Patent Publication Number: US-2018043566-A1

Title: Guide bar with internal cavity

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. provisional application No. 62/127,905 filed on Mar. 4, 2015, the entire contents of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     Example embodiments generally relate to hand held power equipment and, more particularly, relate to a guide bar improvements for a chainsaw. 
     BACKGROUND 
     Chainsaws are commonly used in both commercial and private settings to cut timber or perform other rigorous cutting operations. Because chainsaws are typically employed in outdoor environments, and the work they are employed to perform often inherently generates debris, chainsaws are typically relatively robust hand held machines. They can be powered by gasoline engines or electric motors (e.g., via batteries or wired connections) to turn a chain around a guide bar at relatively high speeds. The chain includes cutting teeth that engage lumber or another medium in order to cut the medium as the teeth are passed over a surface of the medium at high speed. 
     Given that the chainsaw may be employed to cut media of various types of media, it may be appreciated that different sizes and configurations of chainsaw may be desirable. However, particularly when the media to be cut is concrete, masonry, or other very hard materials, the typical chainsaw (and corresponding construction) cannot be employed. The heat generated by cutting hard media and the amount of dust and debris accumulating at the cutting components may damage components of the chainsaw. To enable such cutting, water may be provided to the cutting zone. 
     Accordingly, it may be desirable to consider water transport and delivery methods in relation to design and operation of certain chainsaws. Moreover, it may be desirable to design the guide bar to facilitate such water transport and delivery. 
     BRIEF SUMMARY OF SOME EXAMPLES 
     Some example embodiments may provide for a guide bar constructed with laminate cores that can be glued, welded or otherwise fixed together to incorporate various improvements. In some cases, the glue itself may be used to form water channels and/or nozzles to allow water to be distributed at the chain for cutting certain media (e.g., concrete). Other improvements may also be possible, and the improvements can be made completely independent of each other, or in combination with each other in any desirable configuration. Accordingly, the operability and utility of the chainsaw may be enhanced or otherwise facilitated. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
       Having thus described some example embodiments in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: 
         FIG. 1  illustrates a side view of a chainsaw according to an example embodiment; 
         FIG. 2  illustrates a perspective view of an axial end (e.g., a forward portion or nose) of the guide bar of  FIG. 1  in accordance with an example embodiment; 
         FIG. 3  illustrates an exploded perspective view of the axial end of the guide bar from the same perspective shown in  FIG. 2  in accordance with an example embodiment; 
         FIG. 4  illustrates a side view of the guide bar with one side plate removed to expose water channels formed in accordance with an example embodiment; and 
         FIG. 5  illustrates a cutaway side view of a spray nozzle in accordance with an example embodiment; 
         FIG. 6  illustrates a cutaway side view of a rinse nozzle in accordance with an example embodiment; and 
         FIG. 7  illustrates a cutaway side view of a jet nozzle in accordance with an example embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Some example embodiments now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all example embodiments are shown. Indeed, the examples described and pictured herein should not be construed as being limiting as to the scope, applicability or configuration of the present disclosure. Rather, these example embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout. Furthermore, as used herein, the term “or” is to be interpreted as a logical operator that results in true whenever one or more of its operands are true. As used herein, operable coupling should be understood to relate to direct or indirect connection that, in either case, enables functional interconnection of components that are operably coupled to each other. 
     Guide bars may be made of laminated bars that are spot welded together. When cutting concrete and/or the like, the guide bars may be configured to include water channels therein. As an example, to transport water to the cutting zone for cooling and waste transport, the water channels may be formed between the laminated bars. In some cases, the laminated bars may be formed by laser cutting or stamping. However, to form the channels and/or nozzles for water delivery, extra machining of the laminated bars may be required. Moreover, it may be difficult to employ design features such as providing specific spray patterns for the nozzles in such a context. Accordingly, example embodiments may be provided to employ plates that can be glued together (e.g., instead of being welded). Moreover, the glue can be used to form channels and control how water flows in the channels. As such, the glue can actually be used to interact with the plates and channels to create nozzles having specific desired water delivery characteristics. 
       FIG. 1  illustrates side view of a chainsaw  100  according to an example embodiment. As shown in  FIG. 1 , the chainsaw  100  may include a housing  110  inside which a power unit or motor (not shown) is housed. In some embodiments, the power unit may be either an electric motor or an internal combustion engine. Furthermore, in some embodiments, the power unit may include more than one electric motor where one such electric motor powers the working assembly of the chainsaw  100  and the other electric motor of the power unit powers a pump that lubricates the working assembly or provides momentum for moving other working fluids within the chainsaw  100 . The chainsaw  100  may further include a guide bar  120  that is attached to the housing  110  along one side thereof. A chain (not shown) may be driven around the guide bar  120  responsive to operation of the power unit in order to enable the chainsaw  100  to cut concrete or other materials. As such, the chain may be, for example, a diamond chain. The guide bar  120  and the chain may form the working assembly of the chainsaw  100 . As such, the power unit may be operably coupled to the working assembly to turn the chain around the guide bar  120 . 
     The chainsaw  100  may include a front handle  130  and a rear handle  132 . A chain brake and front hand guard  134  may be positioned forward of the front handle  130  to stop the movement of the chain  122  in the event of a kickback. In an example embodiment, the hand guard  134  may be tripped by rotating forward in response to contact with a portion of the arm (e.g., the hand/wrist) of the operator of the chainsaw  100 . In some cases, the hand guard  134  may also be tripped in response to detection of inertial measurements indicative of a kickback. 
     The rear handle  132  may include a trigger  136  to facilitate operation of the power unit when the trigger  136  is actuated. In this regard, for example, when the trigger  136  is actuated (e.g., depressed), the rotating forces generated by the power unit may be coupled to the chain either directly (e.g., for electric motors) or indirectly (e.g., for gasoline engines). The term “trigger,” as used herein, should be understood to represent any actuator that is capable of being operated by a hand or finger of the user. Thus, the trigger  136  may represent a button, switch, or other such component that can be actuated by a hand or portion thereof. 
     Some power units may employ a clutch to provide operable coupling of the power unit to a sprocket that turns the chain. In some cases (e.g., for a gasoline engine), if the trigger  136  is released, the engine may idle and application of power from the power unit to turn the chain may be stopped. In other cases (e.g., for electric motors), releasing the trigger  136  may secure operation of the power unit. The housing  110  may include a fuel tank for providing fuel to the power unit. The housing  110  may also include or at least partially define an oil reservoir, access to which may be provided to allow the operator to pour oil into the oil reservoir. The oil in the oil reservoir may be used to lubricate the chain as the chain is turned. 
     As can be appreciated from the description above, actuation of the trigger  136  may initiate movement of the chain around the guide bar  120 . A clutch cover  150  may be provided to secure the guide bar  120  to the housing  110  and cover over the clutch and corresponding components that couple the power unit to the chain (e.g., the sprocket and clutch drum). As shown in  FIG. 1 , the clutch cover  150  may be attached to the body of the chainsaw  100  (e.g., the housing  110 ) via nuts  152  that may be attached to studs that pass through a portion of the guide bar  120 . The guide bar  120  may also be secured with the tightening of the nuts  152 , and a tightness of the chain can be adjusted based on movement of the guide bar  120  and subsequent tightening of the nuts  152  when the desired chain tightness is achieved. However, other mechanisms for attachment of the clutch cover  150  and/or the guide bar  120  may be provided in other embodiments including, for example, some tightening mechanisms that may combine to tighten the chain in connection with clamping the guide bar  120 . 
     As mentioned above, the guide bar  120  may be formed from two laminated sheets that lie in parallel planes along side each other, with a laminate core provided therebetween. These laminated sheets may be made from stainless steel or other sufficiently rigid and durable materials. The outer laminated sheets may be referred to herein as a first side plate  200  and a second side plate  210 , respectively. The first and second side plates  200  and  210 , which can be seen in  FIG. 2 , may generally be spaced apart from each other be at least a certain distance, which may be substantially consistent over the lengths of the first and second side plates  200  and  210 . The laminate core  260  (see  FIG. 3 ) may define the space between the first and second side plates  200  and  210 . In some embodiments, a sprocket wheel  220  may be provided in the space between the first and second side plates  200  and  210  at a distal end, or nose of the guide bar  120 . The sprocket wheel  220  may be rotatable to interface with the cutting chain as the cutting chain turns around the axial end of the guide bar  120 . 
     Rivets  250  may be provided to fix the sprocket wheel  220  and the first and second side plates  200  and  210  together. As such, receiving holes may be formed and aligned in each of these components and the rivets  250  may pass through the aligned receiving holes to hold the entire assembly together. As the rivets  250  bind the first and second side plates  200  and  210  together, the first and second side plates  200  and  210  may bind the laminate core  260  therebetween. As mentioned above, the laminate core  260  may, in some cases, have channels  270  formed therein. The laminate core  260  may therefore have portions thereof that are etched, machined, laser cut, or are otherwise formed or provided with the channels  270  provided therein. Responsive to connection of the chainsaw  100  to an external pressurized water source (e.g., a water hose connected to a spigot), water may be ported through the channels  270  for application to the chain as the chain rotates around the guide bar  120 . 
     However, in accordance with an example embodiment, rather than spot welding the first and second side plates  200  and  210  together, a glue layer  280  may be provided on each side of the laminate core  260  to facilitate affixing the laminate core  260  and the first and second side plates  200  and  210 . The glue layer  280  may also seal against water penetration and further define the channels  270 . As such, portions of the channels  270  may be defined by a combination of the first and second side plates  200  and  210 , the laminate core  260 , and the glue layers  280 . 
       FIG. 4  illustrates a side view of the guide bar  120  with the first side plate  200  removed. The laminate core  260  and the sprocket wheel  220  are therefore exposed. The glue layer  280  between the laminate core  260  and the first side plate  200  is also exposed. As can be appreciated from  FIG. 4 , the glue layer  280  may be discontinuous at certain portions, since the channels  270  may divide the laminate core  260  into separate regions at which the glue layer  280  may be formed. It should also be appreciated that another glue layer also exists, but is not visible in  FIG. 4 , between the second side plate  220  and the laminate core  260  and the glue layer that is not visible may substantially mirror the glue layer  280  shown. 
     As mentioned above, the glue layer  280  may be used to facilitate formation of the channels  270 , and may also allow different nozzle types to be implemented without the need for complicated machining, etching or laser cutting. Thus, for example, spray nozzles, rinse nozzles and jet nozzles may be provided at desirable locations where the channels  270  terminate proximate to the chain. The glue layer  280  may therefore interface with the channels  270  at ejection ports formed to allow water to exit the channels  270  toward the chain. The ejection ports may have geometries that are formed at least in part based on the application of the glue layer  280  proximate to (and in some cases on opposing sides of) the ejection ports. The glue layer  280  can therefore tailor or at least directly impact water ejection or delivery characteristics of the ejection ports to form different nozzle types. 
     In the example of  FIG. 4 , a spray nozzle  300  is shown proximate to the heel of the guide bar  120 . The spray nozzle  300  may be effectively employed to provide cooling and debris removal proximate to the drive sprocket (not shown), which may actually turn the chain. In some cases, a rinse nozzle  310  may be formed along middle portions of the guide bar  120  (e.g., between the heel and the nose) to rinse debris out of the chain, while also providing some cooling. Meanwhile, a jet nozzle  320  may be provided proximate to the sprocket wheel  220 . The jet nozzle  320  may be formed to generate increased water pressure since this region is closest to the cutting zone. The jet nozzle  320  may therefore be important for cooling proximate to the sprocket wheel  220  and for facilitating ejection or repelling of debris from the chain and cooling of the chain at this dirtiest and hottest part of the guide bar  120 . 
       FIG. 5  illustrates a closer view of the spray nozzle  300  in accordance with an example embodiment. As shown in  FIG. 5 , water may pass through channel  270  toward the ejection port  400 . However, the glue layer  280  provided on each side of the ejection port  400  may, by virtue of the glue layer&#39;s waterproof nature, further impacts the water dispensing characteristics of the ejection port  400  to form the ejection port  400  into spray nozzle  300 . Of note, the spray nozzle  300  can be provided at the heel since glue will be less likely to leak than a welded assembly. Thus, components in the housing  110  may be less likely to see any negative impact from exposure to water, since there is likely to be less leakage, and water will instead be directed more efficiently onto the chain for cleaning and cooling. The water may also reach the chain as the chain leaves the guide bar  120  to contact the drive sprocket. At this point, the chain is more accessible or “out in the open,” so it is a good time to apply water to improve the effectiveness of both cooling and cleaning. 
       FIG. 6  illustrates a closer view of the rinse nozzle  310 , several of which may be provided along middle portions of the guide bar  120 . Again, the channel  270  may be formed to lead water toward ejection port  410 . The glue layer  280  may again be provided on each side of the ejection port  410  to further impact the water dispensing characteristics of the ejection port  410  to form the ejection port  410  into rinse nozzle  310 . 
       FIG. 7  illustrates a closer view of the jet nozzle  320  in accordance with an example embodiment. As shown in  FIG. 7 , water may pass through channel  270  toward the ejection port  420 . However, the glue layer  280  provided on each side of the ejection port  420  may further impact the water dispensing characteristics of the ejection port  420  to form the ejection port  420  into jet nozzle  320 . Of note, the jet nozzle  320  can be provided at the nose and proximate to the sprocket wheel  200  to clean and cool the chain nearest the source of heat and debris generation. 
     For at least some of the nozzles, water may pass through the channel  270  toward the corresponding ejection port, but may pass on both sides of the laminate core  260  in the nozzle area. This further gives the opportunity to spray and clean both sides of the chain. As such, for at least some nozzles, the nozzle is formed by the gap that the glue layer  280  forms between the laminate core  260  and the closest one of the side plates. Moreover, the nozzle is formed as two separate gaps on opposing sides of the laminate core  260 . Accordingly, the nozzle can be formed without any machining. 
     Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe exemplary embodiments in the context of certain exemplary combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and/or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. In cases where advantages, benefits or solutions to problems are described herein, it should be appreciated that such advantages, benefits and/or solutions may be applicable to some example embodiments, but not necessarily all example embodiments. Thus, any advantages, benefits or solutions described herein should not be thought of as being critical, required or essential to all embodiments or to that which is claimed herein. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.