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US 5,848,520 AGranted
Control for hydrostatic transmissions
AssigneeDeere & Company
InventorsJack Edward Arfstrom, Stephen Alphonse Braun, Llewellyn Everett Williams
Life of this patent
Estimating the term…
Abstract
A vehicle having a hydrostatic transmission is provided with a main speed control lever for governing the vehicle's maximum forward speed and an independently adjustable tracking control mechanism for coordinating output of left and right hydraulic wheel motors.
Claims27
A self-propelled vehicle having a frame and first and second ground engaging traction devices, said self-propelled vehicle comprising:
- an engine mounted to the frame;
- a first hydrostatic transmission operably connected to the engine for converting output of the engine into rotational movement of the first ground engaging traction device;
- a second hydrostatic transmission operably connected to the engine for converting output of the engine into rotational movement of the second ground engaging traction device;
- first and second steering controls operably connected to the first and second hydrostatic transmissions for individually varying speed attained by the first and second ground engaging traction devices in a range from a maximum forward speed to neutral;
- a main speed control lever operably coupled to the first and second hydrostatic transmissions for setting the maximum forward speed of the vehicle, said main speed control lever having a plurality of positions between and including a stop position for stopping the vehicle and a full-ahead position;
- and
- a tracking control operably connected to at least one of the first and second hydrostatic transmissions for adjusting the speed of the first ground engaging traction device relative to the speed of the second ground engaging traction device, said tracking control being adjustable without altering the position of the main speed control lever.
4 more elements
A walk-behind lawn mower having a frame and first and second drive wheels, said lawn mower comprising:
- an engine mounted to the frame;
- a blade coupled with the engine for cutting vegetation;
- a first hydrostatic transmission operably connected to the engine for converting output of the engine into rotational movement of the first drive wheel;
- a second hydrostatic transmission operably connected to the engine for converting output of the engine into rotational movement of the second drive wheel;
- first and second steering controls operably connected to the first and second hydrostatic transmissions for individually varying speed attained by the first and second drive wheels in a range from a maximum forward speed to neutral;
- a main speed control lever operably coupled to the first and second hydrostatic transmissions for setting the maximum forward speed of the mower, said main speed control lever having a plurality of positions between and including a stop position for stopping the vehicle and a full-ahead position;
- and
- a tracking control operably connected to at least one of the first and second hydrostatic transmissions for adjusting the speed of the first drive wheel relative to the speed of the second drive wheel, said tracking control being adjustable without altering the position of the main speed control lever.
5 more elements
A walk-behind lawn mower having a frame and first and second drive wheels, said lawn mower comprising:
- an engine mounted to the frame;
- a blade coupled with the engine for cutting vegetation;
- a first hydrostatic transmission operably connected to the engine for converting output of the engine into rotational movement of the first drive wheel;
- a second hydrostatic transmission operably connected to the engine for converting output of the engine into rotational movement of the second drive wheel;
- first and second steering controls operably connected to the first and second hydrostatic transmissions for individually varying speed attained by the first and second drive wheels in a range from a maximum forward speed to neutral;
- a main speed control lever operably coupled to the first and second hydrostatic transmissions for setting the maximum forward speed of the mower, said main speed control lever having a plurality of positions between and including a stop position for stopping the vehicle and a full-ahead position;
- a tracking control operably connected to at least one of the first and second hydrostatic transmissions for adjusting the speed of the first drive wheel relative to the speed of the second drive wheel, said tracking control being adjustable without altering the position of the main speed control lever and said main speed control lever being adjustable without altering the setting of the tracking control;
- a brake operably connected to the first and second drive wheels, said brake responsive to positioning of the main speed control lever in its stop position for preventing movement of the drive wheels when the main speed control lever is in its stop position;
- and
- said tracking control comprising a rotatable tracking adjustment knob, left and right control tubes operably connected to the tracking adjustment knob for varying relative position of said left and right control tubes upon rotation of the tracking adjustment knob, and left and right control rod guides connected to the left and right control tubes.
7 more elements
Dependencies are inferred from the claim text.