Abstract:
An adjustable control pedal assembly for a motor vehicle, presenting a compact arrangement of throttle control and brake pedals having a fixed spatial relationship throughout a range of adjustability. The pedals present a constant control set to the operator of the motor vehicle throughout the range of adjustability both in their separation distances, pedal face step-over relationship, and the attitude of the pedal faces with respect to the vehicle operator.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to control pedals for a motor vehicle. In one of its aspects, the invention relates to a control pedal assembly for a motor vehicle. In another of its aspects, the invention relates to adjustable control pedals. In another of its aspects, the invention relates to an adjustable control pedal assembly for a motor vehicle. 
     2. Description of the Related Art 
     In a motor vehicle, the control interface between the driver and the motor vehicle mechanisms for acceleration, braking, and a clutch, takes the form of foot-operated pedals located underneath the instrument panel in front of the driver. These foot-operated pedals are commonly mounted on a lever arm that is pivotally mounted to a fixed point in the vehicle and arranged to exert a compression or tensile force on a linkage with the respective mechanism, whether it be acceleration, braking, or clutch. 
     A given motor vehicle, however, might be operated by multiple drivers, potentially having different physical dimensions, such as leg length or foot size. This necessitates some adjustability in the motor vehicle to accommodate drivers of different sizes. The most common adjustability built into the automobile has been incorporating adjustability into the driver&#39;s seat, and to some extent to the steering wheel of the vehicle, to place the operator at the proper distance from the foot pedals and steering wheel. This has some limitations, however, as it is known to be undesirable to have an operator placed too close to the steering wheel, and there are practical limits to the adjustability of the driver&#39;s seat and/or steering wheel while still providing proper spacing from the otherwise positionally fixed foot pedals. 
     Efforts have been made to provide some adjustability to the control pedals of the motor vehicle, but such efforts have had limited commercial success. Prior art attempts to develop adjustability have resulted in a bulky construction, and have generally failed to take into consideration the functional relationship between the accelerator, brake and clutch, particularly the relative positioning of the pedals throughout the adjustment range, and the expectations of the operator as to that relative positioning. A uniform and optimum relationship between the pedals will aid the operator in efficient operation of the motor vehicle. 
     It would be advantageous to develop an adjustable system of control pedals, or a control pedal assembly, for a motor vehicle, wherein the control pedal assembly provides a compact, unified construction, and maintains a uniform relationship between the pedals independent of the position of the assembly throughout its range of adjustability. 
     SUMMARY OF THE INVENTION 
     The invention relates to a control pedal assembly for a motor vehicle, including a first pedal and a second pedal, a cradle for pivotal connection to the motor vehicle about a cradle pivot axis, and a pedal positioning assembly, wherein the pedals are pivotally connected to the cradle about a pedal pivot axis, and wherein the cradle is pivotable about the cradle pivot axis by the pedal positioning assembly throughout a range of adjustability. In a preferred embodiment, the pedal positioning assembly comprises a motor-driven ball screw threadably connected with a drive nut pivotally mounted to the cradle. 
     The pedal positioning assembly can further include a second motor-driven ball screw threadably connected with a second drive nut pivotally mounted to one of the pedals. Both ball screws can be driven by a single motor, and can have the same or differing thread pitches. 
     In one aspect of the invention, one of the ball screws is carried by a rotation socket operably connected to a brake push rod. 
     In another aspect of the invention, the first and second ball screws are configured to simultaneously adjust the position of the cradle and the pedals, whereby the first pedal maintains a fixed spatial relationship to the second pedal throughout the range of adjustability. The assembly is further configured to maintain the pedals in a constant attitude to an operator of the vehicle throughout the range of adjustability. 
     In another aspect of the invention, wherein the ball screw rotates in a rotation hub pivotally connected to the brake push rod, the connection between the rotation hub and the brake push rod is restricted to move in an arc by an idler arm pivotally connected at a first end to the vehicle and at a second end to the connection between the rotation hub and brake push rod. 
     In another aspect of the invention, the control pedal assembly for a motor vehicle comprises a cradle, an electronic throttle control, and a brake pedal, wherein the brake pedal is pivotally mounted to the cradle about a brake pedal pivot axis, the electronic throttle control includes a throttle control pedal and is connected to a bracket pivotally mounted to the cradle about the brake pedal pivot axis, and the cradle is pivotally mounted to the motor vehicle about a cradle pivot axis, the control pedal assembly further comprising a pedal positioning assembly for adjustably positioning the pedals within a range of adjustability. The assembly further includes a guide pin configured to ride in a guide pin slot for maintaining the throttle control pedal at a constant attitude to the vehicle operator. 
     In another aspect of the invention, an adjustable control pedal for a motor vehicle comprises an arm-mounted pedal operably connected to a vehicle control apparatus and pivotally connected to a support structure that is pivotally connected to the motor vehicle, the support structure including a positioning assembly for positioning the control pedal at a constant attitude, relative to an operator of the vehicle, within a range of adjustability. The control apparatus can include a vehicle throttle control system or vehicle brake system. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings: 
     FIG. 1 is a left side perspective view of an adjustable control pedal assembly for a motor vehicle according to the invention; 
     FIG. 2 is a right side perspective view of the assembly of FIG. 1; 
     FIG. 3 is a front elevation of the adjustable control pedal assembly of FIGS. 1 and 2; 
     FIG. 4 is a partial side view of a support bracket for the adjustable control pedal assembly of FIGS. 1-3; 
     FIG. 5 is a partial opposite side view of the support bracket for the adjustable control pedal assembly of FIGS. 1-3 
     FIG. 6 is a partial cross-sectional view taken through line  6 — 6  of FIG. 3 showing only the brake pedal in two adjusted positions; 
     FIG. 7 is a partial cross-sectional view taken through line  7 — 7  of FIG. 3 showing only a throttle pedal in two adjusted positions; and 
     FIG. 8 is a partial cross-sectional view as in FIG. 6 showing both pedals in a first adjusted position. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the figures, and with particular reference to FIG. 1, the pedal assembly  10  according to the invention comprises a cradle  12  in the form of an inverted “U” having a top strap  14  and two depending arms  16 ,  18 . Cradle arms  16 ,  18  are substantially mirror images of one another. Cradle pivot pin openings  20  pass through the lower end of each cradle arm  16 ,  18 , each aligned with the other; likewise, brake arm pivot pin openings  22  pass through an upper portion of each cradle arm  16 ,  18 . Brake arm pivot pin  26  is received in brake arm pivot pin openings  22 . An upstanding cradle nut mounting ear  24  extends from cradle top strap  14 . 
     Pedal assembly  10  further comprises an electronic throttle control (hereinafter ETC)  30  mounted to an ETC mounting bracket  32  pivotally received on brake arm pivot pin  26 . ETC  30  is a rheostat-type switch for generating the control signal for an engine throttling system, as such as electronic fuel injection, the function of which is beyond the scope of this disclosure, but is well known to those of ordinary skill in the art. ETC  30  further comprises a throttle arm  31  pivotally mounted at one end to ETC  30  and comprising a throttle pedal  34  at an opposing end for foot control by a vehicle operator. A brake arm  36  is pivotally connected at a first end to brake arm pivot pin  26 , and further comprises a brake pedal pad  38  at an opposing end for foot control of a vehicle&#39;s brakes by the vehicle operator. Brake arm  36  further comprises a brake arm nut pivot opening  40  for pivotally receiving brake arm nut  42 . Brake arm nut  42  comprises an internally threaded portion  44 . 
     Pedal assembly  10  further comprises a pedal positioning assembly for adjustably positioning the pedals  34 ,  38  throughout a range of adjustability. The pedal positioning assembly includes at least two controllable linear displacement mechanisms, one for each of the pedals  34 ,  38 . The linear displacement mechanisms can take the form of a worm drive, servo-motor, or other mechanism well-known to those skilled in the art. In the preferred embodiment depicted, a first ball screw  48  is threadably received in cradle nut  50 , which is pivotally attached to ear  24 . First ball screw hub  52  rotatably receives first ball screw  48 , and is rotatably attached to pedal assembly support bracket  100  (see FIG. 3) by idler arm pivot pin  54 . Idler arm  56  is pivotally attached to idler arm pivot pin  54  at a first end and is pivotally attached to brake booster push rod  58  at a second end by push rod pivot pin  60 . 
     Referring now to FIGS. 2-5, support bracket  100  includes two depending side walls  102 ,  104  fixedly connected by a top wall  106 . Side walls  102 ,  104  each include a cradle pivot pin opening  108 . Each of the cradle pivot pin openings  108  aligns to correspond with the cradle pivot pin openings  20  of the cradle  12 , for pivotal connection of the cradle  12  to the side walls  102 ,  104  by a pair of cradle pivot pins  110 . Side wall  102  further comprises an idler arm pivot opening  112  for receiving idler arm pivot pin  54 . Side wall  104  further comprises a slot  114  for slidably receiving an ETC bracket guide pin  116 . Guide pin  116  extends perpendicularly through side wall  104  from a tail portion  33  of ETC bracket  32 . 
     Referring now to FIG. 6, second ball screw  46  is rotatably received in a second ball screw hub  62  pivotally attached to push rod pivot pin  60  at lower end of idler arm  56 . Second ball screw  46  is threadably received in threaded portion  44  of brake nut  42 . 
     In a static position, it can be seen that the pedal assembly  10  is fixed in position with respect to support bracket  100  in that while cradle  12  is pivotally mounted to support bracket  100  at cradle pivot pins  110 , the upper end of cradle  12  is fixed in place by first ball screw  48  threadably received in cradle nut  50 , first ball screw  48  being restricted from longitudinal movement, its rotational hub  52 , being positionally fixed with respect to support bracket  100  by idler arm pivot pin  54 . Pedal assembly  10  is therefore positionally anchored to support bracket  100  at cradle pivot pins  110  and idler arm pivot pin  54 . Cradle  12  is further rotationally fixed with respect to support bracket  100 , so long as first ball screw  48  is longitudinally fixed at hub  52  and threadably received in cradle nut  50  which is pivotally attached to ear  24 . 
     It can further be seen that brake pedal arm  36  has a fixed position relative to idler arm  56 , so long as second ball screw  46  is threadably received in brake nut  44  and rotatably received in second ball screw hub  62 , each of which are pivotally attached to brake arm  36  and idler arm  56 , respectively. Application of force to brake pedal pad  38  will necessarily transfer force to brake booster push rod  58  through brake nut  44 , second ball screw  46 , second ball screw hub  62 , and push rod pivot pin  60 . Brake booster push rod  58  is mechanically linked to the motor vehicle&#39;s brake system (not shown). Brake booster rod  58  receive a uniformly directed braking force at push rod pivot pin  60 , regardless of the position of brake arm  36 , as pivot pin  60  can only rotate in the arc defined by idler arm  56  about idler arm pivot pin  54 . 
     Each of the ball screws  46 ,  48  is operably connected to an electrically operated and controlled motor  70 , such as by cables  72 , motor  70  and cable  72  operating to rotate ball screws  46 ,  48  in a controlled and coordinated fashion. Referring to FIGS. 6 and 7, brake arm  36  and throttle arm  31  are adjustable throughout the range of adjustability, with a first position illustrated, and a second position shown in phantom. As first ball screw  48  rotates, cradle nut  50 , being threadably received on first ball screw  48 , travels longitudinally along first ball screw  48 , causing cradle  12  to pivot about cradle pivot pins  110  as ear  24  and top strap  14  of cradle  12  travel longitudinally along first ball screw  48 . As cradle nut  50  travels along first ball screw  48 , it pivots with respect to ear  24  to prevent any binding of ball screw  48  in nut  50  as cradle  12  describes an arc about cradle pivot pins  110 . As cradle  12  pivots about cradle pivot pins  110 , brake arm pivot pin  26  describes an arc about cradle pivot pins  110 . In traversing this arc, brake arm pivot pin  26  moves the pivot point of the brake arm  36  and the upper end of the ETC mounting bracket  32 . It is clearly necessary to provide a structure to control the movement of the ETC mounting bracket  32  and the brake arm  36  to keep the pedals  34 ,  38  in position for operation by a vehicle operator. For instance, if the brake nut pivot point  40  were maintained in a constant position as brake arm pivot pin  26  were rotated about cradle pivot pins  110 , brake pedal  38  would be rotated about brake nut pivot pin  40  in a direction opposite to the movement of cradle nut  50  along first ball screw  48 . The same result would occur with pedal  34  if the ETC mounting bracket  32  were fixed to cradle  12 . 
     To keep brake arm  36  in a uniform relationship to the vehicle operator, second ball screw  46  is rotated in consonance with first ball screw  48  so as to displace brake nut  44  longitudinally along second ball screw  46  a complementary distance with respect to the travel of brake arm pivot pin  26 , to keep brake pedal  38  at a uniform attitude. This can be accomplished in one of a number of manners, such as strategically placing brake nut pivot pin  40  on brake arm  36 , relative to the positions of cradle nut  50  and brake arm pivot pin  26 , or can be further adapted by a strategic selection of the thread pitch of first ball screw  48  and second ball screw  46 , these methods using a common rotational speed for first and second ball screws  46 ,  48 . In the alternative, first and second ball screws  46 ,  48  can be driven at different rotational speeds, such as by gearing between motor  70  and cables  72 . 
     In like fashion, ETC bracket  32  is maintained in a constant relationship with the vehicle operator and with respect to brake arm  36 . ETC bracket  32  shares a common pivot point in brake arm pivot pin  26 , with brake arm  36  as cradle  12  rotates about cradle pivot pins  110 . Brake arm pivot pin  26  travels in an arcuate path, carrying ETC bracket  32  with it. ETC bracket guide pin  116 , projecting transversely from rear portion  33  of ETC bracket  32 , rides in guide pin slot  114  of support bracket  100 . The guide pin slot is so arranged that as cradle  12  rotates about cradle pivot pin  110 , and guide pin  116  rides in guide pin slot  114 , ETC bracket  32  is kept at a constant attitude with respect to the vehicle operator. 
     Throttle pedal  34  and brake pedal  38  are therefore both maintained in a constant attitude with respect to the vehicle operator, and, having a common anchor point in brake arm pivot pin  26 , pedals  34 ,  38  are also therefore maintained in a uniform relationship with one another, as shown in FIG.  8 . The pedals  34 ,  38  can therefore be placed in an optimal operating relationship for safety and efficiency, and the vehicle operator can operate the foot controls in confidence, knowing that the foot controls will be at a constant attitude with respect to the operator, and the foot controls will have the same relationship to each other, throughout their adjustment range. 
     While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.