Patent Publication Number: US-2013230374-A1

Title: Truck bed lift

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to hoists and more specifically to a lift which may be used to lift objects into the bed of a truck. 
     2. Background Information 
     For many years people have struggled with lifting heavy objects into the bed of a truck such as a pickup. The height of a pickup bed varies somewhat, but it is usually in the neighborhood of about three feet. Lifting a heavy object or a palette of, for example, concrete blocks the three feet from the ground to the pickup bed can be very difficult or impossible unless some effective assisting means is employed. Various lifts have been invented and used to assist in lifting objects onto a truck bed. 
     Some such lifts are affixed to the rear end of the bed and employ hydraulics to move the lift up and down. In other cases a small hoist or crane is affixed to the pickup bed and may be used to lift heavy objects onto the bed. Problems often arise when using a conventional hoist. The object must be adjusted or manipulated to insure that it is lifted in a manner which prevents damage to the truck or the load caused by the object and the truck coming into violent contact with each other. In other instances the shape or composition of the object or objects to be loaded makes it difficult to attach the hoist to the load. 
     The truck bed lift of the instant invention solves the above problems by providing a truck mounted lift which includes a hoist which is capable of being temporarily affixed to a load platform and of lifting and pulling the platform onto or off of the bed of the truck. The ideal invention should also provide for insuring that the load moves smoothly from the ground to the bed without causing damage to either to object or the truck. It should also be simple, reliable, inexpensive, and easy to operate and maintain. 
     SUMMARY OF THE INVENTION 
     The truck bed lift of the instant invention includes a hoist portion which is removably affixed to the truck bed. The hoist includes a hook which is affixed to a frame. The frame is rotatably affixed to the hoist and may be moved forward and rearward using hydraulic pistons. A separate platform is provided. The platform includes a hook pin which may be engaged by the hook. 
     The platform is placed on the ground to the rear of the truck bed and the hook is manipulated using the hydraulics until it moves rearward from the truck bed and engages the hook pin on the platform. The objects to be loaded onto the bed are then placed on the platform. The hydraulics are then used to move the hook upward and rearward. The hook lifts and pulls the platform up onto the bed of the pickup. Guide rollers are provided such that the platform moves smoothly into the bed to prevent damage to the pickup or the load. 
     The load may then be transported to an appropriate location. The object or objects to be unloaded may travel on the platform. The platform may then be unloaded by reversing the loading process. That is, the hook is manipulated until the platform has been moved rearward and downward and it deposited on the ground. 
     One of the major objects of the present invention is to provide a truck mounted lift which includes a hoist which is capable of being temporarily affixed to a load platform and of lifting and pulling the platform onto or off of the bed of the truck. 
     Another objective of the present invention is to insure that the load moves smoothly from the ground to the bed without causing damage to either to object or the truck. 
     Another objective of the present invention is to provide a truck bed lift which is simple, reliable, inexpensive, and easy to use and maintain. 
     These and other features of the invention will become apparent when taken in consideration with the following detailed description and the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of the hoist portion of the instant invention; 
         FIG. 2  is a side view of the platform portion of the instant invention; 
         FIG. 3  is a sectional view of the hoist portion taken along the line  3 - 3  of  FIG. 1 ; 
         FIG. 4  is a sectional view of the platform portion of the instant invention taken along line  4 - 4  of  FIG. 2 ; 
         FIG. 5  is a side view of the hoist and platform in operation; and 
         FIG. 6  is a side view of the hoist and platform with the platform on the ground. 
     
    
    
     DESCRIPTION OF A PREFERRED EMBODIMENT 
     Referring to the drawings,  FIGS. 1-6  there are shown a preferred embodiment of the instant invention. Truck bed lift of the instant invention is shown and described as having the hoist portion of the invention being removably affixed to the bed of a pickup, but the invention could be used for other purposes such as lifting loads onto a loading dock. A pickup  3  (not shown in detail) is considered to have a bed in the rear and a cab in the front. The following description will use front and rear or forward and rearward following this convention. 
     Now referring to  FIG. 1 , a side view of the hoist portion of the invention is shown. A base  2  is provided which may be affixed to the bed of the pickup  3 . A frame  4  is rotatably affixed to the base  2  by means of a base pin  6 . (It will be understood that the base pin  6  could be replaced by a hinge.) The frame  4  is generally “L” shaped with the end of the longer leg of the “L” affixed to the base pin  6 . This leg is generally horizontal. The shorter leg of the “L” is generally vertical and is located just rearward of the cab of the pickup. A hook  8  is affixed to the end of the shorter leg of the “L” of the frame  4  and opens forward. A strut  10  protrudes rearward from the rearward end of the frame  4  and the rearward end of the strut  10  is located near the end of the pickup bed. A hoist roller  12  is affixed to the rearward end of the strut  10  such that the roller protrudes slightly rearward and upward from the strut  10 . 
     Referring now to  FIG. 2 , a side view of the platform portion of the invention is shown. A platform base  14  is provided which is slightly smaller than the interior of the bed of the pickup. A pin frame  16  is affixed to the forward end of the platform base  14 . The platform base  14  is generally horizontal and the pin frame  16  is generally vertical. A brace  20  is provided between the pin frame  16  and the platform base  14  to provide stability. A platform strut  24  extends rearward from the rearward end of the platform base  14  and a platform roller  26  is affixed to the rearward end of the platform strut  24 . A platform pin  18  is affixed to the top portions of said pin frame  16 . 
     Referring now to  FIG. 3 , a sectional view of the hoist portion of the invention taken along line  3 - 3  of  FIG. 1  is shown. This view better shows the configuration of the various elements. The base  2  has two rails, one on either side of the base. A base strut  28  connects the two rails to provide stability. The base pins  6  (See  FIG. 1 ) rotatably affix the two sides of the frame  4  to the base  2 . The vertical portion of the frame  4  is at the forward end of the bed, but in the middle of the bed between the bed sides. As may be seen, this configuration leaves the middle portion of the truck bed open. While the rearward portion of the two sides of said frame  4  are secured by means of said base pins  6 , the forward portion is secured to a frame bracket  29  which secures the forward end of said frame  4  and provides a mounting point for the shorter, vertical portion of said frame  4 . This view further shows a second embodiment of the instant invention in which the vertical portion of said frame  4  is removably affixed to the frame bracket  29  by means of a collar  31  which is affixed to said frame bracket  29 . The vertical portions of said frame  4 , is secured within the collar  31  by any conventional means such as set screws. 
     Referring now to  FIG. 4 , a sectional view of the platform portion of the invention taken along line  4 - 4  of  FIG. 2  is shown. The pin frame  16  consists of two plates located near the front of the bed, but in the middle of the bed between the bed sides. The platform pin  18  is affixed between the two plates. As may be seen in this view, the brace  20  supports the pin frame  16  in two directions. 
     Referring now to  FIG. 5 , a side view of the instant invention in operation is shown. As may be seen, the hook  8  has engaged the platform pin  18 . Hydraulic pistons  30  are rotatably affixed to the base  2  and the frame  4  near the forward end of the base  2  and the rearward end of the frame  4 . The pistons  30  may be used to move the frame  4  either forward or rearward. The bend toward the rearward portion of the frame  4  is necessary to insure that the frame  4  is properly aligned with the base  2  when the frame  4  is in the down position. As seen in this view, the hook  8  has engaged the platform pin  18 . If the pistons  30  are shortened, the hook  8  and the platform base  14  are pulled onto the truck bed. If the pistons  30  are lengthened, the hook  8  and the platform base  14  are pushed rearward such that the platform base  14  may be lowered to the ground. The hoist rollers  12  engage the bottom of the platform base  14  to insure that the platform base  14  moves smoothly into or out of the pickup bed. The platform roller  26  rolls on the ground which also helps to insure that the platform base  14  moves smoothly into or out of the pickup bed. 
     Referring now to  FIG. 6 , a side view of the instant invention in operation with the platform base  14  on the ground is shown. The frame  4  has been moved rearward sufficiently by the pistons  30  (see  FIG. 5 ) to deposit the platform base  14  on the ground. In this position, the hook  8  may easily engage with or disengage from the platform pin  18 . 
     In operation, the frame  4  is manipulated using the pistons  30  such that the hook  8  engages the platform pin  18 . The platform base  14  is on the ground and loaded as desired. The pistons  30  may be used to pull the platform base  14  up onto the pickup bed using the hook  8 . The load may then be transported as appropriate. The load may then be unloaded by reversing the process. As may be seen, the frame has an open, wishbone shape. This not only allows for the use of two hydraulic pistons, but is leaves the middle of the pickup bed open. This is particularly important for users who wish to have a fifth wheel hitch ball in the bed of the pickup. The lift of the instant invention may be used without removing such a hitch ball. The hook  8  is removable. This allows the device to lay flat in the pickup bed with not part protruding above the level of the top of the pickup bed. As may also be seen the instant invention works with both short and long box pickups which is an advantage over known devices which require different models for such pickups. 
     In the preferred embodiment all elements are conventional with structural element being made from steel although other materials having similar properties could be used.