Abstract:
This invention relates to a pad spring for use in a disc brake assembly. According to one embodiment of the present invention, the disc brake assembly comprises an anchor bracket adapted to be secured to a vehicle component; a brake caliper adapted to be secured to the anchor bracket; an inboard friction pad and an outboard friction pad carried by the disc brake assembly and adapted to be disposed on opposite axial sides of an associated brake rotor; actuation means for selectively moving the inboard and outboard friction pads into frictional engagement with the rotor; and a pad spring carried by at least one end of one of the friction pads for moving the friction pads from engagement with the rotor when the actuation means is released; wherein the pad spring includes a first portion for applying a first retraction force and a second portion for applying a second retraction force which is different from the first retraction force.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a continuation of PCT/JUS02/30539, filed Sep. 25, 2002, which claims the benefit of U.S. Provisional Application Ser. No. 60/324,705, filed Sep. 25, 2001. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    This invention relates in general to vehicle disc brake assemblies and in particular to an improved structure for a pad spring for a brake shoe assembly adapted for use in such a vehicle disc brake assembly.  
           [0003]    Most vehicles are equipped with a brake system for retarding or stopping movement of the vehicle in a controlled manner. A typical brake system for an automobile or light truck includes a disc brake assembly for each of the front wheels and either a drum brake assembly or a disc brake assembly for each of the rear wheels. The brake assemblies are typically actuated by hydraulic or pneumatic pressure generated when an operator of the vehicle depresses a brake pedal. The structures of these drum brake assemblies and disc brake assemblies, as well as the actuators therefor are well known in the art.  
           [0004]    A typical disc brake assembly includes an anchor bracket which is secured to a fixed, non-rotatable component of the vehicle. A pair of brake shoes are supported on the anchor bracket for sliding movement relative thereto. The brake shoes have respective friction pads which are disposed on opposite sides of a rotor. The rotor, in turn, is connected to the wheel of the vehicle for rotation therewith. To effect braking action, the brake shoes are moved inwardly toward one another so as to frictionally engage the opposed sides of the rotor. Such frictional engagement causes retarding or stopping of the rotational movement of the rotor and, therefore, the wheel of the vehicle in a controlled manner.  
           [0005]    To accomplish this, the disc brake assembly further includes a caliper assembly for selectively moving the brake shoes into frictional engagement with the brake rotor. The caliper assembly typically includes guide pins or other components to slidably support a caliper housing relative to the fixed anchor bracket. The caliper housing is generally C-shaped, having an inboard leg disposed adjacent the inboard brake shoe and an outboard leg disposed adjacent to the outboard brake shoe. One or more hydraulically or pneumatically actuated pistons are provided in respective cylindrical recesses formed in the caliper inboard leg adjacent to the inboard brake shoe. When the brake pedal is depressed, the piston and the inboard leg of the caliper are urged apart from one another. Specifically, the piston is urged outwardly, while the outboard leg of the caliper is urged inwardly. As mentioned above, the piston is disposed adjacent to the inboard brake shoe and, therefore, urges it outwardly toward the inner side of the rotor. Because the caliper is slidably mounted on the pins of the anchor bracket, the caliper outboard leg (and, thus, the outboard brake shoe disposed adjacent thereto) are urged inwardly toward the outer side of the rotor. As result, the brake shoes frictionally engage the opposed sides of the rotor.  
           [0006]    Frequently, an annular roll-back seal is provided within the cylindrical recess in contact with the outer surface of the piston. The roll-back seal is conventional in the art and performs several functions. First, the roll-back seal provides a seal to define the extent of the cylindrical recess within which the piston is disposed. Second, the roll-back seal is designed to retract the piston inwardly away from the rotor by a predetermined distance from the fully engaged position when the brake pedal is released after being depressed. To accomplish this, the roll-back seal frictionally engages the outer surface of the piston, resiliently resisting movement thereof when the brake pedal is depressed. Thus, when the brake pedal is released by the operator of the vehicle, the resilience of the roll-back seal causes the piston to retract within the cylindrical recess and out of contact with the inboard brake shoe.  
           [0007]    With repeated usage, the friction pads of the brake shoes wear and become increasingly thinner. When this occurs, the piston and the caliper must move greater distances relative to one another to effect the same braking action as when the friction pads were new. Despite this increased distance of movement of the piston in the outboard direction, it is desirable that the roll-back seal retract the piston only by the same predetermined distance away from the rotor in the inboard direction. Thus, known roll-back seals are designed to accommodate increased movement of the piston in the outboard direction when the brake pedal is depressed, but to retract the piston inwardly by approximately the same predetermined distance when the brake pedal is subsequently released.  
           [0008]    Ideally, when the brake pedal is released, the brake shoes should also be spread apart from one another to prevent any incidental frictional engagement with the rotor. To accomplish this, it is known to provide the disc brake assembly with one or more retraction springs for moving the brake shoes apart from one another to prevent frictional engagement with the rotor when the brake pedal is released. For example, U.S. Pat. No. 4,364,455 to Oshima, U.S. Pat. No. 4,491,204 to Dirauf et al., U.S. Pat. No. 4,629,037 to Madzgalla et al., U.S. Pat. No. 4,658,938 to Thiel et al, U.S. Pat. No. 4,867,280 to Von Gruenberg et al., U.S. Pat. No. 4,940,119 to Kondo et al., U.S. Pat. No. 5,069,313 to Kato et al., U.S. Pat. No. 5,249,647 to Kobayashi et al., and U.S. Pat. No. 5,251,727 to Loeffler et al. all disclose disc brake assemblies which include a retraction spring structure. It is desirable that such retraction springs exert an amount of force which is large enough to urge the brake shoes apart from one another to prevent engagement with the rotor, but small enough not to overcome the roll-back seal to move the piston deeper within the associated cylindrical recess formed in the inboard leg of the caliper.  
           [0009]    Unfortunately, when the friction pads of the brake shoes wear thinner as described above, conventional retraction springs are typically compressed to a greater extent when the friction pads of the brake shoes are worn than when they are new. The additional compression of known brake shoe retraction springs can result in the exertion of a force against the associated brake shoe which can overcome the roll-back seal and undesirably move the piston away from the rotor by a distance which is greater than the predetermined distance discussed above. U.S. Pat. No. 5,549,181 to Evans, a copy of which is attached hereto and the disclosure of which is incorporated herein, discloses a retractor clip which exerts a substantially uniform force on the brake shoes regardless of the amount of wear on the friction pads of the brake shoes.  
         SUMMARY OF THE INVENTION  
         [0010]    This invention relates to a pad spring for use in a brake shoe assembly of a disc brake assembly and a disc brake assembly including such a brake shoe assembly. According to one embodiment of the present invention, the disc brake assembly comprises an anchor bracket adapted to be secured to a vehicle component; a brake caliper adapted to be secured to the anchor bracket; an inboard friction pad and an outboard friction pad carried by the disc brake assembly and adapted to be disposed on opposite axial sides of an associated brake rotor; actuation means for selectively moving the inboard and outboard friction pads into frictional engagement with the rotor; and a pad spring carried by at least one end of one of the friction pads for moving the friction pads from engagement with the rotor when the actuation means is released; wherein the pad spring includes a first portion for applying a first retraction force and a second portion for applying a second retraction force which is different from the first retraction force.  
           [0011]    According to another embodiment of the present invention the disc brake assembly comprises: an anchor bracket adapted to be secured to a vehicle component; a brake caliper adapted to be secured to the anchor bracket; an inboard friction pad and an outboard friction pad carried by said disc brake assembly and adapted to be disposed on opposite axial sides of an associated brake rotor; actuation means for selectively moving the inboard and outboard friction pads into frictional engagement with the rotor; and a pad spring carried by at least one end of one of the friction pads for moving the friction pads from engagement with the rotor when said actuation means is released; wherein the pad spring permanently yields and applies a corresponding force from a geometrically decreasing spring rate as the lining of the friction pad wears.  
           [0012]    According to yet another embodiment of the present invention the disc brake assembly comprises: an anchor bracket adapted to be secured to a vehicle component; a brake caliper adapted to be secured to the anchor bracket; an inboard friction pad and an outboard friction pad carried by the disc brake assembly and adapted to be disposed on opposite axial sides of an associated brake rotor; actuation means for selectively moving the inboard and outboard friction pads into frictional engagement with the rotor; and a pad spring carried by at least one end of one of the friction pads; wherein the pad spring is carried by the friction pad with a portion of the spring spaced apart at an angle from contact an adjacent surface of the friction pad in a normal position when the brake is not actuated.  
           [0013]    According to yet a further embodiment of the present invention, the disc brake assembly comprises an anchor bracket adapted to be secured to a vehicle component; a brake caliper adapted to be secured to the anchor bracket; an inboard friction pad and an outboard friction pad carried by the disc brake assembly and adapted to be disposed on opposite axial sides of an associated brake rotor; actuation means for selectively moving the inboard and outboard friction pads into frictional engagement with the rotor; and a pad spring carried by at least one end of one of the friction pads for moving the friction pads from engagement with the rotor when the actuation means is released; wherein the pad spring is carried by the friction pad in an asymmetrical manner.  
           [0014]    According to still yet a further embodiment of the present invention, the disc brake assembly comprises an anchor bracket adapted to be secured to a vehicle component; a brake caliper adapted to be secured to the anchor bracket; an inboard friction pad and an outboard friction pad carried by the disc brake assembly and adapted to be disposed on opposite axial sides of an associated brake rotor; actuation means for selectively moving the inboard and outboard friction pads into frictional engagement with the rotor; and at least one pad spring carried by the disc brake assembly and including a first end and a second end, the first end adapted to be secured to the anchor bracket and the second end adapted to be secured to an end of one of the friction pads for moving the friction pads from engagement with the rotor when the actuation means is released; wherein the pad spring is secured to the anchor bracket in a symmetrical manner.  
           [0015]    According to another embodiment of the present invention the disc brake assembly comprises: an anchor bracket adapted to be secured to a vehicle component; a brake caliper adapted to be secured to the anchor bracket; an inboard friction pad and an outboard friction pad carried by said disc brake assembly and adapted to be disposed on opposite axial sides of an associated brake rotor; actuation means for selectively moving the inboard and outboard friction pads into frictional engagement with the rotor; and at least one pad spring carried by the disc brake assembly and including a first end, a second end, and a third end; wherein the first end is adapted to be positioned adjacent a surface of the anchor bracket so as to react thereagainst, the second end is adapted to be operatively connected to an end of the friction pads, and the third end is adapted to be operatively connected to the anchor bracket.  
           [0016]    According to a further embodiment of the present invention, the brake shoe assembly comprises: a backing plate having a pair of opposed ends; a friction pad secured to the backing plate; and a pad spring carried by at least one end of the backing plate for moving the friction pad from engagement with a brake rotor of the disc brake assembly when the brake is released; wherein the pad spring includes a first portion for applying a first retraction force and a second portion for applying a second retraction force which is different from the first retraction force.  
           [0017]    According to still a further embodiment of the present invention, the brake shoe assembly comprises: a backing plate having a pair of opposed ends; a friction pad secured to the backing plate; and a pad spring carried by at least one end of the backing plate for moving the friction pad from engagement with a brake rotor of the disc brake assembly when the brake is released; wherein the pad spring permanently yields and applies a corresponding force from a geometrically decreasing spring rate as the friction pad wears.  
           [0018]    According to yet a further embodiment of the present invention, the brake shoe assembly comprises: a backing plate having a pair of opposed ends; a friction pad secured to the backing plate; and a pad spring carried by at least one end of the backing plate; wherein the pad spring is carried by the backing plate with a portion of the pad spring spaced apart and at an angle from contact with an adjacent surface of the backing plate in a normal position when the disc brake assembly is not actuated.  
           [0019]    According to yet another embodiment of the present invention, the pad spring of this invention can incorporate one or more or all of the following features, which are more fully described below: a symmetrical/asymmetrical shoe retraction feature; a symmetrical/asymmetrical shoe attachment feature; and an impact/anti-rattle feature.  
           [0020]    Other advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, when read in light of the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]    [0021]FIG. 1 is a perspective view of a portion of a vehicle disc brake assembly including a first embodiment of a pad retraction spring, adapted for use in the prior art disc brake assembly illustrated in FIGS. 33-35, in accordance with this invention.  
         [0022]    [0022]FIG. 2 is a perspective view of the pad retraction spring illustrated in FIG. 1, showing the spring attached to the brake shoe assembly in accordance with this invention.  
         [0023]    [0023]FIG. 3 is a perspective view of the pad retraction spring illustrated in FIGS. 1 and 2 in accordance with this invention.  
         [0024]    [0024]FIGS. 4 and 5 are perspective views of a second embodiment of a pad retraction spring in accordance with this invention.  
         [0025]    [0025]FIGS. 6 and 7 are perspective views of a third embodiment of a pad retraction spring in accordance with this invention.  
         [0026]    [0026]FIGS. 8 and 9 are perspective views of a fourth embodiment of a pad retraction spring in accordance with this invention.  
         [0027]    [0027]FIGS. 10 and 11 are perspective views of a fifth embodiment of a pad retraction spring in accordance with this invention.  
         [0028]    [0028]FIGS. 12 and 13 are perspective views of a sixth embodiment of a pad retraction spring in accordance with this invention.  
         [0029]    [0029]FIG. 14 is a partial view of a portion of a brake shoe including the pad retraction spring illustrated in FIGS. 12 and 13 installed thereon.  
         [0030]    [0030]FIGS. 15 and 16 are perspective views of a seventh embodiment of a pad retraction spring in accordance with this invention.  
         [0031]    [0031]FIGS. 17 and 18 are perspective views of an eighth embodiment of a pad retraction spring in accordance with this invention.  
         [0032]    [0032]FIGS. 19 and 20 are perspective views of a ninth embodiment of a pad retraction spring in accordance with this invention.  
         [0033]    [0033]FIG. 21 is a perspective view of a tenth embodiment of a pad retraction spring in accordance with this invention.  
         [0034]    [0034]FIGS. 22 and 23 are perspective views of an eleventh embodiment of a pad retraction spring in accordance with this invention.  
         [0035]    [0035]FIGS. 24 and 25 are perspective views of a twelfth embodiment of a pad retraction spring in accordance with this invention.  
         [0036]    [0036]FIG. 26 is a perspective view of a thirteenth embodiment of a pad retraction spring in accordance with this invention.  
         [0037]    [0037]FIG. 27 is a perspective view of a fourteenth embodiment of a pad retraction spring in accordance with this invention.  
         [0038]    [0038]FIGS. 28 and 29 are perspective views of a fifteenth embodiment of a pad retraction spring in accordance with this invention.  
         [0039]    [0039]FIG. 30 is a perspective view of a sixteenth embodiment of a pad retraction spring in accordance with this invention.  
         [0040]    [0040]FIG. 31 is a perspective view of a portion of a vehicle disc brake assembly including the pad retraction spring illustrated in FIG. 30 in accordance with this invention.  
         [0041]    [0041]FIG. 32 is a partial view of a portion of a brake assembly illustrated in FIG. 31 in accordance with this invention.  
         [0042]    [0042]FIG. 33 is a perspective view of an seventeenth embodiment of a pad retraction spring in accordance with this invention.  
         [0043]    [0043]FIG. 34 is a sectional elevational view of a portion of a prior art disc brake assembly.  
         [0044]    [0044]FIGS. 35-38 illustrate various end positions of the pad retraction spring in accordance with this invention.  
         [0045]    [0045]FIG. 39 is a graph showing the spring rate for the positions shown in FIGS. 35-38 of the pad retraction spring in accordance with this invention.  
         [0046]    [0046]FIG. 40 is another view of the eleventh embodiment of the pad retraction illustrated in FIGS. 22 and 23 in accordance with this invention.  
         [0047]    [0047]FIGS. 41 and 42 are further views of the thirteenth embodiment of the pad retraction spring illustrated in FIG. 26 in accordance with this invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0048]    Referring now to the drawings, there is illustrated in FIG. 1 a portion of a vehicle disc brake assembly, indicated generally at  10 , including a first embodiment of a pad retraction spring or clip, indicated generally at  20 , in accordance with the present invention. The general structure and operation of the vehicle disc brake assembly  10  is conventional in the art. Thus, only those portions of the vehicle disc brake assembly  10  which are necessary for a full understanding of this invention will be explained and illustrated. Although this invention will be described and illustrated in conjunction with the particular vehicle disc brake assemblies disclosed herein, it will be appreciated that this invention may be used in conjunction with other vehicle disc brake assemblies.  
         [0049]    The disc brake assembly  10  includes an anchor plate, indicated generally at  12 , having a pair of brake shoes or pad assemblies  14  (only one of such brake shoes  14  illustrated in FIG. 1), supported thereon for sliding movement between a braking position and an non-braking position in a known manner. The disc brake assembly  10  also includes the pad retraction spring  20  in accordance with the first embodiment of the present invention. A pad retraction spring  20  is preferably disposed on each of the opposed ends or end tabs of the associated brake shoes  14  (only one of such springs  20  illustrated on one of the ends of the brake shoe  14 ). In this embodiment, each of the springs  20  is identical in structure and operation, although such is not required if so desired. Each of the springs  20  is preferably stamped from a flat strip or blank of a suitable material. Examples of suitable materials can include SAE 1050 or 1070 steel and stainless steel. Alternatively, the spring  20  can be formed from other suitable metal and non-metal materials and/or from other suitable flat and/or non-flat materials. Also, selected surfaces of the spring  20  can be coated, insulated, or otherwise have applied thereto a suitable “damping” material, such as rubber or silicone material, to help in reducing the transmission or generation of noise in the brake assembly.  
         [0050]    As best shown in FIG. 3, the pad retraction spring  20  includes a first end  24 , which is operatively connected to the anchor bracket  12 , and a second end  28 , which is operatively connected to an associated backing plate  14 A of the brake shoe  14 , best shown in FIG. 2. In the illustrated embodiment, the first end  24  of the spring  20  is generally V or U shaped and includes a pair of protruding mounting tabs  24 A and  24 B extending from a main or center body portion  24 C. The tabs  24 A and  24 B of the first end  24  of the spring  20  are adapted to be received in an outer recess  12 A provided in a slot  12 B of the anchor bracket  12 . In particular, the tabs  24 A and  24 B are necked down along the remote ends thereof and define respective shoulders  24 A′ and  24 B′. The shoulders  24 A′ and  24 B′ engage the side walls of the recess  12 A and are operative to seat or position the first end  24  of the spring  20  generally in the center of the slot  12 B of the anchor bracket  12 . The second end  28  of the spring  20  is generally flat and includes a slightly curled portion  28 A. In this embodiment, the tabs  24 A and  24 B are symmetrical and provide both a symmetrical shoe attachment feature with respect to the anchor bracket, and a symmetrical shoe retraction feature.  
         [0051]    The pad retraction spring  20  further includes a plurality of arms. In this embodiment, the spring  20  includes four arms  30 ,  32 ,  34 , and  36 . The arm  30  is connected to the first end  24  by a curved portion  40 . The arm  32  is connected to the arm  30  by a curved portion  42  and to the arm  34  by a curved portion  44 . The arm  36  is connected to the arm  34  by a curved portion  46  and to the second end  28  by a curved portion  48 . In the original formed uninstalled condition, shown in FIG. 3, the arms  32  and  36  and the first end  24  are generally parallel to one another; the arms  30 ,  34  and the second end  28  are generally parallel to one another and generally perpendicular relative to the arms  32  and  36  and the first end  24 ; and at least a portion of the first end  24  of the spring  20  (in this embodiment, at least a portion of the remote ends  24 A′ and  24 B′ of the tabs  24 A and  24 B) extends beyond the arm  34  (and therefore an associated rear or back surface  14 C of the backing plate  14 A to which the spring  20  is attached), in order to provide the spring  20  with a predetermined initial spring retraction force preload when it is installed on a new brake shoe and then subsequently, when the brake shoe is installed in the brake assembly.  
         [0052]    In this embodiment, the arm  34  is provided with a pair of arms  34 A and  34 B (arm  34 B only partially shown in FIG. 3), extending from the opposed sides thereof. The arms  34 A and  34 B are adapted to be disposed over the end or tab of the backing plate  14 A and in combination with the second end  28  and the arm  34 , cooperate to assist in securing or attaching the spring  20  onto the backing plate  14 A of the brake shoe  14 . In this embodiment, the arms  34 A and  34 B are symmetrical and provide a symmetrical shoe attachment feature.  
         [0053]    In operation, one or more of the curved portions  40 ,  42 ,  44 ,  46  and  48  of the spring  20  preferably permanently and elastically deforms or yields as the friction pad  14 B of the brake shoe  14  wears so that the spring  20  can provide a generally uniform retraction force on the brake shoe  14  regardless of the amount of wear of the friction pad  14 B of the brake shoe  14 . Alternatively, all of the curved portions  40 ,  42 ,  44 ,  46  and  48  do not have to permanently deform but can elastically deform whereby that the spring  20  provides a generally increasing retraction force on the brake shoe  14  as the friction pad  14 B wears. Alternatively, the structure of the pad retraction spring  20  can be other than illustrated if so desired.  
         [0054]    Referring now to FIGS. 4 and 5, there is illustrated a second embodiment of a pad retraction spring, indicated generally at  120 , in accordance with the present invention. As shown therein, the pad retraction spring  120  includes a first end  124 , which is adapted to be operatively connected to the anchor bracket  12 , and a second end  128 , which is adapted to be operatively connected to an associated backing plate  14 A of the brake shoe  14 . In the illustrated embodiment, the first end  124  of the spring  20  is generally M or W shaped and includes a pair of protruding mounting tabs  124 A and  124 B and a main or center body portion  124 C. The tabs  124 A and  124 B of the first end  124  of the spring  120  are adapted to be received in the outer recess  12 A provided in the slot  12 B of the anchor bracket  12 . In particular, the tabs  124 A and  124 B are necked down and define respective shoulders  124 A′ and  124 B′ along the remote ends thereof. The shoulders  124 A′ and  124 B′ are adapted to engage the side walls of the recess  12 A and are operative to seat or position the first end  24  of the spring  20  generally in the center of the slot  12 B of the anchor bracket  12 . In this embodiment, the tabs  124 A and  124 B are symmetrical and provide both a symmetrical shoe attachment feature with respect to the anchor bracket, and a symmetrical shoe retraction feature.  
         [0055]    The second end  128  of the spring  120  is generally U or channel shaped and includes a pair of arms  128 A and  128 B extending from a main body portion  128 C. In the illustrated embodiment, the remote ends of the arms  128 A and  128 B are slightly curled or rolled over. The arms  128 A and  128 B of the second end  128  of the spring  120  are adapted to be disposed over the end of the backing plate  14 A and in combination with the main body portion  128 C and the arm  134 , cooperate to assist in securing the spring  120  onto the backing plate  14 A of the brake shoe  14 . In this embodiment, the arms  128 A and  128 B are symmetrical and provide a symmetrical shoe attachment feature. The pad retraction spring  120  further includes a plurality of arm3s. In this embodiment, the spring  120  includes four arms  130 ,  132 ,  134  and  136 . The arm  130  is connected to the first end  124  by a curved portion  140 . The arm  132  is connected to the arm  130  by a curved portion  142  and to the arm  134  by a curved portion  144 . The arm  136  is connected to the arm  134  by a curved portion  146  and to the second end  128  by a curved portion  148 . In the original formed uninstalled condition as shown in FIGS. 4 and 5, the arms  132  and  136  are generally parallel to one another; the arm  134  and the second end  128  are generally parallel to one another and generally perpendicular relative to the arms  132  and  136 ; and the arm  130  extends at an angle with respect to the arm  132  and is generally perpendicular with respect to the first end  124 .  
         [0056]    In operation, one or more of the curved portions  140 ,  142 ,  144 ,  146  and  148  of the spring  120  preferably permanently and elastically deforms as the friction pad  14 B of the brake shoe  14  wears so that the spring  120  can provide a generally uniform retraction force on the brake shoe  14  regardless of the amount of wear of the friction pad  14 B of the brake shoe  14 . Alternatively, all of the curved portions  140 ,  142 ,  144 ,  146  and  148  do not have to permanently deform but can elastically deform whereby that the spring  120  provides a generally increasing retraction force on the brake shoe  14  as the friction pad  14 B wears. Alternatively, the structure of the pad retraction spring  120  can be other than illustrated if so desired.  
         [0057]    Referring now to FIGS. 6 and 7, there is illustrated a third second embodiment of a pad retraction spring, indicated generally at  220 , in accordance with the present invention. As shown therein, the pad retraction spring  220  includes a first end  224 , which is adapted to be positioned adjacent a surface  12 C of the anchor bracket  12  so as to react thereagainst (the surface  12 C shown in FIG. 1), and a second end  228 , which is adapted to be operatively connected to an associated backing plate  14 A of the brake shoe  14 .  
         [0058]    In the illustrated embodiment, the first end  224  of the spring  220  is generally U shaped and includes a pair of protruding tabs  224 A and  224 B extending from a main or center body portion  224 C. In particular, the tabs  224 A and  224 B are angled or bent back relative to the main body portion  224 C and are provided with respective tapered outer side wall portions  224 A′ and  224 B′. The second end  228  of the spring  20  includes a generally flat portion  228 A and a curled over outermost end portion  228 B. In operation, an end surface  228 B′ of the outermost end portion  228 B is adapted to contact a surface of a brake rotor (not shown) when the pad  14 B is sufficiently worn so as to emit an audible signal or noise to indicate that the pad is worn and that the brake shoe should be replaced. In this embodiment, the tabs  224 A and  224 B are symmetrical and provide a symmetrical shoe retraction feature.  
         [0059]    The pad retraction spring  220  further includes a plurality of arms. In this embodiment, the spring  220  includes four arms  230 ,  232 ,  234 , and  236 . The arm  230  is connected to the first end  224  by a curved portion  240 . The arm  232  is connected to the arm  230  by a curved portion  242  and to the arm  234  by a curved portion  244 . The arm  236  is connected to the arm  234  by a curved portion  246  and to the second end  228  by a curved portion  248 . In the original formed uninstalled condition, the arms  232  and  236  and a portion of the main body  224 C of the first end  224  are generally parallel to one another; the arms  230 ,  234  and the portion  228 A of the second end  228  are generally parallel to one another and generally perpendicular relative to the arms  232  and  236  and said portion of the first end  224 ; and at least a portion of the first end  224  of the spring  220  (in this embodiment, at least a portion of the main body  224 C), extends beyond the arm  234 .  
         [0060]    In this embodiment, the arm  234  is provided with a pair of arms  234 A and  234 B extending from opposed sides thereof. The arms  234 A and  234 B are adapted to be disposed over the end of the backing plate  14   a  and in combination with the second end  228  and the arm  234 , cooperate to assist in securing the clip  220  onto the backing plate  14 A of the brake shoe  14 . In this embodiment, the arms  234 A and  234 B are symmetrical and provide a symmetrical shoe attachment feature.  
         [0061]    In operation, one or more of the curved portions  240 ,  242 ,  244 ,  246  and  248  of the spring  220  preferably permanently and elastically deforms as the friction pad  14 B of the brake shoe  14  wears so that the spring  220  can provide a generally uniform retraction force on the brake shoe  14  regardless of the amount of wear of the friction pad  14 B of the brake shoe  14 . Alternatively, all of the curved portions  240 ,  242 ,  244 ,  246  and  248  do not have to permanently deform but can elastically deform whereby that the spring  220  provides a generally increasing retraction force on the brake shoe  14  as the friction pad  14 B wears. Alternatively, the structure of the pad retraction spring  220  can be other than illustrated if so desired.  
         [0062]    Referring now to FIGS. 8 and 9, there is illustrated a fourth embodiment of a pad retraction spring, indicated generally at  320 , in accordance with the present invention. As shown therein, the pad retraction spring  320  includes a first end  324 , which is adapted to be positioned adjacent the surface  12 C of the anchor bracket  12  so as to react thereagainst, and a second end  328 , which is adapted to be operatively connected to an associated backing plate  14 A of the brake shoe  14 .  
         [0063]    In the illustrated embodiment, the first end  324  of the spring  320  is generally U shaped and includes a pair of protruding tabs  324 A and  324 B extending from a main or center body portion  324 C. In particular, the tabs  324 A and  324 B are angled or bent back relative to the main body portion  324 C and are provided with respective tapered outer side wall portions  324 A′ and  324 B′. The second end  328  of the spring  320  includes a generally flat portion  328 A and a curled over outermost end portion  328 B. In operation, an end surface  328 B′ of the outermost end portion  328 B is adapted to contact a surface of a brake rotor (not shown) when the pad  14 B is sufficiently worn so as to emit an audible signal or noise to indicate that the pad is worn and that the brake shoe should be replaced. In this embodiment, the tabs  324 A and  324 B are symmetrical and provide a symmetrical shoe retraction feature.  
         [0064]    The pad retraction spring  320  further includes a plurality of arms. In this embodiment, the spring  320  includes four arms  330 ,  332 ,  334 , and  336 . The arm  330  is connected to the first end  324  by a curved portion  340 . The arm  332  is connected to the arm  330  by a curved portion  342  and to the arm  334  by a curved portion  344 . The arm  336  is connected to the arm  334  by a curved portion  346  and to the second end  328  by a curved portion  348 . In the original formed uninstalled condition as shown in FIGS. 8 and 9, the arms  332  and  336  and a portion of the main body  324 C of the first end  324  are generally parallel to one another; the arms  330 ,  334  and the portion  328 A of the second end  328  are generally parallel to one another and generally perpendicular relative to the arms  332  and  336  and said portion of the first end  324 ; and at least a portion of the first end  324  of the spring  320  (in this embodiment, at least a portion of the main body  324 C), extends beyond the arm  334 .  
         [0065]    In this embodiment, the arm  334  is provided with a pair of arms  334 A and  334 B extending from opposed sides thereof. The arms  334 A and  334 B are adapted to be disposed over the end of the backing plate  14 A and in combination with the second end  328  and the arm  334 , cooperate to assist in securing the clip  320  onto the backing plate  14 A of the brake shoe  14 . In this embodiment, the arms  334 A and  334 B are symmetrical and provide a symmetrical shoe attachment feature.  
         [0066]    In operation, one or more of the curved portions  340 ,  342 ,  344 ,  346  and  348  of the spring  320  preferably permanently and elastically deforms as the friction pad  14 B of the brake shoe  14  wears so that the spring  320  can provide a generally uniform retraction force on the brake shoe  14  regardless of the amount of wear of the friction pad  14 B of the brake shoe  14 . Alternatively, all of the curved portions  340 ,  342 ,  344 ,  346  and  348  do not have to permanently deform but can elastically deform whereby that the spring  320  provides a generally increasing retraction force on the brake shoe  14  as the friction pad  14 B wears. Alternatively, the structure of the pad retraction spring  320  can be other than illustrated if so desired.  
         [0067]    Referring now to FIGS. 10 and 11, there is illustrated a fifth embodiment of a pad retraction spring, indicated generally at  420 , in accordance with the present invention. As shown therein, the pad retraction spring  420  includes a first end  424 , which is adapted to be positioned adjacent the surface  12 C of the anchor bracket  12  so as to react thereagainst, and a second end  428 , which is adapted to be operatively connected to an associated backing plate  14 A of the brake shoe  14 .  
         [0068]    In the illustrated embodiment, the first end  424  of the spring  420  includes a protruding tab  424 A extending from a main or center body portion  424 B. In particular, the tab  424 A is angled or bent back relative to the main body portion  424 B. The second end  428  of the spring  420  includes a generally flat portion (not shown) and a curled over outermost end portion  428 B. In operation, an end surface  428 B′ of the outermost end portion  428 B is adapted to contact a surface of a brake rotor (not shown) when the pad  14 B is sufficiently worn so as to emit an audible signal or noise to indicate that the pad is worn and that the brake shoe should be replaced. In this embodiment, the tab  424 A is symmetrical and provides a symmetrical shoe retraction feature.  
         [0069]    The pad retraction spring  420  further includes a plurality of arms. In this embodiment, the spring  420  includes four arms  430 ,  432 ,  434 , and  436 . The arm  430  is connected to the first end  424  by a curved portion  440 . The arm  432  is connected to the arm  430  by a curved portion  442  and to the arm  434  by a curved portion  444 . The arm  436  is connected to the arm  434  by a curved portion (not shown) and to the second end  428  by a curved portion  448 . In the original formed uninstalled condition as shown in FIGS. 10 and 1, the arms  432  and  436  and a portion of the main body  424 B of the first end  424  are generally parallel to one another; the arms  430 ,  434  and the portion  428 A of the second end  428  are generally parallel to one another and generally perpendicular relative to the arm  432  and said portion of the first end  424 ; and at least a portion of the first end  424  of the spring  420  (in this embodiment, at least a portion of the main body  424 B and the tab  424 A), extends beyond the arm  434 .  
         [0070]    In this embodiment, the arm  434  is provided with a pair of arms  434 A and  434 B extending from opposed sides thereof. The arms  434 A and  434 B are adapted to be disposed over the end of the backing plate  14 A and in combination with the second end  428  and the arm  434 , cooperate to assist in securing the spring  420  onto the backing plate  14 A of the brake shoe  14 . In this embodiment, the arms  434 A and  434 B are symmetrical and provide a symmetrical shoe attachment feature. In operation, one or more of the curved portions  440 ,  442 ,  444 , and  448  of the spring  420  preferably permanently and elastically deforms as the friction pad  14 B of the brake shoe  14  wears so that the spring  420  can provide a generally uniform retraction force on the brake shoe  14  regardless of the amount of wear of the friction pad  14 B of the brake shoe  14 . Alternatively, all of the curved portions do not have to permanently deform but can elastically deform whereby that the spring  420  provides a generally increasing retraction force on the brake shoe  14  as the friction pad  14 B wears. Alternatively, the structure of the pad retraction spring  420  can be other than illustrated if so desired.  
         [0071]    Referring now to FIGS. 12 and 13, there is illustrated a sixth embodiment of a pad retraction spring, indicated generally at  520 , in accordance with the present invention. As shown therein, the pad retraction spring  520  includes a first end  524 , which is adapted to be positioned adjacent the surface  12 C of the anchor bracket  12  so as to react thereagainst, and a second end  528 , which is adapted to be operatively connected to an associated backing plate  14 A of the brake shoe  14 . In the illustrated embodiment, the first end  524  of the spring  520  includes a protruding tab  524 A extending from a main or center body portion  524 B. In particular, the tab  524 A is angled or bent back relative to the main body portion  524 B. In this embodiment, the tab  524 A is symmetrical and provides a symmetrical shoe retraction feature.  
         [0072]    The pad retraction spring  520  further includes a plurality of arms. In this embodiment, the spring  520  includes four arms  530 ,  532 ,  534 , and  536 . The arm  530  is connected to the first end  524  by a curved portion  540 . The arm  532  is connected to the arm  530  by a curved portion  542  and to the arm  534  by a curved portion  544 . The arm  536  is connected to the arm  534  by a curved portion  546 . In the original formed uninstalled condition as shown in FIGS. 12 and 13, the arms  532  and  536  and a portion of the main body  524 B of the first end  524  are generally parallel to one another and generally perpendicular to the arm  530  and at least a portion of the first end  524  of the spring  520  (in this embodiment, at least a portion of the main body  524 B and the tab  524 A), extends beyond the arm  534 .  
         [0073]    In this embodiment, the arm  536  is provided with a pair of arms  550  and  552  extending from opposed sides thereof. The arm  550  includes a generally flat side wall  550 A and a partly wavy or curled remote end  550 B. Similarly, the arm  552  includes a generally flat side wall  550 B and a partly wavy remote end  552 B. The arms  550  and  552  are adapted to be disposed over the end of the backing plate  14 A and in combination with the arms  534  and  536 , cooperate to assist in securing the spring  520  onto the backing plate  14 A of the brake shoe  14 . In this embodiment, the arm  536  includes an end surface  536 A. In operation, the end surface  536 A of the arms  536  is adapted to contact a surface of a brake rotor (not shown) when the pad  14 B is sufficiently worn so as to emit an audible signal or noise to indicate that the pad is worn and that the brake shoe should be replaced. In this embodiment, the arms  550  and  552  are symmetrical and provide a symmetrical shoe attachment feature.  
         [0074]    Also, as shown in FIG. 14, when the spring  520  is attached to the backing plate  14 A, the arm  536  of the spring  520  is positioned at an angle A with respect to an end surface  14 A′ of the tab of the backing plate  14 A. In particular, an inner surface  536 B of the arm  536  is positioned at the angle A with respect to the surface  14 A′ of the tab of the backing plate  14 A so as to define a gap therebetween. As a result of this, during movement of the brake shoe  14  during brake applications, the spring  520  is capable of moving or flexing relative to the backing plate  14 A and thereby is capable of functioning to absorb or reduce any “impact” or rattle between the shoe  14  and the bracket  12 . The angle A is generally in the range from about 1 degree to about 15 degrees. Preferably, the angle A is in the range from about 4 degrees to about 12 degrees. More preferably, the angle A is approximately 8 degrees. Alternatively, the angle A can be other than illustrated and described depending upon the particular vehicle application and associated operating characteristics thereof.  
         [0075]    In operation, one or more of the curved portions  540 ,  542 ,  544 , and  546  of the spring  520  preferably permanently and elastically deforms as the friction pad  14 B of the brake shoe  14  wears so that the spring  520  can provide a generally uniform retraction force on the brake shoe  14  regardless of the amount of wear of the friction pad  14 B of the brake shoe  14 . Alternatively, all of the curved portions  540 ,  542 ,  544 ,  546  and  548  do not have to permanently deform but can elastically deform whereby that the spring  520  provides a generally increasing retraction force on the brake shoe  14  as the friction pad  14 B wears. Alternatively, the structure of the pad retraction spring  520  can be other than illustrated if so desired. For example, as shown in FIG. 12, that portion of the spring  520  located “above” dotted line  560  could be eliminated whereby the resulting structure of the spring  520  would not provide any retraction feature but would only provide the “impact” or anti-rattle feature discussed above.  
         [0076]    Referring now to FIGS. 15 and 16, there is illustrated a seventh embodiment of a pad retraction spring, indicated generally at  620 , in accordance with the present invention. As shown therein, the pad retraction spring  620  includes a first end  624 , which is adapted to be positioned adjacent the surface  12 C of the anchor bracket  12  so as to react thereagainst, and a second end  628 , which is adapted to be operatively connected to an associated backing plate  14 A of the brake shoe  14 .  
         [0077]    In the illustrated embodiment, the first end  624  of the spring  620  includes a pair of protruding tabs  624 A and  624 B extending from a main or center body portion  624 C. In particular, the tabs  624 A and  624 B have remote ends  624 A′ and  624 B′ which are angled or flared outwardly. In this embodiment, the tabs  624 A and  624 B are symmetrical and provide a symmetrical shoe retraction feature.  
         [0078]    The pad retraction spring  620  further includes a plurality of arms. In this embodiment, the spring  620  includes seven arms  630 ,  632 ,  634 ,  636 ,  638 ,  640  and  642 . In the original formed uninstalled condition as shown in FIGS. 15 and 16, the arms  632 ,  640  and  642  and a portion of the main body  624 C of the first end  624  are generally parallel to one another and generally perpendicular to the arm  634 . In this embodiment, the arm  636  is provided with a curled over or inwardly turned remote end  636 A. Similarly, the arm  638  is provided with a curled over remote end  638 A. The ends  636 A and  638 A of the respective arms  636  and  638  are adapted to be disposed over the end of the backing plate  14 A and in combination with the arms  634 ,  640  and  642 , cooperate to assist in securing the spring  620  onto the backing plate  14 A of the brake shoe  14 . In this embodiment, the arms  640  and  642  are symmetrical and provide a symmetrical shoe attachment feature.  
         [0079]    In this embodiment, when the spring  620  is attached to the backing plate  14 A, each of the arms  640  and  642  is adapted to be positioned at an angle with respect to an end surface of the tab of the backing plate so as to provide the impact or anti-rattle feature discussed above in connection with the spring  520 . Alternatively, the arms  640  and  642  do not have to be at an angle with respect to the end surface of the backing plate if so desired.  
         [0080]    In this embodiment, the arm  640  includes an end surface  640 A and the arm  642  includes an end surface  642 A. In operation, the end surfaces  640 A and  642 A of the respective arms  640  and  642  are adapted to contact a surface of a brake rotor (not shown) when the pad  14 B is sufficiently worn so as to emit an audible signal or noise to indicate that the pad is worn and that the brake shoe should be replaced.  
         [0081]    In operation, the selected portions of the spring  620  preferably permanently and elastically deforms as the friction pad  14 B of the brake shoe  14  wears so that the spring  620  can provide a generally uniform retraction force on the brake shoe  14  regardless of the amount of wear of the friction pad  14 B of the brake shoe  14 . Alternatively, the spring  620  does not have to permanently deform but can elastically deform whereby that the spring  620  provides a generally increasing retraction force on the brake shoe  14  as the friction pad  14 B wears. Alternatively, the structure of the pad retraction spring  620  can be other than illustrated if so desired.  
         [0082]    Referring now to FIGS. 17 and 18, there is illustrated an eighth embodiment of a pad retraction spring, indicated generally at  720 , in accordance with the present invention. As shown therein, the pad retraction spring  720  includes a first end  724 , which is adapted to be positioned adjacent the surface  12 C of the anchor bracket  12  so as to react thereagainst, and a second end  728 , which is adapted to be operatively connected to an associated backing plate  14 A of the brake shoe  14 .  
         [0083]    In the illustrated embodiment, the first end  724  of the spring  720  includes a pair of protruding tabs  724 A and  724 B extending from a main or center body portion  724 C. In particular, the tabs  724 A and  724 B have remote ends  724 A′ and  724 B′ which are angled or flared upwardly. The second end  728  of the spring  720  includes a generally flat portion (not shown) and a curled over outermost end portion  728 B. In operation, an end surface  728 B′ of the outermost end portion  728 B is adapted to contact a surface of a brake rotor (not shown) when the pad  14 B is sufficiently worn so as to emit an audible signal or noise to indicate that the pad is worn and that the brake shoe should be replaced. In this embodiment, the tabs  724 A and  724 B are symmetrical and provides a symmetrical shoe retraction feature.  
         [0084]    The pad retraction spring  720  further includes a plurality of arms. In this embodiment, the spring  720  includes four arms  730 ,  732 ,  734 , and  736 . In the original formed uninstalled condition as shown in FIGS. 17 and 18, the arms  732  and  736  and a portion of the main body  724 C of the first end  724  are generally parallel to one another; the arms  730 ,  734  and the portion  728 A of the second end  728  are generally parallel to one another and generally perpendicular relative to the arms  732  and  734  and said portion of the first end  724 ; and at least a portion of the first end  724  of the spring  720  (in this embodiment, at least a portion of the remote ends  724 A′ and  724 B′ of the respective tabs  724 A and  724 B), extend beyond the arm  734 .  
         [0085]    In this embodiment, the arm  734  is provided with a pair of arms  734 A and  734 B extending from opposed sides thereof. The arms  734 A and  734 B are adapted to be disposed over the end of the backing plate  14 A and in combination with the second end  728  and the arm  734 , cooperate to assist in securing the spring  720  onto the backing plate  14 A of the brake shoe  14 . In this embodiment, the arms  734 A and  734 B are symmetrical and provide a symmetrical shoe attachment feature.  
         [0086]    In operation, selected portions of the spring  720  preferably permanently and elastically deforms as the friction pad  14 B of the brake shoe  14  wears so that the spring  720  can provide a generally uniform retraction force on the brake shoe  14  regardless of the amount of wear of the friction pad  14 B of the brake shoe  14 . Alternatively, the selected portions of the spring  72 Q do not have to permanently deform but can elastically deform whereby that the spring  720  provides a generally increasing retraction force on the brake shoe  14  as the friction pad  14 B wears. Alternatively, the structure of the pad retraction spring  720  can be other than illustrated if so desired.  
         [0087]    Referring now to FIGS. 19 and 20, there is illustrated a ninth embodiment of a pad retraction spring, indicated generally at  820 , in accordance with the present invention. As shown therein, the pad retraction spring  820  includes a first end  824 , which is adapted to be positioned adjacent the surface  12 C of the anchor bracket  12  so as to react thereagainst, and a second end  828 , which is adapted to be operatively connected to an associated backing plate  14 A of the brake shoe  14 .  
         [0088]    In the illustrated embodiment, the first end  824  of the spring  820  includes a pair of protruding tabs  824 A and  824 B extending from a main or center body portion  824 C. In particular, the tabs  824 A and  824 B have remote ends  824 A′ and  824 B′ which are angled or flared inwardly. The second end  428  of the spring  420  includes a generally flat portion  828 A and a curled over outermost end portion  428 B. In operation, an end surface  428 B′ of the outermost end portion  428 B is adapted to contact a surface of a brake rotor (not shown) when the pad  14 B is sufficiently worn so as to emit an audible signal or noise to indicate that the pad is worn and that the brake shoe should be replaced. In this embodiment, the tabs  824 A and  824 B are symmetrical and provides a symmetrical shoe retraction feature.  
         [0089]    The pad retraction spring  820  further includes a plurality of arms. In this embodiment, the spring  820  includes four arms  830 ,  832 ,  834 , and  836 . In the original formed uninstalled condition as shown in FIGS. 19 and 20, the arms  832  and  836  and a portion of the main body  824 C of the first end  824  are generally parallel to one another; the arms  830 ,  834  and the portion  828 A of the second end  828  are generally parallel to one another and generally perpendicular relative to the arms  832  and  836  and said portion of the first end  824 ; and at least a portion of the first end  824  of the spring  820  (in this embodiment, at least a portion of the main body  824 C and at least a portion of the remote ends  824 A′ and  824 B′ of the respective tabs  824 A and  824 B), extend beyond the arm  834 .  
         [0090]    In this embodiment, the arm  834  is provided with a pair of arms  834 A and  834 B extending from opposed sides thereof. The arms  834 A and  834 B are adapted to be disposed over the end of the backing plate  14 A and in combination with the second end  828  and the arms  834  and  836 , cooperate to assist in securing the spring  820  onto the backing plate  14 A of the brake shoe  14 . In this embodiment, the arms  834 A and  834 B are symmetrical and provide a symmetrical shoe attachment feature.  
         [0091]    In operation, selected portions of the spring  820  preferably permanently and elastically deforms as the friction pad  14 B of the brake shoe  14  wears so that the spring  820  can provide a generally uniform retraction force on the brake shoe  14  regardless of the amount of wear of the friction pad  14 B of the brake shoe  14 . Alternatively, the selected portions of the spring  820  do not have to permanently deform but can elastically deform whereby that the spring  820  provides a generally increasing retraction force on the brake shoe  14  as the friction pad  14 B wears. Alternatively, the structure of the pad retraction spring  820  can be other than illustrated if so desired.  
         [0092]    Referring now to FIG. 21, there is illustrated an tenth embodiment of a pad retraction spring, indicated generally at  1020 , in accordance with the present invention. As shown therein, the pad retraction spring  1020  in this embodiment is generally similar to the pad retraction spring  520  illustrated and describe above in connection with FIGS. 12 and 13 except that in this embodiment, the spring  1020  includes a first end  1024  provided with a generally U-shaped remote end  1024 A.  
         [0093]    Referring now to FIGS. 22 and 23, there is illustrated an eleventh embodiment of a pad retraction spring, indicated generally at  1120 , in accordance with the present invention. As shown therein, the pad retraction spring  1120  includes a first end  1124 , which is adapted to be positioned adjacent the surface  12 C of the anchor bracket  12  so as to react thereagainst, and a second end  1128 , which is adapted to be operatively connected to an associated backing plate  14 A of the brake shoe  14 .  
         [0094]    In the illustrated embodiment, the first end  1124  of the spring  1120  is generally U shaped and includes a pair of protruding tabs  1124 A and  1124 B extending from a main or center body portion  1124 C. In particular, the tabs  1124 A and  1124 B have remote ends  1124 A′ and  1124 B′ which are angled or flared upwardly.  
         [0095]    The pad retraction spring  1120  further includes a plurality of arms, in this embodiment, the spring  1120  includes four arms  1130 ,  1132 ,  1134 , and  1136 . The arm  1136  is further provided with a pair of arms  1150  and  1152  extending from opposed sides thereof. The arm  1150  includes a generally flat side wall  1150 A and a partly wavy or curled remote end  1150 B. Similarly, the arm  1152  includes a generally flat side wall  1150 B and a partly wavy remote end  1152 B. The arms  1150  and  1152  are adapted to be disposed over the end of the backing plate  14 A and in combination with the arms  1134  and  1136 , cooperate to assist in securing the spring  1120  onto the backing plate  14 A of the brake shoe  14 . In this embodiment, the arm  1136  includes an end surface  1136 A. In operation, the end surface  1136 A of the arm  1136  is adapted to contact a surface of a brake rotor (not shown) when the pad  14 B is sufficiently worn so as to emit an audible signal or noise to indicate that the pad is worn and that the brake shoe should be replaced. In this embodiment, the arms  1150  and  1152  are symmetrical and provide a symmetrical shoe attachment feature. Also, in the original formed uninstalled condition as shown in FIGS. 22, 23 and  40 , at least a portion of the first end  1124  of the spring  1120  (in this embodiment, at least a portion of both of the remote ends  1124 A′ and  1124 B′ of the respective tabs  1124 A and  1124 B), extends beyond the arm  1134 .  
         [0096]    In this embodiment, when the spring  1120  is attached to the backing plate  14 A, the arm  1136  is adapted to be positioned at an angle with respect to an end surface of the backing plate so as to provide the “impact” or “anti-rattle” feature discussed above in connection with the spring  520 . Also, in this embodiment, the tab  1124 B and associated end  1124 B′ are wider as compared to the tab  1124 A and associated end  1124 A′. As a result of this “asymmetrical” first end or tab design, the “wider” tab  1124 B provides a higher amount of retraction force compared to a lower amount of retraction force provided by the “narrower” tab  1124 A. This asymmetrical shoe retraction feature can be useful in certain designs or application in order to better balance the associated brake with respect to braking forces generated during application of the brakes.  
         [0097]    In operation, selected portions of the spring  1120  preferably permanently and elastically deforms as the friction pad  14 B of the brake shoe  14  wears so that the spring  1120  can provide a generally uniform retraction force on the brake shoe  14  regardless of the amount of wear of the friction pad  14 B of the brake shoe  14 . Alternatively, the selected portions of the spring  1120  do not have to permanently deform but can elastically deform whereby that the spring  1120  provides a generally increasing retraction force on the brake shoe  14  as the friction pad  14 B wears. Alternatively, the structure of the pad retraction spring  1120  can be other than illustrated if so desired. For example, the tabs  1124 A and  1124 B of the spring  1124  can be symmetrical so as to apply generally the same retraction force.  
         [0098]    Referring now to FIGS. 24 and 25, there is illustrated a twelfth embodiment of a pad retraction spring, indicated generally at  1220 , in accordance with the present invention. As shown therein, the pad retraction spring  1220  includes a first end  1224 , which is adapted to positioned adjacent the surface  12 C of the anchor bracket  12  so as to react thereagainst, and a second end  1228 , which is adapted to be operatively connected to an associated backing plate  14 A of the brake shoe  14 .  
         [0099]    In the illustrated embodiment, the first end  1224  of the spring  1120  includes a protruding tab  1224 A provided on the remote end of a main body portion  1224 B. In this embodiment, the tab  1224 A is symmetrical and provides a symmetrical shoe retraction feature.  
         [0100]    The pad retraction spring  1220  further includes a plurality of arms. In this embodiment, the spring  1220  includes four arms  1230 ,  1232 ,  1234 , and  1236 . The arm  1236  is further provided with a pair of arms  1250  and  1252  extending from opposed sides thereof. The arm  1250  includes a generally flat side wall  1250 A and a generally flat remote end  1250 B. Similarly, the arm  1252  includes a generally flat side wall  1150 B and a generally flat remote end  1252 B. The arms  1250  and  1252  are adapted to be disposed over the end of the backing plate  14 A and in combination with the arms  1234  and  1236 , cooperate to assist in securing the spring  1220  onto the backing plate  14 A of the brake shoe  14 . In this embodiment, the arm  1236  includes an end surface  1236 A. In operation, the end surface  1236 A of the arm  1236  along with associated end surfaces  1250 A′ and  1252 A′ of the arms  1250  and  1252 , respectively, are adapted to contact a surface of a brake rotor (not shown) when the pad  14 B is sufficiently worn so as to emit an audible signal or noise to indicate that the pad is worn and that the brake shoe should be replaced. In this embodiment, the arms  1250  and  1252  are symmetrical and provide a symmetrical shoe attachment feature.  
         [0101]    In operation, selected portions of the spring  1220  preferably permanently and elastically deforms as the friction pad  14 B of the brake shoe  14  wears so that the spring  1220  can provide a generally uniform retraction force on the brake shoe  14  regardless of the amount of wear of the friction pad  14 B of the brake shoe  14 . Alternatively, the selected portions of the spring  1220  do not have to permanently deform but can elastically deform whereby that the spring  1220  provides a generally increasing retraction force on the brake shoe  14  as the friction pad  14 B wears. Alternatively, the structure of the pad retraction spring  1220  can be other than illustrated if so desired.  
         [0102]    Referring now to FIG. 26, there is illustrated a thirteenth embodiment of a pad retraction spring, indicated generally at  1320 , in accordance with the present invention. As shown therein, the pad retraction spring  1320  is generally similar to the pad retraction spring  520  illustrated and describe above in connection with FIGS. 12 and 13 except that in this embodiment, the spring  1320  includes a different profile on remote ends  1350 B and  1352 B of respective arms  1350  and  1352  thereof.  
         [0103]    Referring now to FIG. 27, there is illustrated a fourteenth embodiment of a pad retraction spring, indicated generally at  1420 , in accordance with the present invention. As shown therein, the pad retraction spring  1420  includes a first end  1424 , which is adapted to be positioned adjacent the surface  12 C of the anchor bracket  12  so as to react thereagainst, which is adapted to be operatively connected to an associated backing plate  14 A of the brake shoe  14 .  
         [0104]    In the illustrated embodiment, the first end  1424  of the spring  1420  includes a pair of protruding tabs  1424 A and  1424 B extending from a main or center body portion  1424 C. In particular, the tabs  1424 A and  1424 B have remote ends  1424 A′ and  1424 B′ which are angled or flared upwardly. Also, in this embodiment, the tab  1424 A and associated end  1424 A′ are wider as compared to the tab  1424 B and associated end  1424 B′. As a result of this “asymmetrical” first end or tab design, the wider tab  1424 A provides a higher amount of retraction force compared to a lower amount of retraction force provided by the narrower tab  1424 B. This asymmetrical shoe retraction feature allows can be useful in certain designs to balance the associated brake with respect to braking forces generated during application of the brakes.  
         [0105]    The second end  1428  of the spring  1420  includes a generally flat portion (not shown) and a curled over outermost end portion  1428 B. In operation, an end surface  1428 B′ of the outermost end portion  1428 B is adapted to contact a surface of a brake rotor (not shown) when the pad  14 B is sufficiently worn so as to emit an audible signal or noise to indicate that the pad is worn and that the brake shoe should be replaced.  
         [0106]    The pad retraction spring  1420  further includes a plurality of arms. In this embodiment, the spring  1420  includes four arms, only three of such arms illustrated in FIG. 27 by reference numbers  1430 ,  1434 , and  1436 . In this embodiment, the arm  1434  is provided with a pair of arms  1434 A and  1434 B extending from opposed sides thereof. The arms  1434 A and  1434 B are generally flat with a stepped remote end  1434 A′ and  1434 B′, respectively. The arms  1434 A and  1434 B are adapted to be disposed over the end of the backing plate  14 A and in combination with the second end  1428  and the arm  1434 , cooperate to assist in securing the spring  1420  onto the backing plate  14 A of the brake shoe  14 . In this embodiment, the arms  1434 A and  1434 B are symmetrical and provide a symmetrical shoe attachment feature. Also, in the original formed uninstalled condition as shown in FIG. 27, at least a portion of the first end  1424  of the spring  1420  (in this embodiment, at least a portion of the remote ends  1424 A′ and  1424 B′ of the respective tabs  1424 A and  1424 B), extends beyond the arm  1436 .  
         [0107]    In operation, selected portions of the spring  1420  preferably permanently and elastically deforms as the friction pad  14 B of the brake shoe  14  wears so that the spring  1420  can provide a generally uniform retraction force on the brake shoe  14  regardless of the amount of wear of the friction pad  14 B of the brake shoe  14 . Alternatively, the selected portions of the spring  1420  do not have to permanently deform but can elastically deform whereby that the spring  1420  provides a generally increasing retraction force on the brake shoe  14  as the friction pad  14 B wears. Alternatively, the structure of the pad retraction spring  1420  can be other than illustrated if so desired. For example, the tabs  1424 A and  1424 B of the spring  1424  can be symmetrical so as to apply generally the same retraction force.  
         [0108]    Referring now to FIGS. 28 and 29, there is illustrated a fifteenth embodiment of a pad retraction spring, indicated generally at  1520 , in accordance with the present invention. As shown therein, the pad retraction spring  1520  includes a first end  1524 , which is adapted to be positioned adjacent the surface  12 C of the anchor bracket  12  so as to react thereagainst, and a second end  1528 , which is adapted to be operatively connected to an associated backing plate  14 A of the brake shoe  14 .  
         [0109]    In the illustrated embodiment, the first end  1524  of the spring  1520  includes a protruding tab  1524 A extending from a main or center body portion  1524 B. In particular, the tab  1524 A is angled or bent back relative to the main body portion  1524 B. In this embodiment, the tab  1524 A is symmetrical and provides a symmetrical shoe retraction feature.  
         [0110]    The pad retraction spring  1520  further includes a plurality of arms. In this embodiment, the spring  1520  includes six arms  1530 ,  1532 ,  1534 ,  1536 ,  1538 , and  1540 . In this embodiment, the arm  1536  is provided with a pair of tabs  1536 A and  1536 B. The tabs  1536 A and  1536 B are adapted to contact a surface of a brake rotor (not shown) when the pa  14 B is sufficiently worn so as to emit an audible signal or noise to indicate that the pad is worn and that the brake shoe should be replaced.  
         [0111]    The arm  1538  includes a first folded back portion  1538 A and a second partly folded back portion  1538 B. The first portion  1538 A includes an outwardly extending outermost end  1538 A′ and the second portion  1538 B includes a curled over outermost end  1538 B′. Similarly, the arm  1540  includes a first folded back portion  1540 A and a second partly folded back portion  1540 B. The first portion  1540 A includes an outwardly extending outermost end  1540 A′ and the second portion  1540 B includes a curled over outermost end  1540 B′. Also, in this embodiment, the first portion  1540 A of the arm  1540  extends a distance C and the second portion  1540 B of the arm  1540  extends a distance C′ which is less than the distance C. As a result of this “asymmetrical” shoe attachment design, the longer arm portion  1540 A provides a lower shoe attachment rate whereas the shorter arm portion  1540 B provides a higher shoe attachment rate. This asymmetrical shoe attachment feature can be useful in certain design application in the attachment of the associated brake to the bracket. The arm  1538  has a similar construction to that of the arm  1540 .  
         [0112]    In operation, selected portions of the spring  1520  preferably permanently and elastically deforms as the friction pad  14 B of the brake shoe  14  wears so that the spring  1520  can provide a generally uniform retraction force on the brake shoe  14  regardless of the amount of wear of the friction pad  14 B of the brake shoe  14 . Alternatively, the spring  1520  does not have to permanently deform but can elastically deform whereby that the spring  1520  provides a generally increasing retraction force on the brake shoe  14  as the friction pad  14 B wears. Alternatively, the structure of the pad retraction spring  1520  can be other than illustrated if so desired. For example, the arms  1538  and  1540  of the spring  1524  can have a symmetrical design and/or the spring  1520  can have a first end having an asymmetrical design similar to that described above in connection with spring  1420 .  
         [0113]    Referring now to FIGS. 30-32, there is illustrated a sixteenth embodiment of a pad retraction spring, indicated generally at  1620 , in accordance with the present invention. As shown therein, the pad retraction spring  1620  includes a first end  1624 , which is adapted to be positioned adjacent the surface  12 C′ of the anchor bracket  12  so as to react thereagainst, a second end  1628 , which is adapted to be operatively connected to an associated backing plate  14 A′ of a brake shoe  14 ′, and a third end  1626 , which is adapted to be operatively connected to the anchor bracket  12 ′.  
         [0114]    In the illustrated embodiment, the first end  1624  of the spring  1620  includes a protruding tab  1624 A extending from a main body portion  1624 B. The tab  1624 A of the first end  1624  of the spring  1620  is adapted to be disposed adjacent an outer surface  12 C′ of an anchor bracket  12 ′, as shown in FIG. 31. In particular, the mounting tab  1624 A is provided with a curled back remote end  1624 A′ which is disposed adjacent the surface  12 C′.  
         [0115]    The second end  1626  of the spring  1620  includes a protruding mounting tab  1626 A extending from a main body portion  1626 B. The mounting tab  1626 A of the second end  1626  of the spring  1620  is adapted to be received in a recess  12 A′ provided in a slot  12 B′ provided in the anchor bracket  12 ′, as shown in FIGS. 31 and 32. In particular, the mounting tab  1626 A is provided with a curled back remote end  1626 A′ which is disposed in the recess  12 A′. Additionally, when the second end  1626 A of the spring  1620  is disposed in the slot  12 B′, it functions to retain the spring  1620  in the bracket  12 ′ in generally both a vertical and a horizontal direction with respect to a horizontal axis X of the bracket  12 ′. Also, in this embodiment, when the spring  1620  is attached to the backing plate  14 A′, an inner surface  1626 C of the arm  1626  is positioned away from contact with an associated surface  14 C′ of the backing plate  14 A′, as best shown in FIG. 32, so as to define a gap therewith and provide the “impact” or anti-rattle feature discussed above in connection with the spring  520 .  
         [0116]    The third end  1628  of the spring  1620  includes an angled portion  1628 A and a generally flat outermost end portion  1628 B. In operation, an end surface  1628 B′ of the outermost end portion  1628 B extends past and associated surface of the brake shoe  14 ′ and is adapted to contact a surface of a brake rotor (not shown) when the pad  14 B′ is sufficiently worn so as to emit an audible signal or noise to indicate that the pad is worn and that the brake shoe should be replaced.  
         [0117]    The pad retraction spring  1620  further includes a plurality of arms. In this embodiment, the spring  1620  includes three arms  1630 ,  1632  and  1634 . In this embodiment, the arm  1632  is adapted to be disposed over the end of the backing plate  14 A and in combination with the third end  1628  and the arm  1634 , cooperates to assist in securing the spring  1620  onto the backing plate  14 A of the brake shoe  14 .  
         [0118]    In operation, selected portions of the spring  1620  preferably permanently and elastically deforms as the friction pad  14 B of the brake shoe  14  wears so that the spring  1620  can provide a generally uniform retraction force on the brake shoe  14  regardless of the amount of wear of the friction pad  14 B of the brake shoe  14 . Alternatively, all of the selected portions of the spring  1620  do not have to permanently deform but can elastically deform whereby that the spring  1620  provides a generally increasing retraction force on the brake shoe  14  as the friction pad  14 B wears. Alternatively, the structure of the pad retraction spring  1620  can be other than illustrated if so desired.  
         [0119]    Referring now to FIG. 33, there is illustrated a seventeenth embodiment of a pad retraction spring, indicated generally at  1720 , in accordance with the present invention. As shown therein, the pad retraction spring  1720  includes a first end  1724  having a pair of arms  1724 A and  1724 B, which are adapted to be positioned adjacent the surface  12 C of the anchor bracket  12  so as to react thereagainst, and a second end  1728 , which is adapted to be operatively connected to the associated backing plate  14 A of the brake shoe  14 .  
         [0120]    Referring now to prior art FIG. 34, there is illustrated a portion of one kind of prior art vehicle disc brake assembly, indicated generally at  1800 , which can include any of the various embodiments of the retraction pad springs of the present invention described hereinabove. The general structure and operation of the prior art disc brake assembly  1800  is conventional in the art. Thus, only those portions of the disc brake assembly  1800  which are necessary for a full understanding of this invention will be explained and illustrated.  
         [0121]    The prior art disc brake assembly  1800  is a sliding type of disc brake assembly and includes a generally C-shaped caliper, indicated generally at  1812 . The caliper  1812  includes an inboard leg portion  1814  and an outboard leg portion  1816  which are interconnected by an intermediate bridge portion  1818 . The caliper  1812  is slidably on a pair of pins (not shown) secured to an anchor bracket (not shown but can be similar to the anchor bracket  12  illustrated in FIG. 1). The anchor bracket is, in turn, secured to a stationary component of the vehicle. Such a stationary component can be, for example, an axle flange (not shown), when the disc brake assembly  1800  is installed for use on the rear of the vehicle, or a steering knuckle (not shown), when the disc brake assembly  1800  is installed for use on the front of the vehicle. The pins support the caliper  1812  for sliding movement relative to the anchor bracket in both the outboard direction (left when viewing prior art FIG. 34) and the inboard direction (right when viewing prior art FIG. 34). Such sliding movement of the caliper  1812  occurs when the disc brake assembly  1800  is actuated, as will be explained below. A pair of bolts (not shown) extend through a pair of apertures (not shown) formed in the anchor bracket to secure the anchor bracket to the stationary vehicle component. Alternatively, other known securing methods can be used to secure the anchor bracket to the stationary vehicle component and/or the caliper  1812  to the anchor bracket.  
         [0122]    The anchor bracket includes a pair of guide rails (not shown) which are adapted to slidably support an inboard brake shoe, indicated generally at  1830 , and an outboard brake shoe, indicated generally at  1832 , respectively. The inboard brake shoe  1830  includes a backing plate  1834  and a friction pad  1836 . The outboard brake shoe  1832  includes a backing plate  1838  and a friction pad  1840 .  
         [0123]    The prior art disc brake assembly  1800  includes an actuation means, indicated generally at  1850  in prior art FIG. 34. The actuation means  1850  is provided for effecting the operation of the disc brake assembly  1800 . The actuation means  1850  includes a brake piston  1842  which is disposed in a counterbore or recess  1814 B formed in the outboard surface of the inboard leg  1814  of the caliper  1812 . The actuation means  1850 , shown in this embodiment as being a hydraulic actuation means, is operable to move the piston  1842  within the recess  1814 B in the outboard direction (left when viewing prior art FIG. 34). However, other types of actuation means  1850 , such as for example, electrical, pneumatic, and mechanical types, can be used.  
         [0124]    The prior art disc brake assembly  1800  also includes a dust boot seal  1844  and an annular fluid seal  1846 . The dust boot seal  1844  is formed from a flexible material and has a first end which engages an outboard end of the recess  1814 B. A second end of the dust boot seal  1844  engages an annular groove formed in an outer side wall of the piston  1842 . A plurality of flexible convolutions are provided in the dust boot seal  1844  between the first and second ends thereof. The dust boot seal  1844  is provided to prevent water, dirt, and other contaminants from entering into the recess  1814 B. The fluid seal  1846  is disposed in an annular groove formed in a side wall of the recess  1814 B and engages the outer side wall of the piston  1842 . The fluid seal  1846  is provided to define a sealed hydraulic actuator chamber  1848 , within which the piston  1842  is disposed for sliding movement. Also, the fluid seal  1846  is designed to function as a “roll back” seal to retract the piston  1842  within the recess  1814 B (right when viewing prior art FIG. 34) when the brake pedal is released.  
         [0125]    The prior art disc brake assembly  1800  further includes a brake rotor  1852 , which is connected to a wheel (not shown) of the vehicle for rotation therewith via a hub (not shown). The illustrated brake rotor  1852  includes a pair of opposed friction discs  1854  and  1856 . The brake rotor  1852  extends radially outwardly between the inboard friction pad  1836  and the outboard friction pad  1840 . The construction of the prior art disc brake assembly  1800  is conventional in the art.  
         [0126]    One advantage of the present invention is that if desired, as the pad retraction spring deforms or yields, the geometry of the spring can be selected such that is produces a generally lower spring rate of retraction. This is illustrated in connection with FIGS. 35-39. As shown in FIGS. 35-38, the “end position” of a pad retraction spring S in accordance with this invention is illustrated approximately at 0 mm, 4 mm, 8 mm, and 12 mm. As used herein, the term end position relates to the distance that the brake shoe has moved due to wear of the friction material and FIGS. 35-38 show the structure of the “yielding” spring S at such end position. Also, FIG. 39 is a graph showing the spring rate of the spring S of this invention at selected end positions. Thus, as shown in FIG. 39, due to the geometry of the spring S, the corresponding spring rate of the spring S can be selected so as to produce a decreasing spring rate as the end position of the spring S increases (i.e., as the friction material wears). As a result of this, the geometry of the spring S of the present invention can be selected and used to reduce the load that the spring S applies to the associated brake piston as the friction material of the brake shoe wears. Also, the spring can have angular contacts which are operative to center the spring in the anchor plate slot and which can also provide an anti-rattle feature. In addition, the spring can be configured to incorporate one or more or all of the various features disclosed herein; such as the symmetrical/asymmetrical shoe retraction feature, the symmetrical/asymmetrical shoe attachment feature, and the impact or anti-rattle feature.  
         [0127]    Also, the retraction force provided by the springs of the present invention can be adjusted to apply preselected initial installed retraction loads if so desired. For example, as shown in FIG. 40, in connection with the asymmetrical spring  1120 , the tabs  1124 A and  1124 B can be independently adjusted to apply preselected initial installed retraction loads. In particular, with respect to the tab  1124 B, a length L1 defined between an anchor contact midpoint C 2  of the remote end  1124 B′ with the surface  12 C of the anchor bracket  12  and a shoe contact point C 1  of the arm  1134  with the associated rear surface  14 C of the backing plate  14 A of the brake shoe can be adjusted as desired to apply a preselected initial installed retraction load. Similarly, with respect to the tab  1124 A, a length L2 defined between an anchor contact midpoint C 3  of the remote end  1124 A′ with the surface  12 C of the anchor bracket  12  and the shoe contact point C 1  of the arm  1134  with the surface  14 C of the backing plate  14 A of the brake shoe can be adjusted as desired to apply a preselected initial installed retraction load. Thus, the lengths L1 and L2 of the respective tabs  1124 B and  1124 A can be independently adjusted to apply preselected initial installed retraction loads. Also, as shown in FIGS. 41 and 42, in connection with the symmetrical spring  1320 , a tab  1324  can be adjusted to apply a preselected initial installed retraction load. In particular, a length L3 defined between an anchor contact point C 5  of an end  1324 A with the surface  12 C of the anchor bracket  12  and a shoe contact point C 4  of an arm  1334  with the surface  14 C of the backing plate  14 A of the brake shoe can be adjusted as desired to apply a preselected initial installed retraction load. Thus, the length L3 of the tab  11324  can be adjusted to apply preselected initial installed retraction loads.  
         [0128]    In accordance with the provisions of the patent statutes, the principle and mode of operation of this invention have been described and illustrated in its preferred embodiments. However, it must be understood that the invention may be practiced otherwise than as specifically explained and illustrated without departing from the scope or spirit of the attached claims.