Patent Abstract:
A tool for selectively compressing and expanding work, the tool comprising a handle including bar holders and at least two slidable bars having work engaging surfaces at ends thereof both of which are slidably received in a separate one of the bar holders and both being adapted to be selectively fixed therein whereby at least one of the slidable bars is adapted to be reversibly received in one of the bar holders of the handle.

Full Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to tools and in particular a tool having a slidable bar adapted to allow the tool to function as both a clamp and a spreader jack.  
         BACKGROUND OF THE INVENTION  
         [0002]    Hand tools adapted to clamp, grip or otherwise hold together pieces of wood, steel, or other materials for temporary or permanent connection are known.  
           [0003]    Prior art C clamps have many disadvantages. Prior art C clamps often employ a screw mechanism to generate the clamping forces. Such devices are slow and require both hands to operate. They also have limited displacement which in turn limits the size and shape of the workpiece which can be clamped. While it is know to simply increase the size of a clamp to adapt it to fit a larger workpiece, such clamps are heavy and difficult to maneuver. Further, such prior art clamps are not readily adapted to be used as a spreader jack nor do such clamps permit clamping at the inside apex angle of the workpiece.  
           [0004]    Prior art clamps are also limited in that the maximum span of the clamp is often fixed and limited and the trigger mechanism which advances one of the jaw bars is not reversible and/or is difficult to reassemble following disassembly.  
           [0005]    Each of U.S. Pat. No. 4,893,801 to Flinn; U.S. Pat. No. 5,005,449 to Sorensen et al.; U.S. Pat. No. 5,009,134 to Sorensen et al.; U.S. Pat. No. 5,170,682 to Sorensen et al. and U.S. Pat. No. 5,222,420 to Sorensen et al. disclose hand held clamps having a fixed jaw secured to a hand grip and a movable jaw secured to one end of a single slidable bar member adapted to extend through the hand grip. Sorensen et al. &#39;682 discloses a tool having the capacity to readily convert from a clamp to a spreader jack; however, in order to reverse the face of the movable jaw a force in excess of 200 pounds must be applied to the pins in order to facilitate removal. Further, the use of a coil spring in the trigger mechanism of the handle/bar holder will cause the gripping plate and other elements in the trigger mechanism to fall out of alignment as the bar is withdrawn from the handle and necessarily renders reassembly difficult. U.S. Pat. No. 5,009,134 to Sorensen et al. also mandates the removal and reversal of one of the jaws in order to adapt the device for use as a spreader jack. The hand held clamp of Flinn discloses two parallel bars, however one of the bars is fixed.  
         OBJECT AND SUMMARY OF THE INVENTION  
         [0006]    It is an object of this invention to provide a tool adapted to be easily converted so as to function as a clamp or as a spreader jack.  
           [0007]    Another object is to provide a trigger mechanism for a tool handle that may be rotated 180 degrees to adapt the tool for purposes of offset jacking, for example, when jacking a double hung window.  
           [0008]    A further object is to provide a tool where the at least two slidable bars are adapted to provide a so-called C clamp (FIG. 5) having a greatly expanded capacity to receive the workpiece to be clamped; namely, the entire lengths of each of the slidable bars are separately and adjustably received within the bar holder to thereby increase clamping displacement or volume and/or allow clamping of unusual shapes such as an L or T shaped workpiece and where the clamping force must be applied near the inside apex of the workpiece angle and/or the clamp must reach past an intervening leg of the workpiece angle.  
           [0009]    Another object is to provide a tool having an improved handle mechanism so that the slidable bars received in the handles may readily be reversed without the need to apply a great deal of force and effort as is required during reversal of the prior art devices and further, will not result in the various individual trigger mechanism elements falling apart as is the case in the prior art devices.  
           [0010]    Another object of this invention is to provide a tool having both expansion and compression capability without the need for removal and reversal of a jaw member.  
           [0011]    Another object of the present invention is to provide a tool adapted to permit removal of one of the bars yet still allow the tool to function as a clamp or spreader jack.  
           [0012]    A further object of this invention is to provide an adjustable tool readily adapted to receive one or more pieces of work material.  
           [0013]    Still a further object of this invention is to provide a tool having sufficient clearance for grasping the work at different points or locations.  
           [0014]    A further object of this invention is to provide a work tool having four separate jaws.  
           [0015]    A still further object of the invention is to provide a tool having a readily reversible feature due to the use of a leaf spring in the trigger mechanism that allows the slidable bars to be easily removed from the handle and reversed without the need for tools and without causing the trigger mechanism parts to become displace and therefore difficult to reassemble as is the case with the prior art devices.  
           [0016]    Another object of the invention is to provide a tool having a trigger mechanism in the handle which includes a leaf spring adapted to remain in a working position during disassembly of the trigger mechanism due to the provision of a curved surface at one end of the leaf spring which retains the gripping plate in place.  
           [0017]    Still another object of the present invention is to provide a tool having a auxiliary jaw to enable the device to operate as a true C clamp and thereby permit clamping beyond flanges or other obstructions.  
           [0018]    In addition, the present device provides a tool having a slidable bar, one end of which includes a standing jaw-comprising a pair of opposed face plates at one end thereof so that the tool according to the present invention may be readily converted from a clamp and into a spreader jack.  
           [0019]    In summary, the present invention relates to a work tool for clamping, expanding and/or pushing away of the work material, either temporarily or permanently.  
           [0020]    These and other objects will be apparent from the following description and the drawings which are described as follows. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]    [0021]FIG. 1 is a perspective view of the work tool according to the present invention when in a compression position and showing the work and pin holes in phantom lines;  
         [0022]    [0022]FIG. 2 is a perspective view of the work tool according to the present invention when in the expansion position and showing the work shown in phantom lines;  
         [0023]    [0023]FIG. 3 is an enlarged, fragmentary side elevation view of the work tool with the trigger mechanism in a release position;  
         [0024]    [0024]FIG. 3A is a perspective view of the U-shaped spring shown in FIG. 3;  
         [0025]    [0025]FIG. 4 is an enlarged, fragmentary side elevation view of the work tool shown in FIG. 3 with the trigger in the activation position;  
         [0026]    [0026]FIG. 5 is a side elevation view of a work tool according to the present invention and with the work shown in phantom lines;  
         [0027]    [0027]FIG. 6 is an exploded, perspective view of the work tool shown in FIG. 5; and  
         [0028]    [0028]FIG. 7 is a sectional view taken along lines  7 - 7  in FIG. 3. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0029]    Each of the figures illustrate the work tool T according to the present invention. The tool T includes a handle  2  having an upper bar holder  4  and a lower bar holder  6  each of which are adapted to adjustably receive a separate bar which will be further described below. The handle  2  is provided with a trigger  8  and a release trigger mechanism  10 .  
         [0030]    As best shown in each of FIGS. 3, 4 and  7 , the trigger  8  is provided with a pivot portion  12  adapted to pivot in housing  14  of the handle  2 . Within the housing  14  is provided a U-shaped spring  16 . Spring  16  is best shown in FIG. 3A. Spring  16  is shown to be biased against a gripping plate  18  positioned between spring  16  and the trigger  8 . As can be seen in each of FIGS. 3 and 4, the trigger  8  operates and is moveable in recess  20  of handle  2 . FIG. 3 shows the trigger  8  in a forward position prior to actuation. FIG. 4 shows the trigger  8  during operation or in the actuated position. The trigger  8  is shown to be snap fit into the housing  14  and is of a yoke or design fixing around lower bar holder  6 . As is apparent, a spring design other than that as shown in the drawings is within the scope of the present invention so long as the trigger  8  functions in the manner as described below. Further, an actuation device other than a spring is within the scope of the present invention so long as the actuation device selected permits the device to operate in the manner described below.  
         [0031]    The housing  14 , as best shown in FIGS. 3 and 4, includes the release trigger mechanism  10  which pivots in the hook portion  22  of the housing  14  and is secured by a pivot pin  23 . The release trigger mechanism  10  is best shown in FIG. 6 and includes a window opening  24 .  
         [0032]    Turning to FIG. 6, a lock pin  26  is shown to extend through an opening  28  in the handle  2  and is secured by a nut or lock washer  30 . Lower bar  32  includes work a engaging device  34  having an expansion or face plate  36  and a compression or face plate  38  and is adapted to be slidingly received in lower bar holder  6  and through window  24  of the release trigger mechanism  10 . Upper bar  40  is adapted to be slidingly received in upper bar holder  4  and includes face plate  42  which may be used for compression and/or expansion work. A locking pin  26  is adapted to selectively engage lock positioning notches  44  of upper bar  40 . It is understood that instead of notches  44 , pin holes  46  (FIG. 1) may be substituted on upper bar  40  to lock or otherwise fix the position of upper bar  40  within bar holder  4 . If pin holes  46  are used, the pin  26  is mounted in handle  2  so as to align with pin holes  46 .  
         [0033]    As is apparent, the device as set forth above may be constructed from a variety of materials depending upon design considerations. In particular, the clamping or jacking forces of the device are directly related to the nature of the construction materials used. For example, the use of high strength steels will yield a tool having high durability and strength and which is readily adapted to hold or spread heavy metal object whereas the use of plastic materials will provide a tool having light weight for ease of handling and which may be readily adapted for use with wooden or plastic work materials. In the alternative, a combination of different materials may be used. For example, the upper and lower bars as well as the spring may be constructed from steel or other another metal material for purposes of durability and strength whereas the remaining parts may be constructed from injection molded reinforced plastic to reduce the weight of the device and overall manufacturing costs.  
         [0034]    The tool according to the present invention operates in the following manner. When the trigger  8  is actuated, the gripping plate  18  moves to the right, from a position shown in FIG. 3 to the position shown in FIG. 4, compressing spring  16  and thereby causing the bar  32  to move incrementally in the direction of the arrow on bar  32  as best seen in FIG. 4. Release of the trigger  8  will set the trigger  8  in position for another incremental move permitting the bar  32  to be moved in relation to the bar  40 . Bar  40  is initially positioned by sliding the bar  40  in the bar holder  4  and then locking in position with the pin  26  engaging a notch  44  or hole  46  to lock the bar  40  in position relative to the bar  32 . Depending upon the position of the bars  32  and  40  in the handle  2 , the face plates  36  and  42  will face each other for clamping the work W as shown in each of FIGS. 1 and 5. The work engaging device  34  with the face  38  when positioned for expansion, as shown in FIG. 2, is reversed in the handle  2  so that it will operate in the expansion mode for engaging with the work W. The work engaging device  34  is fixed on the bar  32  and need not be removed therefrom in order to use it as expansion or compression mechanism. Only bar  32  need be removed and reversed in the handle  2  for selectively adapting the device for either compression or expansion mode. Release trigger  10  is designed to lock bar  32  from movement in the direction opposite to the movement of the bar  32  when actuated by trigger  8 . When the release trigger mechanism  10  is operated, the bar  32  can be slipped in lower bar holder  6  for rapid initial adjustment.  
         [0035]    While this invention has been described as having a preferred design, it is understood that it is capable of further modification, uses and/or adaptations following in general the principle of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains, and as may be applied to the essential features set forth, and fall within the scope of the invention or the limits of the appended claims.

Technology Classification (CPC): 1