Abstract:
A golf car having a frame supported on a plurality of wheels and a bracket member fixedly coupled to the frame. A brake pedal assembly and an accelerator pedal assembly are pivotally coupled to the bracket member such that the brake pedal and accelerator pedal are disposed in a generally suspended position behind the cowling, rather than a floor mounted position. This arrangement maximizes the ergonomic placement of the pedals, and minimizes corrosion due to exposure to moisture and chemicals and damaged caused by contact with brush and debris.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is a continuation-in-part of U.S. patent application Ser. No. 09/846,031, filed on Apr. 30, 2001, which is a continuation of U.S. application Ser. No. 09/517,302, filed Mar. 2, 2000, now U.S. Pat. No. 6,223,865 B1, which claims the benefit of U.S. Provisional Application No. 60/122,405, filed Mar. 2, 1999, the disclosures of which are incorporated herein by reference. 

   FIELD OF THE INVENTION 
   The present invention generally relates to golf cars and, more particularly, relates to golf cars having a pedal system that is suspended downwardly from a location generally behind the cowling. 
   BACKGROUND OF THE INVENTION 
   Most golf cars, and other small utility vehicles, have brake systems in one form or another. Examples of such systems may be found with reference to U.S. Pat. Nos. 4,867,289, 5,158,415, and 5,713,189, the disclosures of which are incorporated by reference herein for their technical teachings. While the above referenced patent documents, and other references, discuss application of brakes to utility vehicles and golf cars, brake systems for small vehicles and golf cars may yet be improved to increase the ease of use, feel, performance, serviceability, and the like. 
   One typical golf car brake system includes a brake pedal and interconnected accelerator pedal. When the brake pedal is depressed a predetermined distance, the brake system operates in a normal or service mode. Depressing the brake pedal further and engaging a secondary toe-actuated lever engages a parking mode which maintains the golf car in a stationary position. 
   Traditionally, the brake pedal and the accelerator pedal are constructed such that they pivot about an axis that is generally at or below the floorboard of the golf car. This arrangement is largely due to the limitations imposed by the mechanical linkages and cables required to actuate the throttles and brakes of the vehicle. However, this traditional design may suffer from a number of disadvantages, not the least of which is contamination, corrosion, and/or physical damage. That is, many golf cars operate in severe corrosive environments. For instance, these golf cars are exposed almost daily to caustic elements, such as fertilizers, salt, and detergents. All of these contribute to the corrosion of metallic components on the golf cars, such as conventional braking and accelerator systems. Moreover, damage to the undersurface of the golf car may result from those components snagging on brush, dirt mounds, and other hazards that the vehicle may pass over. Such systems that are disposed along the underside of the golf car also require that the golf car be hoisted in order to perform any necessary service thereon. 
   Furthermore, the low pivot point of conventional pedal systems of golf cars may fail to promote proper ergonomic positioning if the driver&#39;s foot, ankle, and leg. That is, it is more difficult to actuate a pedal whose pivot point is located near the pivot point of the operator&#39;s heal on the floorboard. This close proximity of these pivot points to one another lead to reduced mechanical advantage, which lead to fatigue. This improper positioning thus results in driver discomfort. 
   Accordingly, there exists a need in the relevant art to provide a pedal system for a golf car that is generally protected from the harshness of contamination, corrosion, and/or physical damage. Furthermore, there exists a need in the relevant art to provide a pedal system for golf cars that is suspended for a raised position so as to promote improved ergonomic positioning of the driver&#39;s foot, ankle, and leg. Further, there exists a need in the relevant art to provide a pedal system that may be easily serviced without requiring the golf car to be hoisted. Still further, there exists a need in the relevant art to provide a suspended pedal system that overcomes the disadvantages of the prior art. 
   SUMMARY OF THE INVENTION 
   According to the teachings of the present invention, a pedal arm system for a golf car is provided having an advantageous construction. The golf car includes a frame supported on a plurality of wheels and a bracket member fixedly coupled to the frame. A brake pedal assembly and an accelerator pedal assembly are pivotally coupled to the bracket member such that the brake pedal and accelerator pedal are disposed in a generally suspended position behind the cowling, rather than a floor mounted position. This arrangement maximizes the ergonomic placement of the pedals, and minimizes corrosion due to exposure to moisture and chemicals and damaged caused by contact with brush and debris. 
   Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
       FIG. 1  is an elevational, partial cut-away view of a golf car including a brake system arranged in accordance with the principles of the present invention; 
       FIG. 2  is a block diagram of the brake system arranged in accordance with the principles the present invention; 
       FIG. 3  is a perspective view of the golf car support frame and components of the brake system; 
       FIG. 4  is an assembled view of the brake and accelerator pedal assembly; 
       FIG. 5  is an exploded view of the brake pedal and the accelerator pedal assembly; 
       FIG. 6  is a top view of the brake pedal and accelerator pedal assembly; 
       FIGS. 7 and 8  are a partial, vertical sectional views of the brake pedal and accelerator pedal assembly; 
       FIG. 9  is a graph depicting hydraulic pressure as a function of brake pedal displacement; 
       FIG. 10  is a block diagram of a brake system of the present invention utilizing a drum brake system; 
       FIG. 11  is a block diagram of the brake system of the present invention utilizing a brake band system; 
       FIG. 12  is an interior perspective view of a hub and caliper assembly; 
       FIG. 13  is an exterior perspective view of a hub and caliper assembly; 
       FIG. 14  is an exploded view of a caliper assembly of  FIGS. 12 and 12 ; 
       FIG. 15  is an expanded perspective view of the caliper assembly; 
       FIG. 16  is a bottom view of the caliper assembly; and 
       FIG. 17  as an elevational view of the integral wheel, hub, and rotor assembly. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
     FIG. 1  depicts a golf car  10  having a brake system arranged in accordance with the principles of the present invention. Golf car  10  includes a pair of front wheels  12  and a pair of rear wheels  14 . Front wheels  12  preferably operate as steering wheels to control the direction of travel of golf car  10 . Rear wheels  14  preferably function as drive wheels for propelling golf car  10 . 
   Golf car  10  includes a seat  16  which preferably accommodates a driver and a passenger. Golf car  10  also includes a steering wheel  18  which controls the direction of front wheels  12 . An accelerator pedal  82  and a brake pedal  80  enable the operator to control acceleration and braking of golf car  10 . Accelerator pedal  82  and brake pedal  80  preferably are suspended from support members which hang generally downwardly from underneath a front cowling  24 , as will be described herein. 
   Still referring to  FIG. 1 , an entire brake actuator and release assembly  50  is configured as a modular unit mounted above the floorboard  26  and at least partially beneath the front cowling  24 . It therefore lacks any under hanging components that extend beneath the floorboard  26 . This configuration is advantageous for several reasons. For instance, there is no risk that any components of the brake system  50  will be damaged by obstructions over which golf car  10  may travel. Moreover, the system components are isolated from corrosive substances over which the vehicle may travel such as water, fertilizers, etc. 
     FIG. 2  depicts a particular feature of golf car  10 , namely, brake system  50 . Accelerator pedal  82  controls operation of an electric motor  32  which is powered by a source of electrical energy (not shown). Electric motor  32  includes one or a pair of output shafts  34  which control drive to respective hubs  38 . It should be noted that reference numerals in the drawings may include an R or L suffix to designate a component as corresponding to the left or driver&#39;s side or the right or passenger&#39;s side of golf car  10 . Respective hubs  38  drive rear wheels  14  to propel golf car  10 . While motor  32  is described herein as an electric motor, one skilled in the art will recognize that rear wheels  14  may be propelled by a gasoline powered engine and transmission or other suitable power source. 
   Brake system  50  will generally be described herein as a hydraulically actuated brake system wherein displacement of brake pedal  80  generates a hydraulic force to operate a braking element, such as a disk, drum, or band brake system, as will be described herein. Brake system  50  includes brake pedal  80  which connects to and displaces a linkage  42 . Linkage  42  provides an input to a master cylinder  60 . Master cylinder  60  operates generally as a conventional master cylinder in which depressing brake pedal  80  provides an input to master cylinder  60  which generates an increase in hydraulic fluid pressure output on hydraulic control line  46 . However, according to the suspended arrangement of brake pedal  80  and accelerator pedal  82  of the present invention, master cylinder  60  may now be positioned along an upper section of frame  56 . This upper section positioning enables master cylinder  60  to be placed at the highest elevation of the hydraulic system, thereby maintaining proper pressure in the hydraulic system, minimizing air bubbles, and cavitation. 
   Hydraulic control line  46  provides fluid pressure to caliper assemblies  48 . Each caliper assembly  48  includes opposing pads  44 . A brake rotor  40  moves rotationally in accordance with hubs  38 . Pads  44  apply a frictional force to brake rotor  40  to retard movement of brake disk  52 , thereby applying a braking force upon wheels  14 . Caliper assemblies  48  thus operate generally as is known to one skilled in the art. In order to maximize braking force, an optional second pair of caliper assemblies  54  may be arranged to provide additional retarding force upon brake rotor  40 . A particularly attractive feature of utilizing two caliper assemblies on a single brake disk is to compensate for space limitations inherent with the generally small diameter of wheels  14  of a typical golf car  10 . 
   As described above, depressing brake pedal  80  causes master cylinder  60  to generate a hydraulic fluid output pressure on hydraulic control line  46  which is applied to caliper assemblies  48  and to calipers assemblies  54  if present. An increase in hydraulic fluid pressure causes brake pads  44  to move toward brake rotor  40  to generate a frictional force which retards movement of wheels  14 . 
   Brake system  50  has two modes of operation. A first mode of operation, a service mode, of brake system  50  reduces the speed of golf car  10  to a lower speed, a stop, or to prevent unwanted acceleration of golf car  10  when going down hill. A second mode of operation, a parking mode, of brake system  50  maintains golf car  10  in a stopped position until the parking mode has been released. 
   Brake pedal  80  has a range of travel for causing master cylinder  60  to output a hydraulic fluid pressure suitable for stopping golf car  10  or maintaining golf car  10  in a stopped position. A first portion of the range of travel of pedal  80  effects a service mode of operation for reducing the speed of golf car  10  or to prevent unwanted acceleration of golf car  10  when going down hill. Depressing brake pedal  80  further places brake system  50  in a parking mode. Linkage  42  includes a detent setting for engaging and holding brake pedal  80  in a predetermined position while in the parking mode. When in this parking mode, the accumulator  62  provides a supplemental input to master cylinder  60  to compensate for any hydraulic fluid pressure drop through seal leakage and the like. Accumulator  62  maintains hydraulic fluid pressure so that caliper assemblies  48  provide suitable parking brake force upon brake rotor  40  and associated wheels  14 . 
   Brake pedal  80  and linkage  42  cooperate to include a single detent which is engaged when brake pedal  80  travels a predetermined distance so as to cause master cylinder  60  to output a sufficient hydraulic fluid pressure to prevent displacement of wheels  14 . When brake pedal  80  has engaged a detent position to define a parking mode of operation, brake system  50  can be disengaged from the parking mode of operation by depressing either brake pedal  80  or accelerator pedal  82 . Accelerator pedal  82  is mechanically linked to brake pedal  80  to enable release of the brake system  50  from the parking mode of operation. 
   With particular reference to  FIG. 3 , golf car  10  includes a vehicle frame  56 . Frame  56  provides a support to which brake and accelerator pedal assembly  58  connects. Rear axle assembly  64  supports a rear portion of frame  56  via a suspension (not shown). As shown in  FIG. 3 , brake and accelerator pedal assembly  58  mounts to an upper portion  52  of frame  56  so that brake pedal  80  is suspended downwardly on lever arm  88  and accelerator pedal  82  is suspended downwardly upon accelerator arm  172 . Brake pedal  80  and accelerator pedal  82  lack any under hanging components that extend beneath the floorboard  26 . This configuration is advantageous for several reasons. For instance, there is no risk that any components of the brake system or accelerator system will be damaged by obstructions over which golf car  10  may travel. Moreover, the system components are isolated from corrosive substances over which the vehicle may travel such as water, fertilizers, etc. Still further, this positioning of the brake system and the accelerator system, having a pivot point that is raised above the floorboard  26 , insures that the pivot point of the driver&#39;s foot (namely the heal) is not closely located near the main pivot point of each system (namely an axis extending through pivot  94 ). This leads to increased mechanical advantage to permit the operator to easily apply force to brake pedal  80  and/or accelerator pedal  82 . Furthermore, the suspended arrangement of brake pedal  80  and accelerator pedal  82  further eliminates the need to form holes or openings in floorboard  26  to allow the pass through of pedal components. Still further, service may be easily performed on the brake and accelerator system without the need to hoist golf car  10 . 
   Several features of brake system  50  will now be described. When the parking mode is engaged, brake system  30  generates a single audible click or pop sound. The sound indicates that the parking mode has been properly engaged by the operator. The benefit of a single audible sound is to provide a clear indication that the parking mode has been engaged. This feature improves upon conventional braking systems where multiple audible sounds may be generated when engaging a parking mode. In such systems the operator could incorrectly assume that while the brake pedal is locked in a position that generates a sufficient braking force, an insufficient parking brake force could be applied. 
   Brake system  50  inherently has less hysteresis associated with stiction than brake systems utilizing mechanical components, particularly hysteresis caused by cables running over contact points. Reduced hysteresis provides a brake system  50  which requires less force for selecting either the service or parking modes verses a mechanical system which requires greater force to properly engage a service or parking mode. Because hysteresis is inherently less in a hydraulic system and because hysteresis in mechanical systems typically increases over time, hydraulic brake system  50  significantly reduces hysteresis concerns problem over the lifetime of golf car  10 . 
   Hydraulic brake system  50  has a self-adjusting system which compensates for wear in brake pads  44 . Self adjustment occurs because the system allows extra fluid from the hydraulic reservoir of master cylinder  60  to be added to the system. Using caliper design features well known in the art, the seals of the hydraulic cylinders in the brake calipers insure a uniform return of brake pads  44  to equal distances away from brake disk  52 . These benefits may be further realized by utilizing a bladder-based hydraulic reservoir which provides several additional advantages. The bladder type hydraulic reservoir ensures minimal loss of hydraulic fluid through the top of the reservoir. This avoids introduction of contaminants such as water, dirt, and atmospheric transfer which may occur. 
   Hydraulic brake system  50  utilizes a synthetic fluid which is non-hygroscopic. A non-hygroscopic fluid does not absorb any fluid. Conventional brake fluid, on the other hand, absorbs moisture directly through rubber hoses and seals and other places where conventional brake systems are open to the atmosphere, including the reservoir. This transfer occurs even through seals which are frequently water vapor permeable. Thus, while many seals resist moisture in a liquid form, many such seals do not resist moisture in the form of a gaseous vapor. Hygorscopic brake fluid also often accelerates internal breakdown of metal brake system parts, while non-hygroscopic, synthetic fluid significantly reduces internal breakdown of metal brake system parts. Non-hygroscopic fluids provide a non-polar property, which yields an environmentally friendly brake fluid. Most grass plants will not absorb the non-hygroscopic, synthetic fluid, while typical conventional brake fluids may be absorbed by and damage plant life yet. 
   Conventional brake fluids, while possibly avoiding water absorption, also absorb air. The absorption of air into the brake fluid creates a spongy brake feeling and can also raise other issues such as cavitation and outgassing. Outgassing occurs when a vehicle remains exposed for a lengthy period of time in a high altitude condition. Bringing the golf car down to lower elevations and thus higher atmospheric pressure causes air entrained in the liquid at higher elevations to boil off at the lower elevations. This introduces variation into the hydraulic system. 
   Hydraulic brake system  10  also provides a positively-sealed, pressurized hydraulic brake system. In a parking mode, hydraulic brake system  10  generates at least 750 pounds per square inch (PSI). This pressurization exceeds internal hydraulic fluid pressure typically utilized in conventional hydraulic braking systems, particularly at rest. In conventional hydraulic braking systems, the parking mode is engaged through a mechanical-type emergency brake or transmission lock. Brake system  50  utilizes a hydraulic system which is continuously pressurized when the golf car is not in use and the brake system is engaged in a parking mode. To achieve a positive seal in response to relatively high static hydraulic pressures present in brake system  50 , elastomeric seals replace metal-to-metal contact on all sealing surfaces, including air bleeder valves found on caliper assemblies  48 . 
   Hydraulic brake system  50  also includes a damping systems to provide a controlled release of brake pedal  82 . The damping system utilizes a dampened hydraulic fluid flow to maintain a controlled return of parking brake  82  pedal to its non-operative position. This controlled rate of upward movement minimized noise inherent in the stopping of brake pedals at the top of travel in conventional brake systems. 
   Hydraulic fluid travels through a spiral grooved return path to restrict hydraulic fluid flow during pedal return. The fluid damping path enables a fluid flow return rate which encourages the brake pedal upward at a reasonable rate so as to maintain contact with the foot of the operator while the operator lifts upward with his or her foot. Thus, the operator feels the brake pedal firmly on the bottom of the operator&#39;s foot, while the return rate is sufficiently slow to prevent banging when the brake pedal reaches the top of travel. 
   Referring now to  FIGS. 4-8 , a preferred mode of practicing the invention will be described. The brake actuator and release assembly  50  includes as its major components 1) a master cylinder  60 , 2) a hydraulic accumulator  62 , and 3) an integrated brake pedal and accelerator pedal assembly  58 . All of these components are mounted on a common support bracket  66  that is formed from a single metal stamping. As best seen in  FIGS. 4-8 , the support bracket  66  has an open rear end, inboard and outboard sidewalls  68  and  70 , and a front wall  72  connecting the sidewalls  68  and  70  to one another. Mounting flanges  74 ,  76 , and  78  extend outwardly from the sidewalls  68  and  70  and the front wall  72  for connection to a support such as the front wall  42  of the operator&#39;s compartment. 
   The integrated brake pedal and accelerator pedal assembly  58  and the hydraulic accumulator  62  can be used either in combination or independently of one another and are applicable to the illustrated brake system  50  as well as to a variety of other systems. Each of these components will be described in turn. 
   The integrated brake pedal and accelerator pedal assembly  58  is usable with the hydraulic brake system  50  as well as a more traditional mechanical cable-actuated brake system. It includes a brake pedal  80 , an accelerator pedal  82 , and a locking mechanism  84 . The assembly  58  can perform several distinct functions. First, the brake pedal  80  can be actuated to perform a service braking operation. Second, the locking mechanism  84  can latch the brake pedal  80  in a locked, actuated position to hold the service brakes  52  in their engaged position. Third, the brake pedal  80  can operate, in conjunction with the accumulator  62 , to facilitate brake pedal latching and store energy to help assure that the brakes  52  will remain in their locked position despite creep that may occur within the system. Fourth, the locking mechanism  84  can be released using either the brake pedal  80  or the accelerator pedal  82  without actuating any secondary brake release mechanism. 
   The brake pedal  80  includes a pivot shaft  86 , a lever arm  88  extending downwardly from the pivot shaft  86 , and a pad  90  mounted on the bottom end of the lever arm  88 . As best seen in  FIGS. 6 ,  7 , and  8 , the pivot shaft  86  is mounted on a plastic sleeve  92  so as to be rotatable with respect thereto, and the plastic sleeve  92  is, in turn, mounted on a main pivot shaft  94 . Shaft  94  is rotatably supported on the support bracket  66  and also serves as the pivot shaft for the accelerator pedal  82  (discussed below). The pivot shaft  86  is lubricated via a synthetic damping grease injected into the space between the pivot shaft  86  and the plastic sleeve  92 . The damping grease preferably that comprise one that exhibits good lubrication characteristics at low rotational velocities but that actually serves to damp or inhibit shaft rotation at higher rotational velocities. The preferred grease is NYE PG-44A, which is manufactured by NYE Lubricants, Inc. This grease is an extremely stiff consistency, inorganically gelled, water resistant, rust-inhibited damping grease based on a high molecular weight polymeric-base oil. The lever arm  88  preferably is formed from steel encased in a plastic sleeve (not shown) in order to protect the steel from corrosion. The pad  90  may comprise any suitable foot actuated pad mounted on the end of the lever arm  88 . A torsion spring  96 , serving as a brake pedal return spring, is mounted on the pivot shaft  86  on one side of the lever arm  88 . In addition, a plastic block  98  is mounted on the upper surface of the lever arm  88  to form part of the lock mechanism  84  as detailed below. 
   Referring particularly to  FIG. 5 , a master cylinder actuating pin support arm  100  is mounted on the pivot shaft  86  adjacent the inboard side of the lever arm  88  so as to rotate with the lever arm  88 . An actuating pin  102  is mounted on the support arm  100  so as to rotate with the pivot shaft  86 . The pin  102  is coupled to a main piston  104  of the master cylinder  60  via a roller  103  and a strap  105  so that the brake pedal  80  and master cylinder piston  104  always move together. The actuating pin  102  comprises an eccentric pin that is mounted in an aperture  106  in the support arm  100  so as to extend laterally toward the brake lever arm  88 . A head  108  on the pin  102  can be rotated to rotate the thicker portion of the eccentric pin  102  either towards or away from the master cylinder main piston  104 , thereby eliminating any play or dead space between the brake pedal  80  and the master cylinder main piston  104  after assembly of all components. 
   The locking mechanism  84  is operable to automatically latch the brake pedal  80  in its locked position upon depression of the brake pedal  80  to a latch point and to automatically unlatch the brake pedal  80  from its locked position to release the brakes  52  upon brake pedal over travel beyond the latch point. The locking mechanism  84  also is configured to release the brake pedal  80  under power of the accelerator pedal  82 . The locking mechanism  84  may comprise any structure having at least one of 1) single point latching capability, 2) the ability to release the brakes  52  upon brake pedal over travel beyond its latched position, and 3) a kickoff mechanism that permits accelerator pedal release of the brake pedal  80 . The illustrated locking mechanism  84  includes the block  98  on the brake pedal lever arm  88 , a control arm  110  pivotally mounted on the brake pedal  80 , a swing arm  112  pivotally mounted on the support bracket  66 , and an over-center spring  114  that is coupled to the control arm  110  and to the swing arm  112  so as to bias the swing arm  112  downwardly during service braking and to bias the swing arm  112  upwardly during a latch and release cycle. 
   The control arm  110  comprises a metal plate pivotally mounted on the block  98  of the brake pedal  80  via a pivot pin. Control arm  110  has inner and outer faces and front and rear ends. The rear end presents detents  118  and  120 , and a lug  122  is mounted on the outer face near the rear end near the axis of the pivot pin. During a brake lock and release cycle, detents  118  and  120  cooperate with a dog or pawl  124  on the swing arm  112 . A cushioned stop is mounted on the inner face of the control arm  110  in front of the pivot pin. The stop has first and second arcuate surfaces that selectively engage corresponding first and second cushioned posts on the block  90  during the brake pedal lock and release cycle as detailed below. Finally, a post  136  extends outwardly from a front end portion of the outer face of the control arm  110  for connection to a front end of the over-center spring  114 . 
   The swing arm  112  supports the dog  124  and the cam  125 . It also supports a cam follower  138  that rides along a cam  140  on the block  98 . The entire swing arm  112  is mounted on a pivot tube  142  that extends laterally across the support bracket  66  and that is rotatably supported on a support pin  146 . Support pin  146  is, in turn, mounted in apertures in the opposed sidewalls  68  and  70  of the support bracket  66 . A pair of cam follower support arms  144  extend forwardly from the pivot tube  142  in a spaced-apart relationship. The cam follower  138  is rotatably mounted on the front ends of the support arms  144 , and a cushioned elastomeric bumper  148  is mounted on the rear ends of the support arms  144 . The cam follower  138  comprises a roller mounted on the support arms  144  by a roll pin. The bumper  148  serves as a stop for the brake pedal  80  when the brake pedal is in its at rest or fully released position seen in FIG.  7 . The dog  124  is positioned laterally outwardly of the outboard cam follower support arm  144  and is configured to cooperate with the detents  118  and  120  on the control arm  110 . The cam  125  is formed from a common stepped lug with the dog  124  and is positioned so as to be engaged by the lug  122  on the control arm  110  during a latching operation. A spring support bracket  150 , disposed outboard of the dog  124 , supports a post  152  to which the over-center spring  114  is connected. The locations of the posts  152  and  136  on the swing arm  112  and the control arm  110  are selected relative to 1) one another, 2) the rotational axis of the cam follower, 3) the pivot axis of the brake pedal  80 , and 4) the pivot axis of the swing arm  112  to cause the spring  114  to move across the pivot axis of the swing arm  112  at selected phases of the brake pedal depression and return processes so as to selectively assist brake pedal locking and unlocking. In the illustrated embodiment, the over-center spring is 30°-40° below the horizontal when it is in its first over-center position and a corresponding amount above the horizontal when it is in the second over-center position. 
   The block  98  is mounted directly on the upper surface of the brake pedal lever arm  88  and serves as a support structure for several other components of the locking mechanism  84 . It has the cam  140  formed directly on the upper or rear surface thereof. The cam  140  is straight along the majority of its length but has an arcuate portion  154  at its lower end surface formed from a cutout in the block  98 . Arcuate portion is dimensioned such that the cam follower  138  will rest in the arcuate portion  154  in a locked position of the brake pedal  80 . 
   A generally L-shaped toggle arm  156  is pivotally mounted on the inner lateral surface of the block  98  adjacent the swing arm  112 . The toggle arm  156  includes 1) a first leg  158  and 2) a second leg  160  that extends generally orthogonally from the first leg  158 . The first leg  158  is biased into contact with a post  162  on the block  98  by a return spring  164 . The second leg  160  cooperates selectively with a lug  166  on the swing arm  112  so as to prevent swing arm pivoting motion during the initial phase of brake pedal depression and to subsequently permit the swing arm  112  to fall into its locking position when the lug  166  clears the second leg  160 , thus allowing only one contact sound to be heard. 
   Finally, a kickoff arm  170  is mounted on the inboard end of the pivot tube  142  at a location beyond the inboard cam follower support arm  144 . The kickoff arm  170  extends forwardly and outwardly from the pivot tube  142  so as to extend beyond the inboard sidewall  70  of the support bracket  66  and so as to be engaged by the accelerator pedal  82  upon initial accelerator pedal depression. 
   The accelerator pedal  82  is mounted on the inner distal end of the pivot shaft  94  at a location outside of the inboard sidewall  70  of the support bracket  66 . It includes 1) a lever arm  172  that extends downwardly from the pivot shaft  94  and 2) a pad  174  that is mounted on the distal end of the lever arm  172 . A portion of the lever arm  172  is positioned closely adjacent the kickoff arm  170  so as to engage the kickoff arm  170  upon initial accelerator pedal depression. In addition, a non-contact accelerator pedal position sensor  178  is positioned inside the lever arm  172  in order to provide an indication of accelerator pedal actuation. The accelerator pedal  82  is biased to its deactuated position by a return spring  180 . 
   In operation, the integrated brake pedal and accelerator pedal assembly  54  assumes the position illustrated in  FIGS. 5-6  when the brakes  52  are not engaged. At this time, the brake pedal  80  assumes an at rest or fully released position in which it is pivoted to its rearward-most extent in which the front face on the block  98  engages the bumper  148  on the swing arm  112 . The cam roller  138  on the swing arm  112  is located at its maximum possible distance from the arcuate portion  154  of the cam  140 . In addition, the over-center spring  114  is in its first over-center position in which it biases the control arm  110  to the position in which its centerline is beneath the pivot axis of the swing arm  112 . It therefore biases the swing arm  112  downwardly. 
   Next, the operator engages the brakes  52  by pressing downwardly on the pad  90  to swing the brake pedal  80  clockwise into a service braking position. This pivoting motion causes the master cylinder actuating pin  102  to drive the roller  103  and master cylinder main piston  104  forwardly to effect service braking. After the service braking stroke ends, but before the brake pedal  80  reaches it latch point, the lug  166  on the swing arm  112  rides along the second leg  160  of the toggle arm  156  to hold the cam roller  138  away from the cam face  140  and to hold the dog  124  and cam  125  on the swing arm  112  away from the control arm. As a result, service braking and subsequent brake pedal depression toward the latch point occur without contact between the latching components of the locking mechanism  84 , thereby avoiding the generation of contact sounds that otherwise could give a false audible indication of pedal locking. The over-center spring  114  remains in its first over-center position at this time. The control arm  110  therefore remains in the position in which it cannot latch against the swing arm  112 . As a result, the brake pedal  80  will return to its released position if the operator removes his foot from the pad  90  without additional brake pedal depression. 
   At the end of service braking stroke and well beyond it, the lug  166  on the swing arm  112  clears the second leg  160  of the toggle arm  156  so that the swing arm  112  drops through an arc to a position in which the cam  125  engages the lug  122  on the control arm  110 . This delayed dropping of the swing arm  112  has several benefits. For instance, as described above, it permits the dog  124  and cam  125  on the swing arm  112  to clear the detents  118  and  120  and the dog  122  on the control arm  110  so as to prevent a false audible indication of brake pedal locking. Moreover, it prevents the swing arm  112  from swinging towards its locked position until the over-center spring  114  is stretched sufficiently to store enough potential energy to effectively assist in swing arm movement into its locked position. In addition, the solid contact between the cam  125  and the lug  122  that occurs when the swing arm  112  drops into place produces a distinctive “clicking” sound that provides an audible indication to the operator that the brake pedal  80  has moved into a position in which it can be locked. 
   When the operator releases his foot from the brake pedal  80  after depressing it to its locked position, the brake pedal returns a very small amount to permit the over-center spring  114  to move from its first over-center position to the second over-center position as a result of the swing arm cam  125  pushing the control arm dog  122 . As a result of this movement, the control arm  110  pivots rapidly from this position to the latched position. Because the dog  122  is located very close to the pivot axis of the control arm  110 , a very small range of axial brake pedal movement (on the order of a few thousands of an inch) results in 60° or more of control arm pivoting movement. This relationship reduces the work required of the over-center spring  114  during the latching process. The second face  130  on the stop  126  now engages the second post  134  on the block  98 , and the first or lower detent  118  on the control arm  110  now engages the dog  124  on the swing arm  112  to lock the swing arm  112  in position. This motion provides a distinctive clicking sound that provides an audible indication to the operator that the brake pedal  80  has been locked. The brake pedal  80  will thereafter remain in the locked position under the latching force of the control arm  110  when the operator releases the brake pedal  80 . However, because the spring  114  is now in is second over-center position in which its centerline is above the pivot axis of the control arm  112 , it biases the control arm  112  upwardly rather than downwardly, thereby priming the control arm  112  for subsequent release. 
   The holding force applied on the control arm  110  by the over-center spring  114  at this time should be large enough so as not to be overcome by any force that might inadvertently be placed upon or generated through the accelerator pedal  82  by virtue of the vehicle  30  being jostled during shipment or by rough treatment by errant operators. However, this holding force need not be very large because any moment arm which might tend to cause the swing arm  112  to swing out of its locked position is very small. As a result, a relatively weak spring (having a spring load on the order of 8-12 lb can be used as the over-center spring  114 . 
   The brakes  52  may be released by operating either the brake pedal  80  or the accelerator pedal  82  to unlatch the brake pedal  80  from its locked position. To release the brakes using the brake pedal  80 , all the operator need do is depress the pedal  80  beyond its locked position to an over travel position. This brake pedal movement and consequent swing arm movement will cause the dog  124  on the swing arm  112  to slip out of the first detent  118  on the control arm  110 , permitting the over-center spring  114  to pull the swing arm  112  upwardly so that dog  124  snaps against the second detent  120  as seen in FIG.  10 . The snapping action of the dog  124  against the detent  120  produces a distinctive click that apprises the operator that the brake pedal  80  is unlatched. As a result, the brake pedal  80  will return to its at-rest position under the biasing forces of the return spring  96  and the accumulator spring  246  when the operator releases the brake pedal  80 . 
   The brake pedal  80  places a substantial moment on the swing arm  112  during the return stroke of the brake pedal  80 . The dog  124  on the swing arm  112  produces a corresponding moment on the upper surface of the detent  120  of sufficient magnitude to pivot the control arm  110  counter-clockwise. The over-center spring  114  therefore moves back to its first over-center position so that it again biases the swing arm  112  downwardly. In addition, the lug  166  on the inner lateral surface of the swing arm  112  engages the second leg  160  of the toggle arm  156  during the return stroke to cause the toggle arm  156  to pivot clockwise to permit unobstructed movement of the lug  166  past the toggle arm  156 . The toggle arm  156  then drops back into its initial position under the biasing force of the spring  164  so that it is primed for the next service braking cycle. 
   Brake pedal release using the accelerator pedal  82  occurs in similar sequence. The operator presses downwardly on the accelerator pedal  82  so that the lever arm  172  engages the kickoff arm  170 . This engagement forces the swing arm  112  to swing clockwise about the pivot tube  142  to drive the control arm  110  to pivot as described above. As before, this movement unlatches the swing arm  112  from the control arm  110  and permits the brake pedal  80  to return to its at-rest position under the biasing force of the brake pedal return spring  96  and the accumulator spring  246 . Also as before, this movement forces the control arm  110  and over-center spring  114  back to the initial position. Because the cutout  154  in the cam surface  140  is tangential to the swing arm pivot arc, the cam roller  138  simply moves circumferentially along the cam surface  140  during the initial, accelerator pedal imposed phase of the unlatching operation without resistance from the rather substantial return force imposed on the brake pedal  80  by the brake pedal return spring  96  and the accumulator spring  246 . Brake pedal unlatching therefore imparts little resistance to accelerator pedal motion, and brakes  52  are disengaged after the first 1-3 inches of accelerator pedal stroke with minimal operator effort. As a result, the operator can “feather” accelerator pedal motion so that the brakes  52  can be disengaged without over-depressing the accelerator pedal  82 . This eliminates jerky motion or quick starts often associated with golf carts and other light-duty vehicles. 
   The master cylinder  60  and hydraulic accumulator  62  are configured to translate the mechanical actuating forces generated by brake pedal depression into hydraulic pressure that first engages the brakes  52  and that then stores additional energy for holding the brakes  52  in their engaged condition. This energy storage provides several benefits. For instance, it permits the brake system  50  to make up for “creep” or fluid pressure loss that may occur due, e.g., relaxation of elastomeric components of the system. Moreover, it can assist in returning the brake pedal  80  to its at rest position following release of a locked brake pedal. 
   Referring to  FIGS. 4 ,  5 ,  7 , and  8 , the master cylinder  60  is generally conventional. It includes a housing  200  having an internal horizontal bore  202  formed therein. A reservoir  204  is formed above the bore  202  for storing hydraulic fluid. The bore  202  has an upper fill inlet  206  and a rear outlet  208 . The inlet  206  cooperates with the reservoir  204 . The rear outlet  208  opens into an accumulator chamber  210 , detailed below. The master cylinder main piston  104  is slidably mounted in the bore  202  so as to extend rearwardly from the rear end of the bore  202  and into contact with the roller  103 . As a result of this arrangement, 1) depression of the brake  80  and consequent swinging movement of the actuator pin  102  and roller  103  drives the main piston  104  forwardly through the bore  206  to pressurize the outlet  208 , and 2) release of the brake pedal  80  permits the main piston  104  to move rearwardly through the bore  202  to depressurize the outlet  208 . 
   Referring to  FIG. 7 , accumulator chamber  210 , as well as the remainder of the accumulator  62 , may be located at any pressurized point in the braking system  50 . In the illustrated embodiment, however, the chamber  210  is formed in an extension  212  of the master cylinder housing  200  extending essentially collinearly with the bore  202  so as to reduce the number of parts in the accumulator  62  and to facilitate assembly. The accumulator chamber  210  has a first orifice  218  in a rear wall thereof that opens directly into the master cylinder outlet  208 , and a second orifice  220  in an upper wall thereof that communicates with a bleeder port  222  and a brake supply orifice  224  in the master cylinder housing extension  212 . The orifice  224  is connected to the front and/or rear vehicle brakes  52  via associated brake lines  46  of FIG.  2 . 
   An accumulator drive piston  214  and a one-way restrictor valve  216  are mounted in the accumulator chamber  210 . The accumulator drive piston  214  is slidably mounted in the chamber  210  so as to extend beyond a rear end of the master cylinder extension  212  and into contact with the accumulator spring assembly  58 . The one-way restrictor valve is positioned forwardly of the accumulator drive piston  214  and is biased toward the front of the chamber  210  by a return spring that is seated on the one-way restrictor valve  216  at its front end and on the accumulator drive piston  214  at its rear end. 
   The purpose of the one-way restrictor valve  216  is to damp return fluid flow into the master cylinder  60  from the accumulator chamber  210  upon release of the brakes  52 , thereby inhibiting the pronounced brake pedal snapback effect exhibited by most park and hold brake systems of this type. The energy stored in the accumulator  62  and the brakes  52  instead is released more gradually, permitting a much smoother brake pedal return. 
   The hydraulic accumulator  62  performs several beneficial functions. For instance, it reduces the effort required by the operator to depress the brake pedal  80  to its locked position. It also stores energy generated upon manual pressurization of the hydraulic fluid in a form that can then be used to maintain the brakes  32  in their engaged positions after the brake pedal  80  is locked. Finally, it assists in returning the brake pedal  80  to its released position upon brake pedal unlocking. The preferred accumulator structure is one that has a minimum number of components and that can be readily assembled as a unit offsite and then attached to the remainder of the brake assembly  50  by an unskilled operator. Towards these ends, the hydraulic accumulator  62  is a spring type accumulator taking the form best seen in FIG.  7 . It includes a retainer  240 , a movable compression plate  242  disposed at the rear end of the retainer  240 , a cap  244  affixed to the front end of the retainer  240 , and a compression spring  246  captured between the compression plate  242  and the cap  244 . 
   The retainer  240  includes a front mounting plate  248  and a plurality (preferably two) straps  250  that extend rearwardly from the mounting plate  248 . The mounting plate  248  has an internally threaded post  252  and a pair of tangs  254  located radially outside of the post  254  and bent in opposite directions. The threaded center post  252  screws onto external threads  256  on the master cylinder housing extension  212 , and the tangs  254  lock into slots  258  in the front wall  72  of the support bracket  66  when the post  252  is fully tightened onto the master cylinder housing extension  212 . The accumulator  62  can subsequently be unscrewed from the master cylinder housing extension  212  only by over-torquing the accumulator  62  in a counter-clockwise direction to release the tangs  254  from the slots  258 . The straps  250  serve as mounts for the cap  244  and are configured to guide and support both the spring  246  and the compression plate  242 . Each strap  250  extends rearwardly from the mounting plate  248  and terminates in a hook  260  at its distal end. The bodies of the straps  250  serve as supports and guides for the compression plate  242  and the spring  246 . The hooks  260  latch onto the cap  244  as detailed below to fix the cap in place. 
   The compression plate  242  includes a rear annular spring support portion  262  and a cup portion  264 . The cup portion  264  extends axially forwardly from the center of the rear spring support portion  262  to a front nut portion  266 . Spring support portion  262  presents a seat for the rear end of the accumulator spring  246 . Cup portion  264  is configured to surround the end of the master cylinder housing extension  212  and to abut the front end of the accumulator drive piston  214 . Apertures  268  are formed in the spring support portion  262  for passage of the straps  250 . Upon assembly, this relationship between the straps  250  of the retainer  240  and the apertures  268  in the compression plate  242  permits the compression plate  242  to move axially relative to the retainer  240  but prevents relative rotational movement between the compression plate  242  and the retainer  240 . 
   The cap  244  comprises a metal annular ring having a circular axially front end portion  270  and inner and outer circular flanges  272  and  274 . The flanges  272  and  274  extend rearwardly from the front end portion  270  so as to form a groove serving as a second seat for the spring  246 . A pair of hook receiving apertures are formed in the front end portion  270  adjacent to corresponding notches  278 . The notches  278  are configured to receive the straps  250  and the hooks  260  of the retainer  240 , thereby locking the cap  244  onto the retainer  240 . 
   The spring  246  is precompressed a substantial amount as a result of a preassembly process. As discussed in more detail below, this spring precompression sets a threshold pressure below which substantially all work performed by the master cylinder  60  is applied toward fluid pressurization and above which the majority of the work performed by the master cylinder  60  is applied toward energy storage in the accumulator  62 . The amount of precompression required for a particular pressurization threshold level will vary depending on the spring rate of the spring  246  and its caged height. The spring  246  of the illustrated embodiment has a free length of about 9″ and a spring rate of 25 lbs/in. It is precompressed to an installed length of approximately 4″ during the assembly process to provide a threshold pressure of about 800-850 psi. 
   The precompression of the accumulator spring  246  is selected to set the threshold pressure to a level well above the lockup point of the brakes  52  but well below the single latch point of the brake pedal  80 . In a system in which the brake pedal is latched in position 8″ into its stroke, service braking is performed in the first 2 to 3″ of brake pedal stroke even under panic stop conditions. In fact, brake lockup typically occurs after no more than 2½″ of brake pedal stroke. Typical lockup points for fully burnished and unburnished brakes are denoted as such in FIG.  8 . 
   Additional brake pedal depression past the threshold point  286  compresses the accumulator spring  246 , thereby storing the energy of master cylinder actuation in the form of potential energy in the spring  246 . System pressure rises at a much slower rate during this phase of pedal actuation, as represented by the shallow portion  288  of the curve  282 . This effect results from the fact that the incremental increase in input force required to compress the spring  246  is substantially lower than the incremental increase in input force required to additionally pressurize the hydraulic fluid. As a result, resistance to brake pedal movement during this second phase of brake pedal actuation increases at a much slower rate than during the first phase. 
   In the illustrated embodiment, the transition point  286  between the first and second phases of brake pedal actuation occurs at approximately 800-850 psi of hydraulic pressure. Pressure thereafter rises gradually to about 900-950 psi when the brake pedal  80  is latched in its locked position and the end of the second phase of its actuation stroke. The compression spring  246  is compressed about ½″ at this time. At least 50%, and possibly at least 65% or more, of the total pedal stroke required to latch the brake pedal  80  in its locked position is consumed in the second phase of brake pedal actuation. As a result, by the end of this phase, more than ample energy is stored in the accumulator  62  to hold the brakes  52  and to return the brake pedal  80  with little additional effort by the operator. (The amount of energy stored by the accumulator  62  is represented by the hatched area  292  under the curve  282  in  FIG. 9. ) 
   Considerable work is performed over the rather lengthy second phase of the brake pedal actuation stroke, but at much lower input forces than would be required to perform the same amount of work (and hence to store the same amount of energy) over a shorter stroke. In fact, the transition point  286  is reached at an operator input force of about 35 lbs, and only an additional 25 lbs of input force is required to depress the brake pedal  80  to its latch point. This is in contrast to the drastically higher input force that would be required to pressurize the fluid to a much higher level if the operator were to press the brake pedal  80  to its latch point without an accumulator in the system (see the phantom line  290  in FIG.  9 ). Hence, the accumulator  62  greatly facilitates brake pedal latching and reduces the precision required to achieve the latch point because the operator strokes the pedal a great distance easily. 
   Upon brake pedal release, the one-way restrictor valve  216  immediately seats against the front end of the chamber  210  under the force of the return spring  230 , thereby preventing rapid depressurization of the accumulator chamber  210 . The damping effect provided by this restricted fluid flow imposes a relatively low return speed on the brake pedal  80  that continues for a period of time. The brake pedal  80  consequently returns to its initial position without any undesirable rapid snapback that otherwise would produce substantial wear and tear on the system and even risk injury to the operator. The damping grease between the brake pedal pivot shaft  86  and the stationary sleeve  92  additionally damps brake pedal return movement at this time. However, the combined damping effect provided by the one-way restrictor valve  216  and the damping grease does not overly-damp brake pedal return. Instead, the brake pedal  80  is biased by the springs  96  and  246  to quickly follow the operator&#39;s foot without pushing the foot upwardly too fast. The remaining, small snapback impact forces resulting from this moderate return speed are absorbed by the elastomeric bumper  148  on the swing arm  112  when the brake pedal  80  reaches its at-rest or fully released position, resulting in a virtually noiseless and vibration less pedal return. 
     FIG. 10  depicts a hydraulic brake system  310  arranged similarly to hydraulic brake system  50  of  FIGS. 1-3 . Hydraulic brake system  310  utilizes a drum brake system rather than a disk brake system to apply braking force at the wheels. Components of hydraulic system  310  which are similar to the components described with respect to  FIGS. 1-3  will be referred to using identical reference numerals. 
   Of particular interest in  FIG. 10 , brake system  310  is embodied as a drum brake system which includes a brake cylinder and shoe assembly  312  which operates in response to hydraulic fluid pressure applied through hydraulic control line  46 . Brake cylinder and shoe assembly  312  includes a brake cylinder which presses brake shoes radially outward against brake drum  314 . Brake drum  314  on its outboard side connects to wheels  14 . Application of hydraulic fluid pressure through hydraulic control lines  46  causes brake cylinder and shoe assembly  312  to press against brake drum  314 , thereby generating a frictional force retarding movement of wheels  14 . Accordingly, hydraulic brake system  310  operates as described above, except that application of braking pressure occurs through a drum brake system rather than through a disk brake system. 
   In yet another embodiment of the present invention,  FIG. 11  depicts a hydraulic brake system  320  which utilized a band brake system to retard movement of drive shafts  34 .  FIG. 11  is generally arranged as described above with respect to  FIGS. 1-3  and  10  except that the brake mechanism will be described with respect to a band brake system, rather than a disk or drum brake system. Accordingly, like reference numerals from these figures will be used to described similar components in FIG.  11 . 
   Hydraulic brake system  320  utilizes displacement of brake pedal  80  and linkage  42  to generate a hydraulic fluid pressure from master cylinder  60  into hydraulic control lines  46 . Hydraulic control lines  46  operate a band brake assembly  322 . Band brake assembly  322  includes a brake cylinder  324  rigidly connected to drive shaft  34 . Brake cylinder  324  is encircled by brake band  326 . In response to hydraulic to fluid pressure, brake band  326  circumferentially restricts around brake cylinder  324  to generate a frictional force. A frictional force retards movement of drive shafts  34  and correspondingly retards movement of wheels  14  to thereby crate a braking force. When hydraulic fluid pressure in hydraulic control line  46  is reduced, brake band  326  reduces the circumferential constriction thereby reducing the braking force. 
     FIGS. 12-17  show a preferred embodiment of caliper assembly  48  and its interconnection to golf car  10 .  FIG. 12  shows a left brake assembly  500 L which is composed of the integral hub and rotor assembly  502  which has a rotor portion  504  and a wheel hub portion  505 . Brake assembly  500 L further has a caliper assembly  506  which is attached by two through bolts  508  to affixed flange  510  rigidly mounted to the rear axle housing  511 . 
   Caliper assembly  506  has a caliper outboard half subassembly  512  and a caliper inboard half subassembly  514 . Caliper inboard half  514  has an input fluid port  516  for receiving fluid from the hydraulic brake line  521  and a fluid output port  517  for providing fluid to the right brake system  50 OR (see FIG.  13 ). Caliper inboard half subassembly  514  has a bleeder valve  518  for bleeding air from the brake lines  521  during repair or installation. 
     FIG. 13  shows a right brake assembly  500 R, which is composed of the same components as those shown in the left brake assembly  500 L of  FIG. 12 , in mirror image form. Caliper assembly  506  holds a pair of brake pads  518  and  519  adjacent to rotor  504  of the integrated hub and rotor assembly  502 . Pads  518  and  519  move in response to hydraulic force generated by fluid under pressure applied to input port  516 R. The integrated hub and rotor assembly  502  is held onto drive shaft  536  by a hex castle nut  538  and cotter pin  540 . 
     FIG. 14  shows an exploded view of caliper assembly  506 , which reveals that the caliper inboard half subassembly  514  and caliper outboard half subassembly  512  each have a pair of piston actuators  520 . Each actuator has a conventional polymeric outside seal  522 , which elastically deforms when the pistons are moved forwardly to press against the brake pads  518  and  519 , and which undeform to pull the piston away from the rotor portion  504  when the fluid pressure is removed. Between the halves of the caliper  506  is a pair of conventional elastomeric O-rings  525  which function to help prevent leakage of hydraulic fluid moving through internal passages within each half sub assembly  512  and  514  and between the halves of the caliper  506 . Disposed immediately adjacent the O-rings  225  is a pair of through holes  528  for accepting through mounting bolts  530  (not shown) (in FIG.  14 ). Also shown is through bolt  532  which functions to secure brake pads  519  and  518  in their proper alignment with the rotor portion  504 . Wire spring clips  542  and  544  generally are further provided to hold the brake pads in place. 
     FIG. 15  is a perspective view of caliper assembly  506  of the current invention. Shown are the through bolts  530  which function to hold the caliper inboard half subassembly  514  and caliper outboard half subassembly  516  together. Also shown are through bolts  532  holding the brake pads  518  and  519  in proper position between the piston actuators  520 . 
     FIG. 16  shows a bottom view of the caliper brake assembly  500 . Shown is the relationship of the pads  518  and  519  with the actuating pistons  520 . As can be seen, the pads  518  and  519  define a space wherein the rotor portion  504  is located. 
     FIG. 17  is a diagram of the integral wheel hub and rotor assembly with caliper disposed within the small diameter of the golf cart wheel  542 . As can be seen, the low profile caliper  506  can fit within the small diameter of the golf cart wheel. The lower profile of the caliper  506  allows for incorporation of a disk brake system onto a golf cart. 
   Further details of the brake caliper assembly  506  will now be described. Subassembly  512  includes a metal caliper housing preferably prepared from an iron or aluminum alloy casting, and subassembly  514  includes a similarly made metal caliper housing. Each of these caliper housings may be precision-machined to conventional tolerances to have their flat exterior mating surfaces, the through holes, and substantially cylindrical pockets for receiving the brake pistons, that are shown in the  FIGS. 12 through 15 , formed to proper size. Using conventional techniques, internal passages for hydraulic fluid are formed within caliper housings to provide hydraulic fluid from the inlet port to the backside of the respective brake piston pockets. Flat machined surfaces on the end portions of one caliper housing of subassembly  512  match up with and bear tightly against corresponding flat machined surfaces on the caliper housing of subassembly  514  when the two mounting bolts  530  are drawn tightly against the rigid mounting flange  510  to which the overall assembly  506  is rigidly mounted. The side face of mounting flange  510  contacting the adjacent caliper housing of assembly  512  is parallel to the rotor  504 . The through holes in the caliper housings for the mounting bolts  530  are perpendicular to these machined surfaces, thus ensuring that faces of the brake caliper pistons are sufficiently parallel to the parallel opposed faces of rotor  504  to ensure substantially uniform wear on brake pads  518  and  519 . 
   Each through bolt is substantially centrally positioned relative to opposed flat machined surfaces of the end portions of the caliper housings of caliper subassemblies  512  and  514 . In this manner, tightening bolts  530  ensures slight compression of O-rings  525 , to eliminate the possibility of any hydraulic leak between the adjacent housings. Since only two bolts are required to mount caliper the assembly  512  to flange  510 , minimal effort is required for final assembly to the vehicle axle. This means that brake caliper assembly  512  can be fully assembled in a location remote from the final assembly plant for the small utility vehicle, function-tested, and then shipped while filled with hydraulic fluid if desired. 
   Caliper assembly  506  has a low compact profile when viewed in side elevation. As best shown in  FIG. 17 , the clearance between the radially outermost points of caliper housings of subassemblies  512  and  514 , and the inner generally cylindrical rim surface of the wheel are preferably in the range of about 3 mm (about 0.1 inch) to about 20 mm (about {fraction (8/10)} inch), with a range of about 5 mm (about {fraction (2/10)} inch) to about 12 mm (about 2 inch) being presently preferred. Such tight clearances are made possible in part by using sufficiently thick and stiff caliper housings which are further rigidified and stabilized by the use of two quality mounting bolts  530  and a sufficiently stiff mounting flange to avoid any significant lateral or radial flexing or distortion of the caliper assembly during intense braking, up to and including full rotor/wheel lock-up. In this regard, the outer end portions of caliper housings through which the through bolts  530  are run, are as shown generally thicker (that is, in the direction of the axis of the rear axle of the vehicle) than they are high (that is, a the radially outward direction from the axis of the rear axle of the vehicle). 
   The use of two sets of opposing pistons in the opposed half caliper subassemblies  512  and  514  also provides additional benefits. First, the opposed piston arrangement provides balanced opposing forces on opposite sides of the rotor, thus allowing high hydraulic braking forces to be applied. Secondly, the two piston actuators  520  in subassembly  512  are slightly angularly spaced apart from one another. By using two spaced-apart brake pistons on each caliper subassembly, a generally oblong, kidney-shaped relatively thick brake pad may be used as shown, thus maximizing the amount of surface area of the brake pad. Its large size helps minimize the rate of brake pad surface wear during repetitive braking over a period of months and years. The oblong brake pads are preferably made in any conventional or suitable manner, with reinforcing a back plate portion as shown, to help ensure minimal deflection and good contact between the rotor surface and brake pad surface, even in the central region of the brake pad between the two brake pistons. Armed with the teachings and illustrations within the present disclosure, the design and construction of compact, low-profile dual piston brake caliper assembly of the present invention with its long-life brake pads need not be further described, since the design and construction of larger, less space-efficient conventional two-piston and four-piston brake caliper assemblies are well understood, and details from those design and construction techniques, where space and compact is not an issue, can be readily adapted into the present environment. 
   The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.