Abstract:
Described is a release device for assisting in freeing lock pins that secure truck trailer axles or axle carriages. A gas spring or other form of stored energy is used to provide a lifting or biasing force against a release mechanism or handle associated with the lock pins. A piston and rod or shaft extend out a first end of a cylinder and within an outer cylinder when the device is actuated. A hook or arm is mounted to the outer cylinder or to a hook body affixed to the outer cylinder. A gripping foot is fixed to the second end of the cylinder. The gripping foot is placed against the frame of the trailer when in use. A release mechanism is coordinated with rotation of a knob on the opposite end of the outer cylinder.

Description:
BACKGROUND 
       [0001]    Field 
         [0002]    The present invention relates to a device to assist in freeing or releasing lock pins that secure tandem axles and axle carriages in position with respect to tractor trailers. 
         [0003]    Related Art 
         [0004]    In the trucking or freight industry, tandem wheel carriages of trailers are releasably held in position by one or more lock pins. The wheels of the trailer often have to be moved to a different position relative to the trailer to provide a desired amount of support depending on the load distribution in the trailer and other factors. 
         [0005]      FIGS. 1-2  illustrate two positions of a set of trailer axles relative to a trailer. With reference to  FIG. 1 , a tractor unit, tractor or semi  1  is attached to and pulls a semi-trailer or trailer  2 . A set of wheels or tandem axles  3  are positioned at the extreme rear of the trailer  2 . The front end of the trailer  2  is supported by drive axles  4 . A handle or release bar  5  is visible under the middle section of the trailer  2 . When the handle  5  is pulled or released, the rear wheel carriage or tandem axles  3  are free to move relative to the trailer  2 . 
         [0006]    As is well known, in practice, the brakes of the wheels of the tandem axles  3  are set so as to hold the tandem axles  3  fixed relative to the ground, and a driver then uses the power of the tractor unit  1  to move the trailer  2  horizontally relative to the tandem axles  3  to a new location  6 . At the new location  6 , the front end or drive axles  4  are charged with less of the trailer load. With respect to the lock pins, the driver must exit the tractor unit  1 , walk back to the tandem axles  3  to inspect the position of the trailer  2 , and then repeat the process iteratively until a desired location of the trailer  2  is reached. Then, the driver re-engages the lock pins. 
         [0007]    This process can be very time intensive for several reasons. For example, the lock pins may initially require jostling of the trailer to free the lock pins so that the handle  5  may be manually operated. Thus, a driver may need to use the truck unit  1  just to free the lock pins before being able to pull or release the handle  5 , and only afterward then being able turn to the task of moving the tandem axles  3 . At this point, after having initially released the handle  5  and lock pins, the driver must get into the truck unit  1  to move the trailer  2  relative to the tandem axle  3 . Since the driver generally cannot see or detect with sufficient accuracy from the cabin of the tractor unit  1  whether the lock pins are properly aligned with any hole or with a desired hole in the frame, the driver must repeatedly and iteratively inspect at close range the position of the lock pins relative to the frame holes along the bottom of the trailer  2  before being able to reengage the lock pins. Some attempts have been made to ease the nature of these tasks. However, none have been extremely useful in reducing the time spent in moving tandem axles  3  relative to trailers  2 . 
         [0008]      FIG. 3  is a perspective cut-away view of a portion of a trailer such as one shown in  FIGS. 1-2 .  FIG. 3  illustrates a typical configuration or geometry of the various components involved in pulling lock pins. With reference to  FIG. 3 , the trailer  2  rides on rails  7  above the tandem axles  3 . The rails  7  slide horizontally on the carriage  8  of the tandem axles  3 . Brackets  9  mounted to the carriage  8  keep the rails  7  aligned and releasably connected with the tandem axles  3 . A handle  5  or actuator releases and engages lock pins  10  into apertures or holes  11  in the rails  7 . Ordinarily, the release mechanism is spring loaded which forces the lock pins  10  into position. The handle  5  may be released by pulling the handle  5  outward through the aperture  12 . The handle  5  and lock pin  10  are shown in a released state in  FIG. 3  since the pin  10  is disengaged from the apertures  11  of the rail  7 . 
       SUMMARY 
       [0009]    There has been a significant need to reduce the time spent adjusting tandem axles of truck-trailers. Further, there has been a need for a device to physically assist the occasionally arduous task of freeing jammed lock pins of trailers. There is still a further need for a device to reduce the amount of time a driver spends under a trailer checking for proper position of lock pins relative to trailers. 
         [0010]    In order to meet these and other needs, described herein is a biasing device that provides a force for working with tandem wheels or axles of a truck trailer. According to an illustrated embodiment, a first cylinder includes a longitudinal axis, a first end and an opposing second end. A piston is slidably mounted in the first cylinder to divide the first cylinder into a first chamber and a second chamber on opposite sides of the piston. A shaft is secured to the piston and extends through the first chamber and out of the first end of the first cylinder. A biasing element is present in the second chamber of the first cylinder between the second end of the first cylinder and the piston, the biasing element biasing the piston and shaft into an extended position. A foot is mounted to the second end of the cylinder. A second cylinder is mounted concentric to the first cylinder. A release mechanism is proximate to the first end of the second cylinder and is designed to release the biasing mechanism when the biasing mechanism is in the retracted position and when the device is positioned properly relative to the frame of a trailer and a handle for releasing lock pins of the trailer. One or more engaging arms are mounted to the second cylinder proximate to the second end of the second cylinder. 
         [0011]    In some embodiments, the shaft may include a distal end. In some embodiments, the piston and shaft are movable between a retracted position in which at least a portion of the shaft is within the first cylinder, and an extended position in which a portion of the shaft is extended out of the first cylinder. 
         [0012]    In some embodiments, the foot may include a dedicated region for bearing against a surface. 
         [0013]    In some embodiments, the second cylinder may include a first end proximate to the first end of the first cylinder and distal end of the shaft. 
         [0014]    In some embodiments, the second cylinder may further include a second end proximate to the second end of the first cylinder. 
         [0015]    In some embodiments, the second cylinder may include a longitudinal axis substantially parallel to the longitudinal axis of the first cylinder. 
         [0016]    In some embodiments, the engaging arm projects outwardly from the second cylinder in a generally radial direction transverse to the longitudinal axis of the second cylinder, the engaging arm configured for releasably engaging with a portion of a lock pin mechanism, whereby, when the biasing element is freed, the biasing device provides a biasing force to the lock pin mechanism to facilitate release of a lock pin from its place of engagement, the first cylinder extending exteriorly from the first end of the second cylinder as the biasing element extends the shaft from the first cylinder within the interior of the first end of the second cylinder. 
         [0017]    In some embodiments, the dedicated region may include a gripping feature to facilitate contact between the surface and the foot. 
         [0018]    In some embodiments, the engaging arm is contoured to accommodate a curved surface of the lock pin mechanism so as to facilitate the biasing device remaining in place while an operator moves the truck trailer. 
         [0019]    In some embodiments, the biasing element may include a compressed gas. In some embodiments, the device may further include a pliant and insulating gripping material mated to an outer surface of the second cylinder end along a length of the second cylinder sufficient for at least one hand of a user. 
         [0020]    This summary is not intended to identify key or critical aspects of the invention. Additional features and advantages of the disclosure are set forth in the detailed description which follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    While the appended claims set forth the features of the invention with particularity, the invention, together with its objects and advantages, is more readily appreciated from the following detailed description, taken in conjunction with the accompanying drawings. Throughout, like numerals generally refer to like parts. Unless specifically indicated, the components and drawings are not shown to scale. 
           [0022]      FIGS. 1-2  illustrate two positions of a set of trailer axles relative to a truck trailer. 
           [0023]      FIG. 3  is a perspective cut-away view of a portion of a trailer such as one shown in  FIGS. 1-2 . 
           [0024]      FIG. 4  is a perspective view of one implementation of the device for providing a biasing force, the device being in a fully retracted or compressed configuration. 
           [0025]      FIG. 5  is a perspective view of a portion of a trailer such as one shown in  FIGS. 1-2  with a device in a retracted configuration and positioned proximate to and engaged with a handle for releasing lock pins. 
           [0026]      FIG. 6  is a perspective view of the portion of the trailer shown in  FIG. 5  with the device in a partially extended configuration after having placed the handle in a released position. 
           [0027]      FIG. 7  is a perspective view of the device of  FIG. 4  in a fully extended or released configuration. 
           [0028]      FIG. 8  is a perspective exploded view of the components of the device first shown in  FIG. 4 . 
           [0029]      FIG. 9  is a perspective view of the cylinder and shaft of the biasing device shown in  FIG. 8 . 
           [0030]      FIG. 10  is a perspective view of an extension element according to a second embodiment. 
           [0031]      FIG. 11  is a lateral view of a foot member according to a second embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0032]    As described in the background, there has been a substantial and unmet need for a tool to assist with disengaging lock pins and moving tandem axles relative to trailers in the freight industry. The present invention shown in FIG. was designed to fill such need. 
         [0033]      FIG. 4  is a perspective view of one implementation of a device for providing a biasing force such as against a lever or handle  5 . With reference to  FIG. 4 , the biasing device  13  is in a fully retracted or compressed configuration. The device  13  includes a central tubular or cylindrical body  14  having an outer surface  15  and an axis  16  running through its center. The device  13  and cylinder  14  have a first end  17  and a second end  18 . Affixed to the first end  17  is a knob  19  which includes a connecting neck  20  that is mounted to the lock bone  44 . The knob  19  may be turned relative to the cylinder  14  along a rotational range of motion  21 . 
         [0034]    Mounted to the opposing second end  18  of the cylinder  14  is a hook body  22  having one or more hooks  23  protruding substantially radially from the axis  16  of the cylinder  14 . Each hook  23  includes an engagement region  24  that preferably includes a curved surface to encourage sustained engagement with a pin-disengaging handle. The hooks  23  and hook body  22  are preferably made of metal so as to provide sufficient strength to engage with and manipulate a pin-disengaging handle (shown as handle  5  in  FIGS. 1-3 ) under substantial resistive forces as are common in large commercial machinery such as semi-trailers. The hook body  22  and hooks  23  may be made as a single part so as to encourage economy of manufacture. 
         [0035]    As shown in  FIG. 4 , a foot  25  is mounted at the opposing second end  18  to a component within the outer cylinder  14 , not to the outer cylinder. The foot  25  is formed so as to include a substantially planar and rectangular footprint along a transversal axis  26 . The transversal axis  26  lies in a plane that is substantially perpendicular to the axis  16  of the cylinder  14  The hooks  23  may be aligned with the transversal axis  26  and foot  25  to encourage an efficient and protracted application of mechanical force to the handle  5  when the device  13  is engaged into proper location (described further herein in more detail). The width of the foot  25  is of arbitrary size but is preferably about the same size as the diameter of the cylindrical body  14  of the device  13 . The bottom surface  27  of the foot  25  may include gripping features  28  such as grooves, teeth or spikes, or may be rubber-like feet affixed by glue, adhesive or other means. Other sizes, shapes and geometries of foot  25  may be made that perform substantially the same as the device  13  shown in  FIG. 4  according to further experimentation. 
         [0036]      FIG. 5  is a perspective view of a portion of a trailer such as one shown in  FIGS. 1-2  with a device  13  in a substantially retracted configuration and positioned proximate to and engaged with a handle  5  for releasing lock pins  10 . That is, the device  13  has not yet been triggered and used. A user installs the untriggered device  13  when the pins  10  are engaged through the apertures  11  formed in the rail  7 . The handle  5  provides mechanical connection with the pins  10 ; the handle  5  passes through an aperture  12  in the frame or carriage  8 . 
         [0037]    With reference to  FIG. 5 , a biasing device  13  is installed normal or perpendicular to the surface of the carriage  8  such that the foot  25  is placed flush against the carriage  8 . The hook body  22  is installed under the handle  5  such that the hook  23  is engaged with a portion of the handle  5 . The combined height of the foot  25  and hook  23  is preferably smaller than the space between the handle  5  and the carriage  8  when the device  13  is initially placed against the carriage  8 . The device  13  is preferably installed by placing the foot  25  against the carriage  8  and then, through a twist of the entire device  13 , one of the hooks  23  is placed under the handle  5 . 
         [0038]    Then, in order to apply a biasing force to the handle  5 , the knob  19  is turned so as to activate or release the biasing force from the device  13  (e.g., via a gas spring or mechanical spring within the device  13 ). When initially applied, the biasing force closes any gap between the handle  5  and the hook  23  as the body of the device  13  quickly extends upward against the handle  5  under the influence of the biasing force. The biasing force acts along a motion vector  30  that is consistent with the axis of the range of motion of the handle  5 . Preferably, the biasing force is substantial such that the device applies between approximately 40 and 80 lbs of force to the handle  5 . The device  13  may be configured or assembled with components to be able to apply more or less force than the preferable range of 40 to 80 lbs of force. 
         [0039]    The application of the biasing force causes the hooks  23  to extend relative to the stationary foot  25  that is pressed against the carriage  8 . Instead of pulling the handle  5  by hand, a user may use the biasing device  13  to apply the necessary force lateral and perpendicular to the carriage  8 . The handle  5  stops when it reaches the end of its inherent range of motion. That is, it is preferable that the range of travel of the foot  25  relative to the rest of the device  13  is greater than the range of motion of a handle  5  for most types of trailers  2 . Accordingly, the force applied by the device  13  keeps the device  13  suspended or pressed in place between the handle  5  and carriage  8  when in use. Preferably, when the user installs the device  13 , and the handle  5  moves to a released position (and the pins  10  are thereby released), the device  13  remains forcefully engaged and suspended between the handle  5  and carriage  8  until forcefully removed. The end or knob  19  protrudes beyond the side of the trailer  2  so that the user may be able to visually determine when the device  13  has been actuated. 
         [0040]    During use of the device  13 , the driver may need to return to the cabin of the truck (not shown) and may need to engage the engine of the truck to jostle or otherwise release some of the bind or frictional resistance between the rail  7  and pins  10 . Such jostling may be necessary to reduce an amount of force required to move the handle  5  solely by the device  13 . That is, an initial installation of the device  13  onto the handle  5  may not immediately actuate or move the handle  5 . In such circumstance, the user may be required to reduce binding in the lock pins  10 . Alternatively, the user may opt to pull on the device  13  by gripping the outer surface  15  and pulling on the cylinder  14  to apply additional force to the handle  5  beyond the force applied by the device itself. In such circumstance, the device  13  substantially aids the user in applying a force necessary to free the handle  5  from its engaged position. The device  13  is constructed of strong materials so as to be sufficiently rugged to withstand forces substantially greater than those applied by the biasing force provided from within the device  13 . 
         [0041]      FIG. 6  is a perspective view of the portion of the trailer shown in  FIG. 5  with the device  13  in a substantially extended configuration after having placed the handle  5  in a released position. With reference to  FIG. 6 , the handle  5  has reached its fully extended position by being moved by the device  13  a certain distance  32 . The lock pins (not shown) have been removed from the apertures  11  in the rail or beam  7 . In contrast, the device  13  has not yet reached the end of its range of motion; that is, the device is not fully extended and still maintains itself lodged between the handle  5  and the carriage  8 . Accordingly, the foot  25  remains firmly pressed against the carriage  8  by an inner cylinder  31 . According to one illustrative embodiment, the inner cylinder  31  is part of a gas spring. The gas spring provides the biasing force. In  FIG. 6 , the cylinder  31  and foot  25  still has more range of travel and may be further extended beyond the distance traveled  32  by the handle  5 . The hook body  22  remains under and proximate to the handle  5  and one of the hooks  23  remains engaged with the handle  5 . To be released, a user would grasp the cylinder body  14  and would twist the device  13  clockwise so as to free the hook  23  from the handle  5 . Internally, the cylinder body  14  is free to rotate relative to the inner cylinder  31  such that the foot  25  remains stationary relative to, and pressed against, the carriage. Without anything to press against, the inner cylinder  31  would then be free to extend to the limit of its range of motion as the device  13  is pulled from the vicinity of the handle  5 . Preferably, the knob  19  and a portion of the device  13  (e.g., cylinder  14 ) extend outside the profile of the trailer  2  so that a driver in the cab of the truck would be able to see the knob  19  and cylinder  14  when in the partial extended position. That is, the driver would be able to see the knob  19  and cylinder after the lock pins have been popped loose from their apertures. The driver would then be aware of the freedom of the trailer  2  relative to the carriage  8 , and the driver could then move the location of the tandem axles relative to the trailer  2 . The driver would then manually re-engage the lock pins before driving away with the trailer attached to the truck unit. 
         [0042]      FIG. 7  is a perspective view of the device of  FIG. 4  in a fully extended or released configuration. With reference to  FIG. 7 , the device  13  includes a principal or outer cylinder  14  with an outer surface  15 . On a first end  17 , a knob  19  is installed via its attachment collar or connecting neck  20  to the lock bone or extension (not shown; interior to outer cylinder  14 ). A hook body  22  is mounted on the second end  18  of the cylinder  14 . The hook body  22  includes one or more hooks  23  such as two opposing hooks  23  that extend radially outward from the cylinder  14 . An inner cylinder  31  such as of a gas spring extends out of the second end  18  of the device  13  and across and up to a maximal range  33  that is preferably in excess of a maximum range  32  of the operation of a lock pin handle (not shown in  FIG. 7 ; shown in  FIG. 5 , element  5 ). A foot  25  is attached to a free end of the inner cylinder  31 . 
         [0043]      FIG. 8  is a perspective exploded view of the components of the device  13  first shown in  FIG. 4 . With reference to  FIG. 8 , the device  13  includes a biasing-inducing member that can provide a biasing force. For example, the bias force member may be a compressed gas spring  50 . A compressed gas spring  50  includes an inner cylinder  31  and a shaft  41 . The shaft  41  is preferably made of a metal such as a stainless steel, a non-stainless steel or an aluminum so as to be sufficiently strong so that the device  15  may provide a substantial biasing force. 
         [0044]    The first end of the shaft  41  may include a threaded bolt  42  so as to threadably connect or mount to another component such as to or inside an extension  44 . One or both ends  45 ,  60  of the extension  44  may be fluted or enlarged. A first end  45  may be fluted or enlarged so as to fit over or accommodate a diameter of the shaft  41  and to provide sufficient mechanical strength to the device  13  while at the same time reducing the overall weight of the device  13 . The distal end  60  may be enlarged so as to engage properly with a neck portion  20  of the handle  19 . Alternatively, the extension  44  may be of uniform diameter and may be of a same, smaller or larger diameter than the shaft  41 . The extension  44  may be solid or hollow and may be made of a same, similar or different material than the shaft  41 . 
         [0045]    A first pin  46  and a second pin  47  provide a locking functionality to the device  13 . During assembly, a first pin  46  is inserted through a pair of slots  48  in the distal end  60  of the extension  44  and into a pair of corresponding apertures  53  in the cylinder  14 . The extension  44  is held in place laterally inside the cylinder  14  by the first pin  46 . The first pin  46  lies across a diameter of the hollow cylinder  14 . 
         [0046]    The second pin  47  is inserted into a pair of apertures  51  in the handle  19  and through a pair of apertures  49  in the extension  44 . The second pin  47  mechanically ties the handle  19  to the extension  44 . A leading edge or surface  52  of the handle  19  is preferably physically abutted to an end surface  54  of the cylinder  14  by selective placement of the apertures  49 ,  51  and pair of slots  48  in the respective components. The cylinder  14  and first pin  46  remain stationary in relation to the handle  19 ; the handle  19  can be rotated relative to the cylinder  14  and gas spring  50 . The slot  48  provides a range of rotating motion to the extension  44 , handle  19  and cylinder  14 . 
         [0047]    On or over a first end or distal end  17  of the gas spring  50  may be threaded or assembled a bushing  43 . A pair of arms  55  on the proximal side of the extension  44  lock the shaft  41  into a fixed position relative to the inner cylinder  31  of the gas cylinder  50 . The arms  55  lock into features of a bushing  43  as described and illustrated further herein. Among possible functions, the bushing  43  provides a secure fit for the outer cylinder body or cylinder  14  relative to the inner cylinder  31 . A tubular grip  40  or grip material may be glued, sprayed, wrapped or formed onto the outer surface  15  of the cylinder  14 . Preferably, the outer grip  40  is made of a rubber-like or foam-like material so as to provide a non-heat-conductive experience for a user who grasps the device  13 . The outer grip  40  is designed for all types of weather including extreme heat and cold. The grip  40  provides a more secure surface for handling the device  13  as compared to a smooth metal surface or smooth plastic surface  15  of the cylinder  14 . 
         [0048]    The second end or proximal end  18  of the cylinder  14  may include a fluted or tapered region  39  so that the cylinder  14  properly and tightly fits into the opening  35  of the hook body  22 . The hook body  22  is formed with or includes one or more hooks  23  that extend from the hook body  22 . The second end or proximal end  18  of the inner cylinder  31  may include a threaded post  34  so as to thread into a corresponding and unillustrated female receiver inside the receptacle or hollow  35  of the hook body  22  to provide extra strength to the connection between the inner cylinder  31  and the hook body  22 . The proximal end of the hook body  22  is securely mounted to the foot  25 . The foot  25  includes gripping features  28  such as grooves or teeth, or may be rubber-like feet affixed by glue, adhesive or other means. The bottom surface  27  of the foot  25  is preferably flat so as to provide an engaging surface against a portion of an axle carriage (not shown) when the device  13  is assembled and placed in service. The foot  25  may be contoured to include rounded shoulders  38  and, at the distal end  36 , the foot  25  is tapered and shaped so as to engage and be fastened to the hook body  22 . The foot  25  may include a mechanical fastener or divot  37  to more securely engage with the hook body  22 , and particularly to engage with a tapered portion of the hook body  22 . The divot  37  prevents the foot  25  and cylinder  31  from rotating relative to the extension  44  its arms  55 . 
         [0049]      FIG. 9  is a perspective view of the cylinder  31  and shaft  41  of the biasing device shown in  FIG. 8 . With reference to  FIG. 9 , on the distal end  17  of the cylinder  31  is affixed a bushing  43 . The bushing  43  is preferably made of metal. The bushing  43  includes one or more channels  59  machined out of the bushing  43 . The channel  59  allows air to pass from one side of the bushing  43  to the other when the bushing  43  and other components are assembled inside the outer cylinder  14  (not shown in  FIG. 9  for sake of simplicity). Yet further,  59  the channel  59  serves as a guide to line up the bushing  43  with a pointed portion of the hook body  22  during assembly. The bushing  43  and hook body  22  are fixedly attached during assembly and features of the same must coordinate with each other as further described herein. 
         [0050]    A pair of edges, lips or locking flanges  56  protrude laterally from the distal end of the neck  63 . The flanges  56  do not circumnavigate the circumference of the neck  63 . Instead, the flanges  56  run along a portion of the neck  63  and oppose each other. The flanges  56  are a thickness  58  tall. The flanges  56  provide a surface to bias against when the force of the gas cylinder is active. The flanges  56  thereby hold the shaft  41  stationary when properly engaged with arms or other element of the extension  44  or other component affixed to the end of the shaft  41  as described further in relation to  FIG. 10 . 
         [0051]    The shaft  41  of the gas spring  50  passes and slidably operates through the neck  63 . The flanges  56  are each machined or formed with apertures for receiving vertical pins  57 . One or more of the pins  57  serve as an end of rotatable motion when the handle  19  and extension  44  (not shown) are rotated relative to the bushing  43 . While only one pin  57  is required to prevent rotatable motion, two pins  57  are provided for security, safety and redundancy in the embodiment shown. 
         [0052]      FIG. 10  is a perspective view of an extension element according to a second embodiment. With reference to  FIG. 10 , a first end  45  of the extension  44  includes a pair of arms  55 . Along each end of the arms  55  is machined a ledge or lip  62  for engaging with the flanges  56  shown in  FIG. 9 . The distal end of the shaft  41  engages in the recess  61  machined in the proximal or first end  45  of the extension. At the distal end  60  of the extension, a slot  48  is visible. The slot  48  is preferably one of a pair of slots  48  that provides a passage laterally through the extension for a securing pin  46  (see  FIG. 8 ). The distal end  60  also includes a pair of apertures  49  for receiving a pin (not shown in  FIG. 10 ). Such pin is described in relation to  FIG. 8 . The extension  44  is shown with a uniform outer diameter and of a size larger than the shaft  41  of  FIG. 9  but of small enough diameter to fit inside an outer cylinder  14 . 
         [0053]      FIG. 11  is a lateral view of a foot member according to a second embodiment. A first embodiment of a foot  25  is illustrated and described in relation to  FIG. 4  and  FIG. 8 . With reference to  FIG. 11 , a foot  125  is mounted to a proximate or second end  18  of the cylinder  31  or a biasing component. The foot  125  includes a first end  69  and a second end  70 . A distance  65  to the first end  69  from a median axis through the center of the cylinder  31  is shorter than a distance  66  to the second end  70  from the median axis. Accordingly, a user has the opportunity to place either the first end  69  or the second end  70  under a pin release handle when in use. Depending on the geometry of the same, by having ends  69 ,  70  protruding to different lengths, a user may find that a first end  69  or a second end  70  functions better than the other to pull a pin release handle. The foot  125  also includes a working surface or bottom surface  64  that is concave or curved relative to a flat or horizontal reference line  67 . The curvature of the surface  64  is accentuated for purpose of illustration only. A typical curvature of the bottom surface  64  is preferably two to three millimeters of distance  68  to an apex of the curved bottom surface  64  as measured from a horizontal line or plane  67 . While a single dimension of curvature is shown, curvature in the bottom surface  64  can also be in two dimensions so as to form a a cup-like surface. The surface  64  may be parabolic or may vary in curvature according to a circular trajectory. Further, as shown, a set of three teeth  28  are visible approximately mounted along a front edge of the foot  125  with another set of three gripping features or teeth implied but not visible due to the limitations of the side view illustrated. The foot  125  and gripping features  28  are preferably made of metal so as to endure the substantial forces inherent in the operation of pin pulling. 
         [0054]    Conclusion. A few examples and embodiments of the innovative technology are described above and illustrated in the drawings. It will be apparent to one skilled in the art that the described technology can be practiced without these specific details. Further, it is not possible to describe every combination of components or methodologies for purposes of describing the subject innovation. However, one of ordinary skill in the art should recognize that many further combinations and permutations of the innovation are possible. Accordingly, the innovation is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the description and appended claims. In certain instances, structures, devices, systems and methods are shown only in block diagram or simplified form in order to avoid obscuring the description. 
         [0055]    The term “includes” as used herein is intended to be inclusive in a manner similar to the term “comprising.” Reference to “one embodiment”, “an embodiment”, or “implementation” means that a particular feature, structure, or characteristic described in connection with the embodiment or implementation is included in at least one embodiment or implementation. Appearances of the phrase “in one embodiment” in various places are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others. Similarly, various requirements are described which may be requirements for some embodiments but not other embodiments. Various modification and changes can be made to the illustrated embodiments and description without departing from the broader spirit of the contents of the description. In this technology, advancements are frequent and further advancements are not easily foreseen. The disclosed embodiments may be readily modifiable in arrangement and detail as facilitated by enabling technological advancements without departing from the principles of the present disclosure.