Patent Publication Number: US-2015075925-A1

Title: Floating brake disc assembly

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a floating brake disc assembly and more particularly to a floating brake disc assembly in which a brake rotor is mounted to a hub member and a coned-disc spring is employed to enable the whole brake rotor to float relative to the hub member in parallel. 
     2. Description of the Related Art 
     Conventional floating brake disc assembly  9 , as shown in  FIG. 5 , includes a hub member  92  and a brake rotor  93  connected together by means of a rivet pin  91  running through a connecting hole  90  defined in between the hub member  92  and the brake rotor  93  in a manner that the brake rotor  93  is allowed to move axially relative to the hub member  92  to a limited amount, whilst being constrained to rotate with the hub member  92 . In particular, the floating brake disc assembly  9  further includes a coned-disc spring  94  and a washer  95  mounted around the rivet pin  91  such that the whole rotor  93  can float in parallel relative to the hub member  92 . 
     However, during the manufacture of the floating brake disc assembly  9 , the coned-disc spring  94  may not be well centered on the rivet pin  91  as desired, as shown in  FIG. 6 . Thus, after the rivet punching process, as shown in  FIG. 7 , the coned-disc spring  94  becomes tilted or uneven with one end  94 ( a ) in contact with the hub member  92  while the other end  94 ( b ) suspended over the brake rotor  93 , causing the floating brake disc assembly  9  to malfunction. Therefore, there is then a need for an improved floating brake disc assembly in which the above problem is obviated or at least substantially reduced. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a improved floating brake disc assembly in which the coned-disc spring is constructed to be able to well centered on the rivet pin during the punch-riveting process. 
     To achieve the foregoing objective, the floating brake disc assembly includes generally a disc body and at least one fastener. The disc body includes a hub member and a brake rotor circumferentially around the hub member. The hub member and the brake rotor together define at least one connecting hole through which the fastener is mounted. The fastener includes a rivet pin, a coned-disc spring and a protection washer in close proximity to the coned-disc spring. The coned-disc spring has a conical body having a central hole therein, and at least one positioning post axially extending from the conical body. The protection washer has a central bore and defines in an inner wall of the central bore at least one dent corresponding to the positioning post of the coned-disc spring. The protection washer and the coned-disc spring are engaged to each other with the positioning post of the coned-disc spring being lodged in the dent of the protection washer. The rivet pin passes through the connecting hole of the disc body, the central hole of the coned-disc spring and the central bore of the protection washer so as to fasten the hub member and the brake rotor together while allowing slight floating movement of the brake rotor relative to the hub member therebetween. In such a manner, the engagement between the coned-disc spring and the protection washer ensures that the coned-disc spring is well centered on the rivet pin during the punch-riveting process. 
     Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a floating brake disc assembly in accordance with the preferred embodiment of the present invention; 
         FIG. 2  is an enlarged exploded partial perspective view of the floating brake disc assembly as shown in  FIG. 2 ; 
         FIG. 3  is a partial cross-sectional view of the floating brake disc assembly shown in  FIG. 1 , taken along the line; 
         FIG. 4  is a partial cross-sectional view of the floating brake disc assembly shown in  FIG. 1 , taken along the line IV-IV; 
         FIG. 5  is a partial cross-sectional view of a conventional floating brake disc assembly; 
         FIG. 6  is a partial cross-sectional view of a failed conventional floating brake disc assembly, before the punch-riveting process; and 
         FIG. 7  is a view similar to  FIG. 6 , showing the failed floating brake disc assembly after the punch-riveting process. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Illustrated in the drawings is a floating brake disc assembly  100  employing the invention. As shown in  FIG. 1 , the assembly  100  is adapted to be mounted on a wheel (not shown) of a vehicle and generally includes a disc body  1  having a hub member  11  and a brake rotor  12  circumferentially around the hub member  11 , and a number of fasteners  2  provided to connect the hub member  11  and the brake rotor  12  together. The hub member  11  has a central hole  13  for reception of a hub axle of the wheel. 
     Specifically, as shown in  FIG. 2 , the hub member  11  defines in its outer periphery a plurality of semicircular recesses  110  spaced apart in a distance. On the other hand, the brake rotor  12  defines in its inner periphery a plurality of opposing semicircular recesses  120 . Those semicircular recesses  110 ,  120  in the hub member  11  and the brake rotor  12  are mated respectively to form a plurality of connecting holes  10  in which the fasteners  2  are mounted. 
     Referring again to  FIGS. 2 and 3 , each of the fasteners  2  includes a rivet pin  3 , a coned-disc spring  4  and a protection washer  5  in close proximity to the coned-disc spring  4 . The protection washer  5  has a central bore  50  and defines a plurality of dents  51  in an inner wall of the central bore  50 . The coned-disc spring  4  has a conical body  41 , a central hole  40  defined in the conical body  41 , and a plurality of positioning posts  42  axially extending from the conical body  41  and being lodged in the dents  51  of the protection washer  5 , as best seen in  FIG. 4 . The rivet pin  3  passes into the respective connecting hole  10  of the disc body  1 , the central hole  40  of the coned-disc spring  4  and through the central bore  50  of the protection washer  5  so as to fasten the hub member  11  and the brake rotor  12  together while allowing slight floating movement of the brake rotor  12  relative to the hub member  11  therebetween. In this manner, the engagement between the coned-disc spring  4  and the protection washer  5  ensures that the coned-disc spring  4  is well centered on the rivet pin  3  before or after the punch-riveting process. 
     Referring back to  FIG. 2 , the rivet pin  3  is hollow and has a head  31 , a large-diameter section  32  extending from the head  31 , a small-diameter section  33  extending from the large-diameter section  32 , and a shoulder  34  formed at the junction between the large-diameter section  32  and the small-diameter section  33 . The head  31  of the rivet pin  3  abuts against a side of the disc body  1 . The large-diameter section  32  of the rivet pin  3  passes through the connecting hole  10  of the disc body  1  and has a length substantially equal to the depth of the connecting hole of the disc body  1  such that the shoulder  34  of the rivet pin  3  may be flushed with the other side of the disc body  1 , as shown in  FIG. 3  or  4 . The small-diameter section  33  of the rivet pin  3  extends beyond the other side of the disc body  1  and is formed with a radial flared end  330 , after the rivet punching process, such that the coned-disc spring  4  together with the protection washer  5  is biased against the other side  10  of the disc body  1  to enable the whole rotor  93  to float in parallel relative to the hub member  92 . 
     In the illustrated embodiment, the coned-disc spring  4  and the protection washer  5  are both mounted around the smaller-diameter section  33  of the rivet pin  3  and sandwiched between the shoulder  34  and the radial flared end  330  of the smaller-diameter  33  of the rivet pin  3 . Moreover, the shoulder  34  of the rivet pin  3  is flushed with the other side of the disc body  1  and therefore will not interfere with the movement of the coned-disc spring  4  while in use. 
     It is also noted that, the coned-disc spring  4  has a concave side  33  and a convex side  44  and is attached to the other side of the disc body  1  with the concave side  33 . As such, when a braking force is applied to the brake rotor  12  by means of a brake caliper (not shown), the whole brake rotor  12  can float relative to the hub member  11  in parallel as a result of the coned-disc spring  4  biasing thereto. Similarly, when the brake rotor  12  is released from the caliper, the whole brake rotor  12  can be returned back to its original position due to the elasticity of the coned-disc spring  4 . 
     It is to be understood that the disclosed embodiments are illustrative in nature and the invention is not to be limited to any one or more embodiments except as set forth in the following claims.