Abstract:
Portable saw includes a housing and a continuous saw blade provided in the housing. A throat in housing is shaped and sized for exposing a portion of a continuous saw blade so saw blade contacts and cuts an object brought into contact with the saw blade, in use. A power unit detachably attached to housing includes a drive for driving the saw blade. A side handle is provided on housing, and an end handle is detachably attached to the housing. The housing, saw blade, power unit, and handle are sized so user can carry and use the portable saw. Housing includes two halves detachably attached to each other so the user can take them off and replace them with a different housing having different handles and a different throat to provide a different throat having a different size and shape than the throat of the removed housing.

Description:
FIELD OF THE INVENTION 
     The invention relates to a saw. More specifically, the invention relates to a portable saw. Even more particularly, the invention relates to a portable band saw. 
     BACKGROUND OF THE INVENTION 
     Portable saws, such as hand saws and power saws, including so-called chainsaws are known. 
     Stationary saws, including so-called table saws, are known. Table saws are often termed band saws when they have a saw blade which is a continuous or endless toothed saw blade. Table saws also exist that have a saw blade which is a straight saw blade segment which is reciprocated. 
     There is a need for a portable saw which incorporates the benefits of a band saw with a continuous saw blade and a portable saw. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     An object of the invention is to overcome the drawbacks of the prior art. 
     Another object of the invention is to provide a portable saw which includes the advantages of portability as well as a continuous band saw blade. 
     A further object of the invention is to provide a portable saw which may be used by both left handed and right handed users. 
     A further object of the invention is to provide a portable saw having a portable power unit, such as an electric motor or an internal combustion (IC) engine. 
     A still further object of the invention is to provide a portable saw which may be used at various angles. 
     Yet another object of the invention is to provide a portable saw which includes variable throat widths, so as to accommodate objects of various sizes to be cut by the saw blade. 
     Another object of the invention is to provide a portable saw with parts which can be detached and relocated on the saw to accommodate different users, as well as to be readily changed to suit different uses by the same user. 
     Another object of the invention is to provide a portable saw in which components are readily interchangeable between different housings and models, such as changing a motor or a handle or both to suit a user&#39;s preference, such as left handed and right handed users. 
     Another object of the invention is to provide a portable saw in which two housings are provided, one housing including a cutting area at an end of the housing away from the motor, and another housing having an opening or throat in which the cutting blade is exposed and which is on a side adjacent the motor on the portable saw, so that the user may readily switch between a first throat and a second larger throat to accommodate larger pieces of material to be cut. 
     It is a further object of the invention to provide a portable saw having a housing which can be easily changed so as to provide for switching between a relatively long narrow throat and a relatively short wide throat depending on the needs of the user. 
     It is a further object of the invention to provide a portable band saw including a continuous cutting blade that has a powered drive wheel for the cutting blade and two unpowered guide wheels which are spaced apart from each other so as to form a triangle defined by the driven wheel and the two spaced apart guide wheels, the triangular configuration being selected so that by using the three wheels in a fixed position relative to each other, the open cutting area or throat can be readily changed from a first width and depth to a second width and depth, so as to increase the versatility of the portable band saw. 
     In sum, the invention includes a portable saw including a housing having a first face and a second face, and a continuous saw blade provided substantially inside the housing. A throat is provided in the housing, the throat being configured and sized for exposing a portion of the continuous saw blade so that the saw blade can contact and cut an object brought into contact with the saw blade. There is a power unit provided on the first face of housing, the power unit is detachably attached to the first face, and the power unit includes a drive for driving the continuous saw blade in a first direction for cutting an object brought into contact with the continuous saw blade. Also, a first guide and a second guide are provided for guiding the continuous saw blade, and the second guide is spaced apart from the first guide. A side handle is provided on the housing at a distance from the power unit, the side handle being configured for being held by a user at a desired angle. An end handle is provided on the first face of the housing adjacent the power unit, and the end handle is detachably attached to the housing. The housing, the continuous saw blade, the power unit, and the handle are sized and configured so that a user may support, carry, and use the portable saw for cutting an object brought into contact with the continuous saw blade. 
     The invention further includes a portable saw in which the housing includes a top housing and a bottom housing, and the bottom housing is detachably attached to the top housing. 
     The invention further includes a portable saw in which the drive, the first guide, the second guide, and the continuous saw blade are configured to remain in place relative to each other when the top housing is detachably attached. 
     The invention further includes a portable saw in which a further housing is provided, the further housing having a side handle provided on the housing on a left side at a distance from the power unit, and the further housing having a further throat provided on the further housing, the further throat having a different configuration than the configuration of the throat provided on the housing. 
     The invention further includes a portable saw in which the further throat is provided on the right side of the further housing. 
     The invention further includes a portable saw in which the first guide, the second guide, and the drive are spaced apart from each other and define a triangle, and a first distance between the first guide and the second guide differs from a second distance between the first guide and the drive. 
     The invention further includes a portable saw in which the throat provided in the housing is provided between the first guide and the second guide. 
     The invention further includes a portable saw in which the throat provided in the housing is provided between the first guide and the drive. 
     Relative terms such as left, right, up, and down are for convenience only and are not intended to be limiting. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top perspective view of a preferred embodiment of a portable saw according to the invention; 
         FIG. 2  is a schematic side view of a depth gauge according to the invention; 
         FIG. 3  is a partially broken away top plan view of the preferred embodiment of  FIG. 1 ; 
         FIG. 4  is a top perspective view of a further preferred embodiment of the portable saw according to the invention; 
         FIG. 5  is a top plan view of the embodiment of  FIG. 4 ; and 
         FIG. 6  is a perspective view of the further preferred embodiment of  FIG. 4  according to the invention, in use cutting a branch of a tree. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1-3  illustrate a portable power saw  10  according to a preferred embodiment of the invention. 
     As shown, portable power saw  10  may include a housing  20 , and housing  20  may include a top face  22  provided on an upper half  24  of housing  20 . A lower half  26  of housing  20  may likewise be provided according to the invention. 
     It is contemplated that upper half  24  and lower half  26  of housing  20  may be detachably attached together so that they may be readily removed by a user. Conveniently, one or more fasteners  28 , such as the illustrated bolts  28 , may be provided at various locations so that a user may readily take apart and secure upper and lower housings  24  and  26  together. Further benefits of detachably attached upper and lower housing halves  24  and  26  will be explained in greater detail below. 
     Portable saw  10  may likewise include a portable power supply  18 , such as am electric motor  18  as shown. Power supply  18  may likewise be an internal combustion (IC) engine, which may be a gasoline powered engine for example. 
     A driven blade  14  having teeth  34  may be provided and powered by motor  18 . An opening or throat  30  may be provided in housing  20  so as to expose a portion of blade  14 . As will be readily appreciated, exposed portion of blade  14  is the region in which an object to be cut by teeth  34  will be located when the user is cutting. Throat  30  may be long and narrow as shown in particular in  FIGS. 1 and 2  so as to accommodate elongated objects and objects from which relatively long portions are to be cut, for example a piece of plywood, conduit, or wood, such as a so-called two-by-four. 
     In order to drive blade  14 , a drive wheel  46  and driven or guide wheels or guide pulleys  42  and  44  may be provided around which blade  14  is guided. Drive wheel  46  may be driven by a shaft  52  of motor  18 . In the case of an electric motor, the speed, as well as the direction of rotation of drive wheel  46  may be readily varied or reversed by use of conventional gearing and controls which are not visible in the drawings. 
     One or more handles, such as a right handle  62 , a left handle  64 , and an end or rear handle  66  may be provided. Handle  62  and  64 , which may be termed side handles  62  and  64 , may be defined by removed portions of housing  20  as will be readily understood by a person having ordinary skill in the art. End handle  66  may be termed a rear handle as it is at the end of housing  20  away from throat  30  which is the working end of saw  10 . Rear handle  66  may have a partially rectangular construction, as shown, or may be a curved handle, as will be appreciated. End handle  66  and motor  18  may be provided on a base  80  which is detachably attached by one or more fasteners, such as a number of bolts  82 ,  84 , and  86 . 
     Advantages of the detachability of end handle  66  and motor  18  will be explained in greater detail immediately below. 
     A moved position of handle  66  is designated as moved handle  98  represented by broken lines in  FIG. 1 . Handle  66  and motor  18  shown on upper face  22  are moved to moved position  98  of the handle when the user prefers having handle  66  on the lower face of saw  10 . In order to achieve the moved position  98 , the user loosens and removes bolts  82 ,  84 , and  86 , removes base  80  along with end handle  66 , and moves motor  18  together with them to the opposite face of housing  20 . At that time bolts  82 ,  84 , and  86 , are reinserted into housing  20 , tightened, and moved position  98  has been achieved as will be readily understood. 
     A depth or width gauge  100  may be provided on saw  10 . Depth or width gauge  100  is adjustably displaceable in the direction of double-headed arrow  106  thanks to the provision of one or more fasteners  104 ,  108 , such as the illustrated wing nuts. Throat  30  defined by housing  20  may include a face  110 . A distance between face  110  and depth gauge  100  may be termed a depth or width  118  provided between face  110  and a side of depth gauge  100  facing face  110 . As will be appreciated, in the case where a user is cutting a piece of material, such as a piece of plywood which has a width smaller than width  118  as shown, the user may loosen wing nuts  104  and  108  to sufficiently release the engagement between gauge  100  and the remainder of saw  10  so that gauge  100  may be moved toward face  110 . When the desired width is reached, such as a width substantially the same as the piece of material to be cut, then the user may fix gauge  100  in place by turning wing nuts  104  and  108  in the direction to tighten the engagement between gauge  100  and the remainder of saw  10 ; e.g., the engagement between gauge  100  and housing  20 , for example. 
     Further, a depth or length gauge  130  may be provided for varying the depth or length of cutting region or throat  30 . Depth gauge  130  may be provide with a wing nut  134  and a bolt  138 , as shown more particularly in  FIG. 2 , for detachably securing depth gauge  130  to the remainder of portable saw  10 , such as to upper face  22 , as shown, and to the lower face of housing  20 . In the case where a portion of a piece of plywood, for example, is to be cut off the remainder of the piece of plywood, the user may release the engagement between depth gauge  130  and housing  20  by loosening wing nut  134  relative to bolt  138  having a bolt head  142  so that depth gauge  130  may be moved back and forth in the direction of a double-headed arrow  190 , as shown. 
     Conveniently, distance indicators, such as English measurements  132  or metric measurements  133  may be provided. Thus, if a user wanted to cut off a two inch piece of plywood, the user could release the engagement between depth gauge  130 , and then slide depth gauge  130  toward a front end  160  of saw  10  until the markings  132  corresponding to two inches was reached. Then, the user would secure depth gauge  130  in place and the user would know that a two inch piece could be cut off by engaging a free end of the object to be cut and then actuating motor  18  for rotating blade  14  and pushing rotating blade  14  against the piece of plywood being cut for cutting off a two inch portion of the plywood without further measurement, as will be readily understood. 
     An end opposite front end  160  of saw  10  may be termed a rear or motor end  170  of housing  20 . Rear end  170  is substantially at the opposite end of saw  10  from working or front end  160 . 
       FIG. 4  illustrates a further preferred embodiment of a saw  300  according to the invention. 
     Saw  300  may be provided in that form from the manufacturer; that is, with a housing  320  having a top half  324  and a bottom half  326  of housing  320 . Housing  320  is configured for providing a throat or mouth  330  which governs the width and depth or width and length of a portion of an object to be cut by blade  14  of saw  300  in use. Although the drawings are not to scale, it will be readily seen that mouth  330  is adjacent to motor  18  and handle  66  in this embodiment, as opposed to the location of throat  30  of the preferred embodiment of  FIGS. 1-3 . Even though the illustrated Figs. are not to scale, in the case where housing  320  of saw  300  has substantially the same length (i.e. substantially the same distance between front end  160  and rear end  170  of saw  10  of  FIG. 1  and substantially the same length of the respective distances on saw  300  of the  FIG. 4  embodiment, it will be appreciated that mouth  330  may be sized and configured for cutting up larger portions of an object to be cut when saw  300  is used. 
     As shown, it is contemplated that the user may remove housing  20 , that is, upper half  24  of housing  20  by removing each of bolts  28 , setting aside upper housing  24 , and then removing the upper half  324  of housing  320 . Idler wheels  42 ,  44 , and drive wheel  46 , as well as blade  14  are then moved from housing  20  to housing  320 , upper half  324  is put in place on lower housing  326 , and reattached using bolts  28 . In that manner, the user has completely changed the configuration of the portable saw according to the invention. That is, the user has readily converted saw  10  having left and right handles  62  and  64  and end handle  66 , respectively, to saw  300  of the embodiment of  FIG. 4  having a left handle  328  and an end handle  66 , as well as throat  330  with a different configuration from throat  30  of the preferred embodiment of  FIG. 1 . As the housing  20  is detachably attached, and replaceable with further housing  320 , such may be termed a portable saw kit. 
     It must be emphasized that applicant has provided that drive wheel  46  and guide or idler wheels  42  and  44  along with blade  14  are designed to fit exactly within housing  320 . In that manner, an object of the invention to provide a portable power saw which is readily converted for different users, different uses, left handed users, right handed users, and the like has been achieved. 
     A width gauge  340  may be provided on saw  300 . Width gauge  340  may be adjustably attached to housing  320  by provision of releasably attached fasteners or other securing elements, such as one or more wing nuts  346 ,  348 . Conveniently, a slot  354  may be provided in housing  320  along which releasable securing elements  346  and  348  may slide when released from engagement. In that manner, width gauge  340  may be moved toward and away from handle  66  for adjusting a width  344  of throat  330 , as will be readily appreciated. As shown in  FIG. 4 , width  344  may be set so that an object to be cut may be cut at a width  344  as governed by the width gauge  340 , as will be readily understood. 
       FIG. 5  is a top plan view of saw  300  of  FIG. 4  in which width gauge  340  has been removed for clarity and for use when no width gauge is desired or required. 
     For example, as shown in  FIG. 6 , no width gauge  340  is required when portable saw  300  is in use in the field, such as for cutting a branch  380  on a tree  384 . 
     As shown, the user, whose hands are schematically illustrated, has actuated motor  18  and is driving blade  14  so that teeth  34  are cutting into branch  380 . The user is shown undercutting branch  380  by pulling saw  330  toward himself or herself. This is a conventional way to cut off a branch by first cutting into branch  380  from below so that after a portion of branch  380  has been cut on a lower face thereof, the user then moves saw  300  and cuts branch  380  from above. Depending on the user preference, or the situation, the user can either turn off motor  18  to stop blade  14  from moving, and then rotate the saw and move to a different position for cutting the remainder of branch  380  from the side or from above. If desired, the user could stop the saw, and then detach motor  18  and handle  66  from housing  330 , as described above in connection with the embodiment of  FIGS. 1-3  and then secure base  80 , motor  18 , and handle  66  on bottom half  326  of housing  320 . Then, the user could turn on motor  18 , and then pull saw  330  toward himself and cut the branch  380  from the side or above. 
     It is contemplated that the electric motor may be a 110V/220V motor, with or without a rechargeable battery, or a gasoline or diesel engine. The electric motor may likewise be a rechargeable 18V or 24V motor. The throat width may have any desired size, and may be provided in various sizes such as 2 inch, 3 inch, 6 inch, 12.5 inch, and/or 17 inch, for example. 
     It is contemplated that the housing may be made of metal, or of various plastic materials such as polyethylene, composite materials, and other fiber glass reinforced plastics (FRPs). 
     It is further contemplated that one or more of the driven and tensioning or guide wheels may be made of metal, or preferably may be made of synthetic materials to reduce weight. The wheels may likewise be made of one or more composite materials. The handle adjacent the motor may likewise be made of synthetic materials, including composite materials. 
     While this invention has been described as having a preferred design, it is understood that it is capable of further modifications, and uses and/or adaptations of the invention and following in general the principle of the invention and including such departures from the present disclosure as come within the known or customary practice in the art to which the invention pertains, and as may be applied to the central features hereinbefore set forth, and fall within the scope of the invention.