Abstract:
For a power saw, a dust-capturing device composed of two sides shields with one side shield having an exhaust duct adapted to be attached to a hose of an external vacuum and a rear panel to aid in capturing and containing dust generated by the saw&#39;s use; and the other side shield having a top and rear beveled portion disposed toward the saw to aid in capturing and containing dust generated by the saw&#39;s use. The side shields may be of a one-piece or two-piece construction and are adapted to be securely attached to a saw at or near the upper blade guard of the saw. Capturing dust with only one side shield is effective; but, use of both side shields increases the effectiveness. The attachment mechanism to attach the device to the saw may be stationary or adjustable to accommodate any adjustments necessary for varying depths of cuts.

Description:
BACKGROUND OF THE INVENTION 
     This present invention relates to an improvement in a device for capturing and displacing debris generated when using a power tool, and more particularly to a power circular saw of any size. 
     Power tools are the mainstay of most construction, maintenance, and repair projects; whether done commercially or by a handyman (as used herein, the term ‘handyman’ or ‘handymen’ is meant to encompass both genders and does not relate only to the male). When using a power saw, in particular, a portable power circular saw with exposed rotating blade, as the blade cuts the material upon which it is operating, the cut portions of the material are displaced therefrom in tiny particles which, for administrative clarity for this application will be referred to as dust. The rotation of the saw blade can be extremely fast, the teeth of the saw blade can be extremely hard and sharp, the dust created by cutting materials with this saw can be dense, can create an unsafe environment, and can create an unhealthy environment for the worker using the saw. The dust, if left uncaptured or undercaptured, can permeate and contaminate the workplace. The workplace may be a food processing facility, may be a health care facility, may have dust-sensitive equipment (such as a computer or delicate scientific or medical instruments), may be a home. Various governmental regulatory agencies mandate some forms of dust control under many, if not all, commercial situations. 
     The worker using the circular saw also is at risk, not only from using a potentially dangerous tool but also from inhaling the dust. On-lookers, passers-by, employees of the facility at which work is being performed also will inhale the dust generated by the saw. Attempts to curtail the amount of dust cast into the work space include use of a water spray in conjunction with the cutting [generally used when cutting into concrete for example]. Using a water spray, however, presents another potential hazard in conjunction with electrical power tools—that of electric shock hazards. Another attempt to curtail the amount of dust projected into the work space is the use of a bag attached, at a strategic location, to the power tool into which the dust, by rotational action, reciprocating action, or centrifugal action, is forced into the bag and collected thereat. Though useful to capture some dust, in reality, most dust generated by circular saws is not captured and is emitted into the work place nonetheless to contaminate the work place and breathable air. This has not proven to be as effective as is necessary and desirable. Moreover, dust collection bags are better suited for stationary saws, not portable saws. Stationary saws generally are larger than portable saws, heavier than portable saws, and because of these factors, a dust collection bag can be fitted onto the stationary saw and it can be expected to remain where fitted. Portable saws are not well suited for such bags. Portable saws are routinely moved about from job site to job site, and from work area to work area within a job site. By their very nature, they are moved constantly when being operated. It is the saw which is moved, not the material being cut, when a portable circular saw is being used. Such repeated movements would jostle the dust collector bag, loosen it, and ultimately displace it from the saw. As a result, portable circular saws are not well suited for such dust collectors. 
     Dust collection systems of which the inventors are aware are lacking in use of a dedicated vacuum for dust capture. Generally such systems operate off the vacuum generated by the cooling fan of the motor. This is of limited utility and only generates a slight discernable vacuum to aid in capturing or directing dust into a collection bag or other collection mechanism. Such systems also rely on the centrifugal forces generated, and imparted to the dust, by the rotation of the cutting blade. This, standing alone or in combination with the vacuum generated by the cooling fan is of limited utility in capturing dust. Use of a dedicated vacuum in conjunction with one or more side shields, as envisioned by the present invention is a remarkable and novel improvement over the prior art. 
     Another method of curtailing dust contamination is use of a respirator or face mask to filter out dust before it can be inhaled. This method, however, is suited only for the worker or workers involved in the project and not for the passers-by, on-lookers, and employees of the facility. Use of a respirator, however, increases costs associated with a project, is cumbersome, and adversely affects the mobility of the worker. As for a face mask, a good portion of the dust by-passes the face mask and is nonetheless inhaled by the worker. There is no device available which is simple to use, which is easy to manufacture, and which captures virtually all the dust emitted by a circular power saw. The present invention embodies all these features and more; all which are missing from the prior art. 
     The present invention can be made of virtually any materials including, but not limited to, metals, plastics, and composites. It can be adapted to fit on virtually any type and size of circular power saw. When installed, it will not interfere with the operation of the saw; but, in fact, will enhance the life of the saw and the blade by preventing dust from entering and contaminating the saw motor and by removing excess dust from the blade immediately after a cut is being made. It is crafted to initiate the capturing of dust at the initial point of dust creation; i.e., at the front of the saw at a point where the blade engages the material it is to cut—at that point, capture and extraction occur. The rear baffle and top and rear biased member prevent escape of dust from the top and the rear. The device can be used with an external vacuum system resulting in the ultimate capture and extraction of dust. 
     Accordingly, several objects and advantages of my invention are to: 
     a. capture virtually all dust emitted by a circular saw in operation; 
     b. enhance the useful life of a circular saw and the saw blade; 
     c. create a safer and healthier work environment for a user of a circular saw and for all others in or near the vicinity where such use is ongoing; 
     d. provide a dust capture device capable of being mounted on circular saws of virtually all shapes, sizes, and models without effecting the efficiency and effectiveness of the saw upon which the device is attached; and 
     e. provide an easy-to-install, easy-to-use, and economical dust capture device for circular power saws. 
     The foregoing has outlined some of the more pertinent objects of the present invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or by modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings. 
     BRIEF SUMMARY OF THE INVENTION 
     The above-noted problems, among others, are overcome by the present invention. Briefly stated, the present invention contemplates a dust capturing or containing device for a portable power circular saw composed of two side shields as separate components or as a single-piece unit. One side shield has an exhaust duct adapted to be attached to a hose of an external vacuum and a rear panel to aid in capturing and containing dust generated by the saw&#39;s use. The other side shield has a top and rear beveled portion disposed toward the saw to aid in capturing and containing dust generated by the saw&#39;s use. The side shields are adapted to be securely attached to a saw at or near the upper blade guard of the saw or to the foot of the saw. The attachment mechanism to attach the device to the saw may be stationary or adjustable to accommodate any adjustments necessary for varying depths of cuts. 
     The foregoing has outlined the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so the present contributions to the art may be more fully appreciated. Additional features of the present invention will be described hereinafter which form the subject of the claims. It should be appreciated by those skilled in the art that the conception and the disclosed specific embodiment may be readily utilized as a basis for modifying or designing other structures and methods for carrying out the same purposes of the present invention. It also should be realized by those skilled in the art that such equivalent constructions and methods do not depart from the spirit and scope of the inventions as set forth in the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in conjunction with the accompanying drawings in which: 
     FIG. 1 is a perspective view of the preferred embodiment of the present invention. 
     FIG. 2 is a detailed view of a second embodiment of the present invention. 
     FIG. 3 is a bottom plan view of one side of the second embodiment of the present invention. 
     FIG. 4 is a bottom plan view of a side of another side of the second embodiment of the present invention. 
     FIG. 5 is a detailed partial view of the foot section of a typical circular saw upon which the second embodiment attaches. 
     FIG. 6 is a perspective view of a third embodiment of the present invention. 
     FIG. 7 is a detailed perspective view of the third embodiment of the present invention as viewed from the rear. 
     FIG. 8 is a perspective view of two side shields. 
     FIG. 9 is a cross-section front elevation view of a fourth embodiment of the present invention. 
     FIG. 10 is a detailed view of a bracket used with the fourth embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings in detail and in particular to FIG. 1, reference characters  11  (first side shield) and  21  second side shield) generally designates a dust-capturing saw adaptor constructed in accordance with a preferred embodiment of the present invention. First side shield  11  has a retaining aperture  13 , a rear baffle or plate-like member  15  which projects outward from the first side shield  11  and toward the circular saw  40  and its blade  42 . This baffle  15  is a relatively vertical or vertically-oriented member, the blade-ward extension of which begins at or near the bottom  12  of the first side shield  11  and continues upward terminating on, over, near, or at the top  14  of the first side shield  11 . The function of the baffle  15 , when the first side shield  11  is mounted to the saw  40  is to contain or capture dust generated through the operation of the saw  40  without encroaching upon the rotating blade  42  and, thereby, the efficiency and effectiveness of the saw  40 . The first side shield  11  has an opening  16  over which an exhaust extension  17 , having an exhaust port  18 , is affixed. It is on this exhaust extension  17  that an external hose (not shown) from an external vacuum (not shown) is attached after the first side shield  11  is attached to the saw  40 . The external vacuum draws the captured dust out and into a suitable receptacle. 
     The second side shield  21  also has an aperture  23  and a beveled or biased member  26 , biasing saw-ward from the bottom  22  of the second side shield  21  to and over the top  24  of the second side shield  21 . The function of the biased member  26 , when the second side shield  21  is mounted to the saw  40 , also is to contain or capture dust generated through the operation of the saw  40  without encroaching upon the rotating blade  42  and, thereby, the efficiency and effectiveness of the saw  40 . The biased member  26  is tilted, curved, or angled toward the upper blade guard  44  of the saw  40 . 
     Without the baffle  15  and/or without the biased member  26  the air flow within the cutting area of the saw, and most of the dust generated thereby, would escape to and from the rear on the first side and to and from the rear and top on the second side. The purpose of these components (baffle  15  and biased member  26 ) is to contain the air flow and dust, direct such flow away from those openings and back and instead, toward the shield port  16  and, because of the external vacuum, out the exhaust port  18 . Use of only one side shield yields about an 85% efficiency rating in capturing dust whereas using both side shields increases that efficiency and effectiveness rating to nearly 100%. 
     Most upper blade guards  44  are immovable. To fully realize the functionality of the present invention, the biased member  26  should virtually, but need not, abut the outer side of the upper blade guard  44 . With both sides  11 ,  21  so attached, a containment area is created which captures or contains the dust for ultimate, yet immediate, vacuum removal. Virtually all portable electric circular saws have an immovable upper blade guard  44 , a movable lower blade guard  45 , and a lift lever  46  which lifts and retracts the lower blade guard  45  into and under the upper blade guard  44  but over the saw blade  42  when the saw  40  is cutting an object. A motor  50  powers the rotation of the blade  42 . The blade is held in place on the saw  40  by a suitable fastener  41 ; generally a bolt. This saw bolt  41  is, of course, on the opposite side of the motor  50 . The saw  40  illustrated in FIG. 1 shows the exposed blade  42  to be on the left side (as viewed when using the saw  40 ) and the motor  50  is on the right side. 
     For this saw, the first side shield  11  will be attached to the left side (or blade side) of this saw  40  and the second side shield  21  will be on the right side (or motor side). For saws configured with the motor and exposed blade on opposite sides, the respective shields  11 ,  21  will likewise be switched but need not be. It must also be understood that the exhaust structure  16 ,  17 ,  18  on the first side shield  11  may also be on the second side shield  21  or on both side shields  11 ,  21 . 
     The conventional saws described above also generally have a tilting or lifting mechanism  49  which, when utilized, permits the user to cause the upper blade guard  44 , along with motor  50 , lower blade guard  45 , and blade  42  to drop into a large opening  52  in the foot  47  of the saw  40 . This lowering or dropping permits the user to cut into deeper depths or thicker material. Such saws also have a front pivot mount  55  (upon which the saw  40  pivots up and down when lifted or lowered by the lifting mechanism  49 ) and, on the foot  47 , a rip-guide plate  51  and a rip guide  48 . Fasteners  53  such as screws and small bolts hold the rip-guide plate  51  onto the foot  47 . 
     Such conventional saws also have a bevel mechanism  56  which, when used, permits a user to adjust the cutting angle of the saw  40  so that the saw will cut a bevel cut. The bevel mechanism  56  is mounted to the saw  40  by fasteners  53  on and through the rip-guide plate  51  and onto the foot  47  of the saw  40 ; and by a bevel fastener (not shown) which passes through holes  43 ,  43 ′ of the pivot mount  55  and into a threaded hole  55 ′ on the bevel mechanism  56 . The saw illustrated in the figures is a Skil® saw Model 77. Similarly constructed saws include, but are not limited to Skil® saw Model 77 H and Skil® saw MAG Model. The bevel mechanism  56  for each of these named saws is fastened to the saw  40 , at the pivot mount  55  through opening  43  by a suitable bevel fastener (not shown). 
     The preferred embodiment of the present invention is best suited for the saw models, and similarly constructed models, as described above having a bevel mechanism  56  attached to the saw  40  by way of the pivot mount  55  exposing opening  43  when the bevel fastener (not shown) for the bevel mechanism is removed therefrom. When this fastener is removed, an opening  43  through the pivot mount  55 , from one side to the other side, is exposed. It is through, and with this opening  43 , that the preferred embodiment of the present invention is attachable using the elongated fastener  30  next to be described. 
     Elongated fastener  30  has a sleeve  36 , an extending threaded section  34  at one end of the sleeve  36 , and a head or collar  35  at the other end. The diameter of the extending threaded section  34  is smaller than the diameter of the sleeve  36 , and the diameter of the sleeve  36  is smaller than the diameter or width of the collar  35 . The threaded section  34  terminates at the sleeve termination point  39 . The collar  35  may be any shape round, rounded, square, square-like, rectangular, or poly-sided. As illustrated, it is hex shaped. The shape and size of the hex collar  35  on the elongated member  30  could also be the same shape and size as the nut of the fastener it replaced as this facilitates affixing the elongated member  30  to the saw  40  and minimizes the need for a variety of tools and tool sizes. The hex size on the Skil®-type saws described herein is about three-eighths of an inch to about five-eighths of an inch. The elongated fastener  30  is inserted, threaded end  34  first through the opening  43  of the pivot mount  55 . The threaded end  34  passes through an opening  43 ′ on the other side of the pivot mount  55 . As stated above, the diameter of the sleeve  36  is larger than the diameter of the threaded end  34  but it is not so large as to prevent its insertion into both openings  43 ,  43 ′. The threaded end  34  passes through both openings  43 ,  43 ′ and threads securely into the threaded hole  55 ′ of the bevel mechanism  56 . The length of the elongated fastener  30  for the model saws described above is between approximately 2.85 to 3.25 inches as measured from the collar  35  to the far end of the threaded end  34  with the threaded end section being approximately 0.70 to 1.00 inch long. The elongated member  30  is of sufficient length to pass through the pivot mount  55 , secure into the threaded hole  55 ′, and have sufficient length remaining at the threaded end  34  upon which to secure the second side shield  21  and at the collar  35  to secure the first side shield  11 . 
     After the elongated fastener  30  is inserted into opening  43 , the aperture  23  of the second side shield  21  is placed over the threaded end  34  and fastened thereat by a suitable fastener  37 , the width or diameter of which is larger than the aperture  23  over which it rests. The aperture  13  of the first side shield  11  is then aligned with the threaded aperture  33  of the elongated fastener  30 . This is followed by inserting another fastener  31  (such as, but not limited to a screw or bolt with a threaded end  32 ), adapted to secure to the threaded aperture  33 , into the threaded aperture  33 . The fastener  31  has a head end which is wider than the aperture  13  of the first side shield  11 . This fastener  31  secures the first side shield  11  into place on the types of saw  40  as described above. Although a threaded aperture  33  is illustrated, this end of the elongated fastener  30  may also have a threaded extension (not shown) over which the aperture  13  of the first side shield is placed following by insertion thereon of a suitable fastening nut or nut-like fasteners (not shown). 
     For saw models not having a similarly constructed pivot mount  55 , I have crafted a second embodiment of the present invention which is illustrated in FIGS. 2 through 4 (for the embodiment) and in FIG. 5 for the saw type foot  47  upon which this embodiment may attach. In this embodiment, each side shield  211 ,  221  has a bottom plate  217 ,  227 , respectively, whereas the previously described embodiment did not. Like the first embodiment, the first side shield  211  to this embodiment has a rear baffle or panel  215  and an opening  16  over which an exhaust extension  17 , having an exhaust port  18 , is affixed; which, after attachment of the first side shield  221  to a saw  40 , a hose from an external vacuum is attached. The second side shield  221  of this embodiment, like the first embodiment, also has a beveled or biased member  226 , biasing saw-ward from the bottom  222  and back  225  of the second side shield  221  to and over the top  224  of the second side shield  221 . The bottom plate  217 ,  227  of each side shield  211 ,  221  has slots  213  or apertures  223  which function to attach and secure each side shield  211 ,  221  to the foot  47  of the circular saw  40 . 
     Circular saws  40  with rip-guide plates  51  on the foot  47  of the saw  40  are generally affixed thereto by suitable affixing fasteners  53  such as, but not limited to, screws, nuts, and bolts. The slots  213  and apertures  223  of the bottom plates  217 ,  227  are configured to cooperate, align with the affixing fasteners  53  of the saw  40  such that, when the affixing fasteners  53  are removed, the slots  213  or apertures  223  or both align with the holes on the rip-guide plate  51  from which the affixing fasteners were removed. The respective shields are aligned therewith and either the original affixing fasteners  53  are placed through the slots  213  or apertures  223  and secured thereat; or, if the original affixing fasteners  53  are too short to be replaced because of the additional distance caused by the bottom plates  217 ,  227  in between, another set of longer cooperating fasteners are used if necessary. 
     A third embodiment of the present invention is illustrated in FIGS. 6 through 8. This embodiment does not require that its component parts align, or are matable, with parts of the saw  40  upon which attached. Each side shield (first side shield  311  and second side shield  321 ) is constructed similarly as the first embodiment; i.e., first side shield  311  having a rear baffle or panel  315  and an opening  16  over which an exhaust extension  17 , having an exhaust port  18 , is affixed (for attaching a hose from an external vacuum) and the second side shield  321  having a beveled or biased member  326 , biasing saw-ward from the bottom and back  325  of the second side shield  321  to and over the top  324  of the second side shield  321 . Each side shield  311 ,  321  may be an independent section as were the previous two embodiments (as illustrated in FIG.  8 ), or the two sections may be joined as one by a front side connector  337 . Either or both side shields  311 ,  321  may have an extension  317  with a slot  313  therein. The side shield is to be placed on the foot  47  of a saw  40  and an outline of the slot  313  is to be marked on the saw  40  (generally on the upper blade guard  44 . A hole is to be drilled into the marked area, preferably at a central location. The shield is then placed on the foot of the saw and attached to the saw by a suitable fastening member  320 . In the illustration of FIG. 6, a wing nut and cooperating threaded member are shown. Any type fastening members may be used including, but not limited to sheet metal screws. The extension  317  and slot  313  combination permit attaching the shields to virtually any model circular saw and further accommodating upward and downward adjustments for deeper cuts into or of materials. 
     The extension members may be on the sides of either or both side shields, on the fronts of either or both side shields, or, in the case of a single-piece construction of the side shield [as shown in detail in FIG.  7 ], on the front side connector  337 . 
     FIGS. 9 and 10 represent yet another embodiment of the present invention. Here the mechanism for mounting the respective side shields  11 ,  21  (i.e., side shield illustrated in FIG. 1 which do not have bottom plates  217 ,  227 ) comprises a bracket  117  which is attached to each side shield by fasteners  120  and then attached to the upper blade guard  44 . It is best to attach the brackets to the side shields first, place the side shields on the saw, using the slots  113  on the brackets  117  as guides to mark a drilling location on the upper blade guard  44 , drill one or more holes in the upper blade guard  44  through which fasteners  120  will be inserted, insert fasteners  120  through the slot  113  of the bracket  117  and secure the fastener  120  to the upper blade guard  44  through the newly drilled holes therein. Any type fastener suitable for the intended purpose, including, but not limited to nuts and bolts, sheet metal screws, and the like, may be used as fasteners  120  for the bracket  117  mounting to the side shields  11 ,  21  and to the upper blade guard  44 . 
     The present disclosure includes that contained in the present claims as well as that of the foregoing description. Although this invention has been described in its preferred forms with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and numerous changes in the details of construction and combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.