US3736845A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable length upper guide rod for a three-point loading rack
Assignee: Individual
•
Filing: 1971-05-18
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Granted: 1973-06-05
•
Expires: 1991-05-18
Abstract
Abstract A hydraulic three-point loading rack, for agricultural prime movers, has a variable length upper guide rod in the form of a cylinder, a piston guided in the cylinder, a piston rod connected to the piston and hydraulic supply-return lines connected to the cylinder chambers on opposite sides of the piston. Respective normally closed, pressure-holding valves are connected in each of the two supply-return lines and opened only by a predetermined supply pressure in the associated line, these valves being interposed between a hydraulic pump, with associated return reservoir, and the cylinder chambers. A distributing valve is connected between the pump and the shut-off valves and has a neutral position shutting off both cylinder chambers from the pump, and a pair of operating positions, in each of which one line is supplied with hydraulic fluid and the other line returns hydraulic fluid to the reservoir. A nominal-actual value setter is associated with an actual value selsyn connected to the piston rod, and may be selectably bypassed. A three-way cock is connected to the two supply-return lines and communicates with the reservoir.
Inventors
- 👤 H Weiste
- 👤 F Schumacher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:39
CPC Classifications
A; A01; A01B; A01B59/00; A01B59/002; A01B59/004; Y; Y10; Y10S; Y10S60/00; Y10S60/911
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
151 words
In a variable length upper guide rod for a hydraulic threepoint loading rack, for agricultural prime movers, of the type including a cylinder, a piston guided in the cylinder, a piston rod connected to the piston, and hydraulic supply-return lines connected to the cylinder chambers on opposite sides of the piston, the improvement comprising, in combination, a pump connected to a supply of hydraulic fluid to generate hydraulic working fluid under pressure; respective normally closed, pressure-holding shut-off valves connected in series in each of the two supply-return lines and opened only responsive to a predetermined supply pressure in the associated line; and a distributing valve connected between said pump and said shut-off valves, and operable selectively to shut-off both cylinder chambers from said pump, in a neutral position, and to connect a respective different chamber to said pump and the other chamber to said supply, in each of two operating positions.
Claim 2
Dependent Claim
151 words
In a variable length upper guide rod for a hydraulic threepoint loading rack, for agricultural prime movers, of the type including a cylinder, a piston guided in the cylinder, a piston rod connected to the piston, and hydraulic supply-return lines connected to the cylinder chambers on opposite sides of the piston, the improvement comprising, in combination, a pump connected to a supply of hydraulic fluid to generate hydraulic working fluid under pressure; respective normally closed, pressure-holding shut-off valves connected in series in each of the two supply-return lines and opened only responsive to a predetermined supply pressure in the associated line; and a distributing valve connected between said pump and said shut-off valves, and operable selectively to shut-off both cylinder chambers from said pump, in a neutral position, and to connect a respective different chamber to said pump and the other chamber to said supply, in each of two operating positions.
Claim 3
Dependent Claim
179 words
In a variable length upper guide rod for a hydraulic three-point loading rack, for agricultural prime movers, of the type including a cylinder, a piston guided in the cylinder, a piston rod connected to the piston, and hydraulic supply-return lines connected to the cylinder chambers on opposite sides of the piston, the improvement comprising, in combination, a pump connected to a supply of hydraulic fluid to generate hydraulic working fluid under pressure; respective normally closed, pressure-holding shut-off valves connected in series in each of the two supply-return lines and opened only responsive to a predetermined supply pressure in the associated line; a distributing valve connected between said pump and said shut-off valves, and operable selectively to shut-off both cylinder chambers from said pump, in a neutral position, and to connect a respective different chamber to said pump and the other chamber to said supply, in each of two operating positions; and a three-way cock connected to both cylinder chambers and to said supply, and selectively operable to connect both cylinder chambers to a return line leading to said supply.
Claim 4
Dependent Claim
179 words
In a variable length upper guide rod for a hydraulic three-point loading rack, for agricultural prime movers, of the type including a cylinder, a piston guided in the cylinder, a piston rod connected to the piston, and hydraulic supply-return lines connected to the cylinder chambers on opposite sides of the piston, the improvement comprising, in combination, a pump connected to a supply of hydraulic fluid to generate hydraulic working fluid under pressure; respective normally closed, pressure-holding shut-off valves connected in series in each of the two supply-return lines and opened only responsive to a predetermined supply pressure in the associated line; a distributing valve connected between said pump and said shut-off valves, and operable selectively to shut-off both cylinder chambers from said pump, in a neutral position, and to connect a respective different chamber to said pump and the other chamber to said supply, in each of two operating positions; and a three-way cock connected to both cylinder chambers and to said supply, and selectively operable to connect both cylinder chambers to a return line leading to said supply.
Claim 5
Dependent Claim
73 words
In a variable length upper guide rod, the improvement claimed in claim 1, including an actual selsyn operatively associated with said piston rod and measuring the effective length of said upper guide rod; and a nominal-actual value setter connected to said selsyn and to said distributing valve and operating said distributing valve to set the length of said upper guide rod to correspond to a preset value set by said nominal-actual value setter.
Claim 6
Dependent Claim
40 words
In a variable length upper guide rod, the improvement claimed in claim 3, including operating means operable to set said distributing valve in each of its three positions; and control lines interconnecting said operating means and said nominal-actual value setter.
Claim 7
Dependent Claim
28 words
In a variable length upper guide rod, the improvement claimed in claim 3, including means selectively operable to operate said distributing valve independently of said nominal-actual value setter.
Claim 8
Dependent Claim
40 words
In a variable length upper guide rod, the improvement claimed in claim 1, including a commercial hydraulic system, of the agricultural prime mover, connected to said pump; the working fluid for said cylinder being supplied from said commercial hydraulic system.
Claim 9
Dependent Claim
26 words
In a variable length upper guide rod, the improvement claimed in claim 6, including a restricted flow branch line connecting said system to said distributing valve.
Claim 10
Dependent Claim
35 words
In a variable length upper guide rod, the improvement claimed in claim 1, including respective pressure limiting means connected in each of said supply-return lines between the associated cylinder chambers and the associated shut-off valves.
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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) | 1976-06-04 | 1976-12-04 | 1977-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-04 | 1980-12-04 | 1981-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-04 | 1984-12-04 | 1985-06-05 | $7700.00 | Window Closed / Lapsed |