Patent Publication Number: US-11654597-B1

Title: Handheld hydraulic-powered concrete-cutting handsaw

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of United States Provisional Patent Application No. 62/834,510, filed on Apr. 16, 2019, which is incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to saws, and more particularly, to a handheld hydraulic-powered concrete-cutting handsaw which is easy to handle and operate and suitable for cutting concrete floors, walls, window openings, door openings, subs, wall corners and the like and to flush cut walls from a floor surface. 
     BACKGROUND OF THE INVENTION 
     In the construction of concrete structures such as sidewalks, walkways, parking lots and the like, it may be necessary to cut seams, grooves or other cuts in the concrete to form expansion joints or channels or other openings to facilitate insertion of walls or other structures. Concrete saws are commonly used to form cuts in set concrete. A typical concrete saw may include a saw frame on which a trigger-operated motor is mounted. A circular sawblade having multiple cutting teeth in its edge may be drivingly engaged for rotation by the motor. Upon rotation of the sawblade by the motor, the cutting teeth contact and form the cut in the concrete. 
     One or more handles may be integrally formed with the saw frame to enable an operator to hold and guide the saw during the cutting operation. A slurry guard may also be integrally formed with the saw frame to receive slurry from the concrete in operations in which the saw is used to cut freshly-poured concrete. The handles and slurry guard are often damaged during use of the handsaw. 
     Concrete saws frequently utilize sawblades having diamond-impregnated cutting teeth. The cutting teeth may be attached to the sawblade using soldering or an adhesive material, During the cutting operation, the sawblade and blade hub may become heated to the point at which the solder joint or adhesive breaks, causing the cutting teeth to break from the sawblade. Moreover, stress fractures may form in the sawblade itself, potentially compromising its cutting efficiency. Thus, concrete saws may include a water-cooling system to cool the sawblade during operation of the saw. 
     Hand-operated saws provide several advantages over other types of sawblades. For example, hand-operated saws which utilize a circular sawblade may be capable of making deeper cuts than saws which are not hand-operated. Moreover, hand-operated saws typically offer an ergonomic advantage over saws which are not hand-operated. Thus, hand-operated saws may be easier to balance, handle, guide or manipulate than other types of saws. 
     One of the drawbacks of conventional concrete saws is that the handles and slurry guard on the saw frame may not be positioned for optimal balancing and ergonomic operation of the saw. Additionally, the handles may not be optimally positioned to enable an operator to easily pull the trigger to operate the sawblade motor. 
     Accordingly, there is an established need for a handheld hydraulic-powered concrete-cutting handsaw to handle and operate and suitable for cutting concrete floors, walls, window openings, door openings, subs, wall corners and the like and to flush cut walls from the floor surface, wherein the handsaw solves at least one of the aforementioned problems. For example, there remains a need for a handheld hydraulic-powered concrete-cutting handsaw which is easy to maintain or repair in the event of failure or damage of one or more of its components. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a handheld hydraulic-powered concrete-cutting handsaw which is easy to handle and operate and suitable for cutting concrete floors, walls, window openings, door openings, subs, wall corners and the like and to flush cut walls from the floor surface. The concrete-cutting handsaw may include a base. A blade guard may be provided on the base. A hydraulic blade motor may be mounted on the blade guard. A sawblade may be drivingly engaged for rotation by the blade motor. A hydraulic control valve having a valve plunger assembly may be confluently connected to the blade motor through a motor-actuating line. A hydraulic fluid supply line and a hydraulic fluid return line may be confluently connected to the hydraulic control valve and the blade motor, respectively. A bypass line may connect the hydraulic control valve to the hydraulic fluid return line. A rear handle may be removably mounted on the blade guard. A speed control valve trigger may be pivotally mounted on the rear handle. The speed control valve trigger may have a speed control trigger bearing which actuates the valve plunger assembly of the hydraulic control valve. A front handle may be removably mounted on the blade guard and/or the base. The rear handle and the front handle may be suitably placed and configured to optimize user comfort in pulling the speed control valve trigger on the hydraulic control valve. A coolant flow control valve may be confluently connected to a coolant supply line and a coolant manifold. A pair of coolant discharge lines may be confluently connected to the coolant manifold. The coolant flow control valve, the coolant supply line, the coolant manifold and the coolant discharge lines may be positioned at the upper portion of the blade guard to optimize the positions of these components and eliminate or minimize interference with operation of the handsaw. The hydraulic control valve may adjustably divide distribution of the hydraulic fluid between the motor-actuating line and the bypass line to vary the operational speed of the blade motor responsive to depression or manipulation of the speed control valve trigger. 
     In a first implementation of the invention, a handheld hydraulic-powered concrete-cutting handsaw comprises a base, a blade guard carried by the base, a hydraulic blade motor arranged above the base, and a sawblade drivingly engaged for rotation by the blade motor. A top portion of the sawblade is covered by the blade guard and a bottom portion of the sawblade protrudes downwardly form the blade guard and the base. The handsaw further includes a rear handle arranged above the base, and a front handle arranged forward of the blade motor and above the base. A hydraulic control valve is arranged above the base. The hydraulic control valve includes a valve plunger assembly having a valve plunger, and is configured to regulate a flow of hydraulic fluid to the blade motor responsively to movement of the valve plunger. The handsaw further includes a speed control valve trigger comprising a first trigger portion and a second trigger portion. The first trigger portion is arranged adjacent to the rear handle and is configured to enable manual operation of the first trigger portion by a hand grasping the rear handle. In turn, the second trigger portion is configured to adjustably compress the valve plunger responsively to manual operation of the first trigger portion. 
     In a second aspect, the second trigger portion may be configured to adjustably push against a free end of the valve plunger responsively to manual operation of the first trigger portion. 
     In another aspect, the second trigger portion may include a rotatable bearing configured to push against and roll on the free end of the valve plunger. 
     In another aspect, the valve plunger assembly may include a compression spring biasing the valve plunger to an extended position. 
     In yet another aspect, the compression spring may be configured to exert an expansion force on a free end of the valve plunger, and the second trigger portion may be configured to adjustably push against the free end of the valve plunger. 
     In another aspect, the speed control valve trigger may be rotatable relative to the rear handle about a trigger rotation axis responsively to a torque caused by manual operation of the first trigger portion. 
     In another aspect, the trigger rotation axis may be located adjacent and slightly offset of the valve plunger. 
     In another aspect, the second trigger portion may be configured to adjustably push against a top end of the valve plunger. The trigger rotation axis may be located above and slightly offset of a central longitudinal axis of the valve plunger. 
     In yet another aspect, the first trigger portion may be elongate in shape and arranged in a spaced-apart, generally parallel relationship with the rear handle. 
     In another aspect, the first trigger portion may be arranged below the rear handle. 
     In another aspect, the handsaw may further include a coolant manifold carried by the blade guard, a coolant flow control valve in fluid communication with the coolant manifold, a coolant supply line in fluid communication with the coolant flow control valve, and two coolant discharge lines in fluid communication with the coolant manifold and configured to discharge coolant fluid at opposite sides of the sawblade. The coolant flow control valve, the coolant manifold and the coolant discharge lines may be positioned at the upper portion of the blade guard. 
     In yet another aspect, the handsaw may further include a hydraulic fluid supply line configured to supply hydraulic fluid to the hydraulic control valve, a motor-actuating line providing hydraulic fluid communication between the hydraulic control valve and the blade motor, a hydraulic fluid return line configured to discharge hydraulic fluid from the blade motor, and a bypass line providing hydraulic fluid communication between the hydraulic control valve to the hydraulic fluid return line. The hydraulic control valve may be configured to adjustably divide distribution of hydraulic fluid between the motor-actuating line and the bypass line to vary an operational speed of the blade motor responsive to manual operation of the first trigger portion of the speed control valve trigger. 
     In another aspect, the handsaw may further include a slurry guard detachably attached to the base behind the blade motor. 
     In another aspect, the slurry guard may be attached to and extend rearward from a rear end of the base. 
     In another aspect, the rear a may be removably carried by the blade guard. 
     In another aspect, the rear handle, hydraulic control valve and speed control valve trigger may be attached to one another forming a rear handle unit that is removably secured to the blade guard. 
     In another aspect, the rear handle unit may be selectively and removably securable in more than one position relative to the blade guard with a relative positioning of the rear handle, hydraulic control valve and speed control valve trigger remaining constant. 
     In yet another aspect, the front handle may be removably carried by the blade guard and/or the base. 
     These and other objects, features, and advantages of the present invention will become more readily apparent from the attached drawings and the detailed description of the preferred embodiments, which follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The preferred embodiments of the invention will hereinafter be described in conjunction with the appended drawings provided to illustrate and not to limit the invention, where like designations denote like elements; and in which: 
         FIG.  1    presents a top rear perspective view showing a handheld hydraulic-powered concrete-cutting handsaw in accordance with an illustrative embodiment of the present invention; 
         FIG.  2    presents an exploded top rear perspective view of the handheld hydraulic-powered concrete-cutting handsaw of  FIG.  1   ; 
         FIG.  3    presents a left side elevation view of the handheld hydraulic-powered concrete-cutting handsaw of  FIG.  1   ; 
         FIG.  4    presents a right side elevation view of the handheld hydraulic-powered concrete-cutting handsaw of  FIG.  1   ; and 
         FIG.  5    presents a left side elevation view of the handheld hydraulic-powered concrete-cutting handsaw of  FIG.  1   , cutting a workpiece in typical operation of the handsaw. 
     
    
    
     Like reference numerals refer to like parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     The following detailed description is merely exemplary in nature and is not intended to limit the described embodiments or the application and uses of the described embodiments. As used herein, the word “exemplary” or “illustrative” means “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” or “illustrative” is not necessarily to be construed as preferred or advantageous over other implementations. All of the implementations described below are exemplary implementations provided to enable persons skilled in the art to make or use the embodiments of the disclosure and are not intended to limit the scope of the disclosure, which is defined by the claims. For purposes of description herein, the terms “upper”, “lower”, “left”, “rear”, “right”, “front”, “vertical”, “horizontal”, and derivatives thereof shall relate to the invention as oriented in  FIG.  1   . Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. 
     Shown throughout the figures, the present invention is directed toward a handheld hydraulic-powered concrete-cutting handsaw which is easy to handle and operate and suitable for cutting concrete floors, walls, window openings, door openings, subs, wall corners and the like and to flush cut walls from the floor surface. 
     Referring initially to  FIGS.  1 - 4   , an illustrative embodiment of the handheld hydraulic-powered concrete-cutting handsaw, hereinafter handsaw, is generally indicated by reference numeral  100 . The handsaw  100  may include a base  102 . In some embodiments, the base  102  may be elongated and rectangular, as illustrated. A blade guard  104  may be provided on the base  102 , extending upward from the base  102 , as shown. The blade guard  104  may be elongated and semicircular and may extend along a longitudinal side edge of the base  102 , perpendicularly upward from the base  102 . 
     The handsaw  100  further includes a blade motor  106 , which may be mounted on the blade guard  104  according to the knowledge of those skilled in the art. The blade motor  106  is hydraulic. A hydraulic control valve  112  may be disposed in fluid communication with an inlet of the blade motor  106  through a motor-actuating line  166 . At least one hydraulic fluid supply line  108  may be disposed in fluid communication with the hydraulic control valve  112 . A hydraulic fluid pump and supply mechanism (not illustrated) may be disposed in fluid communication with the hydraulic fluid supply line  108 , as is known by those skilled in the art. A hydraulic fluid return line  110  may be disposed in fluid communication with an outlet of the blade motor  106 . The hydraulic fluid pump and supply mechanism may be disposed in fluid communication with the hydraulic fluid return line  110 . A bypass line  168  may confluently connect the hydraulic control valve  112  to the hydraulic fluid return line  110 . Accordingly, operation of the blade motor  106  may take place responsively to operation of the hydraulic fluid pump and supply mechanism as hydraulic fluid (not illustrated) typically flows through the hydraulic fluid supply line  108 , the hydraulic control valve  112 , the motor-actuating line  166 , the blade motor  106  and the hydraulic fluid return line  110 , respectively, and back to the hydraulic pump and supply mechanism. 
     The hydraulic control valve  112  may have a valve plunger assembly  113 . The valve plunger assembly  113  can include a valve plunger  114  which may be deployable at different positions in the hydraulic control valve  112  to open the hydraulic control valve  112  to various degrees and facilitate corresponding flow rates or volumes of the hydraulic fluid through the hydraulic control valve  112  to the motor-actuating line  166  and the bypass line  168 . A speed control valve trigger  116  is operable by a user to vary the speed of the handsaw  100 . More specifically, depending on the position of the speed control valve trigger  116 , the hydraulic control valve  112  may adjustably apportion or distribute the hydraulic fluid supplied via the hydraulic fluid supply line  108  between the motor-actuating line  166  and the bypass line  168  to operate the blade motor  106  at a corresponding adjustable speed. In some embodiments, the hydraulic control valve  112  may include a hydraulic pressure relief valve (not illustrated) to prevent excessive pressure of the hydraulic fluid flowing to the blade motor  106  which may otherwise cause damage to and/or failure of the blade motor  106 . A compression spring  115  can operably engage the valve plunger  114  to bias the valve plunger  114  to an extended or non-compressed state in which the valve plunger  114  does not activate the hydraulic control valve  112  and thus hydraulic fluid flow from the hydraulic fluid supply line  108  to the motor-actuating line  166  is prevented, and the fluid is instead diverted to the bypass line  168 . In the present embodiment, for instance and without limitation, the compression spring  115  is arranged radially, outward and surrounding the valve plunger  114  and is configured to bias or push the valve plunger  114  outward (e.g., vertically upward) of the hydraulic control valve  112 . 
     As illustrated in  FIGS.  3  and  4   , a sawblade  138  may be drivingly engaged for rotation by the blade motor  106 . In some embodiments, sawblade  138  may be a circular diamond-segmented sawblade known by those skilled in the art for the purpose of cutting concrete. As illustrated in  FIG.  4   , a blade hub  140  may mount the sawblade  138  on the blade motor  106 . In some embodiments, the blade hub  140  may be made of stainless steel. 
     As illustrated in  FIGS.  1  and  2   , a first or rear handle  120  may be removably mounted on the blade guard  104 . In some embodiments, a rear handle mount bracket  122  may mount the rear handle  120  on the blade guard  104 . For instance, in the present embodiment, as best shown in  FIG.  2   , the rear handle mount bracket  122  includes a generally C-shaped body formed by a first, generally flat outer plate  123   a , two transverse, parallel and spaced-apart connecting plates  123   b  extending from opposite front and rear edges of the outer plate  123   a , and two opposing end plates  123   c  extending towards one another from the connecting plates  123   b . The end plates  123   c  may be coplanar and configured to rest on a flat outer surface of the blade guard  104 , as shown. A trigger connector  123   d  may be attached to the front L-shaped arm  123   b  for purposes that will be hereinafter described. As shown, bracket mount bolts  124  may be extended through respective bolt openings  123   e  in the end plates  123   c  of the rear handle mount bracket  122  and threaded or extended through corresponding registering bolt openings  105  in the blade guard  104 . Securing nuts (not illustrated) may be threaded on the respective bracket mount bolts  124  and tightened in order to secure the end plates  123   c , and thus the rear handle mount bracket  122 , against the blade guard  104 . 
     In some embodiments, such as the present embodiment, the hydraulic control valve  112  is carried by the rear handle  120 , such as by having the hydraulic control valve  112  attached or mounted to the rear handle mount bracket  122 , as best shown in  FIG.  1   , More specifically, in the present embodiment, the outer plate  123   a  serves as a mounting area for the hydraulic control valve  112 ; for instance and without limitation, the hydraulic control valve  112  may be adhered, welded or otherwise attached to the outer plate  123   a . As best shown in  FIG.  3   , the rear handle  120  may be positioned above and to the rear of the hydraulic control valve  112 . Alternatively or additionally, the speed control valve trigger  116  may be carried by or affixed to the rear handle  120 . For example, in the present embodiment, the speed control valve trigger  116  is mounted to the trigger connector  123   d , which is in turn attached to the rear handle mount bracket  122 , such as by welding or other well-known methods of attaching or integrally-forming metallic or plastic parts. In some embodiments, the rear handle  120  may be selectively mounted in different positions within the handsaw  100 , i.e. relative to the base  102  and blade guard  104 . For instance, the blade guard  104  may include additional bolt openings  105  to the ones depicted herein, to allow a user to select to which subset of bolt openings  105  the rear handle  120  is attached. Alternatively or additionally, the bolt openings  123   e  and/or bolt openings  105  may be formed as elongated holes or slots which allow sliding and repositioning of the rear handle  120  relative to the blade guard  104  prior to tightening the bracket mount bolts  124  and corresponding nuts. In particularly advantageous embodiments, such as the present embodiment, the rear handle  120  carries both the hydraulic control valve  112  and the speed control valve trigger  116  (e.g., via the rear handle mount bracket  122 ) such that the rear handle  120 , hydraulic control valve  112  and speed control valve trigger  116  form a rear handle assembly  121  or unit that is jointly repositionable to different positions along the blade guard  104 . In being a unit, the relative positioning of all three elements (rear handle  120 , hydraulic control valve  112  and speed control valve trigger  116 ) is maintained, regardless of where on the blade guard  104  the rear handle assembly  121  is specifically and selectively attached. Such repositioning is further facilitated by having the fluid lines described herein that are connected to the hydraulic control valve  112  (i.e. hydraulic fluid supply line  108 , motor-actuating line  166  and bypass line  168 ) formed of one or more flexible materials, or otherwise flexible. 
     As described heretofore, the hydraulic control valve  112  may control the flow of hydraulic fluid through the blade motor  106  by adjustably diving the fluid fed through the fluid supply line  108  into a first flow directed to the blade motor  106  via the motor-actuating line  166  and a second flow directed to the hydraulic fluid return line  110  via the bypass line  168 . As further illustrated in  FIGS.  1  and  2   , in order to facilitate convenient user-operation of the hydraulic control valve  112 , the speed control valve trigger  116  may be pivotally mounted on the rear handle mount bracket  122 , and preferably below the rear handle  120 , as shown, such as generally or approximately parallel to and spaced apart from the rear handle  120 . The speed control valve trigger  116  is rotatable about a trigger rotation axis  117 , located above the hydraulic control valve  112 , as best shown in  FIG.  3   . As best shown in  FIG.  2   , the speed control valve trigger  116  may include a first trigger portion  116   a  and a second trigger portion  116   b  extending from opposite sides of an intermediate portion  116   c , wherein the portions  116   a ,  116   b  and  116   c  may form a single-piece unit or a unit that is jointly rotatable about the trigger rotation axis  117 . More specifically, the intermediate portion  116   c  may be rotatably connected to the trigger connector  123   d  of the rear handle mount bracket  122 , such as by a shaft (not shown), thereby defining the trigger rotation axis  117 . 
     A speed control trigger bearing  118  can be rotatably attached to or carried by the second trigger portion  116   b  and can be configured to rotate relative to the second trigger portion  116   b  about a bearing rotation axis  119  which can be parallel to the trigger rotation axis  117 . The speed control valve trigger  116  may operably engage the valve plunger assembly  113  to open and close the hydraulic control valve  112  responsive to actuation of the speed control valve trigger  116 ; more specifically, in the present embodiment, the speed control trigger bearing  118  is configured to roll upon and axially push on an outer end of the valve plunger assembly  113  (e.g., a smooth top spring-retaining end  114   a  of the valve plunger assembly  113 ) when the user operates the first trigger portion  116   a  and the first and second trigger portions  116   a ,  116   b  consequently rotate jointly about the trigger rotation axis  117 , said axial pushing of the speed control trigger bearing  118  causing the valve plunger  114  to advance into the hydraulic control valve  112  (enabling/increasing hydraulic fluid flow) and the compression spring  115  to compress. Accordingly, finger actuation of the speed control valve trigger  116  facilitates variable positioning of the valve plunger assembly  113  in the hydraulic control valve  112  and corresponding variable flow rates of the hydraulic fluid through the hydraulic control valve  112  to the blade motor  106 , and hence, variable rotational speeds of the sawblade  138 . As best shown in  FIG.  2   , the first trigger portion  116   a  being arranged beneath, spaced-apart from, and generally parallel to the rear handle  120  facilitates the user grasping the rear handle  120  from above and operating the first trigger portion  116   a  by pulling upward on the first trigger portion  116   a  with one or more fingers. Upward pulling of the first trigger portion  116   a  towards the rear handle  120  causes a downward rotation of the second trigger portion  116   b  and speed control trigger bearing  118  towards, and adjustably onto, the valve plunger  114 , to operate the hydraulic control valve  112 . Having the trigger rotation axis  117  above the valve plunger  114 , and in near vertical alignment (i.e. only slightly offset) with a central vertical axis of the valve plunger  114 , as shown, allows to minimize the size of the second trigger portion  116   b , contributing to reduce the overall weight and increase compactness of the handsaw  100 . The rear handle  120  and first trigger portion  116   a  being in turn positioned generally immediately rearward of the trigger rotation axis  117  further contributes to minimize size and weight of the speed control valve trigger  116  and thus of the handsaw  100 . 
     At least one coolant discharge line  132  may be positioned adjacent to at least one of the side surfaces of the sawblade  138 . In some embodiments, such as the present embodiment, a pair of coolant discharge lines  132  may be positioned adjacent to the respective opposite side surfaces of the sawblade  138 , as illustrated. A coolant manifold  128  may be mounted on the blade guard  104  at a fixed position, as shown, or adjustable positions. The coolant manifold  128  may be disposed in fluid communication with a coolant fluid pump and supply mechanism (not illustrated) through a coolant supply line  130 . A coolant flow control valve  134  may be provided in the coolant supply line  130 . The coolant discharge lines  132  may be disposed in fluid communication with the coolant manifold  128 . The coolant discharge lines  132  may extend initially along the upper surface of the blade guard  104  and then through respective openings (not illustrated) in the opposite sides of the blade guard  104 , discharging adjacent to the respective side surfaces of the sawblade  138 . In operation of the handsaw  100 , responsive to operation of the coolant fluid pump and supply mechanism, coolant fluid (not illustrated) may flow through the coolant supply line  130 , the coolant flow control valve  134 , and the coolant manifold  128 , and then through the respective coolant discharge lines  132 , and may be discharged from the respective coolant discharge lines  132  against the respective side surfaces of the sawblade  138  to cool the sawblade  138 . 
     In some embodiments, the coolant manifold  128 , coolant supply line  130 , coolant discharge lines  132  and coolant flow control valve  134  may be positioned at the upper portion of the blade guard  104 , as illustrated, to optimize the positions of these components and eliminate or minimize interference during operation of the handsaw  100 . 
     As shown in  FIG.  1   , a second or front handle  142  may be removably mounted on at least one of the base  102  and the blade guard  104  in front of the blade motor  106 . As illustrated in  FIGS.  1  and  2   , in some embodiments, a front handle mount bracket  144  may mount the front handle  142  to the blade guard  104 . As illustrated in  FIG.  2   , multiple bracket mount bolts  146  may be extended through respective bolt openings  148  in the front handle mount bracket  144  and extended or threaded through corresponding registering bolt openings  149  in the blade guard  104 . Securing nuts (not illustrated) may be threaded on the respective bracket mount bolts  146  and tightened against the blade guard  104 . Accordingly, the rear handle  120  and the front handle  142  may enable an operator (not illustrated) to easily guide and manipulate the handsaw  100  during cutting operations. In some embodiments, the front handle  142  may be selectively mounted in different positions within the handsaw  100 , i.e. relative to the base  102  and blade guard  104 . For instance, the blade guard  104  may include additional bolt openings  149  to the ones depicted herein, to allow a user to select to which subset of bolt openings  149  the front handle  142  is attached. Alternatively or additionally, the bolt openings  148  and/or bolt openings  149  may be formed as elongated holes or slots which allow sliding and repositioning of the front handle  142  relative to the blade guard  104  prior to tightening the bracket mount bolts  146  and corresponding nuts. 
     With continued reference to  FIG.  1   , a slurry guard  150  may be provided on the base  102 , typically on a rear end of the handsaw  100  behind the blade motor  106  and longitudinally opposite to the front handle  142 . In some embodiments, the slurry guard  150  may be removably mounted on the base  102  to allow for rapid and convenient disassembly of the slurry guard  150  when required such as for maintenance or replacement purposes. The slurry guard  150  may include a slurry guard bracket  152 . The slurry guard bracket  152  may have a bottom, slurry guard protecting wall  153 , which may be planar (as shown) or present alternative shapes, a pair of elongated, parallel, spaced-apart slurry guard sidewalls  154  extending upward from the slurry guard protecting wall  153 , and a transverse mounting wall  155  extending between the slurry guard sidewalls  154  and the slurry guard protecting wall  153  at a front end of the slurry guard bracket  152 . A slurry guard mount flange  158  may be provided on the base  102 . As illustrated in  FIGS.  1  and  2   , a pair of slurry guard mount bolts  156  may be extended through registering pairs of bolt openings  155   a ,  158   a  in the transverse mounting wall  155  of the slurry guard bracket  152  and the slurry guard mount flange  158 , respectively, and securing nuts  160  threaded on the respective slurry guard mount bolts  156  to detachably mount the slurry guard  150  on the base  102 . In some embodiments, one or both of the bolt openings  155   a  and  158   a  may be transversely elongated or slot-shaped to allow for relative transverse adjustment between the slurry guard  150  and the base  102 ; for instance, in the present embodiment, as best shown in  FIG.  2   , the bolt openings  155   a  of the transverse mounting wall  155  of the slurry guard bracket  152  are elongated or slot-shaped while the bolt openings  158   a  in the slurry guard mount flange  158  are round. 
     Referring next to  FIG.  5   , in typical application, the handsaw  100  may be operated to cut a concrete workpiece  164  in the construction of concrete structures such as such as sidewalks, walkways, parking lots and the like. Accordingly, the hydraulic fluid pump and supply mechanism (not illustrated) may be connected to the hydraulic fluid supply line  108  and the hydraulic fluid return line  110 . The coolant fluid pump and supply mechanism (not illustrated) may be connected to the coolant manifold  128  through the coolant supply line  130 . 
     An operator (not illustrated) of the handsaw  100  may grip the rear handle  120  with a rear hand and the front handle  142  with the other, front hand. As he or she actuates the speed control valve trigger  116  with a finger on the rear hand, hydraulic fluid may flow from the hydraulic fluid pump and supply mechanism (not illustrated) through the hydraulic fluid supply line  108 , hydraulic control valve  112 , motor-actuating line  166 , bypass line  168 , blade motor  106 , hydraulic fluid return line  110  and back to the hydraulic fluid pump and supply mechanism. Accordingly, the blade motor  106  may rotate the sawblade  138  as the sawblade  138  cuts the workpiece  164 . The operator may vary the operational speed of the blade motor  106  and rotational speed of the sawblade  138  by correspondingly varying the position of the speed control valve trigger  116  using his or her finger(s) as the speed control valve trigger  116  varies the position of the valve plunger assembly  113  in the hydraulic control valve  112  and the hydraulic control valve  112  apportions or distributes the hydraulic fluid between the motor-actuating line  166  and the bypass line  168 . It will be appreciated by those skilled in the art that, due to the smooth top spring retainer (not numbered), the speed control trigger bearing  118  may roll smoothly and easily along the valve plunger assembly  113 . This expedient may impart ease in pulling the speed control valve trigger  116  and smooth progression in control ling the operational speed of the blade motor  106 . 
     As it rotates in the blade guard  104  and cuts the workpiece  164 , the sawblade  138  may heat considerably due to friction. Accordingly, the coolant fluid pump and supply mechanism (not illustrated) may pump coolant fluid through the coolant supply line  130 , the coolant flow control valve  134 , the coolant manifold  128  and the coolant discharge lines  132 , respectively, and discharged against the respective side surfaces of the sawblade  138  to cool the sawblade  138 . It will be appreciated by those skilled in the art that the coolant manifold  128 , coolant supply line  130 , coolant discharge lines  132  and coolant flow control valve  134  may be positioned at the upper portion of the blade guard  104 , as illustrated, to eliminate or minimize interference with operation of the handsaw  100  and to more effectively manage the supply of coolant fluid for the sawblade  138 . 
     During operation of the handsaw  100 , the slurry guard  150  may engage and be dragged along the concrete workpiece  164  to function as a heel and steady the handsaw  100  during operation. In the event that it becomes damaged or wears out, the slurry guard  150  may be replaced typically by removing the slurry guard mount bolts  156 , removing the worn slurry guard  150  from the base  102  and fastening a replacement slurry guard  150  to the base  102  typically using the slurry guard mount bolts  156 . 
     It will be appreciated by those skilled in the art that the rear handle  120  and/or the front handle  142  may be selectively and individually replaced, as necessary, in the case of excessive wearing or damage without having to replace the entire handsaw  100 . Accordingly, the rear handle  120  may be replaced typically by unthreading the bracket mount bolts  124  ( FIG.  2   ) from the rear handle mount bracket  122 , disengaging the rear handle mount bracket  122  with the old rear handle  120  from the blade motor  106 , and fastening the rear handle mount bracket  122  of a replacement rear handle  120  to the blade motor  106  typically using the bracket mount bolts  124 . The front handle  142  may be replaced typically by unthreading the bracket mount bolts  146  from the front handle mount bracket  144 , disengaging the front handle mount bracket  144  of the old front handle  142  from the blade guard  104 , and fastening the front handle mount bracket  144  of a replacement front handle  142  to the blade guard  104  typically using the bracket mount bolts  146 . 
     Since many modifications, variations, and changes in detail can be made to the described preferred embodiments of the invention, it is intended that all matters in the foregoing description and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense. Furthermore, it is understood that any of the features presented in the embodiments may be integrated into any of the other embodiments unless explicitly stated otherwise. The scope of the invention should be determined by the appended claims and their legal equivalents.