Abstract:
The ratchet buckle for tightening a strap under a ratchet action provides a retention arm that constrains folded excess strap to the buckle to prevent it from flapping free during transport of cargo that the strap secures. A guard is provided outside a crank arm that is rotatably journaled to a base by a spindle on its forward end. The crank arm is secured to the guard intermediate the length of the guard with the guard extending rearward of the crank arm. The guard thus covers a ratchet wheel and the crank arm and with the crank arm forms an effective double-layered crank arm. The retention arm is rotatable on a handle shaft mounted to the guard rearward end, biased down onto folded excess strap.

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. This typically leaves excess strap unattached, which is a hazard during travel. This problem was addressed by U.S. Pat. No. 7,296,326 by Madachy et al in which is disclosed a ratchet buckle that includes a rotating shaft around which the loose end of the strap may be wound. The length of strap that can be wound around the shaft is limited by the clearance between the shaft and the cargo. 
     The object of the present invention is to provide an improved excess strap retention apparatus that cooperates with a ratchet buckle to secure excess strap to the buckle during travel. Another object is to provide a guard to shield a user from buckle components such as sprocket wheels that may injure the user while the user is manipulating the strap and ratchet buckle to tighten the strap about cargo and, similarly, to loosen the strap and ratchet buckle from about the cargo. Another object is to provided a double layered crank arm in cooperation with the guard. 
     SUMMARY OF THE INVENTION 
     The ratchet-based ratchet buckle of the present invention features a retention arm that rotates from a handle rearward of the ratchet buckle base over excess strap folded onto the ratchet buckle. The retention arm can be used generally with many tie down buckles and in particular with those buckles that employ a ratcheting action to tighten a strap that is positioned to tie down cargo. Typically, 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 forward strap may be connected to the spindle securely in which case the strap simply wraps around the spindle as the spindle rotates. The length of the strap is then limited to that length that can be wound on the spindle. The forward strap can also be connected to the spindle by inserting the strap through a slot that divides the spindle into equal halves, in which case in operation, after the strap distal end is remote hooked somewhere, the strap is manually pulled through the spindle until it is nearly taut so that only a short strap length need be wound around the spindle. This can leave an appreciable length of strap pulled through the spindle, referred to herein as the unused portion of the strap, or unused strap. A portion of the unused strap will also wind around the spindle as the spindle rotates to tighten the strap. The portion of the unused strap that remains not wound around the spindle is referred to as the excess portion of the strap, or excess strap. It is this excess strap that is folded and secured over the buckle by the retention arm. 
     Ratchet wheels are coaxial with the spindle on each spindle end. In reciprocally operating the handle to tighten or loosen the forward strap, the user is exposed to injury by the buckle components, particularly the ratchet wheels. It is therefore advantageous to provide a guard to shield the components, and in particular the ratchet mechanism from the user. A ratchet guard is therefore provided on each buckle side to cover the ratchet wheel and the crank arm that connects the handle to the spindle. The ratchet guard is outside the crank arm and serves its function as a shield and adds to the aesthetic qualities of the ratchet buckle but also in connecting to the crank arm forms an effective double layered crank for additional strength and for increased leverage it extends rearward beyond the crank arm. 
     The retention arm is typically broad or panel like to also serve as a top to the buckle that covers a substantial portion of the buckle from the handle on which it rotates to the pawl release near the ratchet wheel except a substantial arm recess in the retention arm opposite the handle through which the excess strap may be routed and through which a folded excess strap may lie on top of the buckle and even extend from over the buckle where it is secured by the retention arm to rearward of the buckle thus allowing the excess strap to be very long, limited only by the number of folds that can fit through the arm recess and a distance from the buckle a user is willing to allow the folded excess strap to extend. A representative form for the panel-like retention arm is shown but that form should not be interpreted as a limitation on the shape of the retention arm. Note that the excess strap can also extend forward of the buckle, which when combined with the rearward extent and layers of excess strap the buckle can accommodate a very long excess strap. More typically, the excess strap is folded to rest fully on the buckle. The retention arm is not necessarily broad or panel like for the retention arm to perform its primary function of securing a folded excess strap down on the top of the base, however it is aesthetically more pleasing and does provide a partial shield of the apparatus under it for added and general protection against damage and dirt. In fact, an alternate retention is described below in which the retention arm is in the form of a wire frame. It should be understood that the forms of the described panel-like and the wire frame retention arms are exemplary only and meant to be only representative of the large number of forms and configurations a retention arm could take, all of which are deemed included in the description given. 
     In normal use the excess strap is guided to its retention position on top of the buckle from over the top of the spindle and down through a release gap between pawls on each side of the buckle that engage the sprocket wheels. The excess strap is then guided over the lock plate to the back of the buckle and over the transverse shaft to which the rearward strap is secured. From the transverse shaft the excess strap is routed under the handle and between crank arms on each buckle side, through the retention arm recess and then folded and placed folded on top of the buckle. The retention arm is then rotated from the handle down onto the folded excess strap typically with a portion of the folded excess strap extending through the arm recess. The arm is held down under spring tension, or equivalently, may be constrained with a hard link to an underlying component. For a quick use, the excess strap can be guided from the top of the spindle directly over the top of the buckle where it is folded and held in place by the retention arm. Both manners of use are deemed included in the detailed description below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The ratchet buckle with an excess strap retention arm is illustrated in the following 15 figures. 
         FIG. 1  is an exploded isometric view of the ratchet buckle of the present invention. 
         FIG. 2  is a combined side view and top view of the ratchet buckle of the present invention. 
         FIG. 3  is perspective view of the ratchet buckle of  FIG. 1  and  FIG. 3 . 
         FIG. 4  is a side cross-sectional view of the ratchet buckle viewed along its longitudinal center, showing the excess strap routed through the buckle and then through the recess in the retention arm. 
         FIG. 5  is a side cross-sectional view of the ratchet buckle viewed along its longitudinal center, showing the excess strap routed through the buckle and then over the retention arm. 
         FIG. 6  is a side cross-sectional view of the ratchet buckle viewed along its longitudinal center, showing the excess strap routed from the spindle over the buckle to its retention position under the retention arm. 
         FIG. 7  is a side cross-sectional view of the ratchet buckle viewed along its longitudinal center, showing the excess strap routed through the buckle and then through the recess in the retention arm, shown with the retention arm raised to a limit with the arm in abutment with a stop on the handle. 
         FIG. 8  is a perspective view of the ratchet buckle shown with the retention arm raised. 
         FIG. 9  is a side view of the buckle with a cut-away showing a retention arm spring that biases the retention arm down on the top of the buckle. 
         FIG. 10  is a perspective view of the buckle shown in  FIG. 8  but with a release and strap support absent to show the ratchet plate and base sides, base shaft and handle. 
         FIG. 11  is a top view of the buckle showing an alternate embodiment of the retention arm in ‘mouse trap’ form as a spring loaded wire arm. 
         FIG. 12  is a rear perspective view of the buckle of  FIG. 11 . 
         FIG. 13  is a rear perspective view of the buckle of  FIG. 12 , shown with the retention arm raised against the spring bias. 
         FIG. 14  is a rear perspective view of the buckle of  FIG. 13 , shown in another alternate embodiment with blocks at the retention arm distal end. 
         FIG. 15  is a top cross sectional view of a front portion of the buckle. 
         FIG. 16  is a side cut-away view showing the alternate embodiment of  FIG. 11  additionally showing a cover over the shaft on which the wire arm rotates. 
         FIG. 17  is a perspective view showing the cover of  FIG. 16 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The ratchet buckle for tightening a strap of the present invention comprises a base  10  and a crank arm  12  with opposing crank arm sides  12   a ,  12   b  mutually pivoting at a spindle  14  by a ratchet action. 
     The base  10  includes opposing base sides  10   a ,  10   b  upstanding from a base bottom  16  with each base side  10   a ,  10   b  having a base spindle hole  18  for receiving the spindle  14 , which rotates coaxially within the base spindle holes  18  between the base sides  10   a ,  10   b . Crank arm sides  12   a ,  12   b  partially overlap the base sides  10   a ,  10   b  outside the base sides  10   a ,  10   b  as the base sides  10   a ,  10   b  and the crank arm sides  12   a ,  12   b  mutually journaled to pivot at the spindle  14 . The crank arm  12  also has a pair of crank holes  20  on respective crank arm sides  12   a ,  12   b  aligned with the base holes  18  such that the spindle  14  passes rotatably through the aligned holes  20 ,  18 . A ratchet wheel  22  is located between respective base  12  and crank arm sides  12   a ,  12   b  align coaxially with the spindle  14  and aligned base spindle and crank holes  20 ,  18  and orthogonal to the base and crank arm sides  10   a ,  10   b ,  12   a ,  12   b.    
     The spindle  14  is forward in the ratchet buckle and comprises two half spindles  14   a ,  14   b  disposed with opposing diametric faces  15  spaced apart forming a spindle slot  17  therebetween. Ends  19  of each half spindle  14   a ,  14   b  fit into matching semi circular holes  24  in the respective ratchet wheels  22  with each semi circular hole  24  receiving a half spindle end  19  such that as the crank arm  12  rotates the ratchet wheels  22 , the spindle  14  also rotates. 
     The ratchet buckle functions in the normal manner of a ratchet to controllably rotate the spindle  14 . In implementing the ratchet, each crank arm side  12   a ,  12   b  has a through crank side slot  30  angled radial to the spindle  14 . A ratchet plate  32  extends between the crank arm sides  12   a ,  12   b  (and over the base sides  10   a ,  10   b ) with ratchet plate pawls  62  forward on the ratchet plate  32  disposed to engage both ratchet wheels  22  at respective crank arm sides  12   a ,  12   b . The ratchet plate  32  is withdrawn from engagement with the ratchet wheels  22  by a user&#39;s pull of a ratchet release arm  34  rearward of the spindle that is connected to the ratchet plate  32 . Ends of the ratchet plate  32  fit slidably in a radial direction with respective to the spindle  14  in respectively crank side slots  30 , into and out of engagement with the ratchet wheels  22 . The ratchet plate  32  is disposed to be pulled radially outward by action of the ratchet release arm  34  or released radially inward under bias of a ratchet spring  40 . Sliding the ratchet plate  32  inward through the crank side slots  30  causes the ratchet plate  32  to engage the ratchet wheels  22 . Similarly, sliding the ratchet plate  32  outward through the crank side slots  30  causes the ratchet plate  32  to disengage from the ratchet wheels  22 , therein allowing the crank to rotate with the ratchet plate  32  outside of the ratchet wheels  22 . 
     To effect a ratchet wheel lock, a lock plate  38  is provided in the base  10 , extending between base sides  10   a ,  10   b  and passing through base slots  42 . As with the crank slots  30 , the base slots  42  are directed radially to the spindle  14  and ratchet wheels  22  below the crank arm  12 . As the crank arm  12  is rotated rearward, a notch  44  in the respective crank arm sides  12   a ,  12   b  engage the lock plate  38  with the lock plate  38  engaging the ratchet wheels  22 , thus preventing the lock plate  38  from moving rearward out of engagement with the ratchet wheels  22 , thus preventing the ratchet wheels  22  and the spindle  14  from rotating. The lock plate  38  is released by lifting the crank arm  12  such that the notch  44  does not engage the lock plate  38 . A lock spring  46  continues to bias the lock plate  38  into engagement with the ratchet wheels  22 . As the crank arm  12  is further lifted and the ratchet release arm  34  is pulled backward as the crank arm  12  is rotated forward, a cam  48  forward on the crank arm respective sides  12   a ,  12   b  engages the lock plate  38  and moves the lock plate  38  rearward out of engagement with the ratchet wheels  22 . 
     In use, a proximal end  49  of a rearward strap  50  that extends rearward from the buckle is secured to a transverse base shaft  52  rearward in the buckle between base sides  10   a ,  10   b . A distal end of the rearward strap  50  (typically with a hook) is secured to a remote position rearward of the buckle. A distal end of a forward strap  54 , typically with a hook, is extended forward of the buckle and secured to a remote location forward of the buckle (not shown). A proximal end  56  of the forward strap is then fed between the half spindles  14   a ,  14   b  and pulled through the spindle  14  until the forward strap  54  is nearly taut as may be easily done by a user without the aid of the ratchet. As the user rotates the crank arm  12  relative to the base  10 , the forward strap  54  on both sides of the spindle slot  17  wrap around the spindle  14 . Forward strap  54  that is pulled through the spindle  14  and not wrapped around the spindle  14  is excess strap  58 . 
     The ratchet plate  32  has a gap  60  between ratchet plate pawls  62  through which the excess strap  58  may pass. The excess strap  58  may then be guided through the ratchet plate gap  60  and over the lock plate  38  and over the transverse base shaft  52  to which the rearward strap  50  is secured. From the transverse base shaft  52  the excess strap  58  may be routed under a crank handle  64 , between crank arms  12  and through a retention arm recess  66 . It may then be folded and placed folded on top of the buckle. A release arm  34  extends upward from the ratchet plate  32 , both of which are secured to and deemed to be part of the base  10 , and functions to release the ratchet plate pawls  62  when pulled rearward. The release arm  34  also serves to support the folded excess strap  58  above the ratchet plate  32 . 
     A bench  68  is provided on the base  10  rearward on the crank arm  12  to also support the folded excess strap  58  rearward of the release arm  34  under the retention arm. The bench top  70  may be non-smooth to better keep the forward strap  54  from sliding. A lug  72  forward on each side of the bench  68  inserts into matching holes  74  in the crank arm  12 . A crank arm shaft  76  passes through a transverse hole  78  in the bench  68  rearward of the lugs  72  and through aligned shaft holes  80  in the crank arm  12  to secure the bench  68  to the crank arm  12 . The folded excess strap  58  is then supported over the buckle on the release arm  34  and the bench  68 . 
     A retention arm  88  is provided that extends from the handle  64  over the top of the buckle. Retention arm sides  90  have retention arm holes  91  through which a handle shaft  82  on which the handle is mounted on the crank arm  12  also passes with the retention arm sides  90  located outside of the handle  64 . The retention arm  88  thus is journaled to rotate on the handle shaft  82  between a raised position to allow the folded excess strap  58  to be conveniently placed on the release arm  34  and the bench  68  and a lowered position in which the retention arm  88  holds the folded excess strap  58  down firmly to the release arm  34  and the bench  68 , the retention arm being of length to extend over at least a portion of the base  10  and onto the excess strap  58 . The retention arm  88  is fully raised when it is rotated until a retention arm limiter  92  rearward on the retention arm  88  abuts a stop  93  on the handle  82  that prevents further retention arm rotation. 
     The retention arm  88  is urged downward under bias of a retention arm spring  94  at the handle  64  through which the handle shaft  82  passes. A spring cap  95  covers the spring. (Any other form of spring bias is deemed included in this exemplary description.) The retention arm  88  is typically a panel substantially closed at its top  96  to serve as a cover over the bench  68  to shield the buckle thereunder from damage and dirt. Typically, the retention arm  88  narrows from ends of the handle  64  to its unattached end  98  which is sized to match the width of the excess strap  58  to, in cooperation with the retention arm sides  90 , keep the excess strap  58  from sliding laterally from under the retention arm  88 . In an alternate embodiment, the retention arm  88  may simply comprise a wire frame  99  as shown in  FIGS. 11 ,  12 , and  13 , in “spring loaded mouse trap” style rotating under spring bias on an alternate retention arm shaft  89 . A block  91  may be provided on the frame  99  to assist in holding the excess strap. A cover  114  may be included that wraps around and over rearward and upward portions  116 ,  118  of the alternate retention arm shaft  89  shielding the shaft  90  and providing a smooth support surface  120  adapted to support a folded excess strap  58  thereon. The cover  114  also shields springs  122  thereon that bias the retention arm  88  downward onto the base  10  or folded excess strap thereon. The cover  114  is held in non-rotating position with ears  124  on cover ends  126  that insert into cover slots  128  in a guard  100  (described below). Cover slits  130  intermediate and forward in the guard allow the wire frame to rotate upward to receive the excess strap  58 . 
     The retention arm recess  66  that was mentioned above through which the excess strap  58  may pass as routed from the spindle  14  is opposite the handle  64 . The folded excess strap  58  on the bench  68  typically extends through the recess  66  when the retention arm  88  is in its lowered position. Thus a minimal frame retention arm and a broad panel retention arm are illustrated as representative of a range of retention arms that are possible, all with the same primary function and affect of securing the excess strap to the ratchet buckle. For all purposes herein, it should be understood that all retention arms of any form that operate to secure the excess strap to the ratchet buckle are deemed included in the description of these two representative retention arms. 
     A guard  100  with a forward portion  102  on each buckle side  104  is mounted on its forward end  101  on the spindle ends  106  outside of the respective crank arms  12  and intermediate its length to the crank arm rearward end  103  such that a guard rearward portion  105  extends rearward of the crank arm, thus resulting in a double layer leverage arm relative to the base  10 , which double layer leverage arm comprises the crank arm  12  and the guard  100  thereby effectively achieving a strengthened crank arm with increased leverage relative to the base  12  where the handle  64  is attached to the guard  100  in its rearward portion  105 , rearward of the crank arm  12 . The handle  64  is secured to the guard  100  with the handle shaft  82  passing through a handle hole  84  and matching aligned guard holes  86  with the guard  100  outside the crank arm  12 . The alternate retention arm shaft  89  extends between the guard  100  on each ratchet buckle side. 
     A ring  108  with a bar  110  diametrically therethrough is mountable to the spindle at each spindle end  106  outside the guard  100  and the crank arm  12  with the bar  110  fitting in the spindle slot  17  to secure the guard  100 , crank arm  12  and ratchet wheel  22  to the spindle on each buckle side. Typically, the ring  108  is of size to match the spindle end  106  and fits within a guard recess  112  at the spindle end. 
     In summary, then the invention disclosed herein comprises a ratchet buckle for tightening a strap including a base, a spindle, a ratchet wheel and a pawl cooperating with the ratchet wheel in a ratchet action. The ratchet buckle comprises a crank arm rotatably journaled in the base by the spindle on each ratchet buckle side to which the crank arm and the ratchet wheel are secured, the spindle having a spindle slot through which the strap may pass such that as the crank arm is rotated with the base and crank arm pivoting apart the strap is tightened with a portion of the strap wound on the spindle and with excess strap pulled through the spindle slot and remaining unwound on the spindle after the strap is tightened and foldable over and supported by at least a portion of the base, a handle on the crank arm, a retention arm journaled to rotate on a shaft on the crank arm, typically a handle shaft on the crank arm on which the handle is mounted, and over at least a portion of the base and being of length to extend over said at least a portion of the base and onto said excess strap thereon, the retention arm being biased toward or constrained against said folded excess strap therein securing said excess strap to said at least a portion of the base, wherein the retention arm includes a recess through which the excess strap may pass from the spindle and through which the folded excess strap may extend to at least the handle wherein the retention arm is effectively a panel that covers a substantial portion of the buckle for aesthetic purposes and for protection of the buckle, wherein the retention arm includes sides that constrain the excess strap from moving laterally, and wherein the retention arm narrows from ends of the handle to approximately a width of the strap; a release arm intermediate the base and rearward of the spindle adapted to release the pawl from engagement with the ratchet wheel and adapted to support the folded excess strap; a bench on the base rearward of the release arm for supporting the folded excess strap under the retention arm, wherein the release arm and the bench together with the spindle provide an effective platform on which the folded excess strap may be supported over the length of the base; a guard outside the crank arm on each ratchet side and also rotatably journaled in the base by the spindle on its forward end and pivoting with the crank arm, the crank arm being secured to the guard intermediate the length of the guard forming a double layered leverage arm, the guard extending rearward of the crank arm and the base at a guard rearward end, the guard covering the ratchet wheel and crank arm, the handle being secured to the guard at the guard rearward end with the guard rotatable on the handle shaft, thus increasing the effective strength of crank arm and extending the effective length and therefore the leverage of the crank arm relative to the base. 
     The double layered leverage arm is therefore journaled in the base by the spindle and is adapted to converge and diverge relative to the base in a reciprocating ratchet action in concert with the ratchet wheel and pawl. The double layered leverage arm first layer then comprises the crank arm and the leverage arm second layer comprises the guard outside the crank arm, which guard and therefore the double layered leverage arm extends over the ratchet wheel and crank arm as a protecting shield, the crank arm and the guard forming a double layer the full extent of the crank arm. The ratchet wheel is therefore sandwiched at the spindle between the base and the double layered leverage arm. Therefore, as the double layered leverage arm is reciprocatingly rotated relative to the base, the strap is tightened with a portion of the strap being wound on the spindle and with excess strap being pulled through the spindle slot and remaining unwound on the spindle after the strap is tightened and adapted to fold over and be supported by at least a portion of the base, and the base being adapted to support the folded excess strap.