US4599855A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controls for the drive of a vehicle with differential speed steering
Assignee: Linde GmbH
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Filing: 1983-04-05
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Granted: 1986-07-15
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Expires: 2003-04-05
Abstract
Abstract A control drive is provided for the drive of a vehicle, whose steering is effected by a differential driving of the drive wheels of the two sides of the vehicle, where the drive wheels of each vehicle side are driven through a hydrostatic drive unit, whose final control element is connected with a servo piston capable of sliding in an operating cylinder and is acted upon from both sides, in which case the servo piston is acted upon from one side for controlling the travel speed and the control pressure determining the travel speed is reduced for effecting a turn on one side of the vehicle for large turning radii, and for smaller turning radii a pressure is additionally built up on the opposite side of the servo piston, the said pressure being derived from the control pressure determining the travel speed on the other side of the vehicle.
Inventors
- 👤 Hans H. Seelman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:26
CPC Classifications
B; B62; B62D; B62D11/00; B62D11/02; B62D11/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
504 words
In a control for the drive of a vehicle with differential-speed steering and with a hydrostatic drive unit on each side of the vehicle for operating the drive wheels, a final control element at each of the two drive units controlling the operation thereof and each connected with a spring-loaded servo piston capable of sliding in an operating cylinder, the improvements comprising a pressure chamber on each side of the each servo piston in the operating cylinder, means providing an arbitrarily adjustable control pressure on the servo piston, a first pair of control pressure pickoffs for controlling the forward and reverse travel which can be connected with operating cylinders of the drive units of both sides of the vehicle, two additional second pair of control pressure pickoffs, each assigned to one turning direction connected with the operating cylinder of the drive unit of the vehicle side on the inside of the curve, each servo piston being capable of being acted upon by the control pressure pickoff of said first pair of control pressure pickoffs assigned to the control on one side for controlling the direction and speed of travel, and, on the other side, may be acted upon by a control pressure pickoff of the one pair of said second pairs of pickoffs assigned to turning travel for controloing the turning radius, a pilot valve located in the connection line between a control pressure pickoff of said one pair of said second pairs of pickoffs assigned to turning travel and the operating cylinder of the assigned drive unit, an arbitrarily actuable direction and speed selective lever, means for switching said pilot valve as a function of the position of said arbitrarily actuable direction and speed selective lever, said pilot valve connecting the control pressure pickoff assigned to turning travel with a pressure chamber of an operating cylinder of the drive unit on the inside of the curve, the other pressure chamber of which operating cylinder is acted upon by control pressure from the control pressure pickoff of said first pair of pickoffs that determines at least one of the speed and the direction of travel, means for first operating the control pressure pickoff of said one pair of second pairs of pickoffs assigned to one turning direction of the control pressure pickoff pair of said second pairs of pickoffs determining the direction and radius of turning and designed to reduce the control pressure in the chamber of the operating cylinder acted upon by the control pressure pickoff of said first pair of pickoffs that determines the direction and speed of travel in the case of a slight actuation, and then with increased actuation simultaneously operating a control pressure pickoff of said first pair of pickoffs furnishing a control pressure on the ppposite side of the servo piston, and a connection from said control pressure pickoff of said first pair of pickoffs to the pressure supply at the outlet of the control pressure pickoff of said first pair of pickoffs determining the speed of travel.
Claim 2
Dependent Claim
504 words
In a control for the drive of a vehicle with differential-speed steering and with a hydrostatic drive unit on each side of the vehicle for operating the drive wheels, a final control element at each of the two drive units controlling the operation thereof and each connected with a spring-loaded servo piston capable of sliding in an operating cylinder, the improvements comprising a pressure chamber on each side of the each servo piston in the operating cylinder, means providing an arbitrarily adjustable control pressure on the servo piston, a first pair of control pressure pickoffs for controlling the forward and reverse travel which can be connected with operating cylinders of the drive units of both sides of the vehicle, two additional second pair of control pressure pickoffs, each assigned to one turning direction connected with the operating cylinder of the drive unit of the vehicle side on the inside of the curve, each servo piston being capable of being acted upon by the control pressure pickoff of said first pair of control pressure pickoffs assigned to the control on one side for controlling the direction and speed of travel, and, on the other side, may be acted upon by a control pressure pickoff of the one pair of said second pairs of pickoffs assigned to turning travel for controloing the turning radius, a pilot valve located in the connection line between a control pressure pickoff of said one pair of said second pairs of pickoffs assigned to turning travel and the operating cylinder of the assigned drive unit, an arbitrarily actuable direction and speed selective lever, means for switching said pilot valve as a function of the position of said arbitrarily actuable direction and speed selective lever, said pilot valve connecting the control pressure pickoff assigned to turning travel with a pressure chamber of an operating cylinder of the drive unit on the inside of the curve, the other pressure chamber of which operating cylinder is acted upon by control pressure from the control pressure pickoff of said first pair of pickoffs that determines at least one of the speed and the direction of travel, means for first operating the control pressure pickoff of said one pair of second pairs of pickoffs assigned to one turning direction of the control pressure pickoff pair of said second pairs of pickoffs determining the direction and radius of turning and designed to reduce the control pressure in the chamber of the operating cylinder acted upon by the control pressure pickoff of said first pair of pickoffs that determines the direction and speed of travel in the case of a slight actuation, and then with increased actuation simultaneously operating a control pressure pickoff of said first pair of pickoffs furnishing a control pressure on the ppposite side of the servo piston, and a connection from said control pressure pickoff of said first pair of pickoffs to the pressure supply at the outlet of the control pressure pickoff of said first pair of pickoffs determining the speed of travel.
Claim 3
Dependent Claim
75 words
In a control according to claim 1, wherein each pilot valve is designed as a 4-connection/3-position valve, where a pressure reducing valve of one of the control pressure pickoffs assigned to one turning direction is connected to each connection of the one pair of connections of a pilot valve and each of the two other connections of this pilot valve is connected to a pressure chamber of the operating cylinder of the assigned drive unit.
Claim 4
Dependent Claim
44 words
A control according to claim 1, wherein each of the control pressure pickoffs of said second pairs of pickoffs assigned to one turning direction consists of two pressure reducing valves that are separate with regard to flow, but are mechanically connected to function together.
Claim 5
Dependent Claim
94 words
A control according to claim, 3, wherein the two pressure reducing valves of each control pressure pickoff assigned to one turning direction one is connected directly and the other is connected through a change-over valve located between the two lines each leading to a pressure chamber of the assigned operating cylinder and changing over as a function of the pressure, and pilot valve and pressure reducing valve of the drive unit assigned to the other side of the vehicle, to the control pressure line carrying the control pressure that determines the speed of travel.
Claim 6
Dependent Claim
215 words
A control according to claim 2 having two control pressure pickoffs determining the speed of travel, one of which is assigned to one direction of travel, wherein each of these two control pressure pickoffs assigned to one direction of travel is permanently connected with a pressure chamber of the two operating cylinders, each through a control pressure line, in which case the other control pressure pickoff is connected with the other pressure chambers of the two operating cylinders, and the connection of the pilot valve connected with a pressure chamber is connected through a branch line to this line departing from the control pressure pickoff and each control pressure pickoff assigned to one turning direction has two pressure reducing valves which shut off the connected line in the nonactuated state and open it in a throttling manner in the actuated state, in which case in each control pressure pickoff one of these pressure reducing valves connects the line connected with the pilot valve with a pressureless drain, while the pressure reducing valve connected to the other line connected to the pilot valve is conhected on the inlet side through a connecting line to the connecting line of the other side of the vehicle, which connects the pilot valve with the first assigned pressure reducing valve.
Claim 7
Dependent Claim
43 words
A control according to claim 2 wherein the pilot valves are controlled hydraulically and each of the two first control pressure pickoffs assigned to control of the travel speed is connected to a change-over control pressure space of each of the pilot valves.
Claim 8
Dependent Claim
93 words
A control according to one of claims 1 or 2 or 3 or 4 or 5 or 6, characterized in that the pressure reducing valve connected directly to the control pressure line carrying the control pressure that determines the travel speed is designed as a pressure reducing valve that allows the pressure to pass through unhindered in the nonactuated state, and the other pressure reducing valve connected indirectly to the control pressure line carrying the control pressure determining the travel speed is designed as a pressure-relieving pressure reducing valve in the nonactuated state.
Claim 9
Dependent Claim
82 words
A control according to claims 3 or 4, characterized in that the coupling with regard to function of the two pressure reducing valves of a second pair of control pressure pickoff is designed so that in the case of actuation only the pressure reducing valve connected direction to the control pressure line carrying the control pressure determining the travel speed is always actuated first and only after its modulation is the pressure reducing valve connected indirectly to this control pressure line actuated.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-07-14 | 1990-01-13 | 1990-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-14 | 1994-01-13 | 1994-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-14 | 1998-01-13 | 1998-07-15 | $7700.00 | Window Closed / Lapsed |