US4384443A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mower
Assignee: Toro Co
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Filing: 1981-07-21
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Granted: 1983-05-24
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Expires: 2001-07-21
Abstract
Abstract A mowing machine comprises a plurality of cutting units (4) powered by a parallel hydraulic system with distributing means (30). The cutting units (4) are each powered by a hydromotor (16), all hydromotors (16) being driven by a central hydraulic pump (P). The hydromotors (16) are fed in a parallel relationship by the pump (P). Ahead of the hydromotor (16) in each circuit, is a distributing means (30) with an inlet (26) from the pump (P), and two outlets, (31) back to the supply tank (V), and (33) to the corresponding hydromotor (16). When a hydromotor (16) is deactivated, distributing means (30) automatically diverts the fluid normally flowing through the deactivated hydromotor back to the supply tank (V). This diversion of fluid prevents changing the speed of the remaining hydromotors as a result of increased flow or pressure available due to the deactivated hydromotor.
Inventors
- 👤 Gideon Hoogstrate
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 07:48
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/38; F16H61/40; F16H61/46; F16H61/461; A; A01; A01D; A01D34/00; A01D34/01; A01D34/412; A01D34/42; A01D34/56; A01D34/60; Y; Y10; Y10S; Y10S56/00; Y10S56/11
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
175 words
A power-driven movable device comprising: (a) a frame movable over a ground surface; (b) a plurality of rotatable tools carried by the frame; (c) a plurality of hydraulic motors with a separate hydraulic motor being connected to each tool for individually rotating the tool at a speed dependent upon the flow rate of hydraulic fluid delivered to the motor; (d) a hydraulic pressure source for delivering hydraulic fluid under pressure to a main supply line; (e) a supply duct connecting each hydraulic motor to the main supply line in a parallel arrangement relative to the other motors; and (f) distributing means in each of the supply ducts between the hydraulic motor and the main supply line for bypassing hydraulic fluid back to the pressure source when a corresponding hydraulic motor is shut off to avoid any increase in the flow rate of the fluid delivered to the hydraulic motors which are still operating, whereby the speed of rotation of the operating hydraulic motors remains constant regardless of the numbers of motors that are shut off.
Claim 2
Dependent Claim
175 words
A power-driven movable device comprising: (a) a frame movable over a ground surface; (b) a plurality of rotatable tools carried by the frame; (c) a plurality of hydraulic motors with a separate hydraulic motor being connected to each tool for individually rotating the tool at a speed dependent upon the flow rate of hydraulic fluid delivered to the motor; (d) a hydraulic pressure source for delivering hydraulic fluid under pressure to a main supply line; (e) a supply duct connecting each hydraulic motor to the main supply line in a parallel arrangement relative to the other motors; and (f) distributing means in each of the supply ducts between the hydraulic motor and the main supply line for bypassing hydraulic fluid back to the pressure source when a corresponding hydraulic motor is shut off to avoid any increase in the flow rate of the fluid delivered to the hydraulic motors which are still operating, whereby the speed of rotation of the operating hydraulic motors remains constant regardless of the numbers of motors that are shut off.
Claim 3
Dependent Claim
55 words
A device as claimed in claim 1 characterized in that the distributing means is constructed in the form of a housing having an inlet and two outlets communicating herewith and adapted to be shut off by a movable element, said element being controlled by the pressure in the supply duct leading to the hydraulic motor.
Claim 4
Dependent Claim
21 words
A device as claimed in claim 2 characterized in that the element is formed by a flap pivotable in the housing.
Claim 5
Dependent Claim
30 words
A device as claimed in claim 2 characterized in that the element is controlled by a piston-cylinder unit energized by the hydraulic fluid against the action of a reset spring.
Claim 6
Dependent Claim
36 words
A power-driven movable device as claimed in claim 1, further including means for automatically actuating the distributing means in response to an increase in fluid pressure in the supply duct of the shut off hydraulic motor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-05-23 | 1986-11-22 | 1987-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-23 | 1990-11-22 | 1991-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-23 | 1994-11-22 | 1995-05-24 | $7700.00 | Window Closed / Lapsed |