Cutting saw

Abstract

A cutting saw includes a saw housing having a support arm projecting outwardly from a front end of the housing and supporting a rotatable cutting blade. 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. The saw housing includes a housing feature configured to minimize water ingress into the interior space in applications of water-cooled cutting.

Description

Background Art

[0001] A cut-off saw is a hand-held 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 by 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 certain applications, the saw may incorporate water cooling of the saw blade during operation in order to efficiently cut heavy materials. It is desirable to provide a cut-off saw having a saw housing that is configured to allow air cooling of the internal saw components while preventing the ingress of cooling water into the saw housing. 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 in communication with the interior of the housing. In addition, the housing defines a lateral air outlet opening adjacent to the motor and in communication 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 air flow through the rear air inlet opening. After passing through the interior space of the saw housing, the cooling air flow is discharged from the lateral air outlet opening.

[0004] Since the cutting saw can be used to cut heavy materials, the saw can be combined with water cooling of the saw blade during operation. For this reason, the saw housing includes a housing feature that is configured to inhibit or minimize the entry of liquid into the interior space of the saw housing via the inlet and outlet openings that allow air cooling of the saw. The housing feature that inhibits the entry of liquid into the saw housing may include providing a shutter for each slot of the inlet and / or outlet opening. The housing feature that inhibits the entry of liquid into the saw housing may include a shelf protruding inwardly from the inner surface of the first side, the shelf being aligned with the opening and serving as a bottom plate that can guide the fluid to the outside of the saw. In some embodiments, the shelf is associated with an internal wall structure that serves as a rear stop to redirect the flow outward from the housing and / or as part of a tortuous path between the inlet or outlet opening and the components within the housing. In some embodiments, the housing feature includes a protective wall portion that protrudes from the inner surface of the saw housing into a recess of the saw component. For example, the motor housing may include recesses between motor mounting bosses. These recesses facilitate air flow out of the motor fan. The protective wall portion has the same shape and size as the recess, and by its position within the recess, the protective wall portion obstructs the flow of fluid into the motor.

[0005] In some aspects, a saw includes a saw housing. The saw housing includes a front end, a rear end, a first side, a second side, a third side, a fourth side, a longitudinal axis extending through the front end and the rear end, and a hollow support arm protruding outward from the front end. The rear end is opposite the front end. The first side, the second side, the third side, the fourth side, the front end, and the rear end cooperate to define an interior space of the saw housing. The rear end includes a housing rear inlet opening that allows fluid communication between the environment of the saw and the interior space. The first side includes a housing side outlet opening disposed between the rear end and the front end. The housing side outlet opening allows fluid communication between the environment of the saw and the interior space. The saw includes an electric motor disposed in the interior space, the electric motor including an output shaft, the output shaft being located in a plane parallel to the longitudinal axis and being rotatable about the output shaft axis. The saw includes a motor fan driven by the output shaft and configured to draw cooling air through the saw housing. The saw includes 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 a rotational motion of the output shaft to the cutting blade when the cutting blade is connected to the saw. Additionally, the saw includes a printed circuit board assembly supporting electronics configured to control operation of the saw, the printed circuit board assembly being disposed in the interior space. The saw housing includes housing features configured to minimize ingress of water into the interior space.

[0006] In some embodiments, the first side and the second side correspond to opposite lateral sides of the saw housing, the third side corresponds to a top of the saw housing, and the fourth side of the saw housing corresponds to a bottom of the saw housing. The saw includes a handle having a first end connected to the first side, a second end connected to the second side, and a middle portion facing the third side and spaced from the third side. The housing side outlet opening is disposed in the first side between the third side and the fourth side. The housing feature includes a shelf protruding inwardly from an inner surface of the first side, the shelf being disposed between the housing side outlet opening and the fourth side.

[0007] In some embodiments, the shelf includes a proximal end adjacent to the first side and a distal end opposite the proximal end and spaced apart from the first side, and the shell feature includes a facing wall disposed at the distal end of the shelf, the facing wall extending upward toward the third side relative to the shelf.

[0008] In some embodiments, the shelf protrudes inwardly from an inner surface of the first side relative to the first side at a shelf angle configured to facilitate flow of liquid to an exterior of the saw housing.

[0009] In some embodiments, the shelf protrudes inwardly from an inner surface of the first side at a shelf angle relative to the first side, and the shelf angle is an acute angle relative to a plane including the housing-side outlet opening.

[0010] In some embodiments, the housing-side outlet opening is disposed in the first side at a location longitudinally aligned with the motor.

[0011] In some embodiments, each of the housing rear inlet opening and the housing side outlet opening comprises an array of slots, material between the slots forming a grid configured to prevent material having a size greater than a width of the slots from entering the interior space, and

[0012] The shelves are arranged along the edges of the grille.

[0013] In some embodiments, the housing feature includes an upright wall portion facing and spaced apart from the housing outlet opening; and a shelf located below the housing outlet opening and protruding inwardly from the first side toward the upright wall portion.

[0014] In some embodiments, the housing feature includes a wall portion disposed in the interior space, the wall portion being arranged to provide a tortuous fluid path between at least one of the housing rear inlet opening and the housing side outlet opening and at least one of the motor and the printed circuit board assembly.

[0015] In some embodiments, at least a first one of the wall portions is parallel or substantially parallel to the longitudinal axis, and at least a second one of the wall portions is perpendicular to the first one of the wall portions.

[0016] In some embodiments, at least some of the wall portions are arranged to form closed channel portions.

[0017] In some embodiments, the housing feature includes a tubular baffle that forms a portion of a tortuous airflow path in the interior space.

[0018] In some embodiments, each of the shell rear inlet opening and the shell side outlet opening comprises an array of slots, material between the slots forming a grid configured to prevent material having a size greater than a width of the slots from entering the interior space.

[0019] In some embodiments, a battery pack is disposed in the interior space between the electric motor and the rear end, and the battery pack is configured to provide power to the electric motor.

[0020] In some embodiments, the motor is housed within a motor housing, and the motor housing includes: a motor housing first end; and mounting protrusions spaced around a perimeter of the motor housing first end. The mounting protrusions are configured to receive fasteners. The motor housing includes recesses formed in the motor housing first end such that one of the recesses is disposed between mounting protrusions in each pair of adjacent mounting protrusions. An output shaft of the motor protrudes from the motor housing first end. The housing feature includes a protective wall portion protruding from an inner surface of the saw housing into one of the recesses, the protective wall portion serving as a barrier to liquid flow through the recess.

[0021] In some embodiments, the protective wall portion is shaped and sized to complement the shape and size of the one of the recesses in such a manner that the motor housing and the protective wall portion cooperate to inhibit liquid from flowing into the motor via the one of the recesses.

[0022] In some embodiments, the remaining recess has no protective wall portion.

[0023] In some embodiments, the protective wall portion protrudes from a rearward surface of the support arm.

[0024] In some embodiments, the housing outlet opening is longitudinally aligned with the guard wall portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a perspective view of a first side of a chop saw.

[0026] Figure 2 is a perspective view of a second side of the chop saw.

[0027] Figure 3 is along Figure 7 A cross-sectional view of the cutting saw as seen along line 3-3.

[0028] Figure 4 is along Figure 7 A cross-sectional view of the cutting saw as seen along line 4-4.

[0029] Figure 5 is a side view of a chop saw.

[0030] Figure 6 is along Figure 7 A cross-sectional view of the cutting saw as seen along line 6-6.

[0031] Figure 7 is a rear view of the chop saw, with the dashed arrows showing the direction of air discharge.

[0032] Figure 8 is a top view of a chop saw with dashed arrows showing the direction of air discharge.

[0033] Fig. 9 is along Figure 8 A cross-sectional view of the cutting saw as seen along line 10--10.

[0034] Fig.10 yes Fig. 9 An enlarged view of the portion of the cutting saw enclosed by a dotted line.

[0035] Fig.11 is along Figure 5 A cross-sectional view of the cutting saw as seen along line 11-11.

[0036] Fig.12 It is an enlarged cross-sectional view of the shell side outlet opening.

[0037] Fig.13 is a perspective view of the motor.

[0038] Fig.14 is a perspective view of a support arm of the saw housing.

[0039] Fig.15 is a perspective view of the motor assembled with the support arm. DETAILED DESCRIPTION

[0040] refer to Figure 1-5, the cutting saw 1 is a handheld power tool configured to support and drive a cutting blade 90 for rotation. The cutting blade 90 is circular and may be a segmented blade, a grinding disc, 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 a feature that prevents or inhibits water from entering the saw housing. These and other features of the saw housing 2 will be described in detail below.

[0041] 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.

[0042] 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.

[0043] refer to Figure 6 The saw housing 2 includes a first partition wall 41 and a second partition wall 42, which are arranged in the interior space 18 and extend transversely between the housing first side 5 and the second side 6. 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] The 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.

[0048] 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.

[0049] 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.

[0050] refer to Figure 1 , Figure 2 and Figure 6-10 , 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.

[0051] 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.

[0052] 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.10 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.

[0053] refer to Figure 1 , 2 , 6 and 11-15, 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.

[0054] 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).

[0055] 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.

[0056] 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 ( 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 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 7 ), 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.

[0057] 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.

[0058] 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.

[0059] 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.11 ).

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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 6 Through arrow A T2 express.

[0066] 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 .

[0067] 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.

[0068] refer to Figure 3 , Figure 5 and Figure 8 , 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 ( Figure 8 ), 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.

[0069] 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.

[0070] 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 .

[0071] refer to Figure 3-6 , 8 and 13, 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.

[0072] 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.

[0073] 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. Figure 8 ), 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.

[0074] 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.

[0075] refer to Figure 4 and Figure 6 , 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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, a first side, a second side, a third side, a fourth side, a longitudinal axis extending through the front end and the rear end, and a hollow support arm projecting outwardly from the front end, the rear end being opposite the front end, the first side, the second side, the third side, the fourth side, the front end and the rear end cooperating to define an interior space of the saw housing, the rear end comprising a housing rear inlet opening, the housing rear inlet opening permitting fluid communication between the environment of the saw and the interior space, the first side comprising a housing side outlet opening disposed between the rear end and the front end, the housing side outlet opening permitting fluid communication between the environment of the saw and the interior space; an electric motor disposed in the interior space, the electric motor including an output shaft, the output shaft being located in a plane parallel to the longitudinal axis and being rotatable about an output shaft axis; a motor fan driven by the output shaft and configured to draw cooling air through the saw housing; 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; as well as a printed circuit board assembly supporting electronics configured to control operation of the saw, the printed circuit board assembly being disposed within the interior space; in, The saw housing includes housing features configured to minimize ingress of water into the interior space.

2. The saw according to claim 1, wherein: The first side and the second side correspond to opposite lateral sides of the saw housing, The third side corresponds to a top of the saw housing, and the fourth side of the saw housing corresponds to a bottom of the saw housing, The saw includes a handle having a first end connected to the first side, a second end connected to the second side, and a middle portion facing the third side and spaced apart from the third side, The housing-side outlet opening is arranged in the first side between the third side and the fourth side, And the housing feature includes a shelf protruding inwardly from an inner surface of the first side, the shelf being disposed between the housing side outlet opening and the fourth side.

3. The saw according to claim 2, wherein: The shelf includes a proximal end adjacent to the first side and a distal end opposite the proximal end and spaced apart from the first side, and The housing feature includes a facing wall disposed at a distal end of the shelf, the facing wall extending upward relative to the shelf toward the third side.

4. The saw according to claim 2, wherein: The shelf protrudes inwardly from an inner surface of the first side relative to the first side at a shelf angle configured to facilitate flow of liquid to an exterior of the saw housing.

5. The saw according to claim 2, wherein: The shelf protrudes inwardly from an inner surface of the first side at a shelf angle relative to the first side, and the shelf angle is an acute angle relative to a plane including the housing-side outlet opening.

6. The saw according to claim 2, wherein: The housing-side outlet opening is disposed in the first side at a location longitudinally aligned with the motor.

7. The saw according to claim 2, wherein: Each of the housing rear inlet opening and the housing side outlet opening comprises an array of slots, material between the slots forming a grid configured to prevent material having a size greater than a width of the slots from entering the interior space, and The shelves are arranged along the edges of the grille.

8. The saw according to claim 1, wherein: The housing features include: an upstanding wall portion facing and spaced apart from the housing outlet opening; and A shelf is located below the housing outlet opening and projects inwardly from the first side toward the upright wall portion.

9. The saw according to claim 1, wherein: The housing feature includes a wall portion disposed in the interior space, the wall portion arranged to provide a tortuous fluid path between at least one of the housing rear inlet opening and the housing side outlet opening and at least one of the motor and the printed circuit board assembly.

10. The saw according to claim 9, wherein: At least a first one of the wall portions is parallel or substantially parallel to the longitudinal axis, and at least a second one of the wall portions is perpendicular to the first one of the wall portions.

11. The saw according to claim 9, wherein: At least some of the wall portions are arranged to form closed channel portions.

12. The saw according to claim 9, wherein: The housing feature includes a tubular baffle that forms a portion of a tortuous airflow path in the interior space.

13. The saw of claim 1, wherein: Each of the housing rear inlet opening and the housing side outlet opening includes an array of slots, material between the slots forming a grid configured to prevent material having a size greater than a width of the slots from entering the interior space.

14. The saw of claim 1, comprising a battery pack disposed in the interior space between the electric motor and the rear end, the battery pack being configured to provide power to the electric motor.

15. The saw of claim 1, wherein: The motor is housed in a motor housing. The motor housing comprises: The first end of the motor housing, mounting bosses spaced about a perimeter of the motor housing first end, the mounting bosses being configured to receive fasteners, and forming a recess in the first end of the motor housing such that one of the recesses is disposed between mounting bosses in each pair of adjacent mounting bosses, The output shaft protrudes from the first end of the motor housing, and The housing feature includes a protective wall portion protruding from an inner surface of the saw housing into one of the recesses, the protective wall portion acting as a barrier to liquid flow through the recess.

16. The saw of claim 15, wherein: The protective wall portion is shaped and sized to complement the shape and size of the one of the recesses in such a manner that the motor housing and the protective wall portion cooperate to inhibit liquid from flowing into the motor via the one of the recesses.

17. The saw of claim 15, wherein: The remaining recesses have no protective wall portion.

18. The saw of claim 15, wherein: The guard wall portion protrudes from a rearward surface of the support arm.

19. The saw of claim 15, wherein: The housing outlet opening is longitudinally aligned with the guard wall portion.

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