Abstract:
A brake caliper has a removable bridge that acts as a rigid mount for a pair of brake pad holders. The removable bridge is retained on the caliper body by spring loaded push button that allows quick removal for replacement of the brake pads, which is especially suited for automotive racing situations. The bridge is snapped in place and rigidly retained on caliper body when in use.

Description:
RELATED APPLICATIONS  
       [0001]     This application claims priority under 35 U.S.C. §119(e) to provisional application No. 60/610,543 filed Sep. 17, 2004. The contents of this priority application are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     This invention relates to brake calipers for use with disc brakes.  
         [0004]     2. Discussion of Related Art  
         [0005]     In typical disc brake assemblies, a rotor is mounted on a wheel hub for rotation. One or more pairs of brake pads, generally designed as friction material carried on a backing plate, are supported on either side of the rotor by a caliper or an anchor bracket. Calipers are designed to apply the braking force by moving a piston relative to the rotor to thereby move the brake pad into and out of contact with the rotor. The pistons are supported in a bore and abut the backing plate of the brake pad to move the brake pad toward the rotor upon application of a braking force. The caliper can be hydraulically actuated, for example, to selectively press the brake pads against the surface of the rotor to stop the rotation of the rotor and hence the wheel hub by forcing hydraulic brake fluid into the piston bore.  
         [0006]     The brake pads, which include friction elements, require periodic replacement due to wear. This is especially true in automotive racing where pads may require replacement during a race. In this situation, quick and easy removal is highly desirable.  
         [0007]     The prior art has addressed this problem in several different ways. It is known, for example, to replace the entire caliper assembly, including the brake pad. In this case, the brake pads are constrained by a bridge integrally formed with the caliper body, an example of which is shown in  FIG. 8A . To replace the brake pad, the caliper assembly must be entirely removed from the vehicle. The advantage of this design is that the bridge provides a maximum degree of stiffness, which enhances braking performance, since it is integrally formed with the caliper body. However, as can be appreciated, removal of the entire caliper assembly requires significant effort. The replacement requires an extended change time.  
         [0008]     In another known method of replacement, the bridge is bolted to the caliper body on both sides, as seen in  FIG. 8B . The bridge often is formed as an H and two bolts rigidly securing the bridge to the caliper body. Removal and replacement is still complicated as multiple bolts must be removed and reinstalled during replacement, but the change time is less than removing the entire caliper assembly in the integral bridge design.  
         [0009]     To decrease change time, one design offers a hinge on one side of the bolted bridge. This type of design is shown in  FIG. 8C . That way, a bolt on only one side needs to be removed to swing the bridge and allow for pad replacement. This design offers comparable stiffness to the fully bolted bridge design and allows slightly faster change time.  
         [0010]     To alleviate the bolting issue, some race caliper manufacturers have replaced the bridge with a spring clamp for quick pad changes, as illustrated in  FIG. 8D . The spring clamp holds the pads in vertically, similar to the integral and bolted bridges, but does not offer the stiffness of the integral and bolted bridges. It has also been know to offer combined spring clamp and bolted bridge design so that the design can be chosen based on the particular event and pad change requirements, as shown in  FIG. 8E .  
         [0011]     Thus, there is a need for a caliper that allows quick pad removal while offering a high degree of caliper stiffness.  
       SUMMARY OF THE INVENTION  
       [0012]     An aspect of embodiments of the invention is to provide a caliper assembly with a bridge designed for quick brake pad removal and replacement.  
         [0013]     Another aspect of embodiments of the invention is to provide a caliper assembly that offers stiffness, particularly with respect to the brake pad supporting bridge.  
         [0014]     These and other aspects of the invention can be realized by embodiments of the invention in which a caliper assembly comprises a caliper body, a bridge releasably secured to the caliper body, at least one brake pad mounted to the bridge, and a push button latch assembly provided between the caliper body and the bridge.  
         [0015]     The invention is also directed to a brake assembly comprising a caliper body, a pair of brake pads slidably retained by the caliper body, a removable bridge rigidly coupled to the caliper body and supporting the pair of brake pads, wherein the removable bridge has a snap release connection at each end that releasably connects to the caliper body.  
         [0016]     The invention further relates to a method of replacing brake pads on a vehicle comprising providing a caliper that supports a brake pad on a bridge mounted to a caliper body, compressing a button on the bridge to disconnect the bridge from the caliper body, removing the brake pad from the bridge, mounting a replacement brake pad on the bridge, and snapping the bridge with the replacement brake pad onto the caliper body.  
         [0017]     The invention encompasses the caliper assembly, the brake assembly, and method above in combination with a vehicle, especially a racing vehicle. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]      FIG. 1  is a side perspective view of a caliper assembly in accordance with the invention;  
         [0019]      FIG. 2  is a side perspective view of the caliper assembly of  FIG. 1  with the bridge and brake pads removed;  
         [0020]      FIG. 3  is a side perspective view of the bridge attached to the pins extending from the caliper body;  
         [0021]      FIG. 4  is a top view of the bridge showing the two positions of the buttons;  
         [0022]      FIG. 5  is an enlarged side view of an end portion of the bridge attached to a pin;  
         [0023]      FIG. 6  is an enlarged top view in partial section of the bridge;  
         [0024]      FIG. 7  is an exploded side perspective view of the bridge and latch assembly;  
         [0025]      FIG. 8A  is a side perspective view of a prior art device;  
         [0026]      FIG. 8B  is a side perspective view of a prior art device;  
         [0027]      FIG. 8C  is a side perspective view of a prior art device;  
         [0028]      FIG. 8D  is a side perspective view of a prior art device; and  
         [0029]      FIG. 8E  is a side perspective view of a prior art device. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0030]     This invention is described for use in a vehicular disc brake system. The caliper described below is used for illustrative purposes only and it will be understood that this invention may be used in various types of braking systems and with any rotor.  
         [0031]     Referring to  FIGS. 1 and 2 , a brake caliper assembly  10  includes a caliper body  12  that has side portions  14  and a central opening  16 . A bridge  18  is releasably connected to the top of the caliper body  12 . Brake pads  20 , which are formed by friction material carried on a backing plate, are slidably mounted on the longitudinal sides  22  of the bridge  18 . The sides  22  act as rails that the brake pads slide on to selectively clamp a brake rotor disc, as is known. The brake pads  20  are designed to move toward each other by pistons, not shown, to press on the rotor to effect braking of a vehicle. The bridge  18  is releasably connected to the caliper body  12  by a spring loaded latch assembly  24 , described in detail below.  
         [0032]     As seen in  FIGS. 2, 3 , and  7 , in detail, a pin  26  protrudes upwardly from the caliper body  12  on each side. The pin  26  has a post  28  that fits into a recess in the caliper body  12 . An annular shoulder  29  protrudes outwardly from the post  28 . The top of the pin  26  has an annular groove  30  that forms a head  32 .  
         [0033]     On each end of the bridge  18 , as seen in  FIGS. 3 and 4 , a latch assembly  24  is formed. Each end of the bridge  18  has a through hole  34  passing from the top to the bottom of the bridge  18 , perpendicular to the sides  22 . The through hole  34  is sized to accept the pin  26 , as seen in  FIGS. 3 and 5 . A button hole  36  passes from one side of the bridge  18  to the other side ending in a closed wall. The button hole  36  is perpendicular to the sides  22  and to the through hole  34 . The button hole  36  and the through hole  34  connect. A button  38  is received in the button hole  36 , as seen in  FIGS. 3 and 6 .  
         [0034]     The button  38  has an enlarged head  40 , a central body  42 , and a cup shaped end  44 . The body  42  has an annular stopping flange  46 . A central groove  48  is defined between the cup shaped end  44  and the flange  46 . A spring  50  is retained in the cup shaped end  44 . The end  44  could also be formed as a flat plate, as long as it forms a biasing surface for the spring  50 . A spring pin  52  is retained in the through hole  34  between the button  38  and the pin  26  as seen in  FIGS. 6 and 7 .  
         [0035]     Upon assembly, the button  38  is inserted in the button hole  36  with spring  50  biased between the wall  37  of the hole  36  and the end  44 . The spring pin  52  is adjacent to the flange  46  of the button  38  and is supported by the shoulder  29  of the pin  26 . By this, the pin  26  protrudes inwardly into the hole  36 , as seen in  FIG. 5 . The latch assembly  24  includes the pin  26 , button  38 , spring  50 , spring pin  52 , and the associated holes  34 ,  36  in the bridge  18 . In the normal latch position, the button  38  is biased outwardly against the spring pin  52 , as seen in  FIG. 3 , the right side of  FIG. 4 , and  FIG. 6 . By this, the cup shaped end  44  protrudes and interferes with groove  30  of pin  26 . This interference holds the bridge  18  onto pins  26  and creates a stiff connection between the bridge  18 , and hence the brake pads  20 , and the caliper body  12 .  
         [0036]     To release the bridge  18 , the button  38  is compressed, as seen on the left side of  FIG. 4 . This compresses the spring  50  and allows the groove  48  to align with the pin  26  and allows the head  32  of the pin  26  to pass through the hole  34 , thus releasing the bridge  18 . This push button release is extremely quick and merely requires a simple compression of the buttons  38 . Similarly easy, the bridge  18  is snapped into place by pressing the bridge  18  against the pins  26  to cause the pins  26  to enter the holes  34  and be locked into place by the button  38  when released. As can be appreciated, the connection between the bridge  18  and the caliper body  12  remains secure due to the constant force applied by spring  50  keeping the pin  26  locked to the bridge  18 .  
         [0037]     Thus, when the brake pads  20  need replacement, the buttons  38  are pressed to release the bridge  18 . The bridge  18  is lifted and new brake pads  20  are mounted on the sides  22 . The bridge  18  is then snapped back onto the caliper body  12 , and the replacement is complete. The process is extremely quick and suitable for fast secure replacement required during automotive racing. In addition, when snapped in place, the bridge  18  is rigidly connected to the caliper body  12  providing a high degree of stiffness.  
         [0038]     It will be understood that the embodiments disclosed herein are illustrative only and that the invention encompasses modifications and changes to the particular design features.