Cutting saw

Abstract

A dicing saw housing includes features that define a cooling airflow path through the saw housing that is configured to cool a battery pack, saw electronics, and a saw electric motor. The first cooling path passes through a compartment housing the battery and cools the battery prior to exiting the saw housing. The second cooling path passes below the compartment and through a heat sink of the printed circuit board assembly before exiting the saw housing. Both the first and second cooling paths pass through the electric motor before exiting the saw housing.

Description

Background Art

[0001] A cut-off saw is a handheld power tool that employs a circular blade mounted on the front of the saw housing. Cut-off saws have no lower blade guard and are typically powered with a cutting blade having a diameter in the range of 8 to 14 inches. This type of saw is designed to be a general purpose solution for cutting a variety of heavy materials including reinforced concrete, other masonry materials, and metals including iron and black pipe. Due to the power requirements of cutting heavy materials, it is desirable to have enhanced cooling of the components disposed within the saw housing, including the battery pack, the printed circuit board supporting the control electronics, and the electric motor, as compared to some conventional saws. 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 housing defines a rearward air inlet opening adjacent to the rear handle that communicates with the interior of the housing. In addition, the housing defines a lateral air outlet opening adjacent to the motor and communicates with the interior of the housing. In response to activation of the motor, the motor and the fan driven by the motor draw a cooling airflow through the rear air inlet opening. The cooling airflow follows a first cooling airflow path that enters the battery compartment and flows around all sides of the battery pack in the battery compartment. When leaving the battery compartment, the first cooling airflow path passes over the PCBA and the adjacent heat sink, and then passes through the motor. The first cooling airflow path is then discharged from the lateral air outlet opening. In addition, the cooling airflow follows a second cooling airflow path that passes under the battery compartment to provide cooling for the electrical wiring at that location, passes over the PCBA and the heat sink, and is discharged from the side air outlet opening. Compared to some conventional saws, the first and second cooling airflow paths provide improved cooling of the battery pack, the motor, and the control electronics. Additionally, the air outlet opening directs a large volume of air outward from the housing in a lateral and forward direction, thereby providing an air curtain that pushes cutting dust and debris away from the user and the front of the chop saw, thereby improving the user experience and work area visibility.

[0004] 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.

[0005] In some aspects, a saw includes a saw housing. The saw housing includes a front end and a rear end opposite the front end. The rear end includes a housing rear inlet opening that allows fluid communication between the interior space of the saw housing and the environment of the saw housing. The saw housing includes a longitudinal axis extending through the front end and the rear end. The saw housing includes a first lateral side extending between the front end and the rear end. The first lateral side has a housing side outlet opening that allows fluid communication between the interior space of the saw housing and the environment of the saw housing. The saw housing includes a second lateral side extending between the front end and the rear end. The second lateral side is disposed on a side of the longitudinal axis opposite to the first lateral side. The saw housing includes a hollow support arm protruding outwardly from the front end. The support arm is configured to support a cutting blade. The saw housing includes a main handle protruding outwardly from an outer surface of the housing. In addition, the saw housing also includes a partition wall disposed in the interior space of the saw housing. The partition wall includes a first wall facing the rear end and a second wall facing the front end. The first wall and the second wall extend between the first lateral side and the second lateral side so as to define a first compartment of the interior space, the first compartment being separated from the second compartment of the interior space. The first compartment is configured to receive and support a battery pack. The saw includes an electric motor disposed in a second compartment. The electric motor has an output shaft rotatable about an output shaft axis, and the output shaft is disposed in a plane parallel to the longitudinal axis. The saw includes a motor fan driven by the output shaft. The motor fan is disposed between the electric motor and the front end, and is configured to draw cooling air through the saw housing via a first cooling airflow path. The saw includes a printed circuit board assembly that supports electronic equipment configured to control the operation of the saw. The printed circuit board assembly is disposed between the second wall and the electric motor. The first compartment is disposed between the electric motor and the rear end. The first cooling airflow path begins at a housing rear inlet opening, extends from the housing rear inlet opening to a first compartment inlet orifice formed in the first wall, extends from the first compartment inlet orifice through the first compartment to a first compartment outlet orifice formed in the second wall, extends from the first compartment outlet orifice and into the second compartment, extends through the second compartment, and terminates at a housing side outlet opening.

[0006] In some embodiments, the first cooling air flow path enters the first compartment along a first direction parallel to the longitudinal axis, the first cooling air flow path leaves the first compartment along the first direction, and between entering the first compartment and leaving the first compartment, the first cooling air flow path moves in a direction perpendicular to the first direction.

[0007] In some embodiments, the first compartment outlet orifice is offset relative to the first compartment inlet orifice along an axis perpendicular to the longitudinal axis.

[0008] In some embodiments, the saw includes a battery pack disposed in the first compartment, the battery pack including four sides extending parallel to the longitudinal axis, and the first cooling airflow path traverses each of the four sides of the battery pack.

[0009] In some embodiments, the first cooling airflow path passes through the printed circuit board assembly and through the electric motor after extending through the second compartment and before terminating at the housing-side outlet opening.

[0010] In some embodiments, the printed circuit board assembly includes a printed circuit board and a heat sink adjacent to one side of the printed circuit board. The heat sink is disposed between the printed circuit board and the second wall, the heat sink includes an array of protruding cooling fins protruding toward the second wall, and the first cooling airflow path passes through the array of cooling fins.

[0011] In some embodiments, the array of protruding cooling fins extends in a direction parallel to the first lateral side and the second lateral side.

[0012] In some embodiments, the saw housing includes a third side and a fourth side. The third side extends between the front end and the rear end and between the first lateral side and the second lateral side. The fourth side extends between the front end and the rear end and between the first lateral side and the second lateral side, and the fourth side is disposed on a side of the longitudinal axis opposite to the third side. The saw includes a second cooling airflow path through the saw housing. The second cooling airflow path begins at the housing rear inlet opening, extends from the housing rear inlet opening to a gap between the first compartment and the third side of the saw housing, extends through the gap and exits into the second compartment, and terminates at a housing side outlet opening.

[0013] In some embodiments, the second cooling air flow path passes through the printed circuit board assembly and through the electric motor.

[0014] In some embodiments, the printed circuit board assembly includes a printed circuit board and a heat sink adjacent to one side of the printed circuit board. The heat sink includes an array of protruding cooling fins, and the second cooling airflow path passes through the protruding cooling fins before passing through the printed circuit board and through the electric motor.

[0015] In some embodiments, the saw housing is formed by a first half shell and a second half shell, and the first half shell and the second half shell are connected along a parting line extending from the front end to the rear end. The housing rear inlet opening includes two housing rear inlet openings. One of the two housing rear inlet openings is formed in the first half shell, and the other of the two housing rear inlet openings is formed in the second half shell. In addition, the housing side outlet opening includes two housing side outlet openings. One of the two housing side outlet openings is formed in the first half shell, and the other of the two housing side outlet openings is formed in the second half shell.

[0016] In some embodiments, the printed circuit board assembly lies in a plane perpendicular to the longitudinal axis.

[0017] In some embodiments, the printed circuit board assembly includes a printed circuit board and a heat sink adjacent to one side of the printed circuit board. The saw housing includes a wall portion supporting the printed circuit board assembly, and the wall portion is configured to direct airflow to the heat sink.

[0018] In some embodiments, a blade drive assembly is disposed in the support arm. The blade drive assembly is configured to detachably connect the cutting blade to the support arm and to transfer the rotational motion of the output shaft to the cutting blade when the cutting blade is connected to the saw.

[0019] In some embodiments, a battery pack is disposed in the first compartment. The battery pack is configured to power the electric motor.

[0020] In some aspects, a saw includes a saw housing. The saw housing includes a front end, a rear end opposite the front end, a hollow support arm protruding outward from the front end, a main handle protruding outward from the rear end, and a partition disposed in the interior space of the saw housing. The partition forms a first compartment of the interior space, which is separated from a second compartment of the interior space. The saw includes an electric motor disposed in the second compartment. The electric motor includes an output shaft rotatable about an output shaft axis. The saw includes a battery pack disposed in the first compartment. The battery pack is configured to power the electric motor. The saw includes a printed circuit board assembly that supports electronic equipment configured to control the operation of the saw. The printed circuit board is disposed between the battery pack and 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 support arm and, when the cutting blade is connected to the saw, transmit the rotational motion of the output shaft to the cutting blade. The saw housing includes a feature portion that defines a first cooling airflow path through the saw housing and a second cooling airflow path through the housing. The first cooling path passes through the first compartment before exiting the saw housing, the second cooling path passes around an outer surface of the first compartment before exiting the saw housing, and both the first and second cooling paths pass through the electric motor before exiting the saw housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a perspective view of a first side of a chop saw.

[0022] Figure 2 is a perspective view of a second side of the chop saw.

[0023] Figure 3 is along Figure 8 A cross-sectional view of the cutting saw as seen along line 3-3.

[0024] Figure 4 is along Figure 8 A cross-sectional view of the cutting saw as seen along line 4-4.

[0025] Figure 5 is a side view of a chop saw.

[0026] Fig. 6A is along Figure 8 A cross-sectional view of the saw housing as seen along line 6-6.

[0027] Figure 6B is along Figure 5 A cross-sectional view of the saw housing as seen along line 6B-6B.

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

[0029] Figure 7 is along Figure 8 A cross-sectional view of the cutting saw as seen along line 6-6.

[0030] Figure 8 is a rear view of the chop saw, with the dashed arrows showing the direction of air discharge.

[0031] Fig. 9 is a top view of a chop saw with dashed arrows showing the direction of air discharge.

[0032] Fig.10 is along Fig. 9 A cross-sectional view of the cutting saw as seen along line 10--10.

[0033] Fig.11 yes Fig.10 An enlarged view of the portion of the cutting saw enclosed by a dotted line.

[0034] Fig.12 is along Figure 5 A cross-sectional view of the cutting saw as seen along line 12-12.

[0035] Fig.13 It is an enlarged cross-sectional view of the shell side outlet opening.

[0036] Fig.14 is a perspective view of the motor.

[0037] Fig.15 is a perspective view of a support arm of the saw housing.

[0038] Fig.16 is a perspective view of the motor assembled with the support arm.

[0039] Fig.17 is along Figure 5 A cross-sectional view of the cutting saw as seen along line 17--17.

[0040] Fig.18 yes Fig.17 An enlarged view of the portion of the cutting saw enclosed by a dotted line.

[0041] Fig.19 is an exploded view of the blade connection assembly.

[0042] Fig. 20 is a perspective view of a schematic illustration of a driven gear of a gear set.

[0043] Fig.21 is a cross-sectional view of the distal end of the support arm.

[0044] Fig. 22 is a side perspective view of the distal end of the support arm.

[0045] Fig.23 is a top perspective view of the lock handle of the spindle lock assembly.

[0046] Fig.24 is a bottom perspective view of the lock handle.

[0047] Fig.25 is a top perspective view of the spindle lock assembly shown in isolation with reference to the driven gear and the spindle.

[0048] Fig.26 is a bottom perspective view of the spindle lock assembly in isolation.

[0049] Fig. 27 is along Figure 8 3-3 of a portion of a chop saw, illustrating a first cooling airflow path (indicated by solid arrows) through the saw housing as viewed in side view.

[0050] Fig.28 is along Figure 8 6-6 of the cutting saw, showing a first cooling airflow path (indicated by solid arrows) through the saw housing as seen in the top view.

[0051] Fig.29 is a top perspective view of a chop saw illustrating the air curtain.

[0052] Fig.30 is an enlarged view of a section through a portion of a saw housing showing details of an outlet opening on the housing side, wherein a dashed arrow shows the direction of air discharge.

[0053] Fig.31 is an enlarged view of a cross section of an alternative embodiment housing side outlet opening showing details of the slot opening.

[0054] Fig.32 is a top view of a cutting saw, with arrows showing the Fig.31 An alternative embodiment of the outlet opening corresponds to the air discharge direction.

[0055] Fig.33 is a top perspective view of a cutting saw illustrating the Fig.31 The alternative embodiment outlet opening corresponds to the alternative embodiment air curtain. DETAILED DESCRIPTION

[0056] refer to Figure 1-6A, the cutting saw 1 is a handheld power tool 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, which encloses 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 supporting 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 protruding from the rear end 4 of the saw housing 2, and a support arm 10 protruding from the front end 3 of the saw housing 2 in a direction opposite to the main handle 22. The cutting blade 90 can be quickly and easily mounted to or separated from the distal end 12 of the support arm 10. The saw housing 2 includes features that cool the battery pack 116, the control electronics 118, and the electric motor 101. The saw housing 2 includes features that allow an air curtain 180 to be formed near the cutting blade 90 to remove dust and debris from the workspace and improve visibility of the workpiece. In addition, the saw housing 2 includes features that prevent or inhibit the ingress of water into the saw housing. Each of these features of the saw housing 2 will be described in detail below.

[0057] 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.

[0058] 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 an exact state as well as minor variations due to manufacturing and assembly variations. Therefore, the fourth side 8 can be exactly parallel to the housing longitudinal axis 9, or can 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 the interior space 18 of the saw housing 2.

[0059] refer to Fig. 6A -C, the saw housing 2 includes a first partition wall 41 and a second partition wall 42, which are arranged in the inner space 18 and extend transversely between the first side 5 and the second side 6 of the housing. The first partition wall 41 is arranged between the second partition wall 42 and the rear end 4, so that the narrow gap 19 is arranged between the first partition wall 41 and the rear end 4.

[0060] The first and second partitions 41, 42 cooperate to form a first compartment 18(1) disposed near the rear end 4 and separated from the rest of the interior space 18. The first compartment 18(1) is configured to receive a battery pack 116 and is therefore also referred to as a battery compartment.

[0061] The fourth side 8 of the saw housing closes the lower end of the first compartment 18 (1), while the upper end of the first compartment 18 (1) is closed by a detachable cover 17. Relative directions mentioned herein, such as up, down, lateral, above, below, top, bottom, etc., are relative to Figure 1 The orientation of the chop saw 1 shown in is for descriptive purposes and is not intended to be limiting, as it is understood that the chop saw 1 may be used and / or stored in any orientation.

[0062] The first partition wall 41 includes two first compartment inlet apertures 37(1), 37(2) that allow fluid communication between the gap 19 and the first compartment 18(1). The first compartment inlet apertures 37(1), 37(2) are elongated narrow slots that extend laterally toward the respective first and second sides 5, 6. The first compartment inlet apertures 37(1), 37(2) are partially vertically aligned and are each disposed closer to the third side 7 (e.g., the top surface of the saw housing 2) than to the fourth side 8 (e.g., the bottom surface of the saw housing 2). In the illustrated embodiment, the upper first compartment inlet aperture 37(1) extends across the parting line 25 and is offset toward the second side 6, while the lower first compartment inlet aperture 37(2) extends across the parting line 25 and is offset toward the first side 5.

[0063] The second partition wall 42 is opposite and spaced from the first partition wall 41. The second partition wall 42 includes first compartment outlet apertures 38(1), 38(2), 38(3), 38(4), 38(5) that allow fluid communication between the first compartment 18(1) and the second compartment 18(2) of the saw housing 2. The first compartment outlet apertures 38(1), 38(2), 38(3), 38(4), 38(5) are elongated narrow slots that extend laterally toward the respective first and second sides 5, 6. The first compartment outlet apertures 38(1), 38(2), 38(3), 38(4), 38(5) are vertically aligned and extend across the parting line 25. Each of the first compartment outlet apertures 38(1), 38(2), 38(3), 38(4), 38(5) is disposed closer to the fourth side 8 (e.g., the bottom surface of the saw housing 2) than the third side 7 (e.g., the top surface of the saw housing 2).

[0064] Thus, the first compartment 18(1) includes first compartment inlet apertures 37(1), 37(2) located near the top surface of the saw housing 2, and outlet apertures 38(1), 38(2), 38(3), 38(4), 38(5) located near the bottom surface of the saw housing. With this configuration, the first compartment inlet apertures 37(1), 37(2) are offset relative to the first compartment outlet apertures 38(1), 38(2), 38(3), 38(4), 38(5) along an axis perpendicular to the housing longitudinal axis 9 and passing through the third and fourth sides 7, 8. Thus, a cooling airflow entering the upper portion of the first compartment 18(1) via the first compartment inlet apertures 37(1), 37(2) can exit the first compartment 18(1) at its lower portion via the first compartment outlet apertures 38(1), 38(2), 38(3), 38(4), 38(5). The vertical offset of the inlet aperture relative to the outlet aperture causes the cooling air to flow around all sides of the battery pack 116 before the flow exits the first compartment 18 ( 1 ).

[0065] The first partition wall 41 can support an electrical contact 40 that is configured to form an electrical connection with a corresponding electrical contact (not shown) of the battery pack 116. In some embodiments, the electrical contact 40 can be disposed on the first partition wall 41 between the first compartment inlet apertures 37(1), 37(2) and the fourth side 8. Thus, when cooling airflow is drawn around the battery pack 116 from the upper portion of the battery compartment to the lower portion of the battery compartment, the electrical contact 40 is disposed in the cooling airflow path, thereby facilitating improved cooling of the battery pack 116 compared to some other saws. In addition, by providing multiple inlet apertures and multiple outlet apertures, the amount of airflow through the first compartment is increased.

[0066] refer to Figure 7The area of ​​the interior space 18 disposed between the first compartment 18(1) and the front end 3 is further divided by a third partition wall 43 extending from the front end 3 toward the rear end 4 in a direction parallel to the longitudinal axis 9 of the housing. The third partition wall 43 is located approximately midway between the first side 5 and the second side 6. A second compartment 18(2) accommodating the electric motor 101 is defined between the third partition wall 43, the second half shell 21, and the front end 3 of the housing. The third compartment 18(3) is defined between the third partition wall 43, the first half shell 20, the front end 3, and a fourth partition wall 44. The fourth partition wall 44 is disposed at the rearmost end of the third partition wall 43 and extends transversely between the third partition wall 43 and the second side 6 of the housing.

[0067] There is a space 18(4) between the second partition wall 42 and the third and fourth partition walls 43, 44. The PCBA 112 is disposed in the space 18(4) and is oriented so that the printed circuit board (PCB) of the PCBA 112 is perpendicular to the housing longitudinal axis 9. The second compartment 18(2) is open rearwardly to communicate with the space 18(4), while the third compartment 18(3) is separated from the space 18(4) by the fourth partition wall 44.

[0068] The second and third compartments 18(2) and 18(3) are in fluid communication via an opening 46 in the third partition wall 43, as discussed in detail below.

[0069] refer to Figure 1 , Figure 2 and Figure 7-11 , each of the two half-shells 20, 21 of the saw housing 2 includes a housing rear inlet opening 28 formed in the rear end 4, whereby the saw housing 2 includes a pair of housing rear inlet openings 28. Each housing rear inlet opening 28 communicates with the saw housing interior space 18. In particular, each housing rear inlet opening 28 communicates with the gap 19 provided between the rear end 4 and the first partition wall 41. As seen when the saw housing 2 is viewed from the rear, the rear end 4 includes a surface 4(1) that is acutely angled relative to the housing longitudinal axis 9, which is connected by a central surface 4(2) that is perpendicular to the longitudinal axis 9. The housing rear inlet opening 28 is provided on each angled surface 4(1) and includes a portion that extends into the central surface 4(2). As a result, each housing rear inlet opening 28 is correspondingly angled relative to the housing longitudinal axis 9.

[0070] The housing rear inlet openings 28 are each comprised of an array of closely spaced narrow slots 28a formed through the thickness of the rear end 4. The slots 28a extend transversely, and surfaces 28b of the slots 28a are parallel to a line normal to the rear end 4. With this configuration, air enters the interior space 18 via the slots 28a in a direction normal to the portion of the rear end 4 where the housing rear inlet openings 28 are formed. The material between the slots 28a forms a grill that is configured to prevent material having a size greater than the width of the slots 28a from entering the interior space 18.

[0071] The slots 28a forming the rear inlet opening 28 of the housing each include a louver 28c that allows air to flow through the corresponding slot 28a but prevents or inhibits liquid from entering the saw housing 2. Each louver 28c protrudes inwardly from the inner surface of the saw housing 2 and includes a shelf portion 28d and a wall portion 28e. The shelf portion 28d is cantilevered from the housing 2 and aligned with the lower surface 28b of the slot 28a. The shelf portion 28d may be perpendicular to the housing 2, or may be slightly angled relative to the housing 2 to promote liquid to flow to the outside of the housing 2. The wall portion 28e is disposed along the innermost edge of the shelf portion 28d and protrudes upward from the shelf portion 28d. In the illustrated embodiment, the wall portion 28e is an upright structure having a height equal to or less than the height of the slot 28a. With this construction, the airflow entering the slot 28a is forced to follow a tortuous path to enter the saw housing 2. The tortuous path is Fig.11 Through arrow A T1 In addition, the wall portion 28e of each notch 28a provides a stop surface that blocks liquid from entering the housing 2 and deflects the liquid outward when guided by the shelf portion 28d.

[0072] refer to Figure 1 , 2 , 7 and 12-16, each of the two half-shells 20, 21 includes a housing side outlet opening 30. In particular, the housing side outlet opening 30 is formed in each of the corresponding first side 5 and second side 6. Each housing side outlet opening 30 is connected to the saw housing internal space 18 and is arranged at a position between the front end 3 and the rear end 4 at a position corresponding to the outlet end 103 (2) of the electric motor housing 103. In addition, each housing side outlet opening 30 is arranged at a position separated from the third (top) side and the fourth (bottom) side 7, 8.

[0073] The housing-side outlet opening 30 of the right housing half 21 communicates with the second compartment 18(2) near the saw housing front end 3. The housing-side outlet opening 30 of the left housing half 21 is similarly located on the opposite side of the saw housing 2 and communicates with the third compartment 18(3).

[0074] Each housing-side outlet opening 30 is formed by a series of closely spaced narrow slots 30a. The material between the slots 30a forms a grid that is configured to prevent material having a size greater than the width of the slots 30a from entering the interior space 18. In the illustrated embodiment, the slots 30a extend at an acute angle relative to the vertical direction, for example, at an angle of 30 degrees relative to the vertical direction. However, in other embodiments, the slots 30a may extend vertically or horizontally.

[0075] The slots 30a are formed through the thickness of the corresponding first and second sides 5, 6 in such a manner that the surface 30b of each slot 30a is parallel to a line normal to the portion of the corresponding first and second sides 5, 6 in which the housing-side outlet opening 30 is formed. With this configuration, air leaves the interior space 18 via the slots 30a in a direction normal to the portion of the corresponding first and second sides 5, 6 in which the housing-side outlet opening 30 is formed. In particular, as shown in the top view of the cutting saw 1 ( Fig. 9 ), each housing side outlet opening 30 is configured to discharge air from the housing interior space 18 in a direction indicated by arrow A1, which is at a first angle θ1 relative to the housing longitudinal axis 9. In the illustrated embodiment, the first angle θ1 is substantially perpendicular to the longitudinal axis 9 and is therefore oriented such that the air flowing out of each housing side outlet opening 30 is directed laterally outward. In addition, as shown in the rear view ( Figure 8 ), each housing side outlet opening 30 is configured to discharge air from the housing interior space 18 in a direction indicated by arrow A2, which is at a second angle θ2 relative to the housing longitudinal axis 9. In the illustrated embodiment, the second angle θ2 is approximately 90 degrees to the housing longitudinal axis 9, so that the air flowing out of each housing side outlet opening 30 is directed laterally.

[0076] The saw housing 2 includes housing features configured to prevent or inhibit liquid (i.e., water) from entering the interior space via the housing side outlet openings 30. The housing features include a shelf 32 disposed at each housing side outlet opening, and a housing wall portion 35 that cooperates with the shelf 32 to minimize water penetration.

[0077] Each shelf 32 protrudes inwardly from the inner surface of each of the corresponding first side 5 and second side 6 of the saw housing 2 at a position corresponding to the housing side outlet opening 30. Each shelf 32 has a proximal end 33 abutting the corresponding housing side 5, 6, and a distal end 34 opposite to the proximal end 33 and spaced apart from the corresponding housing side 5, 6. The distal end 34 of each shelf 32 abuts against a housing wall portion 35 facing the housing side outlet opening 30, or is closely spaced apart from the housing wall portion 35.

[0078] The shelf 32 is cantilevered from the housing 2. The shelf 32 may be perpendicular to the housing 2, or may be slightly angled relative to the housing 2 to promote liquid flow to the exterior of the housing 2. In some embodiments, the shelf 32 extends at a shelf angle θs relative to the first side, and the shelf angle θs is an acute angle (θs) relative to a plane P including the housing-side outlet opening 30. Fig.12 ).

[0079] The shelf 32 is arranged between the respective housing-side outlet opening 30 and the fourth (bottom) side 8. In the embodiment shown, the shelf 32 is aligned with the lower edge of the grid defined by the notches 30a.

[0080] In addition to the shelf 32, the housing features configured to prevent or inhibit the ingress of liquid into the interior space also include a facing wall portion 35. The facing wall portion 35 extends upwardly toward the third (top) side 7 of the housing relative to the shelf distal end 34. With this configuration, the facing wall portion 35 provides a stop surface or shield that inhibits (e.g., blocks or partially blocks) the ingress of liquid into the housing 2 and deflects the liquid outward when guided by the shelf 32. In some embodiments, the wall portion 35 is integral with the shelf distal end 34, while in other embodiments, the wall portion 35 is a separate structural element that is immediately adjacent to the shelf distal end 34.

[0081] With respect to the housing-side outlet opening 30 provided in the right half-shell 21 (e.g., in the first side 5), the facing wall portion 35(1) is partially constituted by the wall portion 101(1) of the motor housing 101 and partially by the protruding wall portion 10(1) of the support arm 10. The support arm protruding wall portion 10(1) cooperates with the motor housing wall portion 101(1) to provide a substantially continuous surface facing the housing-side outlet opening 30 without intervening structures. In the illustrated embodiment, the facing wall portion 35(1) has a surface area that is at least the size of the area of ​​the housing-side outlet opening 30 that it faces.

[0082] With respect to the shell-side outlet opening 30 disposed in the left half shell 20 (e.g., in the second side 6), the facing wall portion 35(2) is partially constituted by a portion 43(2) of the third partition wall 43 and partially constituted by a portion 48(2) of the outer surface of a baffle 48 protruding from the third partition wall 43 toward the second side 6. The baffle 48 is tubular, has a generally rectangular cross-sectional shape, and defines a closed path that redirects the airflow passing therethrough by a ninety-degree change of direction. Despite their relative offset, the portion 43(2) of the third partition wall 43 and the portion 48(2) of the outer surface of the baffle 48 each face the shell-side outlet opening 30 without an intervening structure. In combination, the portion 43(2) of the third partition wall 43 and the portion 48(2) of the outer surface of the baffle 48 that constitute the facing wall portion 35 have a surface area at least the size of the area of ​​the shell-side outlet opening 30 that they face.

[0083] Thus, the shell-side outlet opening 30 of each of the first side 5 and the second side 6 comprises a shelf 32 and a facing wall portion 35 which provides a stop surface that prevents or partially prevents liquid from entering the shell 2 and deflects the liquid outwardly when guided by the shelf 32.

[0084] Further with respect to the shell-side outlet opening 30 provided in the second side 6, the baffle 48 encloses the opening 46 in the third partition wall 43 and is open toward the rear end 4. In effect, the baffle 48 provides a closed passage that redirects the airflow from the second compartment 18 (2) to the third compartment 18 (3) by a ninety-degree turn. In particular, the airflow discharged from the motor fan 100 leaves the second compartment 18 (2) laterally via the opening 46 in the third partition wall 43 and is redirected to flow in the longitudinal direction by the baffle 48 open toward the fourth partition wall 44. The airflow leaving the baffle 48 impacts the fourth partition wall 44 and is redirected again by the fourth partition wall 44 to flow toward the front end 3 and toward the outlet opening 30 on the second side 6 of the shell. With this construction, the third partition wall 43, the fourth partition wall 44 and the baffle 48 cooperate to define a tortuous airflow path between the shell-side outlet opening 30 on the second side 6 and the second compartment 18 (2) housing the motor 101. The tortuous path is Figure 7 Through arrow A T2 express.

[0085] Although the housing side outlet opening 30 is illustrated herein as being without louvers, in some embodiments, the housing side outlet opening 30 may include louvers similar to the louvers 28 c provided for the housing rear inlet opening 28 .

[0086] Although the illustrated embodiment of the saw housing 2 includes a single pair of housing rear inlet openings 28 and a single pair of housing side outlet openings 30, the saw housing 2 is not limited to these openings. In some embodiments, additional inlet and / or outlet openings may be provided. Possible locations of such openings are indicated by faux openings 29, 31. The faux openings 29, 31 have a similar appearance to the housing side outlet openings 30, but do not include through openings and therefore do not provide fluid communication between the housing interior 18 and the environment of the saw 1.

[0087] refer to Figure 3 , Figure 5 and Fig. 9 , the right side half shell 21 includes a support arm 10 protruding 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 connected to or integral with the front end 3, and a distal end 12 opposite the proximal end 11 and supporting the cutting blade 90. The support arm 10 includes a support arm axis 13 extending between the proximal end 11 and the distal end 12. Although the proximal end 11 is connected to the front end 3 at the middle 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 ( Fig. 9 ), 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.

[0088] The proximal end 11 of the support arm 10 includes a base plate 11 (1) that cooperates with the half shells 20, 21 to define the saw housing front end 3. The base plate 11 (1) can be secured to the half shells 20, 21, for example using fasteners, or alternatively can be integrally formed with one of the half shells 20, 21. The support arm 10 includes a protruding wall portion 10 (1) that extends into the second compartment 18 at a location between the housing first side 5 and the blade drive assembly 200. In the illustrated embodiment, the protruding wall portion 10 (1) is shaped and dimensioned to be received in a recess 103 (3) of the housing 103 of the motor 101 and completely block the recess. More specifically, the protruding wall portion 10 (1) is configured to be received in the recess 103 (3) facing the housing first side 5. As previously described, the protruding wall portion 10 (1) acts as a shield and cooperates with the motor housing 103 to form a facing wall portion 35 that inhibits the inflow of liquid into the saw housing 2.

[0089] 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 .

[0090] refer to Figure 3-5 , 7, 9 and 14, 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.

[0091] An 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. Operation of the motor 101 is controlled by a controller. The electric motor 101 is housed in a generally cylindrical motor housing 103. The motor housing 103 is supported by the saw housing 2 in an angled orientation relative to the housing longitudinal axis 9 and is secured in this orientation by fasteners received in mounting bosses 103(1) formed in a first end (e.g., outlet end) 103(2) of the motor housing 103. The motor housing 103 includes a recess 103(3) between each pair of adjacent bosses. In the illustrated embodiment, the motor housing 103 includes four bosses 103(1) and four recesses 103(3), whereby the motor housing first end 103(2) has a scalloped appearance. In other embodiments, a greater or lesser number of protrusions 103 ( 1 ) may be used.

[0092] The output shaft 102 of the motor 101 protrudes from the first end 103(2) of the motor housing and rotates about the output shaft axis 98 which is aligned with the support arm axis 13. Fig. 9 ), the output shaft axis 98 extends parallel to the housing longitudinal axis 9 toward the front end 3. 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.

[0093] The motor fan 100 is mounted on the output shaft 102 at a position between the electric motor 101 and the front end 3 of the housing. The motor fan 100 rotates in conjunction with the output shaft 102 and draws air through the housing 103 of the motor 101. The motor fan 100 also enhances the air flow within the housing interior space 18 by drawing air from the rear end 4 to the front end 3, as discussed in further detail below. In the illustrated embodiment, the protrusion 103(1) of the motor housing 103 surrounds the outer periphery of the motor fan 100. Although the recess 103(3) facing the first side 5 of the housing and the housing side outlet opening 30 is blocked by the protruding wall portion 10(1), the remaining recesses 103(3) are not blocked. With this configuration, the remaining recesses 103(3) of the motor housing 103 (e.g., three of the four recesses 103(3)) allow the air exhausted by the motor fan to leave the motor housing 103 in a direction perpendicular to the output shaft axis 98.

[0094] refer to Figure 4 and Figure 7 , PCBA 112 is a complete printed circuit board assembly that includes a PCB and contains controllers and other electronic components required to make the board operate as desired. PCBA 112 is mounted on a heat sink 114. PCBA 112 and heat sink 114 are arranged in space 18 (4) and supported therein via PCBA holder 113 in such a manner that the PCB lies in a plane perpendicular to the longitudinal axis 9 of the housing. Heat sink 114 is a thermally conductive plate coupled to the rearward surface of PCBA 112. Heat sink 114 includes cooling fins 115 extending in a direction parallel to the first and second (lateral) sides 5, 6 and projecting toward the rear end 3.

[0095] In the illustrated embodiment, the PCBA holder 113 is supported via a fifth bulkhead 45 that extends transversely between the PCBA holder 113 and the first and second sides 5, 6 of the saw housing 2. The fifth bulkhead 45 is parallel to the first and second bulkheads 41, 42 and is disposed in the space 18(4) between the second and fourth bulkheads 42, 44.

[0096] 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.

[0097] refer to Figure 1-3 A trigger 23 for operating the cutting saw 1 is located on the main handle 22. The trigger 23 is configured so that the user can depress the trigger 23 using a finger of the hand holding the main handle 22, thereby activating the electric motor 101.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] refer to Figure 3 , Fig.15 and Figure 17-18, 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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).

[0106] 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.

[0107] 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.

[0108] 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).

[0109] 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.

[0110] refer to Figure 18-20 , 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.

[0111] 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.

[0112] 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).

[0113] 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.

[0114] refer to Figure 17-18 as well as Figure 21-26 , 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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).

[0120] 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 the 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.

[0121] 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).

[0122] 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. Fig.12 ). 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).

[0123] 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.

[0124] The lock handle 284 can be pivoted about the pivot pin 292 in the first folded position ( Fig.15 , shown in solid lines) and a second deployed position ( Fig.15 , 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] refer to Figure 6A-7 and Figure 27-28 , the chopping saw 1 includes features for cooling the battery pack 116, the control electronics 118, and the electric motor 101. In particular, the chopping saw 1 includes a housing rear inlet opening 28 and a housing side outlet opening 30, as well as bulkheads 41, 42, 43, 44 and their respective apertures 37(1), 37(2), 38(1), 38(2), 38(3), 38(4), 38(5) configured to direct a cooling airflow through the saw housing 2. The cooling airflow is generated by the rotational motion of the rotor of the electric motor 101 and is also drawn through the saw housing 2 by the motor fan 100. In the illustrated embodiment, the cooling airflow moves through the saw housing 2 along two cooling airflow paths 108, 110.

[0129] The first cooling airflow path 108 (indicated by a solid arrow) begins at the housing rear inlet opening 28, for example, at the housing rear end 4. The first cooling airflow path 108 passes through the gap 19 and enters the first compartment 18(1) via the upper and lower first compartment inlet apertures 37(1), 37(2) disposed in the first bulkhead 41. Within the first compartment 18(1), the first cooling airflow path 108 passes above, below, and around the lateral sides of the battery pack 116 and exits the first compartment 18(1) via the first compartment outlet apertures 38(1), 38(2), 38(3), 38(4), 38(5) disposed in the second bulkhead 42. Since the first compartment inlet apertures 37(1), 37(2) are vertically offset from the first compartment outlet apertures 38(1), 38(2), 38(3), 38(4), 38(5), airflow throughout the first compartment 18(1) is enhanced, whereby airflow through the first compartment 18(1) is both longitudinal and in a direction perpendicular to the longitudinal axis 9 of the housing (at Fig. 27 Schematically shown in FIG.

[0130] After leaving the first compartment 18 (1), the first cooling airflow path 108 enters the space 18 (4) and passes over the heat sink 114 of the PCBA 112. The fins 115 of the heat sink 114 guide the first cooling airflow path 108 upward toward the third side 7, and the first cooling airflow path 108 passes over the upper surface of the PCBA 12 and then passes downward toward the inlet end of the motor housing 103. As a result, the PCB of the PCBA 112 is directly cooled by the first cooling airflow path 108. After cooling the PCBA 112, the first cooling airflow path 108 enters the second compartment 18 (2). In the second compartment 18 (2), the first cooling airflow path 108 passes through the motor 101 and the motor fan 100, thereby cooling the motor. After passing through the motor 101 and the motor fan 100, the first cooling airflow path 108 leaves the saw housing 2 via the housing side outlet opening 30.

[0131] Notably, the first cooling airflow path 108 enters the first compartment 18(1) along a first direction D1 that is parallel to the saw housing longitudinal axis 9. The first cooling airflow path 108 exits the first compartment 18(1) along the first direction D1. Between entering the first compartment 18(1) and exiting the first compartment 18(1), the first cooling airflow path 108 moves in at least a second direction D2 that is perpendicular to the first direction D1 (e.g., vertically, between the top 7 and the bottom 8) to accommodate the offset first compartment inlet and outlet apertures 37, 38.

[0132] The second cooling air flow path 110 (indicated by a dashed arrow) begins at the housing rear inlet opening 28, for example, at the housing rear end 4. The second cooling air flow path 110 passes through the gap 19 and enters a subspace 18(5) disposed between the first compartment 18(1) and the fourth (bottom) side 8. The subspace 18(5) extends from the rear end 4 toward the front end 3 and communicates with the space 18(4). Within the space 18(4), the second cooling air flow path 110 passes above and below the PCBA 112 and then enters the second compartment 18(2). In the second compartment 18(2), the second cooling air flow path 110 passes through the motor 101 and the motor fan 100, thereby cooling the motor. After passing through the motor 101 and the motor fan 100, the second cooling air flow path 110 leaves the saw housing 2 via the housing side outlet opening 30.

[0133] When the second cooling airflow path 110 passes under the first compartment 18 ( 1 ), the second cooling airflow path cools both the first compartment 18 ( 1 ) and the wiring harness passing under the first compartment via the subspace 18 ( 5 ).

[0134] Both the first and second cooling airflow paths 108, 110 pass through the space 18(4) in the area between the second and fourth partition walls 42, 44 and pass over the PCBA 112 after flowing through the heat sink cooling fins 115. After cooling the PCBA 112, both the first cooling airflow path 108 and the second cooling airflow path 110 enter the second chamber 18(2) and pass through the motor 101 and the motor fan 100, thereby cooling the motor 101. After passing through the motor 101 and the motor fan 100, both the first cooling airflow path 108 and the second cooling airflow path 110 exit the saw housing 2 via a tortuous path to the housing-side outlet opening 30. For example, to reach the housing side outlet opening 30 on the housing first side 5, both the first and second cooling airflow paths 108, 110 exit the fan 100 via the unobstructed recess 103(3), flow around the motor housing 103 and into the space between the facing wall portion 35(1) and the first side 5, and are redirected outwardly from the saw housing 2 through the shelf 32 and the facing wall portion 35(1). To reach the housing side outlet opening 30 on the housing second side 6, both the first and second cooling airflow paths 108, 110 exit the fan 100 via the unobstructed recess 103(3), flow around the motor housing 103 and into the baffle 48 via the opening 46 in the third bulkhead 43. The baffle 48 redirects the laterally directed airflow from the second compartment 18(2) to the third compartment 18(3) through a ninety degree turn. The airflow exiting the baffle 48 strikes the fourth bulkhead 44 and is redirected again by the fourth bulkhead 44 to flow toward the front end 3 and toward the outlet opening 30 on the housing second side 6. The tortuous paths to each housing-side outlet opening 30 are advantageous because they prevent or inhibit the ingress of liquid during saw operation.

[0135] refer to Fig.29In addition to the cooling airflow paths 108, 110, the saw housing 2 also includes features that allow an air curtain 180 to be formed near the front end of the saw housing 2 and the cutting blade 90. In particular, the cutting saw 1 includes a housing side outlet opening 30 that is strategically positioned on the saw housing 2 and spatially oriented to provide an air curtain that is configured to remove dust and debris from the workspace and improve visibility of the workpiece. In the illustrated embodiment, the housing side outlet opening 30 is longitudinally positioned adjacent to the outlet of the motor 101 and the motor fan 100 (e.g., at the front end of the saw housing 2) and is configured to direct the high pressure airflow 180(1), 180(2) exhausted from the motor 101 and the motor fan 100 laterally outward from the lateral sides of the saw housing 2 and toward the front end 3. As described above, the housing side outlet opening 30 includes angled slots that exhaust air at appropriate angles (e.g., first and second angles θ1, θ2) relative to the housing longitudinal axis 9. The large amount of air flowing outward from the housing side outlet opening 30 forms an air curtain 180, which is configured to direct cutting dust and debris away from the front of the cutting saw, thereby improving the visibility of the cutting blade 90 and the work area, while also improving the user experience by moving cutting dust and debris away from the user.

[0136] refer to Figure 30-32 In the embodiment of the saw 1 described above, the notch angles of each housing rear inlet opening 28 and housing side outlet opening 30 are formed through the thickness of the respective housing portion so that the surface 28b, 30b defining each notch 28a, 30a is parallel to a line normal to the surface of the respective housing portion. ( Fig.30 ). In other words, the notches 28a, 30a are located relative to the normal With a notch angle θ7 of 0 degrees, the normal exist Fig.24 However, in some embodiments, the notch 30a' of the shell-side outlet opening 30' may have a notch surface 30b' ( Fig.31 ). This allows for more specific directional aiming of the airflow direction providing the air curtain 180. In some embodiments, the notch angle θ7' is in the range of zero to 85 degrees. In other embodiments, the notch angle θ7' is in the range of 25 to 75 degrees. In still other embodiments, the notch angle θ7' is in the range of 30 to 60 degrees. With this configuration, the notch angle θ7' can be set to direct the air exhausted from the interior space 18 generally more forward, and in some embodiments, toward the support arm 10 and the cutting blade 90.

[0137] refer to Fig.33In one example, each housing side outlet opening 30 is configured to discharge air from the housing interior space 18 in a direction indicated by arrow A1' that is oriented laterally and forwardly. To this end, the notch angle θ7' of the housing side outlet opening 30 may be 45 degrees and oriented so that the air flowing out of each housing side outlet opening 30 is directed forward and outward. With this configuration, the notch angle θ7' is set to direct the air discharged from the interior space 18 toward the support arm 10 and the cutting blade 90.

[0138] 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: front end, a rear end opposite the front end, the rear end including a housing rear inlet opening, the housing rear inlet opening allowing fluid communication between the interior space of the saw housing and an environment of the saw housing, a longitudinal axis extending through said front end and said rear end, a first lateral side extending between the front end and the rear end, the first lateral side including a housing-side outlet opening allowing fluid communication between the interior space of the saw housing and the environment of the saw housing, a second lateral side extending between the front end and the rear end, the second lateral side being disposed on an opposite side of the longitudinal axis from the first lateral side, a hollow support arm projecting outwardly from the front end, the support arm being configured to support a cutting blade, a main handle projecting outwardly from an outer surface of the housing, and a bulkhead disposed in the interior space of the saw housing, the bulkhead comprising a first wall facing the rear end and a second wall facing the front end, the first wall and the second wall extending between the first lateral side and the second lateral side so as to define a first compartment of the interior space, the first compartment being separated from a second compartment of the interior space, the first compartment being configured to receive and support a battery pack; an electric motor disposed in the second compartment, the electric motor including an output shaft rotatable about an output shaft axis, the output shaft disposed in a plane parallel to the longitudinal axis; a motor fan driven by the output shaft, the motor fan disposed between the electric motor and the front end and configured to draw cooling air through the saw housing via a first cooling air flow path; and a printed circuit board assembly supporting electronics configured to control operation of the saw, the printed circuit board assembly being disposed between the second wall and the electric motor, in, The first compartment is disposed between the electric motor and the rear end, The first cooling airflow path: Starting at the rear inlet opening of the housing, extending from the housing rear inlet opening to a first compartment inlet aperture formed in the first wall, extending from the first compartment inlet aperture through the first compartment to a first compartment outlet aperture formed in the second wall, extending from the first compartment outlet orifice and into the second compartment, extends through the second compartment, and The outlet port ends at the housing side.

2. The saw according to claim 1, wherein: The first cooling air flow path enters the first compartment along a first direction parallel to the longitudinal axis, The first cooling airflow path exits the first compartment in the first direction, and The first cooling air flow path moves in a direction perpendicular to the first direction between entering the first compartment and exiting the first compartment.

3. The saw according to claim 1, wherein: The first compartment outlet aperture is offset relative to the first compartment inlet aperture along an axis perpendicular to the longitudinal axis.

4. The saw according to claim 1, wherein: The saw includes a battery pack disposed in the first compartment, The battery pack includes four sides extending parallel to the longitudinal axis, and The first cooling airflow path traverses each of the four sides of the battery pack.

5. The saw according to claim 1, wherein: After extending through the second compartment and before terminating at the housing-side outlet opening, the first cooling airflow path passes through the printed circuit board assembly and through the electric motor.

6. The saw according to claim 5, wherein: The printed circuit board assembly includes a printed circuit board and a heat sink adjacent to one side of the printed circuit board, The heat sink is disposed between the printed circuit board and the second wall, The heat sink comprises an array of protruding cooling fins protruding toward the second wall, and The first cooling air flow path passes through the array of cooling fins.

7. The saw according to claim 6, wherein: The array of protruding cooling fins extends in a direction parallel to the first lateral side and the second lateral side.

8. The saw according to claim 1, wherein: The saw housing comprises: a third side extending between the front end and the rear end and between the first lateral side and the second lateral side; and a fourth side extending between the front end and the rear end and between the first lateral side and the second lateral side, the fourth side being disposed on a side of the longitudinal axis opposite the third side, and The saw includes a second cooling airflow path through the saw housing, the second cooling airflow path: Starting at the rear inlet opening of the housing, a gap extending from the housing rear entry opening to between the first compartment and the third side of the saw housing, extends through the gap and out into the second compartment, and The outlet port ends at the housing side.

9. The saw according to claim 8, wherein: The second cooling air flow path passes through the printed circuit board assembly and through the electric motor.

10. The saw according to claim 9, wherein: The printed circuit board assembly includes a printed circuit board and a heat sink adjacent to one side of the printed circuit board, The heat sink includes an array of protruding cooling fins, and The second cooling air flow path passes through the protruding cooling fins before passing through the printed circuit board and through the electric motor.

11. The saw according to claim 1, wherein: The saw housing is formed of a first half shell and a second half shell, the first half shell and the second half shell being connected along a parting line extending from the front end to the rear end, The housing rear inlet opening comprises two housing rear inlet openings, one of the two housing rear inlet openings being formed in the first half shell and the other of the two housing rear inlet openings being formed in the second half shell, and The housing-side outlet opening includes two housing-side outlet openings, one of which is formed in the first half-shell and the other of which is formed in the second half-shell.

12. The saw of claim 1, wherein: The printed circuit board assembly lies in a plane perpendicular to the longitudinal axis.

13. The saw of claim 1, wherein: The printed circuit board assembly includes a printed circuit board and a heat sink adjacent to one side of the printed circuit board, The saw housing includes a wall portion supporting the printed circuit board assembly, and The wall portion is configured to direct airflow to the heat sink.

14. The saw of claim 1, wherein: A blade drive assembly is disposed in the support arm, the blade drive assembly being configured to detachably connect a cutting blade to 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.

15. The saw of claim 1, comprising: A battery pack is disposed in the first compartment, the battery pack being configured to power the electric motor.

16. A saw comprising: A saw housing, the saw housing comprising: front end, a rear end opposite to the front end, a hollow support arm protruding outwardly from the front end, a main handle projecting outwardly from the rear end, and a partition wall disposed in the interior space of the saw housing, the partition wall forming a first compartment of the interior space, the first compartment being separated from a second compartment of the interior space; an electric motor disposed in the second compartment, the electric motor including an output shaft rotatable about an output shaft axis; a battery pack disposed in the first compartment, the battery pack configured to power the electric motor; a printed circuit board assembly supporting electronics configured to control operation of the saw, the printed circuit board being disposed between the battery pack and the electric motor; and a blade drive assembly disposed in the support arm, the blade drive assembly being configured to detachably connect a cutting blade to 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, in, The saw housing includes features defining a first cooling airflow path through the saw housing and a second cooling airflow path through the housing, a first cooling path passing through the first compartment before exiting the saw housing, a second cooling path passes around an outer surface of the first compartment before exiting the saw housing, and Both the first cooling path and the second cooling path pass through the electric motor before exiting the saw housing.

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