Abstract:
A handsaw for holding a saw blade for cutting is disclosed to include a handle having an cantilever bar, an extension bar pivoted to the cantilever bar and turnable relative to the handle between a received position and an extended position, a blade-retaining arm pivoted to one end of the extension bar remote from the handle and turnable about the axis of the extension bar, and two blade retaining members respectively provided at the handle and the blade-retaining arm for the mounting of a saw blade when the extension bar is turned to the extended position.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to hand tools and more particularly, to a collapsible handsaw frame for holding a saw blade of handsaw. 
     2. Description of the Related Art 
     A handsaw is a convenient manual cutting tool for cutting things, for example, for trimming branches of trees during gardening or cutting away obstacles during hunting. However, the frame of a regular handsaw is neither deconstructable nor bendable. When a regular handsaw is not in use, is requires much space for storage. 
     To eliminate the aforesaid problem, Taiwan Patent Publication No. 317215 discloses a handsaw entitled “Improved structure of saw”, which comprises a base frame bar, a grip pivoted to one end of the frame bar, and a saw blade receivable to the base frame bar. This design of handsaw is collapsible. However, the base frame bar has a length approximately equal to the length of the saw blade, such that the collapsed saw is still not convenient for carrying or storage. Further, when collapsing or extending out the saw, the grip is biased relative to the base frame bar through a big angle. Therefore, this design of saw is not suitable for use in a narrow place. 
     SUMMARY OF THE INVENTION 
     The present invention has been accomplished under the circumstances in view. It is one objective of the present invention to provide a handsaw frame for handsaw, which is collapsible to simplify storage management. 
     To achieve this objective of the present invention, the collapsible handsaw frame comprises a handle having a coupling portion; an extension bar having a first end with a coupling portion pivotally coupled to the coupling portion of the handle for allowing turning of the extension bar relative to the handle between a received position and an extended position; and a blade-retaining arm pivoted to a second end of the extension bar and turnable about the axis of the second end of the extension bar. When the extension bar is in the extended position, two opposite ends of a saw blade can be respectively mounted to the handle and the blade-retaining arm. After removal of the saw blade from the handle and the blade-retaining arm, the blade-retaining arm is turned about the extension bar through 180°, and then the extension bar is turned to the received position, and thus the blade-retaining arm and the extension bar are received to the handle, reducing the size of the handsaw frame for storage. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: 
         FIG. 1  is a perspective view of a collapsible handsaw frame according to a preferred embodiment of the present invention; 
         FIG. 2  is an exploded view of the collapsible handsaw frame according to the preferred embodiment of the present invention; 
         FIG. 3  is a perspective view of the collapsible handsaw frame of the present invention in which a saw blade is installed; 
         FIG. 4  is a sectional view taken along line  4 - 4  of  FIG. 1 ; 
         FIG. 5  is a sectional view taken along line  5 - 5  of  FIG. 1 ; 
         FIG. 6  is a sectional view taken along line  6 - 6  of  FIG. 1 ; 
         FIG. 7  is a schematic drawing of the present invention, showing that the blade-retaining arm is turned relative to the extension bar to an upright posture; 
         FIG. 8  is a sectional view taken along line  8 - 8  of  FIG. 7 ; 
         FIG. 9  is a sectional view taken along line  9 - 9  of  FIG. 7 , and 
         FIG. 10  illustrates the collapsed status of the handsaw frame according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in  FIGS. 1-10 , a collapsible handsaw frame  10  for holding therein a saw blade  90  for cutting in accordance with a preferred embodiment of the present invention comprises a handle  20 , an extension bar  30  and a blade-retaining arm  40 . 
     The handle  20  has a cantilever bar  21  provided at the free end thereof with a coupling portion  22  having a through hole  221 . A blade retaining member  24  is inserted through the bottom portion of the handle  20  for holding one end of the saw blade  90 . 
     The extension bar  30  has a coupling portion  32  provided at a first end thereof and pivotally attached to the coupling portion  22  of the handle  20 . The coupling portion  32  of the extension bar  30  has a through hole  321  axially aligned with the through hole  221  of the cantilever bar  21  of the handle  20 . A pivot member, for example, a rivet  92  is inserted through the through holes  321  and  221  such that the extension bar  30  is pivotally connected to the cantilever bar  21  of the handle  20  and the cantilever bar  21  and the extension bar  30  constitute a collapsible handsaw frame body  12 . The extension bar  30  is biasable relative to the cantilever bar  21  between a received position P 1  where the extension bar  30  is parallel attached to the cantilever bar  21  as shown in  FIG. 10 , and an extended position P 2  where the extension bar  30  is axially aligned with the cantilever bar  21  in a line as shown in  FIG. 1 . According to this embodiment, the maximum biasing angle of the extension bar  30  is about 180°. The extension bar  30  has a recessed hole  34  near a second end thereof. The recessed hole  34  accommodates a spring member  36  and a retaining member  38 . The spring member  36  has one end stopped against the extension bar  30  and the other end stopped against the retaining member  38 , which is movable along the direction of the axis of the spring member  36 . 
     The blade-retaining arm  40  has a transverse through hole  40   a  and a receiving hole  40   b  in communication with the transverse through hole  40   a . The blade-retaining arm  40  is pivotally connected with its one end to the second end of the extension bar  30  by a screw bolt  94 , and turnable about the screw bolt  94  relative to the extension bar  30 , i.e., the blade-retaining arm  40  is turnable about the axis of the extension bar  30 . As shown in  FIG. 6 , the second end of the extension bar  30  is pivotally inserted into the transverse through hole  40   a  of the blade-retaining arm  40  in such a manner that the recessed hole  34  of the extension bar  30  is axially aligned with the receiving hole  40   b  of the blade-retaining arm  40 . A sliding block  42  is inserted into the receiving hole  40   b  of the blade-retaining arm  40  and secured to the blade-retaining arm  40  by a pivot pin  43 . The sliding block  42  has an elongated slot  421  through which the pivot pin  43  is inserted such that the sliding block  42  is slidable in the receiving hole  40   b  of the blade-retaining arm  40 . The sliding block  42  is kept in contact with one end of the retaining member  38  opposite to the spring member  36 . The spring member  36  supports the retaining member  38  in a first position P 3 , as shown in  FIGS. 3 and 6 , where the retaining member  38  partially protrudes into the receiving hole  40   b  of the blade-retaining arm  40  such that the blade-retaining arm  40  is prohibited from turning relative to the extension bar  30 . The sliding block  42  can be pressed by an external force to move the retaining member  38  from the first position P 3  to a second position P 4  where the retaining member is totally received in the recessed hole  34  of the extension bar  30 , such that the blade-retaining arm  40  is unlocked and turnable about the axis of the extension bar  30 . The blade-retaining arm  40  has a blade retaining member  44  at the bottom portion for holding the other end of the saw blade  90 . 
     When the user wants to collapse the handsaw frame  10 , the user can operate the steps as follows. 
     a) Press the sliding block  42  to move the retaining member  38  from the first position P 3  to the second position P 4  for allowing turning of the blade-retaining arm  40  about the axis of the extension bar  30 , and then turn the blade-retaining arm  40  about the axis of the extension bar  30  through 180° to change the posture of the blade-retaining arm  40  relative to the extension bar  30 , and then release the sliding block  42 , and therefore the blade-retaining arm  40  is locked to the extension bar  30  at an upright posture (see  FIGS. 7-9 ). 
     b) Turn the extension bar  30  relative to the cantilever bar  21  from the extended position P 2  to the received position P 1 . At this time, the extension bar  30  is closely attached to one side of the handle  20 , i.e. the handsaw frame body  12  is folded up, such that the handsaw frame  10  is collapsed (see  FIG. 10 ). 
     When reversing the aforesaid procedure, the handsaw frame  10  is extended out for the mounting of the saw blade  90 . 
     As indicated above, the handsaw frame of the present invention can be folded up and received in a collapsed manner. When collapsed, the length of the collapsed handsaw frame is about one half of the length of the saw blade. Therefore, the collapsed handsaw frame is convenient for carrying and storage. Further, the operation of the present invention is quite simple. Through a small biasing action, the handsaw frame is extended out. Therefore, the invention is free from space constraint and simplifies storage management. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.