Abstract:
The ratchet buckle for tightening a strap under a ratchet action provides a lock to positively prevent the ratchet buckle from inadvertently releasing the strap. The lock requires a removable handle to be installed on the ratchet buckle before the lock can be released. The removable handle extends the ratchet buckle crank arm for increased leverage in exercising the ratchet buckle and when removed reduces the overall size of the ratchet buckle and eliminates a crank arm portion that would otherwise extend beyond the ratchet buckle base.

Description:
BACKGROUND 
     1. Field of the Invention 
     This invention relates to tie-downs, as may be used to secure cargo to a vehicle. 
     2. Prior Art 
     It is known to have a ratchet buckle that secures cargo to a vehicle. It is also known to have a ratchet buckle in which a strap is pulled nearly taut through the buckle assembly and then tightened by a ratchet action in the buckle. Conventional ratchet buckles have a mechanism to prevent release of the strap after a ratchet mechanism has tightened the strap. However, the strap can still be inadvertently released such as by accidently jarring the ratchet buckle. This could then lead to release of cargo the buckle was securing. Assuring that the ratchet buckle is not released becomes a safety issue as well as important for protecting the cargo. 
     The object of the present invention is to provide an improved ratchet buckle that automatically locks. Another object is to provide a removable handle that results in a ratchet buckle of reduced size during transport. Another object is to provide a lock that can only unlock the ratchet buckle when the handle moves toward the ratchet buckle base, thereby preventing inadvertent release of the ratchet buckle when the handle is removed. 
     SUMMARY OF THE INVENTION 
     These objects are achieved by a lock and key feature that functions in cooperation with a removable handle and positively locks the ratchet wheel from rotating when the handle is not installed on the ratchet buckle. 
     The lock and key feature can be used generally with tie down buckles that employ a ratcheting action to tighten a strap that is positioned to tie down cargo. Typical of ratcheting tie-down buckles, a first or forward strap is secured to a position remote from the buckle, often by a hook on its distal end. A second or rearward strap is also secured to a different position remote from the buckle, also usually through a hook on its distal end with its proximal end secured to a transverse shaft between base sides at the back of the buckle, typically without length adjustment. The proximal end of the forward strap is connected to a spindle that is reciprocally rotated by a user moving a handle relative to a base, which handle in turn rotates a ratchet wheel to which the spindle is attached. The ratchet wheel is prevented from counter rotating by a pawl, all in a normal ratchet action. 
     The positive lock and key elements that can be employed with a ratchet buckle includes the following features. 
     Ratchet wheels are connected on each end of a spindle on which a strap wraps. The lock is achieved by positively preventing rotation of the ratchet wheel. The lock and key ratchet buckle features a removable handle that is conveniently mounted releasably to a crank arm. The crank arm common in ratchet buckles is used to crank the ratchet wheel and spindle in the base. The essence of the lock and key is that the ratcheting action of the buckle is enabled only when the handle is mounted on the crank arm. In use, the handle moves the crank into a lock position. The handle, which acts on a spring-loaded key, acts to move the key out of the lock for operation of the ratchet. However, with the crank arm in lock position, when the handle is disengaged from the crank arm, the key under spring action moves into engagement with the lock. The lock is connected to the ratchet plate. When the crank is in lock position, the ratchet plate engages the ratchet wheel, preventing the ratchet wheel from rotating. When the key engages the lock with the handle removed, the ratchet plate cannot be withdrawn from the ratchet wheel. 
     The lock comprises legs depending from the release arm, which is connected to the ratchet plate, forming an inverted ‘U’ shape. The key extends from the ratchet buckle base and moves between the legs of the inverted U-shaped lock to prevent the lock from moving away from the ratchet wheel. 
     When the handle is mounted with the crank arm lowered or lock position. The handle is the rotated on the crank arm and pushes the key down out of the lock, which then allows the ratchet plate to be withdrawn from its lock position. 
     An added advantage is that the ratchet buckle is compact with the long handle removed. The long handle is advantageous because it adds leverage to the buckle over a short handle the approximate size of the base. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The ratchet buckle with an excess strap retention arm is illustrated in the following 15 figures. 
         FIG. 1 . is a perspective view of the ratchet buckle of the present invention, shown with the removable handle installed on the crank arm. 
         FIG. 2  is a side view of the ratchet buckle of  FIG. 1 , shown with the crank arm and handle in a raised position above the base. 
         FIG. 3  is side cross-sectional view of the ratchet buckle of  FIG. 1 . 
         FIG. 4  is a side cross-sectional view of the ratchet buckle of  FIG. 2 , shown with the crank arm and handle in a lowered position. 
         FIG. 5  is a side cross-sectional view of the ratchet buckle of  FIG. 4  shown in a lock release position with the handle interface portion urging the key downward out of the inverted U-shaped lock. 
         FIG. 6  is a side cross-sectional view of the ratchet buckle of  FIG. 5  shown with the key within the lock. 
         FIG. 7  is perspective view of the ratchet buckle shown in lock position with the handle removed. 
         FIG. 8  is a side cross-sectional view of the ratchet buckle of  FIG. 7 . 
         FIG. 9  is a perspective view of the removable handle. 
         FIG. 10  is a perspective cut-away view of the base and the key. 
         FIG. 11  is a bottom view of the base and key of  FIG. 10   a.    
         FIG. 12  is an exploded perspective view of the ratchet buckle of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The ratchet buckle  10  of the present invention for tightening a strap includes a base  12 , a spindle  14  journaled to the base  12 , a ratchet wheel  16  attached to the spindle  14 , and a ratchet plate  18  as a pawl that cooperates with the ratchet wheel  16  in a conventional ratchet action, a release arm  20  intermediate the base  12  and slidable in a crank arm  22  and connected to the ratchet plate  18 , the release arm  20  being adapted to disengage the ratchet plate  18  from the ratchet wheel  16  when the release arm  20  is pulled, and the crank arm  22  also being rotatably journaled in the base  12  by the spindle  14  on each ratchet buckle side, the spindle  14  being adapted to wind the strap around it as the spindle  14  is rotated by the crank arm  22  relative to the base  12 . 
     The ratchet buckle  10  further comprises a removable handle  30  that is pivotable on and removable from the crank arm  22  when the handle  30  is installed thereon and which when connected thereto effectively extends the crank arm  22  rearward substantially past the base  12 , typically doubling the effective length of the crank arm  22 . 
     A lock  32  cooperates with the ratchet handle  30  to prevent inadvertent release of a tightened strap on the spindle. The lock  32  comprises legs  33  depending from the release arm  20  forming an inverted “U” that moves up and down with the crank arm  22 . A key  34  is urged upward from the base  12  under spring bias into the lock  32  when the crank arm  22  is lowered into a lock position  36  thereby preventing movement of the release arm  20 . With the ratchet plate  18  thus locked into engagement with the ratchet wheel  16 , the spindle  14  cannot move. 
     A depressor portion  37  of the handle  30  is configured to engage a key interface portion  38  such that as the handle  30  is rotated downward on a crank arm connection shaft  40  that extends between crank arm sides, the depressor portion  36  engages the key interface portion  38  such that the key  34  is urged downward as the handle  30  is further lowered until the key  34  is moved out of the lock  32 . Thus, the ratchet plate  18  is able to disengage from its lock position  36  with the ratchet wheel  16  by pulling the release arm  20 . 
     As shown in the figures, when the handle  30  is removed from the crank arm  22  with the crank arm  22  in lock position  36  with the lock  32  engaging the key  34 , as the handle depressor portion  36  is removed with the handle  30  the ratchet plate  18  cannot be withdrawn from engagement with the ratchet plate  18  thus preventing the ratchet plate  18  from rotating and releasing the strap. The key  34  can only be released from the lock  32  by installing the handle  30  on the crank arm  22  and lowering it with the depressor portion  36  urging the key  34  out of the lock  32 . The ratchet plate  18  is then able to be withdrawn from the ratchet wheel  16 . 
     A hook  42  on a handle connect end  43  is adapted such that it can be hooked around a crank arm connection shaft  40  extending between crank arm sides. The handle  30  is thus pivotable on the crank arm connection shaft  40  and removable from the base  12  by disengaging the hook  42  from the crank arm connection shaft  40 . The handle  30  is adapted to function as a rigid extension of the crank arm  22  cooperating with the crank arm  22  to rotate the ratchet wheel  16  when the handle hook  42  engages the crank arm connection shaft  40  and a handle pull  44  slidable longitudinally on the handle engages a ledge  48 . 
     The ledge  48  is on the crank arm  22  as a catch adapted to match and receive the handle pull  44 , typically under a rearward end  46  of the crank arm  22 . The handle pull  44  is urged forward under spring bias and engages the ledge  48  when the handle  30  is pivoted toward the crank arm  22  by extending under the ledge  48  thereby securing the handle  30  to the crank arm  22  in cooperation with the hook  42  on the crank arm connection shaft  40 . The handle pull  44  is releasable from the ledge  48  by pulling the handle pull  44  away from ledge. With the handle pull  44  disengaged from the ledge the handle  30  is able to be pivoted on the crank arm connection shaft  40  away from the crank and the handle hook  42  is able to be removed from the crank arm connection shaft  40 . The handle  30  is thus removed from the crank arm  22 . 
     Typically a lug  50  is provided on base sides  52 ,  54  that divides motion of the crank arm  22  between ratchet position  56  and lock position  36 . In ratchet position  56 , the ratchet plate  18  is above the lug  50 ; in lock position, the ratchet plate  18  is below the lug  50 , engaging both the ratchet plate  18  and the lug  50  to prevent rotation of the ratchet plate  18 . Thus, the lug  50  prevents the ratchet plate  18  from inadvertently moving out of either position. As the handle and crank lifts the ratchet plate  18  over and past the lug  50 , the ratchet plate  18  is moved out of lock position  36 . Consequently, although the key  34  is allowed to extend under spring bias the lock  32  is lifted above the key  34  as the crank arm  22  is moved into ratchet position  56 . When the strap is tightened as desired, the process is reversed and the handle  30  is removed. When the handle  30  is removed the ratchet buckle  10  cannot release the strap until the handle  30  is again mounted on the crank arm  22 .