Patent Publication Number: US-2021179228-A1

Title: Brake pad assembly for a bicycle &amp; method for assembling a brake pad assembly for a bicycle

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application claims the benefit of and/or priority from U.S. Provisional Patent Application No. 62/718,222, filed on Aug. 13, 2018, which is incorporated herein by reference in its entirety. 
    
    
     FIELD 
     This document relates to disc brakes for bicycles. More specifically, this document relates to brake pad assemblies for bicycle disc brakes, and methods for assembling such brake pad assemblies. 
     BACKGROUND 
     U.S. Pat. No. 6,318,514 (Hinkens et al.) discloses a disc brake assembly that includes an improved pad holder for holding a brake pad in the brake assembly. The pad holder takes the form of a simple spring clip, preferably a wire form, that holds the rear surface of the pad tightly against the front surface of the piston or pistons of the associated caliper to prevent brake drag and brake rattle. 
     U.S. Pat. No. 6,394,236 (Matsuishita) discloses a bicycle cable disc brake that is provided with an adjustable return spring for moving the cable disc brake from a braking position to a release position. The cable disc brake has a cable housing, a pair of friction members, a cable actuated mechanism and a biasing member. The first friction member is movably coupled to the caliper housing between a release position and a braking position. The second caliper is also coupled to the caliper housing and arranged substantially parallel to the first friction member to form a rotor receiving slot therebetween. The cable actuated mechanism is movably coupled to the caliper housing to move the first friction member from the release position towards the second friction member to the braking position. The biasing member has a first end adjustably coupled to the caliper housing and a second end adjustably coupled to the cable actuated mechanism to urge the cable actuated mechanism to the release position. 
     SUMMARY 
     The following summary is intended to introduce the reader to various aspects of the detailed description, but not to define or delimit any invention. 
     According to some aspects a brake pad assembly for a bicycle includes a first brake pad, a second brake pad, and a spreader spring. The first brake pad has a first backing plate with a first rotor facing surface, and a first friction pad secured to the rotor facing surface. The second brake pad has a second backing plate with a second rotor facing surface, and a second friction pad secured to the second rotor facing surface and facing the first friction pad. The spreader spring has a first leaf and a second leaf. At least a portion of the first leaf is fixed between the first rotor facing surface and the first friction pad, and at least a portion of the second leaf is fixed between the second rotor facing surface and the second friction pad. The spreader spring is biased towards a spread position in which the first brake pad and second brake pad are spaced apart from each other, and is moveable to a compressed position in which the first brake pad and the second brake pad are moved towards each other relative to the spread position. 
     In some examples, the first friction pad has a first plate-facing surface joined to the first rotor facing surface, and the portion of the first leaf is received and fixed in a groove of the first plate-facing surface. The portion of the first leaf can fixed in the groove by friction. The portion of the first leaf can be fixed in the groove by an adhesive. 
     In some examples, second friction pad has a second plate-facing surface joined to the second rotor facing surface, and the portion of the second leaf is received and fixed in a groove of the second plate-facing surface. The portion of the second leaf can fixed in the groove of the second plate facing surface by friction. The portion of the second leaf can be fixed in the groove of the second plate facing surface by an adhesive. 
     In some examples, the first leaf is forked and includes a first tine and a second tine, the first friction pad has a first plate-facing surface joined to the first rotor facing surface, and the first plate-facing surface includes a first groove and a second groove. The first tine can be received and fixed in the first groove and the second tine can be received and fixed in the second groove. 
     In some examples, the second leaf is forked and includes a third tine and a fourth tine, the second friction pad has a second plate-facing surface joined to the second rotor facing surface, and the second plate-facing surface includes a third groove and a fourth groove. The third tine can be received and fixed in the third groove and the fourth tine can be received and fixed in the fourth groove. 
     In some examples, the first friction pad is adhered to the first rotor facing surface and the second friction pad is adhered to the second rotor facing surface. In some examples, the first friction pad is mechanically secured to the first rotor facing surface and the second friction pad is mechanically secured to the second rotor facing surface. In some examples, the first friction pad is molded onto the first rotor facing surface and the second friction pad is molded onto the second rotor facing surface. 
     According to some aspects, a brake pad assembly for a bicycle includes a first brake pad, a second brake pad, and a spreader spring. The first brake pad has a first backing plate with a first rotor facing surface, and a first friction pad secured to the rotor facing surface. The second brake pad has a second brake backing plate with a second rotor facing surface, and a second friction pad secured to the second rotor facing surface and facing the first friction pad. The spreader spring has a first leaf fixed to the first brake pad and a second leaf fixed to the second brake pad. The spreader spring is biased towards a spread position in which the first brake pad and second brake pad are spaced apart from each other, and moveable to a compressed position in which the first brake pad and the second brake pad are moved towards each other relative to the spread position. 
     In some examples, the first leaf is permanently fixed to the first brake pad and the second leaf is permanently fixed to the second brake pad. 
     In some examples, a portion of the first leaf is positioned between the first rotor facing surface and the first friction pad, and a portion of the second leaf is positioned between the second rotor facing surface and the second friction pad. The first friction pad can have a first plate-facing surface joined to the first rotor facing surface, and the portion of the first leaf can be received and fixed in a groove of the first plate-facing surface. The second friction pad can have a second plate-facing surface joined to the second rotor facing surface, and the portion of the second leaf can be received and fixed in a groove of the second plate-facing surface. 
     In some examples, the first leaf is forked and includes a first tine and a second tine, the first friction pad has a first plate-facing surface joined to the first rotor facing surface, and the first plate-facing surface includes a first groove and a second groove. The first tine can be received and fixed in the first groove and the second tine can be received and fixed in the second groove. 
     In some examples, the second leaf is forked and includes a third tine and a fourth tine, the second friction pad has a second plate-facing surface joined to the second rotor facing surface, and the second plate-facing surface includes a third groove and a fourth groove. The third tine can be received and fixed in the third groove and the fourth tine can be received and fixed in the fourth groove. 
     According to some aspects, a method of assembling a brake pad assembly for a bicycle includes: a) fixing at least a portion of a first leaf of a spreader spring between a rotor facing surface of a first brake backing plate and a first friction pad; and b) fixing at least a portion of a second leaf of the spreader spring between a rotor facing surface of a second brake backing plate and a second friction pad. 
     In some examples, step a) includes i) positioning the portion of the first leaf between the rotor facing surface of the first brake backing plate and the first friction pad, and ii) securing the first friction pad to the rotor facing surface of the first brake backing plate with the portion of the first leaf positioned between the first friction pad and the rotor facing surface of the first brake backing plate. In some examples, step b) includes iii) positioning the portion of the second leaf between the rotor facing surface of the second brake backing plate and the second friction pad, and iv) securing the second friction pad to the rotor facing surface of the second brake backing plate with the portion of the second leaf positioned between the second friction pad and the rotor facing surface of the second brake backing plate. Steps ii) and iv) can be carried out concurrently, after steps i) and iii). 
     In some examples, step ii) includes impaling the first friction pad onto barbs of the rotor facing surface of the first brake backing plate. In some examples, step ii) includes adhering the first friction pad to the rotor facing surface of the first brake packing plate. 
     In some examples, step i) includes positioning the portion of the first leaf in a groove of a plate-facing surface of the first friction pad. In some examples, step i) includes positioning a pair of tines of the first leaf in a pair of grooves of a plate-facing surface of the first friction pad. 
     According to some aspects, a method of assembling a set of brake pads for a bicycle includes a) fixing at least a portion of a first leaf of a spreader spring to a first brake pad; and b) fixing at least a portion of a second leaf of the spreader spring to a second brake pad. 
     In some examples, the method further includes, after steps a) and b), inserting the spreader spring, the first brake pad, and the second brake pad into a brake caliper of a bicycle. 
     In some examples, step a) includes permanently fixing the portion of the first leaf to the first brake pad, and step b) include permanently fixing the portion of the second leaf to the second brake pad. 
     In some examples, step a) includes i) positioning the portion of the first leaf between a rotor facing surface of a first brake backing plate and a first friction pad, and ii) securing the first friction pad to the rotor facing surface of the first brake backing plate with the portion of the first leaf sandwiched between the first friction pad and the rotor facing surface of the first brake backing plate. In some examples, step b) includes iii) positioning the portion of the second leaf between a rotor facing surface of a second brake backing plate and a second friction pad, and iv) securing the second friction pad to the rotor facing surface of the second brake backing plate with the portion of the second leaf sandwiched between the second friction pad and the rotor facing surface of the second brake backing plate. 
     In some examples, steps i) and iv) are carried out concurrently. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings included herewith are for illustrating various examples of articles, methods, and apparatuses of the present specification and are not intended to limit the scope of what is taught in any way. In the drawings: 
         FIG. 1  is a perspective view of an example brake pad assembly; 
         FIG. 2  is a front view of the assembly of  FIG. 1 ; 
         FIG. 3  is a side view of the assembly of  FIG. 1 ; 
         FIG. 4  is a cross-section taken along line  4 - 4  in  FIG. 2 ; 
         FIG. 5  is an enlarged view of a portion of  FIG. 4 ; 
         FIG. 6  is a perspective cutaway view of the assembly of  FIG. 1 ; 
         FIG. 7  is an enlarged perspective view of the brake pads of the assembly of  FIG. 1 , with the second brake pad removed to show the plate facing surface of the friction pad; 
         FIG. 8A  is a perspective view of a backing plate; and 
         FIG. 8B  is another perspective view of the backing plate. 
     
    
    
     DETAILED DESCRIPTION 
     Various apparatuses or processes will be described below to provide an example of an embodiment of the claimed subject matter. No embodiment described below limits any claim and any claim may cover processes or apparatuses that differ from those described below. The claims are not limited to apparatuses or processes having all of the features of any one apparatus or process described below or to features common to multiple or all of the apparatuses described below. It is possible that an apparatus or process described below is not an embodiment of any exclusive right granted by issuance of this patent application. Any subject matter described below and for which an exclusive right is not granted by issuance of this patent application may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicants, inventors or owners do not intend to abandon, disclaim or dedicate to the public any such subject matter by its disclosure in this document. 
     Generally disclosed herein are brake pad assemblies for bicycles, and particularly for use in bicycle disc brakes. The brake pad assemblies can generally include a pair of brake pads and a spreader spring, all three of which are fixed together (e.g. permanently fixed together) and provided as a one-piece unit. Fixing together of the three parts can allow for ease of handling and installation. In some examples, the three parts are fixed together during assembly of the brake pads themselves. That is, in some examples, as opposed to a two-step process of assembling the brake pads and then assembling the spreader spring to the brake pads, there is a single step of assembling the brake pads and concurrently assembling the spreader spring to the brake pads. 
     As used herein, the term ‘fixed to’ means that the referenced parts cannot be manually separated without destroying or damaging the referenced parts such that they cannot be put back together (for example, the referenced parts cannot be separated by manual removal of a pin or clip or by sliding the parts apart manually). As used herein, the term ‘permanently fixed to’ means that the referenced parts cannot be separated, whether manually or otherwise, without damaging or destroying the referenced parts such that they cannot be put back together (for example, the referenced parts cannot be separated with the use of a tool or machine). 
     Referring now to  FIGS. 1 to 3 , an example brake pad assembly  100  is shown. The assembly  100  includes a pair of brake pads,  102   a ,  102   b . Each of the brake pads  102   a ,  102   b  has a respective backing plate  104   a ,  104   b  with a respective rotor facing surface  106   a ,  106   b . A respective friction pad  108   a ,  108   b  is secured to each rotor facing surface  106   a ,  106   b . In this document, the brake pads  102   a ,  102   b  may in some instances be referred to as a ‘first’ brake pad  102   a  and a ‘second’ brake pad  102   b . Furthermore, the backing plate  104   a , rotor facing surface  106   a , and friction pad  108   a  of the first brake pad  102   a  may be referred to as a ‘first’ backing plate  104   a , ‘first’ rotor facing surface  106   a , and ‘first’ friction pad  108   a . Likewise, the backing plate  104   b , rotor facing surface  106   b , and friction pad  108   b  of the second brake pad  102   b  may be referred to as a ‘second’ backing plate  104   b , ‘second’ rotor facing surface  106   b , and ‘second’ friction pad  108   b . The first friction pad  108   a  and second friction pad  108   b  face each other, so that in use, upon application of a braking force (e.g. by the squeezing of hand breaks), the friction pads  108   a ,  108   b  are compressed towards each other to squeeze a rotor of the bicycle (not shown). 
     The backing plates  104   a ,  104   b  may optionally be steel backing plates, and may, for example, be fabricated by stamping. 
     The friction pads  108   a ,  108   b  may be made from any suitable friction material, such as resin with various additives and fillers. As will be described in further detail below, the friction pads  108   a ,  108   b  may optionally be pre-formed and secured to the respective rotor facing surfaces  106   a ,  106   b , for example by using a mechanical fastener or an adhesive. Alternatively, the friction pads  108   a ,  108   b  may be molded onto the respective rotor facing surfaces  106   a ,  106 . Optionally, the rotor facing surfaces  106   a ,  106   b  may include barbs for retaining the friction pads  108   a ,  108   b , for example by impaling pre-formed friction pads  108   a ,  108   b  onto the barbs, or by moulding the friction pads  108   a ,  108   b  onto the barbs. 
     Referring still to  FIGS. 1 to 3 , the brake pad assembly  100  further includes a spreader spring  110 , which functions to spread the friction pads  108   a ,  108   b  apart from the rotor after the braking force is released. Particularly, the spreader spring  110  is biased towards a spread position, shown in  FIGS. 1 to 7 , in which the first brake pad  108   a  and second brake pad  108   b  are spaced apart from each other. The spreader spring  110  is moveable to a compressed position (not shown) in which the first brake pad  108   a  and the second brake pad  108   b  are moved towards each other relative to the spread position. 
     Referring still to  FIGS. 1 to 3 , as mentioned above, the brake pads  102   a ,  102   b  are fixed to the spreader spring  110 —i.e. they cannot be manually separated without destruction or damage of the parts, as described above. More specifically, in the example shown, the brake pads  102   a ,  102   b  are permanently fixed to the spreader spring  110 —i.e. they cannot be separated at all without destruction or damage of the parts as described above. Namely, in the example shown, the spreader spring  110  has a pair of leaves  112   a ,  112   b , also referred to herein as a first leaf  112   a  and a second leaf  112   b . The first leaf  112   a  and the second leaf  112   b  are joined together at a generally U-shaped spring joint  114 , which is resiliently flexible. The first leaf  112   a  is permanently fixed to the first brake pad  102   a , and the second leaf  112   b  is permanently fixed to the second brake pad  102   b.    
     The leaves  112   a ,  112   b  of the spreader spring  110  may be fixed to the respective brake pads  102   a ,  102   b  in a variety of ways, for example by the use of adhesives or mechanical fasteners such as rivets. Furthermore, only a portion of each leaf  112   a ,  112   b  may be fixed to the respective brake pads  102   a ,  102   b , or an entirety of each leaf  112   a ,  112   b  may be fixed to the respective brake pads  102   a ,  102   b . Referring to  FIGS. 4 to 7 , in the example shown, a portion of the first leaf  112   a  is positioned and fixed in place between the first rotor facing surface  106   a  and the first friction pad  108   a , and a portion of the second leaf  112   b  is positioned and fixed in place between the second rotor facing surface  106   b  and the second friction pad  108   b . More specifically, referring to  FIG. 7 , the first friction pad  108   a  has a first plate facing surface  116   a , and the plate facing surface  116   a  has a pair of grooves  118   a ,  118   b  therein (also referred to herein as a first groove  118   a  and a second groove  118   b ). The first leaf  112   a  of the spreader spring  110  is forked, and includes a pair of tines  120   a ,  120   b  (also referred to herein as a first tine  120   a  and a second tine  120   b ). The first tine  120   a  is received and fixed in the first groove  118   a  and the second tine  120   b  is received and fixed in the second groove  118   b . Likewise (and not shown), the second friction pad  108   b  has a second plate facing surface, and the second plate facing surface has a pair of grooves therein (also referred to herein as a third groove and a fourth groove). The second leaf  112   b  of the spreader spring  110  is forked, and includes a pair of tines (also referred to herein as a third tine and a fourth tine). The third tine is received and fixed in the third groove and the fourth tine is received and fixed in the fourth groove. 
     In the example shown, the tines  120   a ,  120   b  are fixed in the grooves by friction and by the use of adhesives—i.e. the tines  120   a ,  120   b  are tightly sandwiched between the respective friction pads  108   a ,  108   b  and backing plates  104   a ,  104   b , and an adhesive is used to further fix the tines  120   a ,  120   b  in place. In alternative examples, adhesives alone can be used to fix the tines in the grooves, or friction alone can be used to fix the tines in the grooves, or another technique can be used to fix the tines in the grooves. 
     Referring to  FIG. 7 , the rotor facing surfaces  106   b  has a plate width  107   b , and the friction pad  108   b  has a pad width  109   b . In the example shown, the plate width and the pad width are approximately equal. That is, because the third and fourth tines are positioned in the third and fourth grooves, it is not necessary to leave a space on either side of the friction pad  108   b  for the tines to sit, and the friction pad  108   b  can extend the full width of the backing plate  104   b . This can allow for improved braking efficiency. 
     Referring back to  FIGS. 1 and 2 , the first backing plate  104   a , first leaf  112   a , second backing plate  104   b , and second leaf  112   b  each have a respective aperture extending therethrough. For simplicity, only the aperture  122  of the first backing plate  104   a  is labelled in  FIGS. 1 and 2 . The apertures are aligned along a common axis. Upon installation of the assembly  100  in a brake caliper of a bicycle, a pin or other fastener can be inserted through the apertures, in order to retain the assembly  100  in place in the caliper. Since in the example shown the apertures are aligned along a common axis and fixed in this position, the pin can be inserted with relative ease. 
     In general, in order to manufacture the assembly, at least a portion of the first leaf  112   a  (e.g. the first tine  120   a  and second tine  120   b ) can be positioned between the first rotor facing surface  106   a  and the first friction pad  108   a , and the first friction pad  108   a  can then be secured to the first rotor facing surface  106   a , with the portion of the first leaf  121   a  positioned between the first friction pad  108   a  and the first rotor facing surface  106   a , to concurrently fix the first friction pad  108   a  to the first backing plate  104   a  and the first leaf  112   a  to the first brake pad  102   a . Likewise, at least a portion of the second leaf  112   b  (e.g. the third and fourth tines) can be positioned between the second rotor facing surface  106   b  and the second friction pad  108   b , and the second friction pad  108   b  can then be secured to the second rotor facing surface  106   b  with the portion of the second leaf  112   b  positioned between the second friction pad  108   b  and the second rotor facing surface  106   b , to concurrently fix the second friction pad  108   b  to the second backing plate  104   b  and the second leaf  112   b  to the second brake pad  102   b . More specifically, with reference to the first brake pad  102   a , the first tine  120   a  and second tine  120   b  of the first leaf  112   a  can be nested within the first groove  118   a  and second groove  118   b  of the first friction pad. A bead of adhesive can then be applied to the first plate facing surface  116   a  and/or to the first rotor facing surface  106   a . The first backing plate  104   a  can then be aligned with the first friction pad  108   a , with the first  120   a  and second  120   b  tines therebetween, and the first backing plate  104   a  and first friction pad  108   a  can be pressed together until the adhesive has set and/or cured and/or dried. This can be repeated with the second brake pad  102   b , optionally concurrently with the first brake pad  102   a.    
     In some examples (not shown), in addition to or as an alternative to the use of adhesives, barbs on the rotor facing surfaces of the backing plates can be used to secure the backing plates to the friction pads, and thereby fix the spreader spring to the brake pads. Such barbs are described for example in U.S. Pat. No. 6,431,331 (Arbesman) and US Patent Application Publication No. 20160363183 (Arbesman et al.), both of which are incorporated herein by reference. In such examples, the friction pads can optionally be molded onto the backing plates, with the tines of the spreader spring between the friction pads and the backing plates. Alternatively, the friction pads can be pre-formed and then pressed on to the backing plates, with the tines of the spreader spring between the friction pads and the backing plates, to impale the friction pads on the barbs. In such cases, the barbs can optionally impale the tines, or can be flattened by the tines. An example of a backing plate  804  including barbs  824  is shown in  FIGS. 8A and 8B . The backing plate  804  is shown prior to being secured to a friction pad. 
     In order to install the assembly, the spreader spring  110 , first brake pad  102   a , and second brake pad  102   b —fixed together as a one-piece unit—can be inserted into a brake caliper. A pin or other fastener can then be inserted through the apertures of the plates and leaves, in order to retain the assembly in position in the brake caliper. Since the parts are fixed together as a one-piece unit, the assembly can be inserted with relative ease, and the pin can be inserted through the assembly with relative ease. Furthermore, in order to remove the assembly (e.g. for replacement), the spreader spring  110 , first brake pad  102   a , and second brake pad  102   b -fixed together as a one-piece unit—can be removed from the brake caliper 
     The brake pads  102   a ,  102   b  shown in  FIGS. 1 to 7  are sized and shaped to fit a particular model of brake caliper. In alternative examples, brake pad assemblies may include various other sizes and shapes of brake pads. 
     While the above description provides examples of one or more processes or apparatuses, it will be appreciated that other processes or apparatuses may be within the scope of the accompanying claims. 
     To the extent any amendments, characterizations, or other assertions previously made (in this or in any related patent applications or patents, including any parent, sibling, or child) with respect to any art, prior or otherwise, could be construed as a disclaimer of any subject matter supported by the present disclosure of this application, such disclaimer is hereby rescinded and retracted.