Patent Publication Number: US-2016244030-A1

Title: Adjustable foot pad for integrated vehicle jack

Description:
RELATED APPLICATIONS 
     This application claims the benefit of co-pending U.S. Provisional Patent Application Ser. No. 62/118,342 entitled “Adjustable Foot Pad For Integrated Vehicle Jack,” filed Feb. 19, 2015 by at least one common inventor, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to jacks, and more particularly to jacks that are fixed to vehicles. Even more particularly, this invention relates to a means of extending the length of jacks that are affixed to vehicles. 
     2. Description of the Background Art 
     Vehicles with integrated jacks are well known. For example, some recreational vehicles (RVs) have jacks affixed to the RV that are used for leveling and/or stabilizing the RV. As another example, semi-trailers typically include a pair of jacks that function to raise and lower the front end of the trailer to facilitate connecting and disconnecting the trailer from a towing truck. 
     The jacks of a vehicle must be capable of extending from a stowed position, where they are safe fur travel, to a fully deployed position that provides the required vehicle lift. In some vehicles, the extension length can be rather significant, because the trailer must be capable of connecting to trucks of different heights. 
     In systems with hydraulic jacks, the amount of extension required determines the length of the hydraulic cylinder used to extend the leg of the jack. In general, the cost of a hydraulic cylinder increases with the length of the cylinder. As a result, jacks with greater extension lengths require longer hydraulic cylinders and are, therefore, more expensive. 
     Telescoping jack legs provide a greater extension range, without increasing the length of the hydraulic cylinders. A typical telescoping jack leg includes two concentric cylinders. One of the cylinders includes a through hole for accepting a retaining pin. The other of the cylinders includes a plurality of through holes arranged along the length of the cylinder. The inner cylinder is withdrawn from or inserted into the outer cylinder until the jack leg is close to the desired length and a through hole of the outer cylinder is aligned with a through hole of the inner cylinder. The retaining pin is then inserted through the aligned through holes of the inner and outer cylinders to lock the inner cylinder and outer cylinder in place with respect to one another. 
     Although telescoping jack legs can provide an extended range of motion without the need for longer hydraulic drive cylinders, they still suffer from some disadvantages. For example, the retaining pins can be lost, rendering the jack leg incapable of supporting any weight. As another example, if an operator fails to replace the retaining pin, or the retaining pin becomes dislodged during transit, the jack leg can fall while the vehicle is in motion, causing serious damage to the jack leg. Telescoping jack legs are also susceptible to other types of damage. If one of the legs becomes even slightly bent, it can become difficult or impossible to slide the inner cylinder of the jack leg into and out of the outer cylinder. In addition, dirt and corrosion can interfere with the telescoping operation of telescoping jack legs, and one cylinder can become stuck in the other cylinder. 
     What is needed, therefore, is a vehicle jack with an increased range of extension that does not require longer drive cylinders. What is also needed is a vehicle jack with an increased range of extension that is not as susceptible to damage as currently known vehicle jacks. What is also needed is a vehicle jack with an increased range of extension that does not include detachable parts that can become lost or dislodged during transit. 
     SUMMARY 
     The present invention overcomes the problems associated with the prior art by providing an extendable jack foot. The extendable jack foot increases the range of extension of the jack without requiring longer drive cylinders. With the extendable jack foot, the vehicle jack is less susceptible to damage than currently known vehicle jacks. The extendable jack foot provides an increased range of extension, but does not include detachable parts that can become lost or dislodged during transit. 
     An example extendable jack foot includes a foot pad and an extension member. The foot pad has a bottom surface and a top surface. The extension member is coupled to and extends from the top surface of the foot pad. The extension member also defines a slot, which is configured to receive a connecting pin. The slot defines a plurality of interconnected seat positions for receiving the connecting pin. 
     In a particular example embodiment, the extendable jack foot further includes the connecting pin for coupling the extendable jack foot to the distal end of a jack leg and a retainer coupled to prevent the connecting pin from sliding out of the slot. An example connecting pin includes a central portion, an end portion, and an engaging feature. The central portion is too large to pass through the slot, but the end portion is small enough to pass through the slot. The engaging feature is configured to engage the retainer. 
     In a more particular example embodiment, the slot is disposed on a first side of the extension member, and there is a complementary slot on a second side of the extension member. 
     In an even more particular example, the extension member includes a first plate and a second plate, and the second plate is spaced apart from the first plate. The first plate defines the slot and the second plate defines the complementary slot. The first plate also extends in a first upward direction and a first transverse direction. The second plate extends in a second upward direction and a second transverse direction. The first upward direction is parallel to the second upward direction, and the first transverse direction is parallel to the second transverse direction 
     In a more particular example embodiment, the interconnected seat positions include a plurality of transverse portions and an intermediate portion. The transverse portions are disposed to accept the connecting pin in a stable position. The intermediate portion facilitates the movement of the connecting pin between any two of the transverse portions. The transverse portions and the intermediate portion provide a means for adjusting the position of the extendable jack foot with respect to the connecting pin. More particularly, the transverse portions include an upper horizontal portion and a lower horizontal portion. Even more particularly the slot and the complementary slot are C-shaped. Alternatively the slot and the complementary slot can be E-shaped, or any other shape that facilitates the adjustment of the effective length of the jack leg. 
     In an even more particular example embodiment, the extendable jack foot also includes a handle. The handle can be fixed to the upper surface of the foot pad. The handle can also be disposed on the extension member. In alternate embodiments the handle can extend between the extension member and the foot pad, fixed to both. Even more particularly, the handle is formed from steel. Even more particularly, the handle includes a rubber cover to improve grip and comfort for a user. 
     A method of manufacturing an extendable jack foot is also disclosed. The method includes forming a foot pad, an extension member, and a slot within the extension member. The method further includes fixing the extension member to the foot pad, wherein the slot is configured to accept a connecting pin such that the extendable jack foot can be slidably coupled to the connecting pin. The method further includes providing a jack leg with a connecting pin and positioning the connecting pin through the slot. The method further includes attaching a retainer to the connecting pin to keep the connecting pin positioned within the slot. 
     A method of using an extendable jack foot is also disclosed. The method includes providing a jack leg with a connecting pin and coupling the extendable jack foot to the connecting pin. The method further includes adjusting the position of the extendable jack foot with respect to the connecting pin such that the effective length of the jack leg is extended when the jack leg is in a lifting configuration and the effective length of the jack leg is shortened when the jack leg is in a transit configuration. 
     Means for extendably coupling a foot pad to a jack leg are disclosed. For example, an extendable jack includes a jack leg, an actuator, a foot pad and a means for extendably coupling the foot pad to the jack leg. The jack leg has a first portion and a second portion movably coupled to the first portion. The actuator is coupled between the first portion of the jack leg and the second portion of the jack leg. The foot pad has a bottom surface and a top surface. In an example embodiment, the means for extendably coupling the foot pad to the second portion of the jack leg includes a rigid body with a bottom surface fixed to the top surface of the foot pad and a plurality of side surfaces. The rigid body also defines a slot extending from one side surface to an opposite side surface. The slot is configured to receive a connecting pin, such that by moving the rigid body with respect to the connecting pin, the effective length of the jack leg is extended or retracted. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is described with reference to the following drawings, wherein like reference numbers denote substantially similar elements: 
         FIG. 1  shows a perspective view of an extendable jack foot coupled to the distal end of a jack leg via a connecting pin; 
         FIG. 2  shows a hydraulic cylinder disposed inside the jack leg of  FIG. 1 ; 
         FIG. 3  is a perspective view of the extendable jack foot of  FIG. 1 ; 
         FIG. 4A  is a side view of the extendable jack foot coupled to the jack leg in a travel position with no extension; 
         FIG. 4B  is a side view of the extendable jack foot coupled to the jack leg in a lifting (load bearing) position with no extension; 
         FIG. 4C  is a side view of the extendable jack foot coupled to the jack leg in a lower slide position; 
         FIG. 4D  is a side view of the extendable jack foot coupled to the jack leg in an upper slide position; 
         FIG. 4E  is a side view of the extendable jack foot coupled to the jack leg in a travel position with extension; 
         FIG. 4F  is a side view of the extendable jack foot coupled to the jack leg in a lifting position with extension; and 
         FIG. 5  shows a perspective view of an alternate extendable jack foot. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention overcomes the problems associated with the prior art by providing an extendable jack foot that extends the effective length of a jack leg, does not include detachable parts, and/or is not as susceptible to damage as the prior art. The invention facilitates simple extension of a jack leg by moving the jack foot about a connecting pin disposed through a slot in the jack foot. In the following description, numerous specific details are set forth (e.g., shape of the slot, configuration of extension member, etc.) in order to provide a thorough understanding of the invention. Those skilled in the art will recognize, however, that the invention may be practiced apart from these specific details. 
       FIG. 1  shows an extendable jack foot  100 , a connecting pin  102 , and a jack leg  104 . Extendable jack foot  100  is adjustably coupled to jack leg  104  by connecting pin  102 . Extendable jack foot  100  extends the effective length of jack leg  104 , which is coupled to a vehicle (not shown) by brackets  105 . 
     Extendable jack foot  100  includes a foot pad  106 , an extension member  108 , and a handle  110 . Foot pad  106  includes an upper surface  112  and a lower surface  114  Extension member  108  and handle  110  are fixed to upper surface  112  of foot pad  106 . Extension member  108  defines a slot  116 , configured to accept connecting pin  102 , and couples jack foot  100  to jack leg  104  by accepting connecting pin  102  within slot  116  in a slidable engagement. Thus, slot  116  provides a means for adjusting the position of extendable jack foot  100  with respect to connecting pin  102 . Foot pad  106  distributes the weight of a load supported by extendable jack foot  100  and jack leg  104  over a larger area of the ground, preventing the lower end of jack leg  104  from being driven into the ground. In alternate embodiments foot pad  106  can have any of a variety of different shapes and thicknesses adequate to disperse the intended load. 
     In this example embodiment, handle  110  is a cylindrical rod that is bent at 90-degree angles at two points along its length, creating a C-shaped rod. Each end of the rod is fixed (e.g., welded) to upper surface  112 . Handle  110  is oriented parallel to an axis of connecting pin  102 . In alternate embodiments, handle  110  can be fixed to extension member  108 , or handle  110  can be oriented perpendicular to the axis of connecting pin  102 . Handle  110  can optionally include a rubber grip or contour features to make it even easier to grasp and manipulate jack foot  100 . 
     Jack leg  104  includes a lower jack leg  118  and an upper jack leg  120 , slidably engaged with one another. Lower jack leg  118  and upper jack leg  120  extend or shorten the length of jack leg  104  by sliding into and out of one another, responsive to an actuator (e.g., hydraulic cylinder  200  of  FIG. 2 ). In alternate embodiments lower jack leg  118  and upper jack leg  120  can be any of a variety of complementary shapes that allow extension or retraction of jack leg  104 . 
     Connecting pin  102  includes retainers  122  (only 1 visible in  FIG. 1 ), each fixed to a respective end of connecting pin  102 . Retainers  122  maintain the engagement of connecting pin  102  and slot  116 , but allow movement of extension member  108  with respect to connecting pin  102 . Alternatively, connecting pin  102  can define channels configured to receive the edges of slot  116 , preventing connecting pin  102  from sliding out of slot  116 . As another alternative, the ends of connecting pin  102  can be threaded in order to receive a complementary threaded fastener, which will prevent connecting pin  102  from sliding out of slot  116 . As yet another alternative, connecting pin  102  can be omitted and replaced by any similarly functioning protrusion from the surface of lower jack leg  118 . 
       FIG. 2  shows a hydraulic cylinder  200  disposed within jack leg  104 . Hydraulic cylinder  200  includes a cylinder barrel  202 , which is fixed to a cylinder head  204 , and a piston rod  206 , which is disposed within cylinder barrel  202 . Piston rod  206  is fixed, by a lower connecting pin  208 , to lower jack leg  118 , and cylinder head  204  is fixed, by an upper connecting pin  210 , to upper jack leg  120 . Hydraulic cylinder  200  is a double-acting cylinder that extends or retracts the length of jack leg  104 . When hydraulic cylinder  200  is driven by a hydraulic pump (not shown), piston rod  206  extends from or retracts into cylinder barrel  202 . When piston rod  206  extends from cylinder barrel  202 , lower jack leg  118  slides out of upper jack leg  120 , thus extending the length of jack leg  104 . When piston rod  206  retracts into cylinder barrel  202 , lower jack leg  118  slides into upper jack leg  120 , thus shortening the length of jack leg  104 . 
     In alternate embodiments hydraulic cylinder  200  can be replaced by any conceivable type of actuator, including, but not limited to, mechanical, pneumatic, and/or electric actuators. 
     Additionally, lower connecting pin  208  can also function as connecting pin  102 , thereby reducing the number of required parts while retaining their function. 
       FIG. 3  shows extendable jack foot  100  removed from connecting pin  102  and jack leg  104  ( FIG. 1 ). Extension member  108  includes a first plate  300  and a second plate  302 , defining a first slot  304  and a complementary second slot  306 , respectively. First slot  304  and second slot  306  are configured to each accept an opposite end of connecting pin  102  in a slidable engagement and to each include a lower transverse portion  308 , an upper transverse portion  310 , and an intermediate portion  312 . In the example embodiment, lower transverse portion  308 , upper transverse portion  310 , and intermediate portion  312  combine to form a C-shaped slot. When connecting pin  102  is seated in lower transverse portion  308 , extension member  108  does not extend the effective length of jack leg  104 . However, when connecting pin  102  is seated in upper transverse portion  310 , extension member  108  does extend the effective length of jack leg  104 . Intermediate portion  312  facilitates the transition of connecting pin  102  between lower transverse portion  308  and upper transverse portion  310 . 
     The slidable engagement between connecting pin  102  and slots  304  and  306  functions as a travel limiter for jack foot  100 . In particular, a user can move jack foot  100  by pivoting extension member  108  about connecting pin  102  and/or sliding extension member  108  over connecting pin  102  in the forward, backward, upward, and/or downward directions. However, the translational motion of jack foot  100  is limited to a two-dimensional plane, and the travel of jack foot  100  within the two-dimensional plane is limited by the borders of slots  304  and  306 . The closed character of slots  304  and  306  prevents extension member  108 , and therefore jack foot  100 , from disengaging pin  102  and lower jack leg  118  ( FIG. 1 ). 
     In alternate embodiments, extension member  108  can be a unitary body (e.g., a sectioned, rectangular cylinder) defining one or more slots. In addition, slot  304  and complementary slot  306  can have any conceivable shape (e.g. E-shaped) that defines a plurality of seat positions and interconnecting passages between the seat positions. 
       FIGS. 4A-E  show extendable jack foot  100  in a variety of positions. Slot  116  defines a plurality of seat positions for connecting pin  102 , including a lower hanging seat position  402  ( FIG. 4A ), a lower lifting (load bearing) seat position  404  ( FIG. 4B ), a lower intermediate seat position  406  ( FIG. 4C ), an upper intermediate seat position  408  ( FIG. 4D ), an upper hanging seat position  410  ( FIG. 4E ), and an upper lifting seat position  412  ( FIG. 4F ). A user can easily manipulate jack foot  100  to position connecting pin  102  in, or move connecting pin  102  between, any of seat positions  402 ,  404 ,  406 ,  408 ,  410 , and  412 . 
       FIG. 4A  shows extendable jack foot  100  in anon-extended position with lower jack leg  118  retracted into upper jack leg  120  (e.g., stowed). Connecting pin  102  is seated within lower hanging seat position  402 , such that extendable jack foot  100  hangs from connecting pin  102 . 
     This position maximizes the distance between jack foot  100  and the ground and, therefore, is suitable for travel 
       FIG. 4B  shows extendable jack foot  100  in a non-extended, load bearing position. Connecting pin  102  is seated in lower lifting seat position  404 , such that extendable jack foot  100  is forced against the ground when jack leg  104  is being extended. In this configuration, extending jack leg  104  will lift and/or support the vehicle, trailer, or other object that is coupled to upper jack leg  120 . 
       FIG. 4C  shows extendable jack foot  100  in a non-extended, transition position. Connecting pin  102  is positioned in lower intermediate seat position  406 . Although jackfoot  100  can bear a load in this position, intermediate position  406  also facilitates the transition of extendable jack foot  100  into an extended, travel position shown in  FIG. 4D . For example, when there is no load on jack leg  104 , retracting lower jack leg  118  will cause connecting pin  102  to travel upward through intermediate portion  312  of slot  116  toward upper intermediate seat position  408 . Thereafter, further retraction of lower jack leg  118  will lift jack foot  100  off of the ground. In addition, when jack foot  100  is in the non-extended stowed position shown in  FIG. 4A , a user can lift jack foot  100  slightly, move jack foot  100  forward (from right to left in the view of  FIGS. 4A-F ) to position connecting pin  102  in intermediate position  406 , then lower jack foot into the extended position shown in  FIG. 4D . Obviously, the reverse process will transition jack foot  100  from the extended position to the non-extended position. 
       FIG. 4D  shows extendable jack foot  100  in an extended, transition position. Connecting pin  102  is positioned in upper intermediate position  408 . Although jack foot  100  can hang suspended by connecting pin  102  in upper intermediate position  408 , position  408  also facilitates the easy transition of connecting pin  102  into upper hanging seat position  410  by sliding jack foot  100  backward (from left to right in the view of  FIGS. 4A-F ). 
       FIG. 4E  shows extendable jack foot  100  in an extended, travel position. Connecting pin  102  is seated within upper hanging seat position  410 , such that extendable jack foot  100  will hang from connecting pin  102  when jack leg  104  is not bearing a load. 
       FIG. 4F  shows extendable jack foot  100  in an extended, load bearing position. Connecting pin  102  is seated within upper lifting seat position  412 , such that extendable jack foot  100  is forced against the ground when jack leg  104  is extended. In this configuration, extending jack leg  104  will lift and/or support the vehicle, trailer, or other object that is coupled to upper jack leg  120 . In addition, in this position, the effective length of jack leg  104  is increased by extendable jack foot  100 , thereby reducing the amount of extension required of hydraulic cylinder  200 . 
     The various positions of jack foot  100  are clearly shown in the side views of  FIGS. 4A-F . However, for the sake of completeness, it should be noted that when the visible end of connecting pin  102  occupies any position within first slot  304 , the opposite end of connecting pin  102  will be positioned in corresponding position within complementary second slot  306 . 
       FIG. 5  is a perspective view of an alternate extendable jack foot  100 A, shown without connecting pin  102  or jack leg  104 . Alternate jack foot  100 A is similar to jack foot  100 , except that it includes an alternate extension member  108 A that defines an increased number of seat positions and, therefore, provides greater flexibility with respect to the extension lengths available. 
     Alternate extension member  108 A includes a first plate  500  and a second plate  502 , configured to receive connecting pin  102  in a slidable engagement and defining a first slot  504  and a second slot  506 , respectively. First slot  504  and second slot  506  each include a lower transverse portion  508 , a middle transverse portion  510 , an upper transverse portion  512 , and an intermediate portion  514 . In the example embodiment, lower transverse portion  508 , middle transverse portion  510 , upper transverse portion  512 , and intermediate portion  514  combine to form an E-shaped slot. When connecting pin  102  is seated in lower transverse portion  508 , the effective length of jack leg  104  is not extended by jack foot  100 . When connecting pin  102  is seated in middle transverse portion  510 , the effective length of jack leg  104  is extended by jack foot  100  by a first distance. When connecting pin  102  is seated in upper transverse portion  512 , the effective length of jack leg  104  is extended by a second distance, greater than the first distance, by extendable jack foot  100 . Intermediate portion  514 , provides a means for transitioning connecting pin  102  between transverse portions  508 ,  510 , and  512 , thereby facilitating adjustment of jack foot  100  between the extended, partially extended, and a non-extended positions. 
     The description of particular embodiments of the present invention is now complete. Many of the described features may be substituted, altered or omitted without departing from the scope of the invention. For example, alternate jack types (e.g., electric jacks, mechanical jacks, etc.) may be substituted for the hydraulic jack shown. As another example, the slot may be any shape that facilitates easy adjustment of the jack foot as well as provides stable seat positions for hanging and lifting. These and other deviations from the particular embodiments shown will be apparent to those skilled in the art, particularly in view of the foregoing disclosure.