting saw 1. The lock handle 284 can be pivoted to a certain orientation, in which the lock handle 284 also serves as a handle that allows the user to more easily control the position of the cutting saw during the attachment and detachment of the cutting blade. The details of the blade drive assembly 200 including the lock handle 284 will also be described in detail below.

[0040] The saw housing 2 is a clamshell housing having left and right cooperating half-shells 20, 21 that are joined along a parting line 25 extending from the front end 3 to the rear end 4. The saw housing 2 is elongated along a housing longitudinal axis 9 that is parallel to the parting line 25 and extends through the opposite front and rear ends 3, 4. The saw housing 2 has four sides extending between the front and rear ends 3, 4, including a first side 5, a second side 6, a third side 7, and a fourth side 8. When the saw 1 is cut as shown in FIG. Figure 1When oriented as shown in , the first side 5 and the second side 6 provide lateral surfaces or side surfaces of the saw housing 2. In addition, the third side 7 provides a top surface, and the fourth side 8 provides a bottom surface. The fourth side 8 is substantially parallel to the housing longitudinal axis 9. As used herein, the term "substantially parallel" refers to a precise state as well as minor variations due to manufacturing and assembly variations. Thus, the fourth side 8 may be exactly parallel to the housing longitudinal axis 9, or may be slightly angled relative to the housing longitudinal axis 9, for example up to plus or minus 5 degrees. The first side 5, the second side 6, the third side 7, the fourth side 8, the front end 3 and the rear end 4 cooperate to define an interior space 18 of the saw housing 2, which is divided into compartments 18(1), 18(2) via an inner wall structure.

[0041] The right side half shell 21 includes a support arm 10 that protrudes from the front end 3 of the saw housing 2 in a direction opposite to the direction of the main handle 22. The support arm 10 is a hollow, elongated structure that includes a proximal end 11 that is connected to or integral with the front end 3, and a distal end 12 that is opposite the proximal end 11 and supports the cutting blade 90. The support arm 10 includes a support arm axis 13 that extends between the proximal end 11 and the distal end 12. Although the proximal end 11 is connected to the front end 3 at the mid-height of the saw housing 2, the distal end 12 is located above the proximal end 11, so that the support arm axis 13 is angled relative to the longitudinal axis 9 of the saw housing. In particular, as shown in the top view ( Figure 1 ), the support arm axis 13 extends outwardly from the front end 3 in parallel with the housing longitudinal axis 9. In addition, as shown in the side view ( Figure 5 ), the support arm axis 13 extends at an acute third angle θ3 relative to the housing longitudinal axis 9. In the illustrated embodiment, the third angle θ3 is approximately thirty degrees, but is not limited to this angle.

[0042] In the illustrated embodiment, the chop saw 1 further includes an auxiliary handle 80 connected to the saw housing 2 between the front end 3 and the rear end 4. The main handle 22 and the auxiliary handle 80 provide gripping areas to facilitate two-handed operation of the chop saw 1. The auxiliary handle 80 is a curved bar that surrounds three sides of the chop saw 1. In particular, the auxiliary handle 80 includes an auxiliary handle first end 81 coupled to a first side 5 of the saw housing (e.g., one lateral side of the saw housing 2) and an auxiliary handle second end 82 coupled to a second side 6 of the saw housing (e.g., an opposite lateral side of the saw housing 2). An intermediate portion 83 of the auxiliary handle 80 is disposed between the auxiliary handle first end 81 and the second end 82 and overlies a third side 7 of the saw housing (e.g., a top side of the saw housing 2). The auxiliary handle first end 81 and the second end 82 are coupled to the sides 5, 6 of the saw housing 2 at a position disposed longitudinally between the housing-side inlet opening 29 and the housing-side outlet opening 30. The auxiliary handle first end 81 is coupled to the first side 5 of the saw housing 2 closer to the third side 7 than the fourth side 8 , and the auxiliary handle second end is coupled to the second side 6 of the saw housing 2 closer to the fourth side 8 than the third side 7 .

[0043] refer to Figure 3 and Figure 4 , a battery pack 116 is disposed in the first compartment 18(1) and is detachably connected to a battery mount located within the first compartment 18(1). The battery mount mechanically interconnects the battery pack 116 with the first compartment 18(1). The battery mount also includes electrical terminals (not shown) that are electrically connected to corresponding electrical terminals on the battery pack 116 during insertion of the battery pack 116 into the first compartment 18(1). The battery pack 116 shown is a power tool battery pack having a plurality of rechargeable battery cells 117. The battery cells 117 may be lithium-based or have any other suitable chemical composition.

[0044] The electric motor 101 is disposed in the second compartment 18(2). The electric motor 101 may be a brushless DC motor, but is not limited to this type of motor. The operation of the motor 101 is controlled by a controller.

[0045] The output shaft 102 of the motor 101 protrudes from the first end 103 (2) of the motor housing and rotates about an output shaft axis 98 aligned with the support arm axis 13. The output shaft axis 98 extends toward the front end 3 parallel to the housing longitudinal axis 9. In addition, as shown in the side view ( Figure 5 ), the output shaft axis 98 extends at an acute fourth angle θ4 relative to the housing longitudinal axis 9. In the illustrated embodiment, the fourth angle θ4 is approximately thirty degrees to correspond to the angle of the support arm axis 13.

[0046] The motor fan 100 is mounted on the output shaft 102 at a position between the electric motor 101 and the housing front end 3. The motor fan 100 rotates in conjunction with the output shaft 102 and draws air through the housing 103 of the motor 101.

[0047] The PCBA 112 is a complete printed circuit board assembly that includes a PCB and contains the controller and other electronic components required to make the board operate as desired. The PCBA 112 is mounted on a heat sink 114. The PCBA 112 and heat sink 114 are supported within the saw housing 2 in such a manner that the PCB lies in a plane perpendicular to the longitudinal axis 9 of the housing. The heat sink 114 is a thermally conductive plate coupled to the rearward surface of the PCBA 112. The heat sink 114 includes cooling fins that extend in a direction parallel to the first and second (lateral) sides 5, 6 and project toward the rear end 3.

[0048] In the illustrated embodiment, the motor 101 and the battery pack 116 together form a high power battery powered system. For example, in some embodiments, the motor 101 and the battery pack 116 can be operated to produce a high power output. For example, the motor 101 and the battery pack 116 can produce a peak power of 1800 watts (W) to 2400 W or more (2.4 horsepower (hp) to 3.0 hp or more). This power output is equal to or greater than the power output of some single cylinder internal combustion engines commonly used in cutting saws.

[0049] A trigger 23 for operating the chop saw 1 is located on the main handle 22. The trigger 23 is configured so that a user can depress the trigger 23 using a finger of a hand holding the main handle 22, thereby activating the electric motor 101.

[0050] The chop saw 1 includes a human machine interface (HMI) 120 to assist a user in operating the chop saw 1. In the illustrated embodiment, the HMI includes a battery charge level display 122 surrounded by a sturdy protective frame 124. The HMI 120 is located on the saw housing 2 and is within the user's line of sight during operation of the chop saw 1. For example, the HMI 120 may be located between the battery cover (detachable cover) 17 and the front end 3 on the third side (top) of the saw housing 2.

[0051] In other embodiments, the HMI may alternatively or additionally include a liquid crystal display (LCD) screen surrounded by a rugged protective frame 124. The LCD screen may display the battery charge level and / or other information of interest to the saw user, including but not limited to an indication of the amount of power used by the cutting saw 1 during operation (i.e., the amount of current drawn from the battery pack 116) or other operational information. In other embodiments, the HMI 120 may be located elsewhere on the saw housing 2.

[0052] The chop saw 1 also includes a light source 126 disposed on a forward-facing surface of the protective frame 124. The light source 126 may include one or more light emitting diodes (LEDs) arranged to illuminate a working area in front of the saw and / or a workpiece disposed in that area.

[0053] refer to Figure 3 and Figure 6-7 , the support arm 10 houses the blade drive assembly 200. The blade drive assembly 200 is a beltless drive system that includes four subassemblies 202, 222, 262, 282 that cooperate to transmit the rotational output of the electric motor 101 to the cutting blade 90. The first subassembly is the intermediate drive assembly 202, which is disposed between the proximal end 11 and the distal end 12 in the support arm 10. The second, third and fourth subassemblies 222, 262, 282 are disposed in the support arm distal end 12. The second subassembly is the blade connection assembly 262, which is used to connect the cutting blade 90 to the support arm distal end 12. The third subassembly is the gear set 222, which connects the intermediate drive assembly 202 to the blade connection assembly 262 and reduces the rotational speed of the motor output shaft 102. The fourth subassembly is the spindle lock assembly 282, which is operable to selectively engage with the gear set 222 to prevent the gear set from moving during attachment and detachment of the cutting blade 90. Each of the four subassemblies 202, 222, 262, 282 will now be described in detail.

[0054] The intermediate drive assembly 202 provides a mechanical connection between the motor output shaft 102 and the gear set 222. The intermediate drive assembly 202 includes an elongated intermediate shaft 207 and a shaft coupler 203. The shaft coupler 203 couples the motor output shaft 102 to one end of the intermediate shaft 207 via a drive pinion 204, which is interposed between the one end and the shaft coupler 203. As a result, the intermediate shaft 207 rotates coaxially with the motor output shaft 102 about the output shaft axis 98. A beveled pinion gear 209 is provided on the opposite end of the intermediate shaft 207. The pinion 209, which couples the intermediate drive assembly 202 to the gear set 222, is retained on the intermediate shaft 207 via a nut 210. The intermediate shaft 207 is supported relative to the support arm via bearings 206, 208 at each end.

[0055] The gear set 222, together with the intermediate drive assembly 202, provides a transmission 216 that transmits the rotational motion of the motor output shaft 102 to the blade connection assembly 262. The gear set 222 includes a spindle 233 that is rotatable about a spindle axis 235 extending in a direction perpendicular to the support arm axis 13. A first end 233(1) of the spindle 233 is supported relative to the support arm 10 via a needle bearing 223, and an intermediate portion 233(3) of the spindle 233 is supported relative to the support arm 10 via a ball bearing 227. The spindle includes a second end 233(2) opposite the first end 233(1). The spindle second end 233(2) protrudes from the support arm 10 in a lateral direction, for example, toward the left side of the cutting saw 1. An end surface of the spindle second end 233(2) includes a threaded blind hole 233(11) configured to engage threads (not shown) of a bolt 268 of the blade connection assembly 262.

[0056] In addition, the main shaft 233 has a non-uniform diameter. Specifically, the main shaft 233 has a maximum diameter portion 233 (6) including the second end 233 (2) of the main shaft, a minimum diameter portion 233 (8) including the first end 233 (1) of the main shaft, and an intermediate diameter portion 233 (7) including the middle portion 233 (3) of the main shaft. In addition, the main shaft 233 includes a first shoulder 233 (9) at the transition between the minimum diameter portion and the intermediate diameter portion, and a second shoulder 233 (10) at the transition between the intermediate diameter portion and the maximum diameter portion.

[0057] The outer peripheral surface of the main shaft maximum diameter portion 233(6) includes a pair of opposite main shaft flat surfaces 233(4) for engaging corresponding flange flat surfaces 264(3), 266(3) provided on the inner peripheral surface of each of the pair of flange plates 264, 266 of the blade connection assembly 262. The main shaft 233 includes an annular protrusion 233(5) provided in the main shaft maximum diameter portion 233(6) at a position closer to the second shoulder 233(10) than the main shaft second end 233(2).

[0058] The gear set 222 includes a helical driven gear 225 which surrounds and is connected to the main shaft intermediate diameter portion 233 (7) via, for example, an internal spline (not shown). As a result, the driven gear 225 can rotate in conjunction with the main shaft 233 about the main shaft axis 235. The external teeth (not shown) of the driven gear 225 mesh with corresponding teeth (not shown) of the helical bevel pinion 209, whereby the driven gear 225 is driven by the intermediate shaft 207. The driven gear 225 is held adjacent to the bearing 227 via a retaining spring 224 surrounding the main shaft 233.

[0059] The driven gear 225 has a first gear face 225(1) facing away from the cutting blade 90, and a second gear face 225(2) opposite the first gear face 225(1) and facing the cutting blade 90. The first gear face 225(1) includes at least one recess, such as a blind hole 225(3), which is sized to receive a locking pin 294 as part of the spindle lock assembly 282, as discussed further below. In the illustrated embodiment, the first gear face 225(1) includes three blind holes 225(3) that are equally spaced along a circle around the spindle 233. The gear second face 225(2) defines a collar portion 225(4) that protrudes in a direction parallel to the spindle axis 235. The inner surface of the collar portion 225(4) faces the outer surface of the spindle 233.

[0060] A ball bearing 227 surrounding the spindle intermediate diameter portion 233(7) is disposed between the end face 225(5) of the bevel gear collar portion 225(4) and the spindle second shoulder 233(10). More specifically, the ball bearing 227 is held against the spindle second shoulder 233(10) via a retaining ring 226. The ball bearing 227 supports the spindle 233 relative to the gearbox cover 230, the inner surface of which includes a groove for receiving the retaining ring 226. An annular seal 232 is disposed between the surface of the ball bearing 227 facing the cutting blade and the spindle annular protrusion 233(5).

[0061] The retaining plate 239 surrounds the spindle annular protrusion 233(5) and is fixed to the end surface 230(1) of the gear case cover 230 via fasteners. The retaining plate 239 has a diameter greater than the gear case cover end surface 230(1), and the inner periphery of the blade guard 85 is clamped between the surface 239(1) of the retaining plate 239 and the surface 230(2) of the gear case cover 230 via intermediate blade guard O-rings 236, 237 in such a manner that the blade guard 85 can rotate relative to the gear case cover 230 and the retaining plate 239. The blade guard O-rings 236, 237 cooperate with another O-ring 229 disposed between the gear case cover 230 and the inner surface of the support arm 10 to prevent moisture and debris from entering the gear set 222.

[0062] refer to Figure 6-9 , the blade connection assembly 262 is supported on the spindle second end 233 (2). The blade connection assembly 262 includes the pair of flange plates 264, 266, which are composed of an inner flange plate 264 and an outer flange plate 266 held against one side of the spindle annular protrusion 233 (5) via a retaining spring 265. Each of the inner flange 264 and the outer flange 266 has substantially the same shape and size, so only the inner flange plate 264 will be described in detail.

[0063] The inner flange plate 264 is a thin plate having a circular peripheral edge 264 (1) and a central opening 264 (2). The central opening 264 (2) is configured to have the same shape and size as the main shaft maximum diameter portion 233 (6), which is received therethrough with a clearance fit. In particular, the central opening 264 (2) includes opposing flange flat surfaces 264 (3) configured to engage with the main shaft flat surface 233 (4) formed on the main shaft maximum diameter portion 233 (6). With this configuration, each of the inner flange 264 and the outer flange 266 rotates in conjunction with the main shaft 233.

[0064] When the inner flange plate 264 is viewed in side view, the central portion 264(4) including the central opening 264(2) is offset relative to the peripheral edge 264(1). As a result, the inner flange plate 264 has a central concave surface 264(5) surrounded by a rim 264(6). The rim 264(6) is parallel to the central portion 264(4).

[0065] In use, the inner flange plate 264 is disposed on the spindle maximum diameter portion 233(6) in an orientation in which the central portion 264(4) abuts the spindle annular protrusion 233(5) and the central concave surface 264(5) is open toward the spindle second end 233(2). The inner flange plate 264 is held against the spindle annular protrusion 233(5) by a retaining spring 265 disposed in a groove of the spindle 233. The outer flange plate 266 is disposed on the spindle maximum diameter portion 233(6) in an opposite orientation in which the central concave surface 266(5) is open toward the spindle first end 233(1). With this configuration, the rims 264(6), 266(6) of the respective inner flange plate 264 and outer flange plate 266 face each other. In use, the cutting blade 90 is mounted between the respective inner flange plate 264 and outer flange plate 266 on the spindle 233. The blade connection assembly 262 includes a bolt 268 received in the hole 233 (11) and a washer 267 disposed on the shank of the bolt 268. In use, the bolt 268 and the washer 267 are used to retain the outer flange plate 266 on the spindle 233. With the bolt 268 fully tightened in the hole 233 (11), the cutting blade 90 is securely clamped between the respective rims 264 (6), 266 (6) of the inner and outer flange plates 264, 266, and the rotation of the spindle 233 is transmitted to the cutting blade 90.

[0066] refer to Figure 6-7 as well as Figure 10-15, a spindle lock assembly 282 is supported on the support arm 10 adjacent the spindle first end 233(1). The spindle lock assembly 282 includes a lock handle 284 that is pivotally mounted on the outer surface of the support arm 10 at the support arm distal end 12. The support arm 10 includes a curved ridge 14 that protrudes from the outer surface of the lateral side of the support arm 10. The ridge 14 is U-shaped and surrounds the lock handle on three of the four sides. In some orientations of the lock handle 284, the ridge 14 protrudes to a certain extent, that is, the lock handle 284 is slightly recessed relative to the ridge 14, whereby the ridge 14 provides structural protection for the lock handle 284 to protect it from impact during transportation or operation of the saw. The lock handle 284 is connected to the support arm 10 via a pivot pin 292 supported on the ridge 14. The lock handle 284 is configured to actuate a locking pin 294 for movement relative to the support arm 10, as will now be described in detail.

[0067] The locking handle 284 is a rigid plate shaped and sized to be grasped between the fingers and thumb of a user's hand. The locking handle 284 covers the outer lateral side surface of the support arm 10. In the illustrated embodiment, the locking handle is disposed on a side of the support arm 10 opposite to the cutting blade 90. The locking handle 284 includes a handle first end 285 and a handle second end 286 opposite to the handle first end 285. The locking handle 284 includes a handle longitudinal axis 283 extending between the handle first end 285 and the second end 286. In the illustrated embodiment, the locking handle 284 is elongated in a direction parallel to the handle longitudinal axis 283, but is not limited to this configuration. The locking handle 284 includes a wide handle inner surface 287 facing the outer surface of the support arm 10. In addition, the locking handle 284 includes a wide handle outer surface 288 opposite to the handle inner surface 287 and away from the support arm 10. The handle inner and outer surfaces 287, 288 extend between the handle first and second ends 285, 286.

[0068] The lock handle 284 includes a through opening 291 shaped and sized to receive a pivot pin 292. The through opening 291 is disposed closer to the handle second end 286 than to the handle first end 285. In the illustrated embodiment, the through opening 291 is generally parallel to the inner and outer surfaces 287, 288 of the lock handle 284 and is perpendicular to the handle longitudinal axis 283 and the spindle axis 235.

[0069] The spindle lock assembly 282 includes a pivot pin 292 that connects the lock handle 284 to the support arm 10. The pivot pin 292 is disposed in the through opening 291. The pivot pin 292 has a sufficient length so that opposite ends of the pivot pin 292 protrude from opposite sides of the lock handle 284 and are supported on opposite portions of the support arm spine 14. In use, the lock handle 284 pivots about the pivot pin 292, whereby the pivot pin 292 defines a pivot pin rotation axis 300.

[0070] The spindle lock assembly 282 includes a torsion spring 293 configured to bias the lock handle 284 toward a first folded orientation relative to the support arm 10. The torsion spring 293 surrounds the pivot pin 292, and opposite ends of the torsion spring 293 are fixed to the lock handle 284 and the support arm 10, respectively.

[0071] The lock handle 284 includes a pair of bearing ridges 289 projecting from the handle inner surface 287. Each bearing ridge 289 is located below the through opening 291 and is elongated in a direction parallel to the handle longitudinal axis 283. The bearing ridges 289 are spaced apart from each other in a direction parallel to the pivot pin rotation axis 300. Each bearing ridge 289 defines a curved bearing surface 289(1) that bears on a corresponding curved surface of the post 15 projecting from the support arm outer surface 10(2).

[0072] The lock handle 284 includes a cam surface 290 formed at the handle second end 286. The cam surface 290 is a curved, outwardly convex surface. In the illustrated embodiment, the cam surface 290 extends from the handle outer surface 288 to a position between bearing ridges 289 on the handle inner surface 287. The cam surface 290 is configured to engage with a locking pin 294 and drive the locking pin 294 to translate relative to the support arm 10 based on the rotational orientation of the lock handle 284 about the pivot pin rotation axis 300, as discussed in further detail below.

[0073] The handle outer surface 288 may include surface features 288(1) that enhance manual gripping. For example, the handle outer surface 288 may include channels (shown), ridges, knurling, dimples, or other features. In the illustrated embodiment, a central portion 288(2) of the handle outer surface is slightly recessed, and the channel 288(1) is located in the central portion 288(2).

[0074] The spindle lock assembly 282 also includes a locking pin 294. The locking pin 294 includes a head 294(1) and an elongated shank 294(2) protruding from the head 294(1). The shank 294(2) has an end 294(3) opposite the head 294(1). A surface 294(4) of the head 294(1) on a side opposite the shank 294(2) is convex and curved. In the illustrated embodiment, for example, the surface 294(4) has a hemispherical shape. The locking pin 294 has a longitudinal axis 294(5) extending through the head 294(1) and the shank end 294(3). The locking pin 294 is disposed within the opening 26 of the support arm 10 and is oriented such that the locking pin longitudinal axis 294(5) is parallel to and offset from the spindle axis 235 and such that the locking pin longitudinal axis 294(5) passes through the driven gear 225( at a position between the spindle 233 and the bevel gear teeth. Figure 7). In particular, at certain rotational orientations of the driven gear 225, the locking pin longitudinal axis 294(5) is aligned with the hole 225(3) of the driven gear 225. The locking pin 294 is translatable within the support arm opening in a direction parallel to the longitudinal axis 294(5).

[0075] The spindle lock assembly 282 also includes a compression spring 299 surrounding the locking pin shank 294(2). One end of the compression spring abuts the head 294(1), and the opposite end of the compression spring 299 abuts the inner surface of the support arm 10. With this configuration, the compression spring 299 applies a force to the head 294(1) of the locking pin 294, which urges the locking pin 294 against the cam surface 290 of the lock handle 284, e.g., urging the locking pin 294 out of engagement with the hole 225(3) of the driven gear 225. Due to the spring force of the compression spring 299, the locking pin head 294(1) remains in direct contact with the cam surface of the lock handle 284 regardless of the orientation of the lock handle 284 about the pivot pin 292.

[0076] The lock handle 284 can be pivoted about the pivot pin 292 in the first folded position ( Fig.10 , shown in solid lines) and a second deployed position ( Fig.10 , shown in phantom). When the locking handle 284 is in the first position, the handle longitudinal axis 283 is at a first handle angle θ5 relative to the outer surface of the support arm. In the illustrated embodiment, when the locking handle 284 is in the first position, the longitudinal axis 283 of the locking handle 284 is oriented substantially parallel to the outer surface 10(2) of the support arm 10. In other words, the first handle angle θ5 is zero degrees or substantially zero degrees relative to the outer surface 10(2) of the support arm (e.g., within plus or minus five degrees of parallel to the outer surface 10(2) of the support arm). In this first position, the locking handle 284 is stowed within the area surrounded by the spine 14.

[0077] The cam surface 290 is curved so that when the lock handle 284 is in the first position, the portion of the cam surface 290 that contacts the locking pin 294 protrudes minimally toward the support arm 10. As a result, when the lock handle 284 is in the first position, the pin end 294(3) is spaced apart from the driven gear 225, for example, the pin end 294(3) is disengaged from the hole 225(3) provided in the first gear face 225(1). Since the locking pin 294 is disengaged from the hole 225(3), the spindle 233 is allowed to rotate freely about the spindle axis 235.

[0078] When the locking handle 284 is in the second position, the handle longitudinal axis 283 is at a second handle angle θ6 relative to the support arm outer surface 10(2). In the illustrated embodiment, when the locking handle 284 is in the second position, the longitudinal axis 283 of the locking handle 284 is oriented substantially perpendicular to the support arm outer surface 10(2) such that the handle first end 285 is located outside the area surrounded by the ridge 14. In other words, the second handle angle θ6 is 90 degrees, or within plus or minus five degrees of perpendicular to the support arm outer surface 10(2). In this orientation, the locking handle 284 protrudes outwardly relative to the support arm 10 and serves as a manual grip or handle that allows a user to easily hold and stabilize the cutting saw 1 during attachment or detachment of the cutting blade 90. Thus, the locking handle 284 in the second position serves as a handle and actuates the spindle lock assembly 282, which prevents the spindle 233 from rotating, thereby facilitating attachment or detachment of the cutting blade 90 from the cutting saw 1.

[0079] When the lock handle 284 is in the second position, the portion of the cam surface 290 that contacts the locking pin 294 protrudes maximally toward the support arm 10. As a result, when the lock handle 284 is in the second position, the locking pin 294 is driven by the cam surface 290 toward the driven gear 225, and the pin end 294(3) becomes engaged with one of the holes 225(3). When the locking pin 294 is engaged with the hole 225(3), the driven gear 225, and therefore the spindle 233, is prevented from rotating about the spindle axis 235.

[0080] Selected illustrative embodiments of a chopping saw are described above in considerable detail. Only structures considered necessary to illustrate the chopping saw are described herein. Other conventional structures and structures of auxiliary and accessory components of the chopping saw are assumed to be known and understood by those skilled in the art. Furthermore, although working examples of the chopping saw have been described above, the chopping saw is not limited to the working examples described above, but various design changes may be made without departing from the chopping saw as set forth in the claims.

Claims

1. A saw comprising: a saw housing, the saw housing comprising a front end, a rear end opposite the front end, and a hollow support arm protruding outwardly from the front end, the support arm comprising a proximal end adjacent to the front end and a distal end opposite the proximal end; an electric motor disposed in the saw housing, the electric motor including an output shaft rotatable about an output shaft axis; a battery pack disposed in the saw housing, the battery pack being configured to supply power to the electric motor; as well as a blade drive assembly disposed in the support arm, the blade drive assembly being configured to detachably connect a cutting blade to the distal end of the support arm and to transmit rotational motion of the output shaft to the cutting blade when the cutting blade is connected to the saw, The blade drive assembly comprises: a spindle connected to the output shaft and rotatable about a spindle axis, the spindle comprising a spindle first end supported by the support arm for rotation, and a spindle second end projecting outwardly from the support arm; a transmission connecting the output shaft to the main shaft; a blade connection subassembly disposed on the second end of the spindle, the blade connection subassembly being configured to detachably secure a cutting blade to the second end of the spindle; a lock handle covering an outer surface of the support arm, the lock handle comprising a handle first end, a handle second end opposite the handle first end, and a handle longitudinal axis extending between the handle first end and the handle second end, the lock handle being connected to the support arm via a pivot pin, the pivot pin being disposed closer to the handle second end than to the handle first end; and A locking pin is disposed in the opening of the support arm, the locking pin being capable of translating relative to the support arm in the opening, the locking pin comprising a first pin end directly contacting the lock handle and a second pin end facing the rotatable element of the transmission device, wherein: The lock handle is rotatable about the pivot pin relative to the support arm between a first position and a second position, wherein in the first position, the longitudinal axis of the handle is at a first angle relative to the outer surface of the support arm, and in the second position, the longitudinal axis of the handle is at a second angle relative to the outer surface of the support arm, the second angle being greater than the first angle. The locking pin is driven by the locking handle to translate relative to the support arm when the locking handle rotates about the pivot pin. When the lock handle is in the first position, the pin second end is spaced apart from the rotatable element of the transmission so that the rotatable element of the transmission is free to rotate, and When the lock handle is in the second position, the pin second end engages the rotatable element of the transmission such that the rotatable element of the transmission is prevented from rotating. 2 . The saw of claim 1 , including a spring surrounding the locking pin and biasing the locking pin against the lock handle.

3. The saw according to claim 1, wherein: The lock handle second end defines a curved cam surface.

4. The saw according to claim 3, wherein: The locking pin is biased against the lock handle via a resilient member so that a first end of the locking pin directly contacts the cam surface.

5. The saw according to claim 4, wherein: The cam surface is shaped such that the pin second end is spaced from the rotatable element of the transmission when the lock handle is in the first position and the pin second end is engaged with the rotatable element of the transmission when the lock handle is in the second position.

6. The saw according to claim 1, wherein: The locking pin is movable along a locking pin axis that is perpendicular to the rotational axis of the pivot pin.

7. The saw according to claim 1, wherein: A curved ridge protrudes from an outer surface of the support arm, the ridge partially surrounding the lock handle.

8. The saw according to claim 7, wherein: When the locking handle is in the first position, a surface of the locking handle facing away from the support arm is recessed relative to the ridge.

9. The saw according to claim 1, wherein: The main shaft axis is perpendicular to the output shaft axis; the transmission comprising a gear set connecting the output shaft to the main shaft, the gear set comprising the rotatable element of the transmission in the form of a driven gear fixed relative to the main shaft and rotatable about the main shaft axis; The driven gear includes a gear surface perpendicular to the main shaft axis, The gear surface defines a recess, and When the lock handle is in the second position, the pin second end is disposed in the recess such that the driven gear is prevented from rotating about the spindle axis.

10. The saw of claim 1, wherein: The pivot pin extends in a direction perpendicular to the output shaft axis and the main shaft axis.

11. The saw according to claim 1, wherein: The saw housing comprises: a main handle projecting from said rear end; and An auxiliary handle, the auxiliary handle comprising: an auxiliary handle first end coupled to a first side of the saw housing, an auxiliary handle second end coupled to a second side of the saw housing, and An auxiliary handle middle portion is disposed between the auxiliary handle first end and the auxiliary handle second end, and the auxiliary handle middle portion covers the third side of the saw housing.

12. The saw of claim 1, wherein: The transmission comprises an intermediate shaft disposed in the support arm, the intermediate shaft being rotatable about the output shaft axis and connecting the output shaft to the gear set.

13. A saw comprising: a saw housing, the saw housing comprising a front end, a rear end opposite the front end, and a protruding handle; an electric motor disposed in the saw housing, the electric motor including an output shaft; a battery pack disposed in the saw housing, the battery pack being configured to supply power to the electric motor; as well as a blade drive assembly configured to detachably connect a cutting blade to the saw and to transmit the rotational motion of the output shaft to the cutting blade when the cutting blade is connected to the saw, the blade drive assembly comprising: a spindle driven via a transmission connected to the output shaft to rotate about a spindle axis, the spindle transmitting the rotation of the output shaft to the cutting blade when the cutting blade is connected to the saw, a locking handle disposed on an outer surface of the saw housing, the locking handle being pivotable relative to the saw housing between a first folded position and a second unfolded position, and a locking pin supported in the saw housing and in direct contact with the lock handle, the locking pin being configured to translate relative to the saw housing based on a handle position, in: When the lock handle is in the first folded position, The lock handle is oriented substantially parallel to and minimally protrudes relative to the saw housing outer surface, and The locking pin is disengaged from the gear, whereby the blade drive assembly is configured to allow the spindle to freely rotate about the spindle axis, and When the lock handle is in the second deployed position, The locking handle is oriented substantially perpendicular to the saw housing outer surface and protrudes maximally relative to the saw housing outer surface, whereby the locking handle serves as a manual grip that allows a user to stabilize the saw when attaching and detaching a cutting blade, and The locking pin engages the transmission whereby the blade drive assembly is configured to prevent the spindle from rotating about the spindle axis.

14. The saw according to claim 13, wherein: When the locking handle is in the first position, a ridge protruding from the outer surface of the saw housing partially surrounds the locking handle.

15. The saw according to claim 14, wherein: When the locking handle is in the first position, a surface of the locking handle facing away from the support arm is recessed relative to the ridge.

16. The saw of claim 13, including a spring surrounding the locking pin and biasing the locking pin against the lock handle.

17. The saw of claim 13, wherein: The lock handle second end defines a curved cam surface.

18. The saw of claim 17, wherein: The locking pin is biased against the lock handle via a resilient member so that a first end of the locking pin directly contacts the cam surface.

19. The saw according to claim 18, wherein: The cam surface shape and dimensions are set so that: When the lock handle is in the first position, the second end of the pin is spaced apart from the driven gear, and When the lock handle is in the second position, the second end of the pin engages with the recess of the gear.

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