Abstract:
The present invention comprises additional embodiments in a circular saw aligning device which is not only easily releaseable but also entirely removeable from functioning engagement with either a specially made or prior art portable circular saw. An abutting assembly of the device rotates from an engaging position to a non-engaging position so the saw can be used without interference. This rotation is also the first step in removing the device entirely from the saw. The invention allows use of the circular saw when the saw blade is positioned at an acute angle with respect to the base plate. The invention also allows the user to easily and releasably lock the workpiece abutting piece out of the way.

Description:
[0001]    This application is a continuation in part of application Ser. No. 09/553,650 filed Apr. 21, 2000. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention relates to cutting aids for portable circular saws. U.S. Pat. No. 5,901,450A discloses a rip guide for a circular saw. The circular saw includes a housing including a shoe plate for supporting the circular saw on a workpiece. The circular saw also includes a motor supported by the housing and a saw blade rotatably driven by the motor about an axis. The saw blade is operable to cut the workpiece in a cutting direction. The guide comprises a support member supported on the housing; an arm supported by the support member and extending from the housing in the cutting direction; and a guide member supported by the arm so that the guide member is pivotally supported by the support member. The guide member extends from the housing in the cutting direction. The guide member includes first and second guide surfaces for selectively guiding the circular saw relative to first and second edges, respectively, of the workpiece.  
           [0003]    U.S. Pat. No. 4,777,726 discloses a guide for use with a portable circular hand held power saw in making square cuts across a board or plank. A spring biased hinged flap slidably secured beneath the base plate of the saw bears against the edge of the plank throughout the course of the cut, maintaining the perpendicular orientation of the saw relative to the work piece.  
           [0004]    U.S. Pat. No. 4,483,071 discloses a saw guide for a power-driven circular hand saw machine or jig saw machine which consists of a bar member provided with a graduation and attachable to the base plate of the machine perpendicular to the base plate and of a gauge member, which gauge member is shiftable along and fixable on the bar member by means of a sliding member.  
           [0005]    U.S. Pat. No. 4,453,312 discloses a saw aligning mechanism or assembly in the preferred structure of this disclosure is supported on a power hand saw by a support. The saw comprises a motor, a handle, a blade and a trigger switch. The assembly comprises the support, an elongated shaft and an aligning device or plate. The shaft extends longitudinally in substantially the same direction as the cutting movements of the saw and is connected to the support. The aligning plate extends substantially transversely to the shaft for butting against an object to be cut. The aligning plate is connected to the shaft by a bore which allows the aligning plate to slide and pivot on the shaft. A second form of the disclosure presents an assembly wherein the elongated shaft is slidably connected to the support.  
           [0006]    The prior art devices are notable for their need for a substantial change in the base plates of the saws to which they are to accommodate the function of aligning the saw blade to a cutting piece. There is a need for a device which is substantially simpler, thereby less expensive, and immediately and removeably attachable to prior art saws.  
         SUMMARY OF THE INVENTION  
         [0007]    The present invention comprises a circular saw aligning device which is not only easily releaseable but also entirely removeable from functioning engagement with either a specially made or prior art portable circular saw. An abutting assembly of the device rotates from an engaging position to a non-engaging position so the saw can be used without interference. This rotation is also the first step in removing the device entirely from the saw. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a side view of a generalized portion of a portable circular saw showing in broken lines an exemplary piece of workpiece wood cut in two.  
         [0009]    [0009]FIGS. 1A, 1B and  1 C are the side views of FIG. 1 with the invention device engaged with the saw and the workpiece in respectively first abutting, second part sawn and third completely sawn positions.  
         [0010]    FIGS.  2 - 5  are respectively back, bottom top and back views of an abutting piece of the invention device.  
         [0011]    [0011]FIGS. 6 and 7 are respectively top and front views of a mounting and spring resistance assembly of the invention device.  
         [0012]    FIGS.  8 - 10  show respectively top, front engaged and front disengaged views of the abutting piece and mounting and spring assembly engaged with a generalized support plate for a portable circular saw as in FIG. 1.  
         [0013]    FIGS.  11 - 13  show top views of the side views of FIGS. 1A, 1B and  1 C respectively showing only the saw blade of the circular saw and the workpiece, such that an essential part of the operation of the invention device is more easily understood.  
         [0014]    [0014]FIGS. 14 and 15 are top and front views of an alternate embodiment of the invention device with respect to mounting of the device on a saw plate edge nearest the saw blade.  
         [0015]    [0015]FIG. 15 is an exploded view of an alternate embodiment of the invention assembly, workpiece abutting piece and a rear shaft support.  
         [0016]    [0016]FIGS. 16 and 17 show perspective assembled views of the shaft support of the assembly and slider part of the workpiece abutting piece in a latched and unlatched position respectively. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]    The invention is now discussed with reference to the Figures. The item and aspect numbers of the Figures identify substantially the same item or aspect when duplicated between the Figures.  
         [0018]    [0018]FIG. 1 is a side view of a portable circular saw  100  without the drive motor to enhance the understanding of the operation and engagement of the invention device. It is well known in the art (which cited prior art is incorporated herein) that portable circular saws comprise a wide variety of motors and casings (and their engaging connections) for driving the saw blade  101 . The location, size and engagement or angling features of such saw motors to a generalized saw  100  affect the choice of location of the invention device  200 / 300  on the right side or left side of the saw plate  106 . Saw  100  comprises a blade  101  engaged to a motor at connection  105  and having an upper protector  102  and lower protector  103 , protector  103  being adapted to rotate clockwise in FIG. 1 to position  104  for advance of a workpiece (shown in broken lines slideably abutting the bottom plate  106 . A standard feature on most prior art portable circular saws are, extending from the upper edge of plate  106 , a pair of upper edge extensions  107  having slots  108 . As disclosed in the prior art above, the extensions and slots are provided to allow attachment for devices such as ripping guides.  
         [0019]    As shown in FIG. 1A, in one embodiment, the invention device  200 / 300  comprises an assembly  200  connected with a piece  300 , the two joined devices held in rigid one dimensional motion alignment with plate  105  by insertion of an extension of shaft support  204  through slots  108  and additional securement as described below. Assembly  200  comprises a shaft  203  and spring  202  releaseably having shaft  203  supportingly in its axis. Threaded shaft and nut combination  203  retains spring  202  on shaft  201  whereby the other end of spring  202  abuts a part of piece  300 , i.e., a back end of shaft slider  301 . Slider  301  comprises a hole just larger than shaft  201  such that slider  301  creates a connection to shaft  201  whereby piece  300  may rigidly be moved only in the direction of the axis of shaft  201  by pressure against a first abutting plate  303  by a workpiece  400 . This is generally accomplished by manual pushing of the circular saw by its handle in the direction  500  such that blade  101  saws workpiece  400  as in FIGS. 1B and 1C. Loop  302  is formed such that it blade  101  may pass through it, as shown in FIG. 1B wherein the lowest edge of blade  101  is effectively substantially above an inside bottom section of loop  302 . Loop  302  is adapted to either allow passage through of protector  103  such that its rotation toward the direction of location  104  is accomplished by engaging the bottom or leading edge of workpiece  400  or by engaging a back edge of loop  302  such that protector  103  is caused to rotate without engaging the workpiece, as in FIG. 1B wherein protector  103  will be rotated to location  104 ′ (as shown in broken lines).  
         [0020]    [0020]FIGS. 1A, 1B and  1 C show invention device  200 / 300  with saw  100  engaging and sawing through a workpiece  400  by moving in direction  500 . FIG. 1B shows that as piece  300  is moved directly opposite and lightly opposes motion in direction  500 , workpiece  400  is sawn through in portion  401  and whereby its bottom side causes a slight rotation of protector  103 . In that process, shaft  201  is shown as shaft portions  201 A and  201 B, portion  201 A exposed as slider  301  causes compression of spring  202  within a length of portion  201 B.  
         [0021]    [0021]FIG. 1C shows a fully sawn workpiece portion  401  in broken lines, whereby piece  300  is at a furthest compression position whereby spring  202  is substantially compressed on portion  201  B. The motion of the saw  100  and device  200 / 300  in direction  500  has caused plate  106  to slide over a top surface of workpiece  400  and caused the workpiece to engage first abutting plate  303  and a second abutting plate  304  in a manner such that for the entire series of actions in FIGS.  1 A- 1 C plates  303  and  304  are maintained substantially normal to direction  500 .  
         [0022]    FIGS.  2 - 5  disclose a preferred embodiment of the piece  300 . Plates  303  and  304  are attached to a continuous plate beginning at the formation of slider  301  about hole  301  A, extending down via portion  301 B to support  305 , which in turn connects to loop  302  and returns to substantially the level of support  305  to form support  306 , therefrom extending upward to form saw plate engagement piece  307  having a notch  316  which releaseably and slideably engages a long edge of plate  106  opposite a plate side associated with shaft  201  and spring  202 . Loop  302  forms a space  309  through which at least blade  101  may pass in the steps shown in FIGS.  1 A- 1 C.  
         [0023]    Loop  302  defines a width  311  and height  312 . Height  312  is variable depending on the construction of the several saw manufacturers or blade  101  diameters, although a typical 7 inch blade  101  will preferably have a height  312  of about two and a half inches and a width  311  of about one inch whereby the protector  103  may usually pass untouched by loop  103 . In this embodiment, loop  103  is a required rigid attachment between plates  303  and  304 , without which the invention would be ineffective. The prior art devices in this art fail to effectively and rigidly connect two leading plates  303  and  304  such that the two plates slideably abut a leading edge of a workpiece  400  in the sawing operation to force the blade  101  into a necessarily normal angle to the leading edge of the workpiece  400 . This enforced relationship allows the user to obtain a square cut across the workpiece with respect to the leading edge of the workpiece. The attachment and sliding means for loop  302  and plates  303  and  304  comprise a wide selection of such pieces and assemblies. The present specific example of such means are a particularly low cost, easily removeable and easily understood set of pieces and assemblies.  
         [0024]    FIGS.  2 - 4  show views of slider  301  wherein it has a length  315  of about 1-3 inches or more, the length of which is determined with reference to that required to maintain a rigid alignment of plates  303  and  304  as described above. The same such considerations are true for the diameter of shaft  201  and hole  301 A. The relationship of slider  301  to plate  305  is determined by piece  301  B, whereby the necessary angle and distance therefore is determined by the axis location of slider shaft  201  with respect to the bottom plate  106  of the circular saw. An alternate embodiment of the present invention will permit mounting the shaft  201  directly above a longitudinal edge portion of plate  106 , i.e., where the plate  106  comprises sufficient space on that edge portion on a right or left side such that, except for a curved portion of piece  301 B, spring  202  and shaft  201  and piece  300  will be out of the way of workpiece portions of other objects that abut or drag along that longitudinal edge. Thus, the distance  310  in FIG. 5 would be reduced for such an embodiment and piece  301 B would be curved in a C- or U-shape to reach a protectively mounted shaft  201  and spring  202 . Alternately, it may be desireable to mount shaft  201  such that it is relatively more distal to the right or left longitudinal edge of plate  106 . Where a circular saw comprises a small plate  106  relative to its motor and other necessary attachments so that protective mounting is impossible or inconvenient, the invention assembly  200  may be attached to a plate  106  such that the axis of shaft  201  lies parallel to the plane of blade  101  although at a greater distance from the longitudinal edge of plate  106  than the embodiments of the Figures. In such an embodiment, distance  310  will be greater than that shown in FIG. 5.  
         [0025]    In all such embodiments, however, it is critical that distance  313  be maintained as to the distal ends distance for plates  305  and  306 . This distance is approximately that of the width of the plate  106 , such that a support surface is created on which the bottom surface of plate  10  will slide against with ease. In a preferred embodiment, plate  306  is extended upwards to form slideable notch piece  307  with notch  316 . Notch  316  is where a longitudinal edge of plate  106  opposing the longitudinal edge near the mounting of shaft  201  is slideably secured such that that edge is urged into notch  316  by the opposing action of the mounting of piece  300  at slider  301  to shaft  201 . It has been found that although the notch  316  is shallow enough to permit easy release from engagement with that plate  106  edge and that piece  300  slides easily along that edge constantly securingly engaging it, the preferred piece  307  provides very secure engagement to that edge so that even in heavy usage plates  305  and  306  do not substantially fall away from the bottom of plate  106  and rotate about the axis of shaft  200 .  
         [0026]    Plate  304  as shown in FIGS.  2 - 5  is shown in general length ratio relationship to plate  303  of about 1.3 to 1, although that ratio may range from 2:1 to 1:5. The length of plate  303  preferably extends to about the same length as plate  305  such that the workpiece abutting surface is about as wide as the plate  106  width for that embodiment.  
         [0027]    [0027]FIGS. 6 and 7 show assembly  200  having in addition to the above described aspects an support bar  205  integral with shaft  201  support  204  with hole  204 A for securing therein shaft  201 . Bar  205  is adapted to be insertable into a shaft  201  side slot  108  and extending therefrom to the opposite side slot  108  such that the majority support and attachment of the invention device is established with respect to the circular saw. It has been found that securing bar  205  in slots  108  in combination with the slideable securement of piece  307  to a plate  106  edge and contact of plates  305  and  306  are sufficient invention device to circular saw connection to accomplish the objects of the invention. Thus, the user with a saw  100  and an embodiment of the invention device as shown in FIGS.  2 - 7  would first unscrew the nut from the shaft at portion  203  and remove the spring  202 . Second, slider  301  is inserted onto shaft  201  such that section  314  (FIG. 3) abuts shaft support  204 . Third, spring  202  is returned to shaft  201  and the nut returned to portion  203  as in FIG. 6. Fourth, bar  205  is inserted into slots  108  as in FIGS.  8 - 10  and piece  300  is rotated about shaft  201  axis as in FIG. 10 such that the plate  106  edge opposite shaft  201  is spring-wise urged into notch  316  of piece  317  and securing interfaces  206 /  108  are established for bar  205 .  
         [0028]    For saw  100 , FIGS.  8 - 10  show only plate  106  and blade  101  so that the workpiece-effective portions of the invention are more clearly indicated. FIGS.  11 - 13  eliminate the plate  106  of FIGS.  8 - 10  to show how a workpiece  400  is sawn in a top view of the invention device attached to a circular saw. Plates  303  and  304  of FIGS.  11 - 13  respectively abut leading edges  403  and  402  as in FIGS.  1 A- 1 C.  
         [0029]    It is surprising that the relatively long length of shaft  205  required for sawing through of workpiece  400  is accomplished with such minimal invention device to saw contact and support. It will be possible to accomplish the objects of the invention with alternate embodiments than those shown in FIGS.  1 - 13 . Shaft support  204  having a hole  204 A may be welded, bolted or otherwise equivalently attached to a top surface or edge of plate  106 , such that a receiving bore is established that will effectively support shaft  201  for the objects of the present invention. It is intended that shaft support  204  comprise a wide range of means and assemblies to accomplish shaft  201  support. In one embodiment therefore, shaft  201  may comprise an enlarged end distal to portion  203 , such enlarged end abutting a leading edge opening of shaft support  204  so that shaft  201  can be removed from hole  204 A and saw  100  requires only a bolt-wise removable or welded shaft support  204  on saw  100  while the rest of the invention device is easily removable. Or shaft  201  can be welded or pressure fit to shaft support  204  in welded or other connection with a top or edge of plate  106 , thereby allowing removal of spring  202  and piece  300  via slider  301 .  
         [0030]    [0030]FIGS. 14 and 15 show an alternate embodiment of the invention device. Edge  110  is established as the above described shaft edge along which is oriented shaft  201 . Thus, shaft  201  may be maintained and supported on the plate  106  longitudinal edge closest to blade  101 . Plates  303 ′ and  304 ′ are adapted to effect equivalent workpiece abutment as provided by plates  304  and  303  in a previous embodiment. The embodiment of FIGS. 14 and 15 introduces to the user&#39;s visual field near blade  101  the shaft  201  and spring  202  aspects of the invention device. Thus, the opposite edge mounting of the invention device as in FIGS.  8 - 10  will be more preferable in some cases than that of FIGS. 14 and 15.  
         [0031]    Additional Embodiments  
         [0032]    FIGS.  15 - 17  show additional embodiments of the invention. In one additional embodiment, the U-shaped space defined by the loop or inverted arch support  302  of the previous embodiments is expanded. That space is adapted so that the circular saw may accomplish a standard function of currently available circular saws, i.e., rotation of the base plate  106  of the saw along a lengthwise axis relative to the blade and saw motor to allow the blade to cut a workpiece at an angle acute to vertical. The typical circular saw, when viewed from the front, rotates the plane of the blade in a clockwise direction relative to its normal relationship with the base plate  106 . It will be clear from examination of the loop  302  of the previous embodiments that little or no such rotation is permissible with the U-shaped loop shown in FIG. 15. This additional embodiment as shown in FIG. 16 is a piece  320  with loop  322  similar in function to piece  300  of the previous embodiments although now defining an expanded space  328  by descending sides  323  and  325  and bottom connector  324 . Side  323  substantially defines about the same inside (blade side) support wall as in the previous embodiments. However, side  325  is dramatically swept up and to the left (in a front view) and connected with curved inside wall connector  324 . Space  328  is formed so that the circular saw blade rotated relative to its base plate  106  for cutting at an acute angle from vertical will easily pass through the space  328  and forward as in the previous embodiments to move in a direction of about 90 degrees relative to the leading edge of a workpiece that abuts the abutting plates  321  and  331 . It is optional to design the clearance between the bottom of the saw blade passing above the inside surface of connector  324  so that the saw blade guard  103  abuts a back side (toward the rear of the saw) of connector  324  to rotate upward and rearward to allow sufficient clearance so that the blade guard may move forward past loop  322  without interference. Latch means  326  comprise a similar function to the latch means  307 / 316  of previous embodiments.  
         [0033]    In an another additional embodiment of the present invention, FIGS.  16 - 18  show a convenient latch for the locking the invention assemblies  300  or  320  in an out of the way position when the invention device is not in use. The latch is a relatively simple additions to the previous slider  301 , now slider  329 , and to the shaft support  204 , now shaft support  221 . Support  221  comprises a rearward extension of a partial cylinder  222 , as slider  329  comprises a forward extension of a similarly dimensioned partial cylinder  330 . The action of spring  202  causes slider and shaft support to be urged together to form an interface. In the present embodiment, when piece  320  is moved out of the locked back position, the ends of partial cylinders  222  and  330  abut slidingly so that piece  320  can easily rotate about the axis of shaft  201 . This sliding abutment is shown in FIG. 18, where support  221  and slider  329  form a gap  225  when piece  320  is not locked in an out of the way position.  
         [0034]    However, when piece  320  is rotated to an out of the way position, as shown in FIG. 10 for piece  300 , spring  202  urges the top of partial cylinder  330  into gap  226  to form interface  225  and two sides of partial cylinders  222  and  330  abut to form interface  224 . This action changing the relationship of partial cylinders  222  and  330  causes piece  320  to be locked into an out of the way position. The locking mechanism can be easily disengaged by moving slider  329  in direction  327  for a short distance and rotating piece  320  in a counterclockwise position so that the locking position shown in FIG. 17 is disengaged as in FIG. 18. Thus, with little change in slider and shaft support, an effective and easily released latch is formed in the invention device.  
         [0035]    [0035]FIG. 16 shows an optional rear support  120  for shaft  201  for stabilizing shaft  201  during sawing operations. Support  120  comprises attachment means  121  to attach to the back of the base plate, extension  122  rising upward to second shaft support  123  that operates to support the rearmost part of shaft  201  when it is in the rest position. Means  121  is releaseable and moveable along the back edge of the base plate  106  to allow the user to change the alignment of the shaft with respect to the lengthwise axis of base plate  106 . This side to side adjustment is important to additional embodiments where the angle of the saw blade may be changed to a miter cut or other than 90 degrees in a forward direction relative to the leading edge of a workpiece.  
         [0036]    Another additional embodiment of the invention comprises means to cause the plane of the front faces of the abutting plates to be move a few degrees away from perpendicular of the forward direction of the saw blade in a sawing operation for out of square for trim work.  
         [0037]    Another additional embodiment of the invention comprises forming an additional shaft support on the opposite lengthwise edge of the base plate for securing of another shaft similar in dimension and operation as the shafts of the above embodiments, although the ends of the two shafts would extend rearward as to the base plate and connect in a horseshoe or U-shape. This embodiment would provide the user with greater stability in sawing operations.  
         [0038]    Another additional embodiment of the invention comprises means to make plunge-square cuts. A plate with about the same saw blade opening and dimensions as base plate  106  is attached by a hinge at a front edge to the front or leading edge of base plate  106  so that the new plate could rotate into face to face contact with the bottom side of base plate  106 . Preferably, a spring would urge the faces of the plates apart to rotate about the hinge. A typical sawing operation where this is useful is for cutting board measuring about up to 2 inches by 6 inches.  
         [0039]    The above design disclosures present the skilled person with considerable and wide ranges from which to choose appropriate obvious modifications for the above examples. However, the objects of the present invention will still be obtained by the skilled person applying such design disclosures in an appropriate manner.