Speed control mechanism for a hydrostatically driven vehicle

A speed control mechanism for a vehicle powered by an engine having a throttle for driving a hydrostatic propulsion system which includes a pump with an inching valve and swash plate therein controlled by a stroking valve for positioning the swash plate in at least one propulsion speed range for driving a wheel of the vehicle by means of at least one hydrostatic motor, the improvement comprising;

• selector lever means pivoted about an axis between a variable engine speed position and a high engine speed position, said selector lever including finger means projecting laterally therefrom;
• first arm means mounted for pivotal movement about said axis in position to be contacted by said finger means and be pivoted thereby to a higher engine speed position in response to movement of said lever means into said high engine speed position;
• second arm means mounted for pivotal movement about said axis;
• lost motion connector means operatively connected to said arms for causing pivotal movement of both of said arms in one direction in response to pivoting said second arm in said one direction, and to pivot only said first arm in said one direction in response to moving said selector lever to said high engine speed position,
• a depressable accelerator pedal movable in a range between engine idle and engine high speed positions,
• first connecting means connecting said accelerator pedal to said second arm means,
• second connector means for connecting said accelerator pedal to said inching valve,
• third connector means connecting said first arm means to said engine throttle, and
• means operatively connected to said arms and said accelerator pedal for urging said arms in a direction opposite to said one direction and to urge said accelerator pedal toward said idle speed position.

A speed control mechanism for a vehicle powered by an engine having a throttle for driving a hydrostatic propulsion system which includes a pump with an inching value and swash plate therein controlled by a stroking valve for positioning the swash plate in at least one propulsion speed range for driving a wheel of the vehicle by means of at least one hydrostatic motor, the improvement comprising:

• first arm means mounted for pivotal movement about a predetermined axis,
• second arm means mounted for pivotal movement about said axis,
• first abutment means secured to one of said arm means and engaging the other arm means for pivoting both arms as a unit in one direction and for allowing independent pivotal movement of said arms in the opposite direction,
• selector lever means mounted for pivotal movement about said axis between a variable engine speed position and a governor control high engine speed position,
• second abutment means secured to said lever means in position to engage and pivot said first arm means to a governor controlled high speed position in response to said selector lever being pivoted into its governor controlled engine speed position and for allowing pivotal movement of said arm means as a unit in said one direction in response to said selector lever means being in said variable speed position,
• a depressable accelerator pedal movable in a range between engine idle and engine high speed positions,
• first connecting means connecting said accelerator pedal to said second arm means;
• second connecting means for connecting said accelerator pedal to the inching valve, and
• third connecting means for connecting said first arm means to said engine throttle;
• positioning said selector lever means in said variable engine speed position and depressing said accelerator pedal being effective to pivot said first and second arm means as a unit in said one direction for progressively opening said engine throttle from said idle to said high engine speed and to progressively close said inching valve;
• positioning said selector lever in said governor controlled engine speed position being effective to maintain said engine speed at high governor speed, and progressively depressing said accelerator pedal being effective to progressively close said inching valve thereby progressively increasing the speed of the vehicle.

A speed control mechanism for a vehicle powered by an engine having a throttle for driving a hydrostatic propulsion system which includes a pump with an inching valve and swash plate therein controlled by a stroking valve for positioning the swash plate in at least one propulsion speed and direction range for driving a wheel of a vehicle by means of at least one hydrostatic motor, the improvement comprising;

• a depressible accelerator pedal movable in a range between engine idle and engine high speed,
• selector lever means movable between variable and governor controlled engine speed positions,
• first arm means being free to move from a governor controlled engine speed position and to a variable engine speed position in response to said selector lever being placed in said variable engine speed position,
• second arm means being free to move between a variable engine speed position and a governor controlled engine speed position when said selector lever means is placed in either of said positions in response to movement of said accelerator pedal between said engine idle and engine high speed positions, said second arm means being effective:
• to move said first arm means from said variable engine speed position to said governor controlled engine speed position,
• connecting means for connecting said accelerator pedal to said inching valve,
• connecting means for connecting said accelerator pedal to said second arm means, and
• a first arm to throttle connecting means for connecting said first arm to said throttle.

A speed control mechanism having an accelerator for controlling the throttle of a governor controlled engine and an inching valve of a hydrostatic pump that is operatively connected to at least one hydraulic motor that is connected to wheel means, the improvement which comprises:

• accelerator means movable in a range between engine idle and high speed positions;
• selector lever means movable between variable and governor controlled engine speed positions;
• engine throttle arm means operatively connected to said engine throttle and movable in first and second directions;
• means operatively connecting said selector lever means to said engine throttle arm means for urging said engine throttle arm means in said first direction;
• accelerator arm means operatively connected to said accelerator and movable in first and second directions;
• inching valve arm means operatively connected to said inching valve and movable in first and second directions;
• means for supporting each of said arm means for movement;
• interconnecting means for interconnecting said engine throttle arm means and said inching valve arm means to said accelerator arm means when moving in said first direction;
• engine idle adjustment means operatively and adjustably connected between said engine throttle arm means and said accelerator arm means;
• inching valve adjustment means operatively and adjustably connected between said inching valve arm means and said accelerator arm means;
• when said selector lever means is moved to a governor controlled high engine speed position, actuation of said accelerator from a low speed to a high speed position being effedtive to move said accelerator arm means and said inching valve arm means in said one direction for progressively closing said inching valve for progressively increasing the speed of said motor;
• and
• when said selector lever means is moved to said variable engine speed position actuation of said accelerator from a low speed to a high speed position being effective to move said accelerator arm means, said inching valve arm means and said engine throttle arm means in said first direction for progressively closing the inching valve and opening the throttle for progressively increasing both the engine speed and the hydraulic motor speed.