Abstract:
A saw guide for hand-held power saws may be adjusted for cutting of wooden I-beams at various angles to the length of the I-beam. A first member abuts one flange, and a second member abuts the other flange, of the I-beam. The second member includes an elongated horizontal surface for support of the saw, and an elongated vertical guide surface for guiding the saw in a straight line to create the straight cut. The second member is pivotable in a horizontal plane and lockable relative to the first member to set and lock the position of the guide surface relative to the first member and the I-beam. The second member preferably includes an adjustable stop that is moveable and lockable to various positions on the second member to place the stop against the inner surface of the second flange no matter at what the angle of second member is set. By securing the saw guide with a friction fit “inside” the web and flanges, rather than outside the flanges or around the flanges, the saw guide securely and non-rotatably installed and, yet, is easily removed for subsequent use and repeated use on many I-beams.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This invention relates generally to saw guides for portable power saws. More specifically, this invention relates to saw guides for making angled cuts of wooden I-beams, such as are desired for roof and other corner structures.  
           [0003]    2. Related Art  
           [0004]    Wooden I-beams have become popular as construction materials. Typically, however, wooden I-beams are difficult to cut with a portable saw on the job site. This is because the I-beam has a center panel of plywood, called a “web,” bordered on both panel edges by two laminated-wood bars, called “cords” or “flanges,” that have a thickness typically 3-5 times the thickness of the web. When cutting across a wooden I-beam, the thickness difference between the two edge flanges and the central web makes it difficult for the carpenter to continue sawing on a straight line. The difficulty exists whether the cuts being made are perpendicular to the length, or at an angle to the length, of the I-beam.  
           [0005]    Several saw guides have been designed for cutting beams. Downard et al. (U.S. Pat. No. 5,787,782, August 1998) illustrates a beam-cutting saw guide preferably free of moving parts and comprising, in effect, saw support surfaces, saw guide surfaces and bracing surfaces that are all fixed relative to each other in a given saw guide. Downard et al. discloses that, while the portrayed saw guide is designed for perpendicular cuts across the I-beam exactly normal to the longitudinal axis of the I-beam, other saw guide embodiments may have the support surfaces, guide surfaces, and brace surfaces oriented to result in cuts across the I-beam at angles other than 90°.  
           [0006]    DeFelice et al. (U.S. Pat. No. 5,983,767, November 1999) describes a saw guiding device that is a generally right-triangular piece with various holes along its hypotenuse. One corner end of one edge of the device rests against the outside surface of one of the flanges of the I-beam. A movable workpiece-edge engaging peg is fixable in the various holes and rests against the same outside surface of the flange at a distance from the one corner end, so as to set the angle of the hypotenuse relative to the I-beam (FIG. 8 of DeFelice et al.). The DeFelice et al. device has little structure for securing the device relative to the I-beam, but rather rests on top of the I-beam and abuts against the outer surface of one flange.  
           [0007]    Ekker (U.S. Pat. No. 5,509,338, April 1996) discloses a saw guide with a first assembly that clamps onto one flange of an I-beam and includes an integral arm that extends out over the center of the web of the I-beam. Pivotally connected to the integral arm near the center of the I-beam, by means of a single wing-nut, is a second assembly the pivots to various angles relative to the I-beam. The first assembly clamping system abuts against and grips both the outer and inner surfaces of the one cord. The second assembly comprises a face plate (saw guide surface) that spans the cords of the I-beam, but has only a short saw support with a length only about ⅓ the length of the face place and therefore only about ⅓ as long as the width of the I-beam. The second assembly, therefore, contacts the top surfaces of the cords and the web top surface but not the inner or outer surfaces of the cords.  
           [0008]    Sadler (U.S. Pat. No. 1,535,042, April, 1925) discloses a handsaw guide that is intended for angle-cuts of planks and boards. A first assembly of the Sadler device has a portion with a handle that abuts against a first outer edge surface of the plank and has a clamping bar the extends entirely across the plank and turns down at the outer end to form a clamping jaw that engages over the opposite outer edge surface of the plank opposite from the portion with the handle. A second assembly of this Sadler device is pivotally connected to the first assembly near the first outer edge surface. The second assembly extends over the plank but does not attach to the plank.  
           [0009]    Still, there is a need for a secure and safe saw guide for accurate and precise angle-cutting of I-beams. There is a need for a light-weight saw guide that can be adjusted for angle-cutting, as well as perpendicular cutting. There is a need for a saw guide that may be very securely and safely installed on an I-beam, and, yet, that is economical to manufacture and simple to use. There is a need for a saw guide that fully supports a saw across the entire cut, for increased safety and accuracy.  
         SUMMARY OF THE INVENTION  
         [0010]    The present invention comprises a saw guide for use in cutting I-beams at a variety of angles relative to the longitudinal axis of the I-beam. The saw guide comprises a first member that rests against the inside of a flange, but preferably does not clamp to the flange. A second member of the saw guide serves as a saw support/guide. The second member pivots relative to the first member and has a member that rests against the inside of the opposite flange. With minimal structure, complexity, and moving parts, this design allows very secure placement of the saw guide on the web and in-between the flanges, in such a way that the invented saw guide does not tend to pivot, slide, or shift during use. Preferably, the invented saw guide is adjusted to fully and rigidly extend the entire distance between the inner surfaces of the two I-beam flanges, so there is no room for movement or rotation of the saw guide on the web during use. This secure installation, and the adjustability of the saw guide for various angles of cutting and various sizes of I-beams, are critical for safety and accuracy.  
           [0011]    Preferably, the invented saw guide first member rests on the top surface of the web, and includes an abutment surface for contacting the inner surface of one flange, the “first flange,” but preferably does not clamp onto or attach to the flange. The first member preferably has an area adapted in size and orientation for acting as a handle, so that the user may him/her-self grasp the handle area of the saw guide at the same time and with the same hand that he/her grasps the first flange, thus further securing the saw guide relative to the I-beam and giving the user a further sense of security and orientation for accurate and safe cutting.  
           [0012]    The saw guide second member pivotally connects to the first member, and extends entirely across the I-beam to rest on the top surfaces of both flanges no matter at what angle the second member is set relative to the first member, and, therefore, relative to the longitudinal axis of the I-beam. A linearly-adjustable stop member on the second member is movable and fixable at various locations along the length of the second member, preferably parallel to the saw guide surface of the second member, to abut against the inner surface of the second flange. Both the saw support surface and saw guide surface of the second member are substantially the same length, to provide elongated surfaces without any interruption across a distance greater than the entire width of the I-beam. The second member is supported by the flanges near the outer ends of the support surface, and is supported by the first member for a substantial distance along its central region, that is, underneath the second member about half way across the I-beam. Further, the stop member is preferably designed to extend all the way from the second member to contact the web surface, and is preferably a non-slick material for frictional gripping contact with the web surface and the second flange inner surface. These several supports, plus the second member being built to be strong and rigid, help prevent the second member from substantial bending or sagging into the web area. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a top view of one embodiment of the invented saw guide, positioned on an I-beam and adjusted for cutting across the I-beam at about 60 degrees to the longitudinal axis of the I-beam.  
         [0014]    [0014]FIG. 2 is a top view of the saw guide of FIG. 1, adjusted for cutting across the I-beam at 90 degrees to the longitudinal axis of the I-beam.  
         [0015]    [0015]FIG. 3 is a bottom view of the saw guide of FIGS. 1 and 2, removed from the I-beam.  
         [0016]    [0016]FIG. 4 is an end view of the saw guide of FIGS.  1 - 3 , in place on an I-beam as viewed from the lines  4 - 4  in FIG. 2.  
         [0017]    [0017]FIG. 5 is an end view of the saw guide of FIGS.  1 - 4 , in place on an I-beam as viewed from the lines  5 - 5  in FIG. 2.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0018]    Referring to the Figures, there is shown one, but not the only, embodiment of the invented saw guide for angle-cutting of I-beams. The saw guide  10  comprises a first member  12  and second member  14 , pivot system  16  that allows the second member  14  to pivot relative to the first member  12  to adjust the angle of the second member  14  to the first member  12 , one or preferably a plurality of locks  18  to fix the chosen angle of second member to first member, and an adjustable stop system  20 . As may be seen in the drawings, the preferred saw guide is made with many cut-outs or molded interior spaces to make the saw guide light weight and easy and economical to manufacture, and easy to handle.  
         [0019]    The saw guide  10  sets on an I-beam  22  contacting the web  24  and the opposing two flanges  26 , 28 . The bottom surface  32  of the first member  12  preferably rests flat on the web, that is, on web top surface  34 . The bottom surface  36  of the second member  14  preferably rests on the top surfaces  27 ,  29  of the flanges  26 ,  28 . Also, preferably, the bottom surface  38  of the snubber  21  also rests on the web top surface  34 . Due to tolerances of manufacture of I-beams, however, when the second member rests on the flanges, the first member and the snubber may not rest on and contact the web in all cases, and this still produces an effective and operable cooperation between the invented saw guide  10  and the I-beam.  
         [0020]    First member  12  edge surface  42  rests against and abuts the inner surface  44  of the first flange  26 . While it is preferred than this edge surface  42  is about ½-⅔ the width of the I-beam so that it extends quite a distance along the first flange, it may be various lengths as long as it fulfills the goal of being a hand grip member sufficient in length to assist the user to hold the saw guide firmly on the I-beam. The length of the edge surface  42 , along with the stop system  20  discussed below, aids in anchoring the saw guide for safe use. The first member  12  preferably also comprises a ledge  46  that extends a part of the way across the top surface  27  of the first flange  26 . Thus, the edge surface  42  and the bottom  48  of the ledge  46  form about a 90 degree corner  47  that receives the top inner corner  49  of the first flange. Near the outer end  50  of the first member  12  is located finger aperture  52  or recess that receives the user&#39;s fingers, typically of his/her left hand in the orientation of FIG. 1. The palm of the user&#39;s hand extends across the top surface of the first member near the outer end  50  and the user&#39;s thumb and thenar eminence portion of the hand rest/grip the outer surface  54  of flange  26 . Thus, the portion of the first member  12  nearest the first flange  26  forms handle  60  and is sized to have a width for an average hand. Gripping the handle tends to force the first portion  12  against the inner surface  44  of the flange toward the user. The inventors have found that this handle, along with the other safety features discussed below, are an efficient way of anchoring the saw guide  10  on/in the I-beam without the need for any clamp, fastener, or other means for attaching the saw guide to the I-beam. As further discussed below, the saw guide  10  rests on the I-beam, and presses outward on both the flanges, but is not clamped, attached, bolted or pegged to the I-beam.  
         [0021]    The first member  12  is preferably a generally flat plate shape, with the first member  12  being about the same thickness at its outer end  50  as near inner end  70 . An exception to this is preferably the handle top surface  61 , which is slightly raised relative to the rest of the first member top surface  63 , so that it can extend out across the flange and be contoured or grooved to give a secure and comfortable grip.  
         [0022]    On the top surface  63  of the first member  12  near the inner end  70  rests the central region  80  of the second member  14 . The second member  14  is generally a flat plate shape, parallel to first member  12 . At pivot point  82 , the first member  12  and second member  14  are rotatably/pivotally connected, that is, the second member  14  rotates around the axis at point  82  that extends normal to the planes of the first member and second member. The pivot point  82  may be of various designs of rotating axis, including a simple pin axis without bearings. Two locks  18  extend up from the first member  12 , pass through apertures  86  in the second member, and connect to wing nuts  88  or other tighteners. By tightening the wing nuts  88 , force is applied on the top of the second member to compress the second member central region  80  between the wing nuts  88  and the first member and, hence, lock the two members relative to each other. Having two independent locks  18 , preferably at 180 degrees from each other around the pivot point  82  or a plurality of more than two locks otherwise spaced apart, serves to more tightly and reliably lock the second member  14  relative to the first member  12  in a particular orientation (angle).  
         [0023]    The outer edge  90  of the second member  14  runs along the length of the second member and is an elongated support member  91  with an upper support surface  92  for supporting the saw during cutting so that the saw is supported slightly above the plane of the top surfaces  27 , 29  of the flanges, and not interfered with by the differences of thickness of the web and the flanges. The support member  91  and its support surface  92  both have a length that is greater than the width of the I-beam, preferably about 1.5 times the width of the I-beam, but this will vary depending on the I-beam being cut. Preferably, the support member  91  and support surface  92  are long enough to span all across the I-beam even at cutting angles corresponding to the greatest pitch angles, for example, a 14-12 pitch or a 16-12 pitch. Thus, the support member rests firmly and predictably on the top surfaces  27 ,  29  of the flanges and the support surface extends all the way across the I-beam, for safe and accurate cutting, no matter at what angle the second member is set relative to the first member and I-beam length. It may be noticed that the bottom surface  93  of the support member and the (top) support surface  92  are substantially parallel, flat and planar along their entire lengths all the along the length of the second member. This way, the second member and the saw are supported flat and parallel to the top surface  34  of the web and the top surfaces  27 ,  29  of the flanges. Also, this way, there are no protrusions downward from the second member that interfere with the unlocked second member being pivoted/rotated to any of many angles relative to the I-beam length, except the movable stop system that is purposely moved out of the way for adjustment of the second member angle and then locked in place against the second flange. Also, the second member  14  and the support member  91  are rigid and strong enough to minimize the bowing or sagging of the support member on the I-beam during cutting from the force and weight of the saw. At a minimum, however, the support member is strong and rigid enough so that any sagging on the I-beam (which is more likely the wider the I-beam and the greater the pitch angle) does not permanently bend and bow the support member, but, rather, the support member spring back to its original shape after the saw is removed from it.  
         [0024]    Adjacent to the support surface  92  and preferably spaced in from the extremity edge  87  about 1.5 inches (which is preferred for the conventional worm-drive saw used by many professional carpenters), elongated guide surface  94  extends up perpendicular to the support surface  92  to be perpendicular to the web top surface  34  and flange top surfaces  27 ,  29 . Thus, it may be said that, when the I-beam if placed horizontally on a surface, and the saw guide  10  is installed horizontally on the I-beam, the support surface  92  is also horizontal, and the guide surface  94  extends vertically up from the support surface. The support surface  92  serves to keep the saw in a horizontal plane. The guide surface  93  serves to keep the saw on a straight line during cutting of the I-beam, which causes the cut across the I-beam to be parallel to the guide surface, and, hence, at the same angle relative to the longitudinal axis of the I-beam and lengths of the flanges. Thus, it may be seen, that, by locking the second member  14  relative to the first member  12 , one is actually choosing the angle of the guide surface  93  to the first member edge surface  42 . Because the edge surface  42  abuts against the flange  26 , the guide surface  93  is therefore set at that chosen angle relative to the flange. The central region  80  of the second member preferably has indicia  95  on both the first member and second member that indicate the chosen angle in degrees, so that a reproducible, accurate angle may be chosen. The angle of the guide surface, therefore, is perpendicular to the top surfaces of the web and flanges of the I-beam, and at an angle relative to the length of the I-beam. By running the saw along the guide surface and the support surface, the saw is controlled in a straight line in a horizontal plane for accurate and safe cutting.  
         [0025]    In some embodiments, the extremity edge is adapted so that it may be shaved off to an exact fit for the user&#39;s particular saw, at the time of the user&#39;s first cut with that saw guide, by the saw itself doing the shaving during the first cut of the I-beam. This way, a user tends to use the same saw guide with the same saw, and that saw guide has a support surface properly sized for that saw, that is, with the extremity edge being spaced accurately from the guide surface  94  to match that particular saw&#39;s dimensions.  
         [0026]    Preferably, a stop system  20  is used to create an abutment member that presses out against the inner surface  97  of flange  28 , adapting the saw guide  10  to “press” out against the inner surfaces of the both flanges for secure and non-rotational use. The stop system is preferably a linearly-adjustable member, for example, a snubber member  21  that may be moved and locked in place at various locations along the length of the support member, in effect, providing a “leg” that preferably both extends down to the web and presses out against the inner surface  97 . The snubber pressing out against the inner surface  97 , or, preferably at a minimum being very closely adjacent to the inner surface  97 , prevents rotation of the saw guide in its entirety or the second member (if loosened accidently), by the force of the saw moving and cutting from end  99  to end  99 ′ and pressing against the guide surface  94 . The force of the saw would tend to rotate the second member counter-clockwise in FIG. 1 relative to the pivot point  82 , and, hence, the snubber  21  forms an effective bumper/stop against such counter-clockwise movement. Also, abutment of the first member edge surface  42  stops counter-clockwise movement of the locked saw guide. It should be noted that the user will stand, in effect, at the bottom of FIG. 1, and, with his/her right hand, will move the saw toward the top of the FIG. 1, pushing it along the support member. Any need for a left-handed version of saw guide  10  may easily be met and explained by manufacturing a mirror image of the drawn saw guide  10 .  
         [0027]    The stop system  20  may be designed to be a snubber unit that is lockable by a wing-nut, round nut or triangular nut, for example, and that is slidable in an elongated slot  101 , or otherwise slidable along a path parallel to the length of the saw support member. The lower portion of the snubber  21  is preferably a rigid or non-compressible material, and may be a non-compressible material with a surface that tends to grip the wooden I-beam, so that the snubber  21  grips the inner surface  97  and preferably the web top surface  34 , preferably without any significant compression of the snubber material. This preferred structure provides a secure and stable placement of the invented tool on the I-beam without slippage and shifting relative to the I-beam. For example, Delrin™ acetal resin or other plastics, synthetic materials, or even natural materials may be used for the snubber lower portion.  
         [0028]    Preferably, the snubber is cylindrical and is pushed as far as possible with normal strength against the flange  28 , so that the saw guide fits fairly tightly in between the flanges. The snubber  21  preferably is not significantly compressible, so that the force of cutting the I-beam does not compress the snubber and shift the saw guide. Optionally, but not preferably, the stop system  20  may include a cam design to more forcefully press the snubber out against the inner surface.  
         [0029]    The invented saw guide in designed for adjustment to a wide range of angels, for example all the way from 30 degrees relative to the first flange  26  continuously to 90 degrees relative to the first flange  26 . The indicia  95  may be designed to indicate degree of angle and/or pitch, as may be preferred by carpenters. For example, the proper angle for cuts to produce roof pitches of 4 feet, 6 feet, 8 feet, etc., in 12 feet of roof width may be indicated in the indicia  95 .  
         [0030]    Once the invented saw guide  10  is locked in a desired angle, the saw guide may be used over and over again for cutting that angle, without further adjustment. Because the saw guide may be lifted off the I-beam without loosening the locks  18 , the angle need not be changed until a different angle is desired. The snubber stop system  20  may be loosened prior to removal from the I-beam and then re-locked in proper position when the saw guide is replaced on another I-beam. More likely, the saw guide  10  may be moved or pivoted enough on the I-beam, once the user&#39;s hand releases handle  60 , to lift the saw guide  10  off the I-beam without loosening the stop system and then replaced, without readjusting the stop system or the pivot, on an I-beam of the same dimensions for a cut of the same angle.  
         [0031]    The invented saw guide features simple, accurate, and efficient means for cutting I-beams at angles or even transverse to the length of the I-beam. The invented saw guide does not require clamps or moving parts except for the pivotal connection between the first member and the second member, and, preferably, also the stop system. The invented saw guide preferably does not extend around the flanges to clamp to, grip, or otherwise contact the outer surfaces  54 ,  103  of the flanges. The saw guide works, instead, by being installed tightly inside the flanges with frictional engagement with the web surface and the flange inner surfaces, and by resting also on the top surfaces of the flanges. One may see that the invented saw guide design may be easily scaled up or down to fit various sizes of I-beams, and that one size may be used on a variety of widths of I-beams because the snubber is adjustable to fit the width of the particular I-beam at any particular chosen cut angle.  
         [0032]    The invented saw guide is preferably made of injection-molded ABS (Acrylonitrile Butradiene Styrene), but may be of other preferably durable, strong, and rigid materials.  
         [0033]    Although this invention has been described above with reference to particular means, materials and embodiments, it is to be understood that the invention is not limited to these disclosed particulars, but extends instead to all equivalents within the scope of the following claims.