Abstract:
A hack saw having a blade holding assembly and a blade lock assembly. The blade lock assembly having moveable blade lock means adapted to receive a blade therebetween, mechanism for moving the blade lock means to a position to hold a blade in place.

Description:
RELATED APPLICATION 
   This application is a continuation of U.S. patent application Ser. No. 11/268,892 filed Nov. 8, 2005 now abandoned. 

   BACKGROUND 
   The present invention relates to a hack saw and more particularly to close quarter hack saw which has a replaceable blade. 
   Close quarter hack saws have been known for a number of years. They consist of a frame or handle with a hack saw blade mounted on and extending from the front of the handle. However, some of such close quarter hacksaws may not easily be used or manipulated for effective close quarter work. In other of such close quarter hacksaws the blade may not be easily adjusted relative to the handle and/or may not be easily replaced. Some of such close quarter hack saws are expensive and complicated to manufacture and/or which are difficult to use. 
   OBJECTS 
   The present invention overcomes these difficulties and has for one of its objects the provision of an improved close quarter hack saw which may be easily used for close quarter work. 
   Another object of the present invention is the provision of an improved close quarter hack saw in which the blade may be easily removed. 
   Another object of the present invention is the provision of an improved close quarter hack saw in which the blade may be easily adjusted relative to the handle. 
   Another object of the present invention is an improved hack saw which is simple to use. 
   Another object of the present invention is an improved hack saw which is simple and inexpensive to manufacture and assemble. 
   Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to 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 showing the close quarter hack saw of the present invention. 
       FIG. 2  is an exploded perspective view of the close quarter hack saw of the present invention. 
       FIG. 3  is a sectional view taken along lines  3 - 3  of  FIG. 1 . 
       FIG. 4  is a sectional view taken along line  4 - 4  of  FIG. 1 . 
       FIG. 5  is a fragmentary side view, partly in section, showing the manner of locking the blade in place. 
       FIG. 6  is a sectional view taken along line  6 - 6  of  FIG. 5 . 
       FIG. 7  is a fragmentary side view, partly in section, showing the blade being released from its locked position. 
       FIG. 8  is a sectional view taken along line  8 - 8  of  FIG. 7 . 
   

   DESCRIPTION 
   Referring to the drawings, the close quarter hacksaw  1  of the present invention comprises a handle  2  and a frame assembly  3 . 
   The handle  2  has upper, lower and rear walls  4 ,  5  and  6 , respectively, with opposed side walls  8  and an open front  7  adapted to receive at least a portion of the frame assembly  3 . 
   The frame assembly  3  has a rear blade-receiving assembly  10 , a front blade-holding assembly  11  and an intermediate blade lock assembly  12  which are preferably made integral (one piece) with each other. The blade-receiving assembly  10  comprises upper, lower and rear walls  15 ,  16  and  17 , respectively, and is insertable in the open front  7  of the handle  2  and held in place by means of any well known fastening means (not shown) extending through openings  9  and  9 A in the handle  2  and the blade-receiving assembly  10 , respectively. A plurality of staggered (offset) partitions  18  and  19  extend between the upper and lower walls  15 - 16  of the blade holding assembly  10  on each side of its longitudinal center line to provide a passageway  20  for a blade B. 
   The front blade-holding assembly  11  comprises and is in the form of a u-shaped blade holder having a front leg  25  and a rear leg  26  connected together by an upper base  27 . The front leg  25  has a u-shaped lower notch  28  to receive the front part of a blade B therein. The rear leg  26  is connected to the intermediate blade lock assembly  12 . The blade B is slidably mounted within the rear blade-receiving assembly  10  within the passageway  20  formed between the spaced offset partitions  18 - 19  and is inserted in the notch  28  in the front leg  25 . 
   The blade lock assembly  12  comprises a control compartment  30  formed by front, rear top and bottom walls  37 ,  38 ,  39  and  40 , respectively. The front wall  39  has a slot  36  therein to receive blade B and the top wall has a threaded opening  42  therein. A blade lock assembly L is provided and comprises a pair of moveable blade lock elements preferably in the form of a pair of opposed cams  31  which are pivotally mounted on pivots  32  located in elongated journals  33  on the front and rear walls  37  and  38  of the compartment  30 . Each cam  31  has an upper control finger  34  and a lower lock base  35  from which the pivots  32  extend. The upper control fingers  34  and lower lock bases  35  are on opposite sides of the pivots  32  so that movement of the upper fingers  34  in one direction will move the lower lock bases  35  in the opposed direction and vice versa. The blade B is interposed between the lower lock bases  35 . The upper control fingers  34  swing on pivots  32  from a position away from each other to a position toward each other and the lower lock bases  35  swing in the opposite direction. As the cams  31  swing as described above, the pivots  32  slide up and down the journals  33 . 
   A controller  50  (in the preferred form of a thumb screw) is threadably mounted by its threaded shaft  51  in the threaded opening  42  at the top of the control compartment  30 . The lower end  52  of the threaded shaft  51  extends within the control compartment  30  and is interposed between the upper control fingers  34  of the cams  31  ( FIGS. 5-8 ). When the controller  50  is screwed down and lowered, as shown in  FIGS. 5 and 6 , its lower end  52  will spread the upper control fingers  34  of the cams  31  apart around pivots  32  thereby allowing the lower lock bases  35  to move toward each other to press and bear against the blade B from both sides to grip and lock the blade B in place. When it is desired to release the blade B, the controller  50  is screwed in the opposite direction to move it upwardly, as shown in  FIGS. 7 and 8 . Its lower end  52  moves upwardly away from upper control fingers  34  of the cams  31  so that they are now free to move toward each other around the pivots  32  and the lower lock bases  35  are free to move away from each other and the blade B to release their grip on the blade B permit the blade B to be adjusted or removed and replaced. 
   It will thus be seen that the present invention provides an improved close quarter hack saw which may be easily used for close quarter work in which the blade may be easily removed, in which the blade may be easily adjusted relative to the handle, which is simple to use and which is inexpensive to manufacture and assemble. 
   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.