Abstract:
A holder device attaches a circular saw to a T square. The device includes a body having opposite left-hand and right-hand ends and opposite forward and rearward sides that extend between the ends. A passageway formed through the body interconnects the left-hand and right-hand ends for movably receiving the longitudinal arm of the T square. A receptacle formed in one of the sides receives the base plate of the saw to interengage the body with the saw. The lateral arm of the T square is abuttably positionable against and movable against an edge of a work piece for guiding the circular saw to make a selected cut in the work piece.

Description:
RELATED APPLICATION 
   This application is a continuation in part of U.S. patent application Ser. No. 10/199,252 filed Jul. 22, 2002. 

   FIELD OF THE INVENTION 
   This invention relates to a holder device for attaching a circular saw to a carpenter&#39;s T square such that the T square is capable of conveniently guiding the saw to make a precise cut in drywall, plywood or other material. 
   BACKGROUND OF THE INVENTION 
   A circular saw is commonly used to perform “rip” cutting operations in various materials including drywall, plywood, wood paneling, etc. Using the circular saw in this manner often presents a number of difficulties. In order to form a precise rip cut with straight and accurate edges, the work piece first must be properly measured and marked. This can be a time consuming and tedious procedure. Oftentimes, the work piece is not marked accurately and, as a result, is mis-cut. Material and time are wasted. Even if the work piece is marked correctly, maintaining a straight cut while moving the saw can be difficult. 
   Rip guides have been developed to assist the cutting operation. However, these devices tend to be relatively large and unwieldy. Typically, straight edges must be assembled and clamped to each end of the work piece to be ripped. Conventional rip saw guides are inconvenient to set-up and tend to limit the rip capacity of the saw. 
   Newell, U.S. Pat. No. 5,921,161, discloses a conversion device that supports a circular saw above a work table. The conversion device is mounted to the table and the saw is supported on the device. A piece of lumber or other work piece is then slid beneath the conversion device and cut by the saw. This guide is not designed to be conveniently portable and instead is secured to the table. In addition, at least two workers are required to perform the cutting operation. One must manipulate the work piece while the other operates the saw. 
   SUMMARY OF THE INVENTION 
   It is therefore an object of the present invention to provide a compact and easy to use holder device that enables a circular saw to be quickly and conveniently attached to a T square, which can then be used by a single person to guide the saw to make a precise rip cut in a selected work piece. 
   The design of the present device arises out of the need for a compact and simple to use device that will assist a person using a circular saw in the performance of rip cutting operations. The device of the present invention, unlike other rip guides does not limit the rip capacity of the saw and does not require that straight edges be assembled and clamped to each end of the work piece. The present invention also eliminates the need to measure and mark both ends of the work piece before it is cut. 
   This invention features a holder device that attaches a circular saw to a T square for guiding the saw to make a selected cut in a work piece. The saw has a base plate and the T square has a longitudinal arm and a lateral arm attached perpendicularly thereto. The holder device includes a body having opposite left-hand and right-hand ends and opposite forward and rearward sides that extend between the ends. A passageway is formed through the body and interconnecting the left-hand and right-hand ends for movably receiving the longitudinal arm of the T square. A receptacle is formed in at least one of the forward and rearward sides for receiving the base plate of the saw to interengage the body with the saw. The lateral arm of the T square is abuttably positionable against and movable along an edge of the work piece to position the circular saw for making a selected cut in the work piece. The holder device holds the saw steady, in a straight-line cutting position while the T square guides the saw along the work piece to perform rip cuts on plywood, drywall or other sheet-like materials. 
   In a preferred embodiment, the device includes a releasable fastener for locking the body at a selected position on the longitudinal arm of the T square. The fastener may include a threaded connector that is engaged with a complementary threaded opening in the body, which opening communicates with the passageway. The threaded body is tightened in the opening to engage the longitudinal arm and fasten the body at the selected position thereon. 
   A stop may be received by and secured within the receptacle to adjust the size of the receptacle such that the base plate of the saw is snugly retained within the receptacle. The stop may be positionally adjustable within the receptacle to adjust the size of the receptacle for accommodating a corresponding saw base plate. The stop may be selectively movable toward the right-hand and left-hand ends of the body. A releasable locking component may be provided for securing the base plate within the receptacle. The locking component may include a set screw threadably interengaged with a complementary set screw opening in the body. The opening may be in communication with the receptacle and the set screw may be tightened within the set screw opening to engage the stop and retain the base plate of the circular saw within the receptacle. 

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   Other objects, features and advantages will occur from the following description of a preferred embodiment and the accompanying drawings, in which: 
     FIG. 1  is an isometric view of a preferred version of the holder device of this invention; 
     FIG. 2  is a side view of the preferred holder device; and 
     FIG. 3  is an isometric view of the holder device as mounted on a T square and positioned to receive a circular cutting saw. 
   There is shown in  FIGS. 1 and 2  a holder device  10  for attaching a circular saw to a carpenter&#39;s T square  11  in accordance with this invention. The device comprises a body  1  that is preferably composed of a molded plastic or other durable material such as metal. An elongate passageway A extends from a left-hand end of body  1  to a right-hand end of the body. Passageway A slidably receives the longitudinal arm  3  of T square  11  in the manner shown in  FIG. 3 . The longitudinal arm  3  is slidable through passageway A as indicated by doubleheaded arrows  5 . This allows the holder to be adjusted to a selected position along longitudinal arm  3 . 
   A threaded thumbscrew hole C is formed through the upper surface of body  1 . Hole C communicates with passageway A as shown in  FIGS. 1 and 2 . The thumbscrew threaded hole C is interengaged by a thumbscrew  14  as shown in  FIG. 3 . The thumbscrew is tightened sufficiently within hole C to lockably engage T square  11 . This locks the holder in a selected position along longitudinal arm  3  of the T square  11 . 
   Body  1  further includes elongate forward and rearward sides that interconnect the left-hand and right-hand ends. An elongate receptacle B is formed in the rearward side of body  1 . Receptacle B may have a length of approximately 7″ such that it is capable of snugly receiving the 7″ base plate of a standard circular saw. 
   In  FIGS. 1–3 , receptacle B is shown further accommodating a removable saw stop E. This is typically a plastic or metal element that is selectively received within receptacle B so that the length of the receptacle may be adjusted. For example, stop E may have a length of approximately 2″ so that, with the stop inserted, the receptacle B has an opening that is effectively about 5″ long. This allows the holder to accommodate the 5″ base plate of a smaller standard saw. Stop E is fixed in place by a set screw  15 ,  FIG. 2 , that is threadably interengaged with a corresponding hole D formed through body  1  and in communication with receptacle B. 
   It should be noted that the effective length of receptacle B may be adjusted in several other ways. In particular, set screw  15 ,  FIG. 2 , may be loosened and stop E adjusted within the receptacle to further decrease the length of the receptacle for even smaller base plates. In still other embodiments, the receptacle may extend fully from the left-hand end to the right-hand end of body  1 . In such cases, the stop may be moved in either a left-hand or right-hand direction, as required, to respectively decrease or increase the size of receptacle B. This allows for all different sizes of circular saw base plates to be received within the receptacle B of the holder. As a result, various sizes of saws may be connected to device  10 . 
   After holder  10  is locked into position on the longitudinal arm  3  of T square  11 , the front edge of any standard circular saw base plate  17  can be inserted into receptacle B. If required, stop E is then introduced into the receptacle and adjusted as required and locked to retain the base plate snugly within the receptacle. 
   In operation, a sheet of plywood, drywall or other flat work piece is placed horizontally on sawhorses or a work table. A standard piece of plywood, for example, has a width of 4′. The desired cutting measurement or cut line is marked on the respective ends of the sheet. 
   Next, holder  10  is attached to the T square  11  and saw S. Specifically, longitudinal arm  3  of T square  11  is slid through passageway A as shown in  FIG. 3 . The bottom surface of holder  10  and the bottom surface of T square  11  are laid generally flat upon the marked end of the work piece. The front lip of the base plate of saw S is then inserted into receptacle B as depicted by arrow  19  in  FIG. 3 . If necessary, the stop E is installed, adjusted and locked as previously described so that base plate  17  is snugly retained within the receptacle. The saw is then adjusted laterally left or right, as needed, along arm  3 . Holder  10  slides along longitudinal arm  3  of T square  11  until the saw blade is located over the cutting mark formed on the work piece. The user then tightens thumbscrew  14 . This locks the holder and the attached saw laterally in position relative to the work piece. The holder and saw are prevented from moving further along arm  3 . The worker then uses his free hand to maintain the lateral edge guide  12  of T square  11  firmly against the edge  24  of the work piece  26  to be ripped. The user pushes the saw forwardly as indicated by arrow  28 . Lateral edge guide  12  is moved along the edge  24  of the work piece  26 . The base plate  17  of the saw is held snugly in the receptacle so that the saw blade forms a precise, consistent and straight cut for the entire length of the work piece being ripped. A single worker quickly performs the cut. Time, material and manpower are saved. 
   The present invention establishes certain advantages and prompts speed and productivity in repetitive cutting operations by omitting the need to use a straight edge and clamps to mark the work piece in sheet material rip-cut operations. The device also eliminates the need to measure and mark both ends of the material to be ripped. The user no longer needs to re-measure identical size cuts on additional material, as long as he does not move the position of the saw on the longitudinal arm of the T square. The saw is held automatically and consistently to cut accurately along the desired line. Because the device is attached to the T square, it leaves the saw unencumbered to perform other cutting operations when needed, without the need to remove or reattach a device to the saw. The saw is simply and quickly disengaged from the receptacle of the holder. It is much easier to disengage the saw from holder  10  than from conventional ripsaw guides. 
   Lateral adjustment of the device is easily achieved by simply loosening thumbscrew  14 . Saw S remains mounted in receptacle B and the saw is moved laterally from left to right or vice versa so that the saw blade can be re-set and aligned with an appropriate cutting mark. The thumbscrew is then retightened and the next guided cutting operation is performed. In each case, as the saw is pushed forwardly, the lateral arm of the T square remains flushly engaged with edge  24  of work piece  26 . This maintains a straight and effective rip-cutting operation. A single user can effectively perform repeated cuts in a quick and accurate manner. Multiple workers are not required to operate the saw and move the work piece. 
   It should be noted that in alternative embodiments, various other features may be employed. For example, the passageway or slot that receives the longitudinal arm of the T square may have different configurations. In particular, the passageway may be exposed either through the upper or lower surface of the body. In such cases, the passageway may comprise a pair of inwardly turned lips that frictionally engage or grip respective sides of the longitudinal arm of the T square. The holder may be slid along the longitudinal arm of the T square and the holder may be frictionally held at a selected position along the longitudinal arm. Preferably, however, a thumbscrew or other positive form of fastening is utilized so that the holder is effectively locked in place at a selected position along the longitudinal arm. 
   From the foregoing it may be seen that the apparatus of this invention provides for a holder device for attaching a circular saw to a carpenter&#39;s T square such that the T square is capable of conveniently and accurately guiding the saw to make a precise straight cut in drywall, paneling or other material. While this detailed description has set forth particularly preferred embodiments of the apparatus of this invention, numerous modifications and variations of the structure of this invention, all within the scope of the invention, will readily occur to those skilled in the art. Accordingly, it is understood that this description is illustrative only of the principles of the invention and is not limitative thereof. 
   Although specific features of the invention are shown in some of the drawings and not others, this is for convenience only, as each feature may be combined with any and all of the other features in accordance with this invention. 
   Other embodiments will occur to those skilled in the art and are within the following claims.