Abstract:
A caliper hardware clip including a frame having a top edge, a bottom edge, and a front surface, a first recess formed in the front surface to receive an end of a first brake pad, a second recess formed in the front surface to receive an end of a second brake pad, a separator integrally formed with the frame, the separator including a bridge portion extending forward from a central portion of the top edge of the frame, a first spring arm extending down and left from a left side of the bridge portion along the front surface of the frame, and a second spring arm extending down and right from a right side of the bridge portion along the front surface of the frame.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to disc brakes, and more specifically to caliper hardware for disc brakes which provides separation between the pads and rotor. 
       BACKGROUND OF THE INVENTION 
       [0002]    Disc brakes have been commonplace in automobiles for decades. Most modern cars have disc brakes on the front wheels, and often on all four wheels. Disc brakes generally include a rotor or disc connected to the wheel and/or axle, and a pair of brake pads on either side of the rotor that are squeezed inwardly against the rotor by means of a caliper. The caliper may be actuated, for example, hydraulically or pneumatically. 
         [0003]    Brake pads generally consist of a metal backing plate with friction material on one side to contact the rotor. The brake pads move inward in relation to the rotor when the brakes are actuated and return in an outward direction thereafter. The caliper typically includes hardware or clips that are mounted in the caliper at the ends of the brake pads to position the brake pads in the caliper. While the hardware generally retains the position of the brake pads in some respects, it often does not ensure the brake pads return to and remain in their outward position after brake actuation. 
         [0004]    It is common in disc brakes to have a return spring mounted between the two brake pads to assist with returning the brake pads to a rest position after braking. Typically, a single spring is mounted in the middle of the two brake pads and engages the upper parts of the backing plates. See, for example, U.S. Pat. No. 7,467,693 to Barbosa et al. The return spring helps to prevent the pads from dragging on the rotors when braking is not desired. However, such a spring may provide an uneven return and retention force on the brake pads. Thus, in some instances, the brake pads may become misaligned with respect to rotor and portions of the brake pads could drag on the rotor despite the presence of the spring. Further, the spring generally requires that holes in each of the backing plates to receive the spring. Drilling of these holes adds cost and delay to manufacturing. 
         [0005]    Some attempts have been made to position return mechanisms at the axial ends of brake pads. U.S. Pat. No. 8,869,950 to Maehara et al. describes a disc brake with pad clips and return springs. Maehara uses a return spring which is attached to a pad clip. This design requires a series of constraining sections and protruding pieces on the pad clip to retain the spring. It also requires two separate pieces which complicates manufacturing and reduces reliability in that the parts can separate. 
         [0006]    U.S. Pat. No. 8,397,880 to Chelaidite discloses a pad retraction device. As shown in  FIG. 6 , some embodiments employ a separate spring as in Maehara. As recognized in Chelaidite, adding a spring can adversely affect the vibration and/or noise performance of the braking system. The remaining embodiments use arms with an overlapping portion or lip on the end of the arm to pull the brake pads outward. This design is complex to manufacture requiring several bends and may lack rigidity due to the overlapping portion and may wear over time. A similar design is disclosed in U.S. Patent Application Publication No. 2010/0051393 to Arioka. 
         [0007]    Such attempts at providing return mechanisms do not provide a viable solution to overcome the drawbacks of the customary central return spring. 
       SUMMARY OF THE INVENTION 
       [0008]    Accordingly, it is an object of the present invention to provide an improved means to ensure alignment of brake pads in disc brake systems and prevent brake pad drag. It is a further object to provide caliper hardware for with a separator element that acts between the brake pads, and in a pushing manner rather than pulling. It is a further object to provide such caliper hardware that is adapted to replace original equipment parts that may not have such a feature for preventing pad drag. 
         [0009]    These and other objectives are achieved by providing a caliper hardware clip having a frame, a first recess or gap for receiving an end of a first brake pad, a second recess or gap for receiving an end of a second brake pad, a first spring element extending from the frame towards the first brake pad and a second spring element extending from the frame towards the second brake pad. In some embodiments, a distal end of the first spring element is positioned in the first recess or gap and a distal end of the second spring element is positioned in the second recess or gap. 
         [0010]    Each of the first and second spring elements extend outward from a central portion of the frame. In some embodiments, the frame includes a central separator portion and each of the first and second spring elements are mounted to or formed integrally with the central separator portion. 
         [0011]    Further provided is a caliper hardware clip including a frame having a top edge, a bottom edge, and a front surface, a first recess formed in the front surface to receive an end of a first brake pad, a second recess formed in the front surface to receive an end of a second brake pad, a separator integrally formed with the frame, the separator including a bridge portion extending forward from a central portion of the top edge of the frame, a first spring arm extending down and left from a left side of the bridge portion along the front surface of the frame, and a second spring arm extending down and right from a right side of the bridge portion along the front surface of the frame. 
         [0012]    Further provided is a disc brake with a rotor, a caliper, two brake pads positioned on opposite sides of the rotor, each brake pad having a proximal end and a distal end, a first caliper hardware clip receiving the proximal ends of the two brake pads, and a second caliper hardware clip receiving the distal ends of the two brake pads. Each of the caliper hardware clips includes a first spring element extending outward towards a first one of the brake pads and a second spring element extending outward towards a second one of the brake pads. 
         [0013]    In some embodiments, each of the caliper hardware clips has a first recess for receiving one of the ends of each of the two brake pads and a second recess for receiving an opposite one of the ends of the two brake pads. A distal end of the first spring element is positioned in the first recess and a distal end of the second spring element is positioned in the second recess. 
         [0014]    Other objects of the invention and its particular features and advantages will become more apparent from consideration of the following drawings and accompanying detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  illustrates a disc brake according to an exemplary embodiment of the present invention. 
           [0016]      FIG. 2  is a perspective view of the caliper hardware of the disc brake shown in  FIG. 1 . 
           [0017]      FIG. 3  is a front view of the caliper hardware of the disc brake shown in  FIG. 1 . 
           [0018]      FIG. 4  is a top view of the caliper hardware of the disc brake shown in  FIG. 1 . 
           [0019]      FIG. 5  is a side view of the caliper hardware of the disc brake shown in  FIG. 1 . 
           [0020]      FIG. 6  is a rear view of the caliper hardware of the disc brake shown in  FIG. 1 . 
           [0021]      FIG. 7  is a top partial view of the disc brake in a braking position. 
           [0022]      FIG. 8  is a top partial view of the disc brake in a non-braking position. 
           [0023]      FIG. 9  is a perspective view of another embodiment of the caliper hardware of the disc brake shown in  FIG. 1 . 
           [0024]      FIG. 10  is a perspective view of another embodiment of the caliper hardware of the disc brake shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]      FIG. 1  shows a disc brake according to an exemplary embodiment of the present invention. The disc brake includes a rotor  10  and a caliper  20 . Within the caliper  20 , there are two brake pads  30 ,  32  disposed on opposite sides of the rotor  10 . Each of the brake pads  30 ,  32  includes a backing plate on the outboard side and friction material on the inboard side adjacent to the rotor  10  (as shown in  FIGS. 7-8 ). 
         [0026]    The disc brake includes two caliper hardware elements or clips  40  disposed at opposite ends of the brake pads  30 ,  32  and within the caliper  20 . As discussed below, the caliper hardware  40  advantageously includes a separator element that pushes the brake pads  30 ,  32  apart. The inventors have found that the separator of the present design that pushes the brake pads  30 ,  32  outward, rather than pulling outward as in some prior art designs, provides an even and repeatable force with minimal deformation and/or reduction in force over time. The caliper hardware  40  of the present invention is also easier to manufacture and requires less material than prior art designs. Further, the design advantageously leaves the central opening of the caliper hardware  40  clear of any obstructions that could interfere with braking or complicate installation. The caliper hardware  40  can be used on original equipment manufacturer (“OEM”) brakes, but is particularly useful in the aftermarket for replacing OEM caliper hardware that does not have such a feature for preventing pad drag. 
         [0027]      FIGS. 2-6  show views of one embodiment of the caliper hardware  40  or caliper hardware clip. The caliper hardware  40  is preferably stamped or formed from a single piece of material, thus avoiding the necessity to manufacture and join separate parts. The caliper hardware  40  has a frame  42  defining two cavities or recesses  44 ,  46  to receive proximal or distal portions of the brake pads  30 ,  32 . The frame  40  is shaped to conform to and/or interlock with the caliper  20 . The frame  40  may also include a retaining element extending rearward with tabs to interlock or connect with caliper  40  (see  FIG. 5 ). 
         [0028]    As depicted in  FIG. 1 , typically two caliper hardware pieces are used, one on each end of the caliper  20 . Thus, recess  44  receives a distal portion of a first brake pad  30  (or backing plate thereof) and recess  46  receives a distal portion of a second brake pad  32  (or backing plate thereof). Proximal portions of each of the first and second brake pads  30 ,  32  (or backing plates thereof) are received in respective recesses of the second caliper hardware piece positioned at the opposite end of the caliper  20 . 
         [0029]    Each of the cavities are defined by a top wall, a back wall, and a bottom wall. For example,  FIG. 5  shows a top wall  46   a,  a back wall  46   b,  and a bottom wall or shelf  46   c.  Within each of the cavities  44 ,  46 , there is a tab  48 ,  50  that abuts or is adjacent to a rear surface of the backing plates of the brake pads  30 ,  32  when the brake pads  30 ,  32  are in non-braking positions. 
         [0030]    In the exemplary embodiment, the caliper hardware  40  has a separator  60  which, when in use, is located between the distal or proximal ends or two brake pads,  30 ,  32 . The separator  60  includes a central bridge portion and two spring elements  62 ,  64 . As shown in  FIG. 2 , the bridge portion extends forward from the frame  42  in a direction towards the center of brake pads  30 ,  32 . The spring elements  62 ,  64  extend on an angle both outward (towards respective brake pads  30 ,  32 ) from opposite ends of the bridge portion of the separator  60  and downward towards the bottom walls (e.g.,  46   a ). In one embodiment, the spring elements  62 ,  64  extend downward at an angle of at least thirty degrees or approximately forty-five degrees. 
         [0031]    In the exemplary embodiment, the caliper hardware  40  is made a single piece of material, such as sheet metal, with a uniform thickness. The spring elements  62 ,  64  have a thickness substantially equal to a thickness of the rest of the caliper hardware  40  (e.g., the frame) and a width of at least three times, such as five times or ten times, that of the thickness. 
         [0032]    As shown in  FIG. 5 , in the exemplary embodiment, the spring elements  62 ,  64  have a shape that curves forward towards the center of the brake pads, extends along a straight portion, and curves backwards and away from the center at a distal end  65 . In the exemplary embodiment, the distal end  65  of each of the spring elements  62 ,  64  is at least partially positioned within one of the cavities  44 ,  46  and below and/or adjacent to the top wall (e.g.,  46   a ) thereof. This design keeps the spring elements  62 ,  64  away from the friction material  35 ,  37  and minimizes or avoids any intrusion of spring elements  62 ,  64  into the area where the brake pads  30 ,  32  contact the rotor  10 . The distal end  65  may also extend downward in the cavities  44 ,  46  to provide increased surface area to contact the brake pads  30 ,  32 . In the exemplary embodiment, the distal ends  65  of the spring elements  62 ,  64  are spaced apart from one another by approximately 2.5 inches. 
         [0033]      FIGS. 7-8  illustrate the use of the caliper hardware  40  on a disc brake. In  FIG. 7 , the disc brake is actuated and the brake pads  30 ,  32  are against the rotor  10 . The spring elements  62 ,  64  are at compressed inward by the brake pads  30 ,  32 . In  FIG. 8 , the disc brake is released and the brake pads  30 ,  32  are returned to their rest positions. In the rest position, the spring elements  62 ,  64  are extended and providing a minimal retaining force to keep the brake pads  30 ,  32  away from the rotor  10 . By having a caliper hardware piece or clip  40  at each end of each brake pad  30 ,  32 , the pads are retained evenly away from the rotor to avoid any pad drag on either end. 
         [0034]    As shown in  FIGS. 7-8 , each brake pad includes a backing plate  31 ,  33  and friction material  35 ,  37 . The friction material  35 ,  37  covers at least a portion of the interior surface of the backing plate  31 ,  33 . However, there is generally a portion of the interior surface of the backing plate  31 ,  33  that remains free of friction material  35 ,  37  such as at the distal and proximal ends of the backing plate  31 ,  33  and/or around the entire perimeter of the backing plate  31 ,  33 . 
         [0035]    The distal ends of the spring elements  62 ,  64  contact and apply an outward force against the inside of each of the brake pads  30 ,  32 , and particularly on an exposed portion of the interior surface of the backing plates  31 ,  33  at the distal ends and proximal ends of the backing plates  31 ,  33  in the cavities  44 ,  46 . After the brakes have been actuated and released, the brake pads  30 ,  32  return to their rest position as shown in  FIG. 8 . 
         [0036]    The spring elements  62 ,  64  provide outwardly directed forces against the brake pads  30 ,  32 , to ensure that both the proximal and distal ends of each of the brake pads  30 ,  32  return to and stay in the rest position and are sufficiently spaced away from the rotor  10 . In particular, when the brakes are not applied, the spring elements  62 ,  64  (being at both ends of the brake pads  30 ,  32 ) retain the pads  30 ,  32  in an even position spaced away from the rotor  10 . Applying an outward pushing force, rather than a pulling force, provides for an even and repeatable force. 
         [0037]    As shown, some embodiments of the disc brake could also include a spring  26  mounted between the backing plates of each of the brake pads  30 ,  32 . The spring  26  attaches to each of the backing plates via holes  27  in the backing plates. While the spring  26  assists in returning the brake pads  30 ,  32  to their rest positions after the brakes are actuated, acting alone it may provide an uneven return force on the brake pads  30 ,  32  and/or still allow some drag during rest given that no force is being applied at the proximal and distal ends of the pads  30 ,  32 . Thus, the caliper hardware  40  of the present invention provides additional spring force on each end of the brake pads  30 ,  32  ensure even and complete spacing between the brake pads  30 ,  32  and the rotor  10 . In preferred embodiments, particularly when the caliper hardware is used in OEM applications, no such spring  26  is used. This avoids having to drill holes  27  in the backing plates  31 ,  33  saving time and cost. 
         [0038]    The caliper hardware of the present may take different shapes and forms to accommodate different brake applications, sizes, and shapes.  FIG. 9  illustrates another embodiment of the caliper hardware  140  for use on the brake shown in  FIG. 1 . The caliper hardware  140  is preferably stamped or formed from a single piece of material. The caliper hardware  140  has a frame  142  defining two recesses  144 ,  146  to receive proximal or distal portions of the brake pads  30 ,  32 . The recesses  144 ,  146  have a top wall, a back wall, and a bottom wall. Within each of the recesses  144 ,  146 , there is a tab  148 ,  150  that is positioned against and retains a rear surface of the backing plates of the brake pads  30 ,  32 . 
         [0039]    The caliper hardware  140  has spring elements  162 ,  164  that extend outward from an inside edge of the back wall of the recesses and towards the backing plates and/or the tabs  148 ,  150 . Distal ends of each of the spring elements  162 ,  164  are positioned within one of the recesses  144 ,  146 . The backing plates are retained between the tabs  148 ,  150  and the distal ends of the spring elements  162 ,  164 . As with the previous embodiment, the hardware  140  provides an even outwardly directed force against the brake pads  30 ,  32 . 
         [0040]      FIG. 10  illustrates another embodiment of the caliper hardware  140  for use on the brake shown in  FIG. 1 . The caliper hardware  240  is preferably stamped or formed from a single piece of material. The caliper hardware  240  has a frame  242  with two gaps  244 ,  246  to receive proximal or distal portions of the brake pads  30 ,  32 . Within or defining each of the gaps  244 ,  246 , there is a tab  248 ,  250  that is positioned against and retains a rear surface of the backing plates of the brake pads  30 ,  32 . 
         [0041]    The caliper hardware  240  has a central opening with vertical edges from which spring elements  262 ,  264  extend. The spring elements  262 ,  264  that extend outward towards the backing plates and/or the tabs  248 ,  250 . The backing plates are retained between the tabs  248 ,  250  and the distal ends of the spring elements  262 ,  264 . As with the previous embodiments, the hardware  240  provides an even outwardly directed force to the brake pads  30 ,  32 . 
         [0042]    Although the invention has been described with reference to a particular arrangement of parts, features and the like, these are not intended to exhaust all possible arrangements or features, and indeed many modifications and variations will be ascertainable to those of skill in the art.