Patent Publication Number: US-2015060218-A1

Title: Brake disc assembly

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to brake discs and more particularly to a brake disc assembly including a ring and a central part releasably secured to the ring, the central part having a low thermal conductivity so as to reduce heat transferred to the bearing in the hub. 
     2. Description of Related Art 
     A conventional brake disc A shown in  FIG. 1  is a unit and includes a plurality of holes (two different sizes are shown) A 1  and a central hole A 2  surrounded by the hole A 1 . The brake disc A is formed of cast iron. Brake pads are actuated to clamp both side surfaces of the brake disc A when braking. Thus, high heat is generated and it can quickly transfer to a hub (not shown) secured to the central hole A 2 . Further, the heat may transfer to balls of a bearing (not shown). The bearing may be damaged after a short period of time of use. Thus, the need for improvement still exists. 
     SUMMARY OF THE INVENTION 
     It is therefore one object of the invention to provide a brake disc assembly comprising a ring including a plurality of holes and a plurality of protrusions equally spaced along an inner edge, each protrusion having an aperture distal the holes; a central part includes a plurality of through holes equally spaced along a periphery, a central hole, and a plurality of spaced hole members surrounding the central hole; a plurality of externally threaded bolts; and a plurality of internally threaded nuts; wherein the through holes and the protrusions are in register; and wherein the externally threaded bolts are driven through the apertures and the through holes into the internally threaded nuts to fasten the ring and the central part together. 
     The above and other objects, features and advantages of the invention will become apparent from the following detailed description taken with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a conventional brake disc; 
         FIG. 2  is an exploded view of a brake disc assembly according to a first preferred embodiment of the invention; 
         FIG. 3  is an exploded view showing the ring and the ring to be fastened by a fastening member; 
         FIG. 4  is a perspective view of the bolt shown in  FIG. 3 ; 
         FIG. 5  is a perspective view of the assembled brake disc assembly shown in  FIG. 2 ; 
         FIG. 6  is a sectional view showing the fastening member and adjacent portions of the ring and central part of  FIG. 5 ; 
         FIG. 7  is a perspective view of a brake disc assembly incorporating a second configuration of the ring; 
         FIG. 8  is a view similar to  FIG. 3  showing a second configuration of the fastening member and adjacent portions of the ring and central part; 
         FIG. 9  is a sectional view showing the fastening member and adjacent portions of the ring and central part of  FIG. 8 ; 
         FIG. 10  is a view similar to  FIG. 3  showing a three configuration of the fastening member and adjacent portions of the ring and central part; 
         FIG. 10A  is a perspective view of the first fastening element of the fastening member; 
         FIG. 11  is a sectional view showing the fastening member and adjacent portions of the ring and central part of  FIG. 10 ; 
         FIG. 12  is a perspective view of the brake disc assembly incorporating the fastening members shown in  FIG. 10 ; 
         FIG. 13  an exploded view of a brake disc assembly according to a second preferred embodiment of the invention; 
         FIG. 14  is an exploded view showing the ring and the ring to be fastened by the fastening member of  FIG. 13 ; 
         FIG. 15  is a perspective view of the assembled brake disc assembly shown in  FIG. 13 ; and 
         FIG. 16  is a sectional view showing the fastening member and adjacent portions of the ring and central part of  FIG. 15 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 2 to 6 , a brake disc assembly  1  in accordance with a first preferred embodiment of the invention comprises the following components as discussed in detail below. 
     A ring  1  includes a plurality of holes  11 , a plurality of projections  12  equally spaced along an inner edge, and a plurality of half-circular cavities  13  each formed on the projection  12 , the half-circular cavity  13  having two opposite inclined ends  131 . A central part  2  includes a plurality of half-circular depressions  21  equally spaced along a periphery, a central hole  23 , and a plurality of spaced hole members  22  surrounding the central hole  23 . The half-circular depression  21  has two opposite inclined ends  211 . 
     A plurality of fastening members each includes a bolt  31  having a threaded shank  311  and an internally threaded nut  32  having an inclined ramp  321 . In assembly, the depressions  21  are attached to the cavities  13  to form a circular hole in which the inclined ends  131  of the cavity  13  are in close contact with the inclined ends  211  of the depression  21 . Further, the threaded shank  311  is inserted through the circular hole into the nut  32  to fasten the projections  12  and the depressions  21  together. Thus, the ring  1  and the central part  2  are secured. 
     The ring  1  is made of cast iron and is adapted to transfer heat when heat is generated by two brake pads in the event of braking. 
     The central part  2  is made of a material having low thermal conductivity. Thus, the heat transfer from the ring  1  to the central part  2  is greatly reduced. Thus, a minimum heat is transferred to balls of a bearing (not shown). The bearing is thus thermally insulated. This can prolong the useful life of the bearing. 
     Referring to  FIG. 7 , the circular holes  11  are replaced by elongated holes  11 . 
     Referring to  FIGS. 8 and 9 , a second configuration of the fastening member is shown. The fastening member includes a bolt  31  having a hexagonal head (not numbered) and a threaded shank  311 , and a hexagonal nut  32  having internal threads  321 . 
     Referring to  FIGS. 10 ,  10 A,  11 , and  12 , a three configuration of the fastening member is shown. The fastening member includes a first fastening element  41  having an inclined shoulder  411 , and a second fastening element  42  having an inclined shoulder  421 . The first and second fastening elements  41 ,  42  are joined to fasten the ring  1  and the central part  2  together. The inclined shoulder  411  urges against one inclined end  131 . The inclined shoulder  421  urges against the other inclined end  131 . 
     Referring to  FIGS. 13 to 16 , a brake disc assembly in accordance with a second preferred embodiment of the invention is shown. The characteristics of the second preferred embodiment are discussed below. 
     A ring  1  includes a plurality of holes  11  and a plurality of protrusions  14  equally spaced along an inner edge, each protrusion  14  having an aperture  141  distal the holes  11  and a ramp member  142  on one end of the aperture  141 . 
     A central part  2  includes a plurality of through holes  24  equally spaced along a periphery, a central hole  23 , and a plurality of spaced hole members  22  surrounding the central hole  23 . The through hole  24  has a ramp  241 . 
     A plurality of fastening members each includes a bolt  31  having a threaded shank  312  and a ramp member  312  formed between the head and the threaded shank  311 ; and a nut  32  having internal threads  321  and a ramp element  322  formed between the head and the internal threads  321 . 
     In assembly, the through holes  24  are put on the protrusions  14  to be in register. Further, the threaded shank  311  is inserted through the through hole  24  and the aperture  141  into the internal threads  321  to fasten the through hole  24  and the protrusion  14  together. Thus, the ring  1  and the central part  2  are secured. 
     As shown in  FIG. 16  specifically, the ramp member  312  is urged against the ramp  241  and the ramp member  142  is urged against the ramp element  322 . 
     While the invention has been described in terms of preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modifications within the spirit and scope of the appended claims.