Patent Publication Number: US-6698328-B1

Title: Mitre box

Description:
RELATED APPLICATION 
     This application is a continuation-in-part of pending application Ser. No. 10/038,430 filed Jan. 7, 2002. 
    
    
     BACKGROUND 
     The present invention relates to a mitre box and more particularly to an adjustable mitre box. 
     Adjustable mitre boxes have been in use for a number of years. They comprise a pivoted saw holder which is angularly movable relative to an upstanding side wall. By rotating the saw holder to different angles relative to the side wall, cuts of different angles may be made in a piece of wood. It has been found that existing adjustable mitre boxes are complicated to use and complicated and expensive to manufacture and maintain. 
     OBJECTS 
     The present invention overcomes these drawbacks and has for one of its objects the provision of an improved adjustable mitre box which is simple to use. 
     Another object of the present invention is the provision of an improved mitre box which is simple and inexpensive to manufacture and maintain. 
     Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice 
    
    
     DRAWINGS 
     A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings forming a part of the specification wherein: 
     FIG. 1 is a perspective view of an adjustable mitre box made in accordance with the present invention. 
     FIG. 2 is a top plan view thereof 
     FIG. 3 is a sectional view taken along line  3 — 3  of FIG.  2 . 
     FIG. 4 is a sectional view taken along line  4 — 4  of FIG.  2 . 
     FIG. 5 is a sectional view taken along line  5 — 5  of FIG.  4 . 
     FIG. 6 is a sectional view taken along line  6 — 6  of FIG.  4 . 
     FIG. 7 is a sectional view taken along line  7 — 7  of FIG.  2 . 
    
    
     DESCRIPTION 
     Referring to the drawings, the adjustable mitre box  1  of the present invention comprises an upstanding side wall  2  and a base  3  extending therefrom. A piece of wood W (FIG. 2) to be cut is placed against side wall  2  and is in position to be cut. The side wall  2  has an interruption or space  11  therein. The base  3  preferably has a curved outer front edge surface  4 . However, it will be understood that the outer front edge surface  4  may be made of a different shape without departing from the invention. The top surface  6  of the base  3  has a plurality of top grooves  5  which radiate at different angles from an imaginary pivot point  7  shown in broken lines in FIG.  2 . Lock holes  8  (which will be described in greater detail herein below) are provided adjacent each top groove  5 . 
     A saw holder assembly  10  extends through and is pivotally mounted at its front in the space  11  in the side wall  2 . The saw holder assembly  10  comprises a pair of matching side plates  12  and  13  (described in greater detail hereinafter) mounted together between which a saw  15  extends for reciprocal movement therebetween. The saw  15  preferably comprises a blade  16 , an upper blade clamp  17  and a handle  18 . The saw holder assembly has a rear leg  21  and a front leg  22 . The rear leg  21  is of greater length than the front leg  21  and extends to a position slightly above and adjacent to the surface  6  of the base  3 . The front leg  22  is preferably located in the space  11  in the side wall  2  and is spaced above the surface  6  of the base  3 . The two legs  21 - 22  are connected together by a bridge  23 . 
     The rear edge  24  of the rear leg  21  and the front edge  25  of the front leg  21  has an upper notch  26  to receive the clamp  17  of the saw blade  16  and the lower portions of the legs  21 - 22  are spaced from each other at  28  to receive the saw blade  16 . The space  28  extend to the lower edges of the front and rear legs  21 - 22  and the top bridge  23  in order to permit the blade  16  to extend downwardly therethrough. The inner spaces of each plate  12 - 13  are hollow and the two plates  12 - 13  are adapted to fit together and be held together by any well known mechanism, such as screws  27  to form the saw holder assembly  10 . The inner surface of each rear and front leg  21 - 22 , respectively, has a pair of opposed rear rollers  19  and a pair of opposed front rollers  20  between which the blade  16  slide when the wood W is being cut. 
     The plate  13  has a pivot bearing  30  extending therefrom adjacent the front leg  22  through which extends a pivot rod  31  which is adjacent the imaginary pivot point  7  in the space  11 . The pivot rod  31  extends into a pivot bearing  32  which extends from the inner edge  34  of the side wall  2  into the space  11  in the side wall  2 . This permits the blade holder assembly  10  to pivot on pivot rod  31  around imaginary pivot point  7  so as to move the blade  15  over the various top grooves  5 . 
     The rear leg  21  of plate  13  is provided with a lock bearing  35  extending therefrom within which a lock rod  36  extends. The lock rod  36  is adapted to be inserted in the lock holes  8  in the base  5  in order to lock the blade holding assembly  10  in place at a predetermined angular position over a top groove  5 . The lock hole  8  is spaced from the center of its adjacent top groove  5  a distance which is equal to the spacing between the rod  36  and the saw blade  16  mounted in the blade holder assembly  10 . Hence, when the lock rod  36  is inserted into the lock hole  8  the user is assured that the saw blade  16  will overly the desired top groove  5 . 
     When it is desired to operate the adjustable mitre box of the present invention, the blade holder assembly  10  is pivotally moved around pivot rod  31  to the desired angle overlying a top groove  5 . When the desired angular position is reached, the lock rod  36  is moved down and inserted into the lock hole  8  adjacent that particular top groove  5 . In this position, the saw  15  is reciprocated back and forth to cut the wood W at a particular angle. When it is desired to change the angle of the cut, it is merely necessary to lift the lock rod  36  out of the lock hole  8 , swing the blade holder  10  to the desired angle over another top groove  5  and to reinsert the lock rod  36  into the new lock hole  8  adjacent to that particular top groove  5 . 
     In order for wood W of different thicknesses to be held in place while being cut, spaced holding blocks  40  are slidably mounted for movement along spaced grooves  41  on the surface  6  of the base  3 . Each holding block is independently movable along a groove  41  in the base  3 . Each groove  41  has a channel  42  therebeneath with overhanging top ledges  43 . A locking bolt  44  extends through one of the openings  45  (four shown in the drawings) in each of the blocks  40  with the bolt head  46  extending below the surface  6  of the base  5  and into the channel  42  and slidably held within the channel  42  by the overhanging ledges  43 . The other (upper) end  47  of the bolt  44  extends above the top of each holding block  40  and can be locked in position by a threaded member  46 , such as wingnut. In addition to being independently movable along grooves  41 , each holding block  40  may have a plurality of openings  45  (four shown in drawing) which permits the holding block  40  to be independently adjustable relative to the wood W. With this arrangement, it is possible to cut a piece of wood which is of one thickness at one end and another thickness at the other. 
     As many and varied modifications of the subject matter of this invention will become apparent to those skilled in the art from the detailed description given hereinabove, it will be understood that the present invention is limited only as provided in the claims appended hereto.