Abstract:
A lift having an active opener arm is described. The active opener arm assists a user in stowing and unstowing the lift platform. The active opener arm is capable of receiving the platform from the user when the platform is being stowed and lowering the platform onto the parallelogram linkage. The active opener arm is also capable of lifting the platform off of the parallelogram linkage when the platform is being unstowed and making the platform more accessible to the user.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to lifts for lifting and lowering loads to and from vehicle. More particularly, the present invention relates to an apparatus and method for facilitating the stowing and unstowing of folding lifts.  
         [0003]     2. Description of Related Art  
         [0004]     Lifts raise and lower loads to and from vehicles. Lifts may be mounted to the back or a side of a vehicle, and typically raise and lower a load-carrying platform between the ground and a vehicle bed. Lifts may have lift arms configured in a parallelogram arrangement which maintain the platform in a substantially horizontal orientation through the entire lifting range.  
         [0005]     Lifts may be designed to be stowed when not in use. “Tuck under” style lifts stow the platform underneath the vehicle when not in use. These lifts may use a segmented platform that includes a “flipover.” To stow the platform, the lift arms may be lowered and then the platform folded onto the lift arms. When the lift arms are raised again, the platform is then stowed. To unstow the platform, the lift arms may be lowered, and then the platform unfolded off of the lift arms. The lift is then be ready for use.  
         [0006]     “Tuck under” style lifts may be difficult for a user to fold and unfold, especially in vehicle beds with low ground clearance. Typically, the lower the vehicle bed, the farther in under the vehicle body the user will have to reach. This may result in strain or injury.  
         [0007]     What is needed is a way to make a “tuck under” style platform easier for a user to fold unfold.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  shows one embodiment of a lift of the present invention having an active opener arm.  
         [0009]      FIGS. 2A-2E  show operation of one embodiment of a lift of the present invention.  
         [0010]      FIGS. 3A-3E  show side views of isolated elements of one embodiment of a lift of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0011]      FIG. 1  shows one embodiment of a lift  100  of the present invention having an active opener arm  78 . Lift  100  includes an upper arm  48 , a lower arm  50 , a shackle  52 , a platform  43 , and an active opener arm  78 .  
         [0012]      FIGS. 2A-2E  show operation of one embodiment of a lift  100  of the present invention.  FIG. 2A  shows lift  100  in a fully raised position with platform  43  fully stowed. Platform  43  rests on platform stop  48 / 2 .  FIG. 2B  shows lift  100  in a fully lowered position. Active opener arm  78  has pushed out platform  43  to where it can be easily reached by a user and unstowed for use.  FIG. 2C  shows lift  100  in a fully lowered position with platform  43  in the process of being unstowed.  FIG. 2D  shows lift  100  in a fully raised position with platform  48  unstowed.  FIG. 2E  shows lift  100  in a fully lowered position with platform  43  in the process of being stowed. Platform  43  is folded over so that it rests against active opener arm  78 . When lift  100  is raised, active opener arm  78  lowers platform  43  towards upper arm  48 . When lift  100  is fully raised, active opener arm  78  has lowered platform  43  to rest on platform stop  48 / 2 . Active opener arm  78  is configured so that platform  43  does not contact the underside of vehicle  300  during stowing and unstowing.  
         [0013]      FIGS. 3A-3E  show operation of lift  100  and active opener arm  78 . Upper arm  48  and lower arm  50  are rotatably coupled to main frame  200  and shackle  52 . The four points where upper arm  48  and lower arm  50  are coupled to main frame  200  and shackle  52  substantially form the four corners of a parallelogram.  
         [0014]     Upper arm  48  includes an upper arm pin  48 / 1  and a platform stop  48 / 2 . Lower arm  50  includes a lower arm pin  50 / 1 . Upper arm  48  is configured so that upper arm pin  48 / 1  is lower than lower arm pin  50 / 1 . Upper arm  48  may be configured as a “T” or a “L” shape, or a combination of both. In the embodiment shown, active opener arm  78  includes a pivot  78 / 1 , a channel  78 / 2 , and a roller  78 / 3 .  
         [0015]     Lower arm pin  50 / 1  of lower arm  50  is rotatably coupled to pivot  78 / 1  of active opener arm  78 . Upper arm pin  48 / 1  of upper arm  48  is slidably engaged with channel  78 / 2  of active opener arm  78 . In an alternative embodiment, lower arm pin  50 / 1  may be slidably engaged with channel  78 / 2  of active opener arm, and upper arm pin  48 / 1  rotatably coupled to pivot  78 / 1  of active opener arm. In other embodiments, active opener arm  78  may be slidably engaged with upper arm  48  or lower  50  with a sleeve bearing or with some other arrangement.  
         [0016]      FIG. 3A  shows upper arm  48  and lower arm  50  in a fully raised position with platform  43  in a fully stowed position. Platform  43  rests on platform stop  48 / 2  and active opener arm  78 . As upper arm  48  and lower arm  50  lower in  FIG. 3B , the relative positions of upper arm pin  48 / 1  and lower arm pin  50 / 1  cause active opener arm  78  to rotate, thus pushing platform  43  away from upper arm  48 . As upper arm  48  and lower arm  50  continue to lower in  FIGS. 3C and 3D , active opener arm  78  continues to push platform  43  away from upper arm  48 . When upper arm  48  and lower arm  50  reach a fully lowered position in  FIG. 3E , active opener arm  78  has pushed out platform  43  to where it can be easily reached by a user and unstowed for use.  
         [0017]     Upper arm pin  48 / 1  slides in channel  78 / 2  and causes active opener arm  78  to rotate about lower arm pin  50 / 1 . Active opener arm  78  may be configured to delay unstowing of platform  78 , or to unstow platform  78  at a variable rate. For example, active opener arm  78  may be configured so that platform  43  stays in a substantially stowed position as lift  100  lowers, but then quickly pushes out platform  43  as lift  100  reaches the fully lowered position. Active opener arm  78  may also be configured to accommodate a wide range of vehicle bed heights. Active opener arm  78  may be adjustable in length, or have an adjustable roller  78 / 3 .  
         [0018]     Active opener arm  78  may also be actuated in other ways. For example, an additional actuator such as a hydraulic actuator may be used in conjunction with a sensor to actuate active opener arm  78  as lift  100  approaches the fully lowered position. As another example, a ground plate may be used to actuate active opener arm  78  as lift  100  approaches the ground and the ground plate comes into contact with the ground. More than one active opener arm  78  may also incorporated into the design of lift  100 . An active opener arm  78  may also be used in conjunction with a static opener arm coupled to main frame  200 . The static opener arm may push out platform  78  as lift  100  begins to lower, with active opener arm  78  completing the process as the lift  100  reaches the fully lowered position.  
         [0019]     While the invention has been described in terms of some specific examples and in some specific embodiments, it will be clear that this invention is not limited to these specific examples and embodiments and that many changes and modified embodiments will be obvious to those skilled in the art without departing from the true spirit and scope of the invention as defined in the appended claims.