Abstract:
An offset crank speed wrench with a lever arm that extends laterally and perpendicularly of the axis of rotation of the wrench is provided. The arm may integrally attach, be detachable or pivot at its point of attachment. The wrench can have one or more swivel-like joints that permit the wrench to be moveable in a way to increase leverage.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to offset crank speed wrenches, specifically to offset crank speed wrenches with a lever arm to increase the torque that can be exerted by the offset crank speed wrench.  
       BACKGROUND OF THE INVENTION  
       [0002]     The use of an offset crank speed, wrench in the course of any specific task generally requires the wrench generate varying amounts of torque throughout the task. For example, more torque will be required during the initial stages of unlocking a nut that has been tightly fastened onto a bolt. Once the nut begins to unfasten less torque will generally be needed.  
         [0003]     Generally, offset crank speed wrenches are used in applications where high rotational speed is desirable. As such, they are designed to have a small and fixed moment arm. As a result, a way to increase the torque generated by the offset crank speed wrench is to increase the amount of force being applied to the offset crank speed wrench. If not enough force can be applied to the offset crank speed wrench, the offset crank speed wrench may not generate the torque required for the task, for example, when a nut has been fastened tightly onto a bolt.  
         [0004]     It is, therefore, desirable to have a means of increasing the moment arm of an offset crank speed wrench so that greater torque can be generated from the same force.  
       SUMMARY OF THE INVENTION  
       [0005]     It is an object of the present invention to provide means for attaching a lever arm to an offset crank speed wrench that enables increased torque to be generated by the offset crank speed wrench for any given amount of force.  
         [0006]     According to one aspect of the present invention, there is provided leverage means in the form of an arm, associated with an offset crank speed wrench. The arm increases leverage exerted on the offset crank speed wrench, thereby increasing the torque for any given force.  
         [0007]     In one embodiment, the arm may be fixed in place. In another embodiment, the arm may pivot so that it is able to lie against the other portions of the offset crank speed wrench and out of the way when not in use. In yet another embodiment, the arm may attach and detach from the offset crank speed wrench, depending on whether it is in use or not. The point of contact between the arm and the offset crank speed wrench is configured such that the rotational force being applied to the handle is transferred to the offset crank speed wrench.  
         [0008]     According to another aspect of the present invention, the offset crank speed wrench includes a nut formed thereon and the arm includes a wrench adapted to engage the nut for transmitting a rotational force to turn the speed wrench.  
         [0009]     According to another aspect of the present invention, portions of the offset crank speed wrench become the lever arm. There is provided one or more pivoting points along portions of the offset crank speed wrench such as a swivel. The swivel allows the general shape of the offset crank speed wrench to be altered so that portions of the wrench become the lever arm. The lever arm is positioned laterally away from the axis of rotation in an extended configuration, thereby increasing the moment arm of the speed wrench and imparting increased leverage thereto.  
         [0010]     The present invention provides an offset crank speed wrench which comprises an offset crank handle carrying socket means configured to accommodate a fastener for transmitting a rotational force thereto. Lever means is associated with the offset crank handle for turning the speed wrench. The lever means being operatively arranged on the crank handle such that a force applied to the lever means is transmitted to the crank handle for increased leverage. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The present invention will now be described by way of examples with reference to the following figures wherein:  
         [0012]      FIG. 1  is a side view of an offset crank speed wrench integrally connected to an arm in accordance with an embodiment of the present;  
         [0013]      FIG. 2  is a side view of an offset crank speed wrench pivotally connected to an arm in an extended position for use in accordance with another embodiment of the present invention;  
         [0014]      FIG. 3  is a side view of an offset crank speed wrench pivotally connected to an arm in a retracted position in accordance with another embodiment of the present invention;  
         [0015]      FIG. 4  is a side view of an offset crank speed wrench having a bore and an arm received in the bore in accordance with another embodiment of the present invention;  
         [0016]      FIG. 5  is a side view of an offset crank speed wrench having a nut adapted to received wrench means in accordance with another embodiment of he present invention;  
         [0017]      FIG. 6  is a side view of an offset crank speed wrench having a swivel portion in a normal configuration in accordance with another embodiment of the present invention; and  
         [0018]      FIG. 7  is a side view of an offset crank speed wrench having a swivel portion in an extended configuration to impart increased torque in accordance with another embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0019]     Referring now to  FIG. 1 , which shows an offset crank speed wrench  10  in accordance with one aspect of the present invention. Offset crank speed wrench  10  is, preferably, a standard offset crank speed wrench known to those skilled in the art. Offset crank speed wrench  10  generally includes an offset crank handle  11 , which carries socket means  18  for receiving a fastener in the form of a nut  22 .  
         [0020]     Socket means  18  may be integrally formed on offset crank speed wrench  10  or it may be a detachable socket that releasably couples with offset crank speed wrench  10  as well known to those skilled in the art. Offset crank handle  11  may be turned by the user to impart a rotational force to socket means  18  to rotate nut  22 .  
         [0021]     Offset crank handle  11  of speed wrench  10  includes a rotary portion  12  for hand placement, an upper crank member  14 , a lower crank member  16  and a socket portion  18  adapted to receive a fastener such as nut  22 . Socket portion  18  can be configured to receive any type of fastener known to those skilled in the art.  
         [0022]     Upper crank member  14  and lower crank member  16  are mutually aligned in the axial plane of offset crank speed wrench  10 . An offset portion  20 , positioned away from the central axis of the mutually aligned crank members, connects upper crank member  14  and lower crank member  16 . Offset portion  20  provides for hand placement.  
         [0023]     In operation, the user typically places the hands on rotary portion  12  and offset portion  20  to turn speed wrench  10  in the desired direction and cause axial rotation of speed wrench  10  for loosening or tightening fastener  22 .  
         [0024]     In one aspect of the invention, lever means are provided in the form of an arm  28 , which is integrally formed on lower crank member  16 . Arm  28  can be in the form of a pipe, an extension handle, a wrench or the like. Arm  28  extends generally outwardly and perpendicularly of the axis of rotation of lower crank member  16  of speed wrench  10 . Arm  28  may also be positioned anywhere along the axial length of offset crank handle  11  of speed wrench  10 , such that a force being applied to arm  28  is transmitted to crank handle  11  for increased leverage. A weld  17 , or other means for integrally connecting arm  28  to wrench  10 , is formed between arm  28  and lower crank member  16 .  
         [0025]      FIG. 2  shows offset crank speed wrench  10  being pivotally connected to arm  28  in an extended position for use. A pivoting mechanism  26  such as an elbow, joint or the like is preferably associated with a lower curved section  24  of offset portion  20  of wrench  10 . Arm  28  pivots on pivoting mechanism  26  to move it between a retracted position, out of the way for storage ( FIG. 3 ), and an extended position for use ( FIG. 2 ). In the extended position, a force may be applied to the extended arm  28  by the user, to turn offset crank handle  11  in the desired direction.  
         [0026]      FIG. 4  shows offset crank speed wrench  10  having a bore  30 , preferably located at lower curved section  24  of offset portion  20  of offset crank handle  11 . Bore  30  may extend through offset crank handle  11 . Arm  28  is configured in such a manner to be detachably received within bore  30  and secure thereto for transmitting the rotational force. Preferably arm  28  is a pipe or the like carrying a tapered section  32 , which is sized and shaped to removably secure within bore  30  in sliding fit.  
         [0027]      FIG. 5  shows offset crank speed wrench  10  in accordance with another aspect of the invention. Speed wrench  10  comprises lever means in the form of a nut  34  adapted to received wrench means  36  to transmit the rotational force to offset crank handle  11 . Nut  34  may be a typical nut, a squared-off portion or the like known to those skilled in the art. Nut  34  is preferably associated with lower curved section  24 , but may be operationally located anywhere along the length of crank handle  11 . Wrench means  36  may be a typical wrench or an adjustable wrench or the like well known to those skilled in the art. Wrench  36  comprises a wrench mouth  38  that is fitted around nut  34  and a wrench handle  40  for the placement of a user&#39;s hand to impart a rotational force to nut  34 , thereby turning crank handle  11 . It is preferred that the size, shape and composition of the material of nut  34  is dependent on the intended application of offset crank speed wrench  10 . If for example, heavy-duty application is intended, speed wrench  10  may be manufactured with nut  34  having a larger size and stronger metal composition. If, however, light-duty application is intended, speed wrench  10  may be engineered to incorporate nut  34  that is configured smaller and/or formed using a lightweight material composition.  
         [0028]      FIGS. 6 and 7  show offset crank speed wrench  10  having a swivel portion  42  in a normal configuration and in an extended configuration, respectively. At least one swivel portion  42  may be formed on lower curved section  24  of offset portion  20  of offset crank handle  11 . However, swivel portion  42  may be located anywhere along the length of offset crank handle  11  so as to allow movement of a portion of offset crank handle  11  laterally away from the axis of rotation, thereby forming lever means for increasing the leverage imparted on speed wrench  10  ( FIG. 7 ). The extended configuration, wherein lever means is extended substantially outwardly and perpendicularly of the axis of rotation of offset crank handle  11 , may be returned to the normal configuration (shown in  FIG. 6 ) via swivelling action of offset crank handle  1   1 .  
         [0029]     Although preferred embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention. The terms and expressions used in the preceding specification have been used herein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, it being recognized at the scope of the invention as defined and limited only by the claims that follow.