Abstract:
A clinch clip for a leaf spring which is rotationally restrained in to mutually orthogonal axes. An upper clip member and a lower clip member are provided. A non-circular rivet connects a leaf of a leaf spring to the lower clip member so as to preclude mutual rotation around a rivet axis. A non-circular bolt connects together the upper and lower clip members so as to preclude rotation around a bolt axis perpendicular to the rivet axis.

Description:
TECHNICAL FIELD 
     The present invention relates to clinch clips used for motor vehicle leaf springs, and more particularly to a clinch clip having rotational restraint about two mutually orthogonal axes. 
     BACKGROUND OF THE INVENTION 
     Leaf springs are widely used for springably supporting the sprung mass of a motor vehicle with respect to an axle (usually the rear axle) adjacent a wheel. A leaf spring is composed of a number of stacked leaves of progressively longer length, increasing from a shortest leaf disposed adjacent the axle to a longest leaf disposed distal from the axle. The leaf spring is connected at its central portion to the axle, for example via U-bolts and a bracket. Each end of the longest leaf has an end fitting for connecting to the sprung mass. The leaf spring forms a semi-elliptical shape in which the concave shape thereof faces away from the axle. 
     At a generally medial location between the leaf spring central portion and each end fitting is disposed a clinch clip which serves to engird the leaves thereat so that the leaves can flex and yet be kept clinched together in a closely stacked configuration. In this regard,  FIGS. 1A through 1D  show an example of a prior art clinch clip  10 , wherein  FIG. 1A  depicts a typical example of operation with respect to a leaf spring  12 , an axle A and sprung mass M. 
     As depicted at  FIG. 1C , the leaf spring  12 , includes a plurality of leaves  12 L, a longest  12   a , a shortest  12   b  and, merely by example, several additional leaves  12   c ,  12   d ,  12   e  disposed in between. 
     As shown best at  FIGS. 1B and 1D , the prior art clinch clip  10  is composed of an upper clip member  14  and a lower clip member  16 , each having a U-shape. The upper clip member  14  has a first lateral bar  14   a  to which at either end thereof is integrally connected a perpendicular first leg  14   b ,  14   c . The lower clip member  16  has a second lateral bar  16   a  (disposed in parallel relation to the first lateral bar  14   a ) to which at either end thereof is integrally connected a perpendicular second leg  16   b ,  16   c  (each disposed in parallel relation to the first legs  14   b ,  14   c ). A cylindrical rivet  18  connects the shortest leaf  12   b , via a circular hole  20  formed therein, to the second lateral bar  16   a , via a circular hole  22  formed therein. The upper clip member  14  is connected to the lower clip member  16  via first and second pairs of aligned circular holes  24   a ,  24   b  formed in a superposition  26  of the first and second legs, respectively, through which a cylindrical bolt  28  passes and is tightly secured thereto by a nut  30  threaded onto end threads of the bolt. A relatively large, generally U-shaped elastomeric spacer  32  is provided, having a pair of robust sidewalls  32   a ,  32   b  interconnected by a relatively thin bottom wall  32   c  disposed between the shortest leaf  12   b  and its adjacent leaf. 
     As can be understood from  FIGS. 1C and 1D , the leaves  12 L of the leaf spring  12  pass into the clinch clip  10 . In this regard, the first lateral bar  14   a  is disposed parallel to the flat upper surface  34  of the longest leaf  12   a , the second lateral bar  16   a  is disposed parallel to the flat of the shortest leaf  12   b , and the first legs are disposed parallel to the edges  12   g  of the leaves. The sidewalls  32   a ,  32   b  of the spacer  32  serve to locate the first legs  14   b ,  14   c  with respect to the leaf edges  12   g , as well as provide a sliding interface therebetween. 
     In operation, as shown at  FIG. 1A , the leaf spring  12  is connected at its central portion  12   f  to the axle A, and each end of the longest leaf  12   a  is an end fitting  42   a ,  42   b  for connecting to the sprung mass M. The prior art clinch clip  10  keeps the leaves of the leaf spring  12  clinched together in a compact configuration as the axle moves in relation to the sprung mass. 
     Problematically, since the prior art clinch clip  10  is free to rotate around the bolt axis B (see arrow A B  of  FIG. 1B ) and free to rotate around the (relatively perpendicular) rivet axis R (see arrow A R  of  FIG. 1B ), when under high force and/or the spacer  32  has failed, the prior art clinch clip  10  can squeak in relation to the leaf spring, and/or the longest leaf may generate a “helicopter-like” noise relative to its adjoining leaf, and/or the prior art clinch clip  10  may rotate on either or both the bolt and rivet axes, disrupting the functionality of the leaf spring due to the undesirable load path management of the leaves during operation. 
     Accordingly, what remains needed in the art is a clinch clip which can somehow be rotationally restrained around the bolt and rivet axes, and yet can be configured such that the attachment of the upper and lower clip members has a compact packaging. 
     SUMMARY OF THE INVENTION 
     The present invention is a clinch clip for a leaf spring which is rotationally restrained in two mutually orthogonal (bolt and rivet) axes, and configured such that the attachment of the upper and lower clip members is compactly packaged such that underbody clearance is maximized. 
     The rotationally restrained clinch clip according to the present invention is composed of an upper clip member and a lower clip member, each having a U-shape, wherein the upper clip member preferably includes an offset leg end portion where it superposes, and attaches to, the lower clip member. The upper clip member has a first lateral bar to which at either end thereof is integrally connected a perpendicular first leg, each preferably having an offset leg end portion. The lower clip member has a second lateral bar (disposed in parallel relation to the first lateral bar) to which at either end thereof is integrally connected a perpendicular second leg (each being disposed in parallel relation to respectively superposed first legs). 
     A non-circular, preferably oval, rivet connects the shortest leaf of a leaf spring, via a correspondingly shaped non-circular hole formed therein, to the second lateral bar, via another correspondingly shaped non-circular hole formed therein. A first set of mutually aligned, non-circular, preferably rectilinear, leg holes are formed at a first superposition of one mutually abutting set of the first and second legs, respectively. A bolt having a non-circular portion corresponding to the non-circular first leg hole set is seated thereat. The bolt further passes through a second leg hole set formed in a second superposition of the other mutually abutting set of the first and second legs, respectively, and is thereupon tightly secured to the first and second legs by a nut threaded onto threads of the bolt. A pair of thin elastomeric liners are preferably provided at each first leg facing the edges of the leaves of the leaf spring which are disposed within the rotationally restrained clinch clip. 
     The rotationally restrained clinch clip has a significant advantage over the prior art clinch clip in that the non-circular shapes of the attachments in the bolt and rivet axes prevent the clinch clip from rotating about either of these axes, thereby eliminating noise and load path management problems associated with prior art clinch clips. An additional significant advantage is that by providing the first legs with an offset leg end portion at the above mentioned first and second superpositions, the head of the bolt and the threaded on nut are received, respectively, by the offsets (with respect to the non-offset portion of the first legs), whereby clearance is provided for any adjacent components of the underbody of the vehicle. 
     Accordingly, it is an object of the present invention to provide a clinch clip for a leaf spring which is rotationally restrained around the bolt and rivet axes, and compactly configured such that the attachment of the upper and lower clip members provides maximal underbody clearance. 
     This and additional objects, features and advantages of the present invention will become clearer from the following specification of a preferred embodiment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a perspective view of a conventional leaf spring schematically connected to an axle and a sprung mass, showing the location of two associated prior art clinch clips. 
         FIG. 1B  is a partly exploded, perspective view of the prior art clinch clip of  FIG. 1A , the spacer being removed for clarity. 
         FIG. 1C  is a broken-away side view of a conventional leaf spring, showing a prior art clinch clip associated therewith. 
         FIG. 1D  is a sectional view, seen along line  1 D- 1 D of  FIG. 1C . 
         FIG. 2  is a perspective view of a leaf spring modified according to the present invention, shown schematically connected to an axle and a sprung mass, showing the location of two associated rotationally restrained clinch clips according to the present invention. 
         FIG. 3  is a partly exploded, perspective view of a rotationally restrained clinch clip according to a first preferred form of the present invention, wherein the liner is removed for clarity. 
         FIG. 4  is a broken-away side view of a conventional leaf spring, showing the first form of rotationally restrained clinch clip of the present invention associated therewith. 
         FIG. 5  sectional view, seen along line  5 - 5  of  FIG. 4 . 
         FIG. 6  is a partly sectional bottom view, seen along line  6 - 6  of  FIG. 5 , wherein the leaf spring is removed for clarity. 
         FIG. 7  is a side view, seen along line  7  of  FIG. 5 , wherein the leaf spring is removed for clarity. 
         FIG. 8  is a top plan view of the liner of the rotationally restrained clinch clip according to the present invention. 
         FIG. 9  is a partly exploded, perspective view of a rotationally restrained clinch clip according to a second form of the present invention, wherein the liner is removed for clarity. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the Drawings,  FIGS. 2 through 9  depict examples of a rotationally restrained clinch clip according to the present invention. 
     Turning attention to  FIGS. 2 through 8 , a preferred rotationally restrained clinch clip  100  is depicted. 
       FIG. 2  depicts a pair of the rotationally restrained clinch clips  100  in operation with respect to a leaf spring  12 ′ generally similar to that of  FIG. 1A  except for a non-circular hole formed in the shortest leaf, as will be described hereinbelow. As in  FIG. 1A , central portion  12   f ′ of the leaf spring  12 ′ is connected with an axle A′, and a sprung mass M′ is connected to a pair of end fittings  42   a ′,  42   b ′ respectively at each end of the longest leaf  12   a ′. As depicted at  FIG. 1C ,  FIG. 4  depicts a leaf spring  12 ′ having a plurality of leaves  12 L′, including a longest  12   a ′, a shortest  12   b ′ and, merely by example, several additional leaves  12   c ′,  12   d ′,  12   e ′ disposed in between, all of which passing into the rotationally restrained clinch clip  100 . 
     The rotationally restrained clinch clip  100  includes an upper clip member  102  and a lower clip member  104 , each having a U-shape. 
     The upper clip member  102  is formed of a first lateral bar  108  and a pair of first legs  110   a ,  110   b  integrally connected with the first lateral bar at each end thereof, respectively. Each first leg has an offset leg end portion  106   a ,  106   b  whereby the leg end portions are offset in the sense of being mutually in closer spaced relation to each other than that of the non-offset portion of the first legs (i.e., the portion of the first and second legs adjoining the first lateral bar). 
     The lower clip member  104  has a second lateral bar  112 , disposed in parallel relation to the first lateral bar  108 , and a pair of second legs  114   a ,  114   b , integrally connected with the second lateral bar at each end thereof, respectively, each disposed in parallel relation to the (mutually abutting portion of) first legs. The mutual spacing of the second legs  114   a ,  114   b  is such that they abut the first legs  110   a ,  110   b  at the inside of the respective offset leg end portion  106   a ,  106   b  at respective first and second superpositions  116   a ,  116   b.    
     A rivet  120  has a shank  122  that is non-circular (that is, the shank has a non-circular cross-section), the non-circularity being for example oval (as preferably shown), rectilinear or otherwise non-circular as for example having an axial keyway or key. As shown collectively by  FIGS. 3 ,  5  and  6 , the second lateral bar  112  has a non-circular cross-sectioned bar hole  124  formed therein, the size and shape corresponding to that of the non-circular cross-section of the shank  122  such that the shank fits therethrough but cannot relatively rotate when seated therein. As shown at  FIG. 5 , the shortest leaf  12   b ′ of the leaf spring leaves  12 L′ has a non-circular cross-sectioned leaf hole  126  formed therein, the size and shape corresponding to that of the non-circular cross-section of the shank  122  such that the shank fits therethrough but cannot relatively rotate when seated therein. The rivet  120  has, preferably, a beveled foot  128  which is countersunk into the leaf hole  126 . The rivet  120  also has an oppositely disposed head  130  which is deformed in order to trap the leaf  12   b ′ to the second lateral bar  112 , wherein the cooperative noncircularity of the shank  122  with respect to the bar and leaf holes  124 ,  126  prevent the second lateral bar from rotating around the rivet axis R′ with respect to the shortest leaf  12   b′.    
     A bolt  132  has a bolt head  134  and adjoining non-circular bolt portion  136 , in the preferred form of a bolt neck  136   a , having a non-circular cross-section, the non-circularity being for example oval, rectilinear (preferred) or otherwise non-circular as for example having an axial keyway or key. The preferred bolt  132  is a carriage bolt with an elongated square cross-sectioned bolt neck (as shown). A threaded bolt portion  138  is threadable with a nut  140 . 
     As shown collectively by  FIGS. 3 ,  5  and  7 , at the first superposition  116   a , the first leg  110   a  at its respective offset leg end portion  106   a  and its abutting second leg  114   a  have formed therein a mutually aligned first leg hole set  142 , wherein each non-circular leg hole  144   a ,  144   b  thereof has the same non-circular cross-section which corresponds to the size and shape of the non-circular cross-section of the non-circular bolt portion  136  such that the bolt neck  136   a  fits therethrough but cannot relatively rotate when seated therein. At the second leg superposition  116   b , the other first leg  110   b  at its respective offset leg end portion  106   b  and its abutting second leg  114   b  have formed therein a mutually aligned second leg hole set  146 , wherein each leg hole  148   a ,  148   b  thereof is configured so that the threaded bolt portion  138  of the bolt  132  is able to pass therethrough. 
     The bolt  132  is placed through the first leg hole set  142  and then through the second hole set  146 , wherein the non-circular bolt portion  136  is seated at both non-circular leg holes  144   a ,  144   b  of the first leg hole set  142 , whereby the cooperative non-circularity of the bolt neck  136   a  with respect to and the non-circular leg holes  144   a ,  144   b  prevent the upper clip member  102  from rotating around the bolt axis B′ with respect to the lower clip member  104  and, consequently, from rotating around the bolt axis B′ with respect to the shortest leaf  12   b ′ about the bolt axis B′. The nut  140  is threadingly engaged tightly onto the threaded bolt portion  138  of the bolt  132 . 
     A pair of thin elastomeric liners  150   a ,  150   b  are provided at each first leg  110   a ,  110   b  facing the edges  12   g ′ of the leaves  12 L′ of the leaf spring  12 ′, as shown at  FIG. 4 . 
     In operation, the leaves  12 L′ of the leaf spring  12 ′ are received into the rotationally restrained clinch clip  100 , whereby the first lateral bar  108  is disposed parallel to the flat upper surface  152  of the longest leaf  12   a ′, the rivet  130  holds tightly the second lateral bar  104  non-rotatably to the shortest leaf  12   b ′, and wherein the first legs  110   a ,  110   b  are oriented parallel to the stacked leaf edges  12   g ′ such that the liners  150   a ,  150  are separated from the leaf edges  12   g ′ so that there is no mutual contact therebetween. 
     The rotationally restrained clinch clip  100  has the significant advantage that the non-circular shapes of the attachments of the rivet and the bolt prevent the rotationally restrained clinch clip from rotating around either of the rivet or bolt axes R′, B′, thereby eliminating noise and load path management problems associated with prior art clinch clips. An additional significant advantage of the rotationally restrained clinch clip  100  is that by providing the first legs  110   a ,  110   b  with the offset leg end portions  106   a ,  106   b  at the respective superpositions  116   a ,  116   b , the head  134  of the bolt  132  and the threaded on nut  140  are recessed with respect to the non-offset portion of the first legs (i.e., with respect to the first legs adjacent the first lateral bar  108 ). In this regard as shown at  FIG. 5 , the offset leg end portions are configured such that the offset leg end portion  106   a  of first leg  110   a  receives therein the bolt head  134  and such that the offset leg end portion  106   b  of first leg  110   b  second leg  110   b  receives therein the nut  140 , whereby clearance is provided for any adjacent components of the underbody of the vehicle. 
     Turning attention now to  FIG. 8 , an alternate example of the rotationally restrained clinch clip  100 ′ is depicted, wherein like parts have like numbering to the rotationally restrained clinch clip  100  at  FIG. 3 , but now with a prime. 
     Exactly as in the rotationally restrained clinch clip  100 , the non-circular shapes of the attachments of the rivet  120 ′ and corresponding non-circular holes  124 ′ and  126  of the shortest leaf (per  FIGS. 5 and 6 ), and of the non-circular blot portion  136 ′ (i.e., the bolt neck  138   a ′) and the corresponding non-circular first hole set  142 ′ are exactly as previously described, preventing the rotationally restrained clinch clip  100 ′ from rotating about either of the rivet or bolt axes R″, B″, and thereby eliminating noise and load path management problems associated with prior art clinch clips. The change in the rotationally restrained clinch clip  100 ′ from the rotationally restrained clinch clip  100  is that now the first legs  110   a ′  110   b ′ of the upper clip member  102 ′ are straight (there is no offset leg end portion), and the second clip member  104 ′ has a longer second lateral bar second  112 ′ (while being yet parallel to the first lateral bar  108 ′), so that the second legs  114   a ′,  114   b ′ abut the first legs at the first and second superpositions  116   a ′,  116   b ′, respectively. 
     To those skilled in the art to which this invention appertains, the above described preferred embodiment may be subject to change or modification. Such change or modification can be carried out without departing from the scope of the invention, which is intended to be limited only by the scope of the appended claims.