Patent US3729211A successfully refreshed from Google Patents.
US3729211A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pneumatic suspension for a motorcar
Assignee: Robert Bosch GmbH
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Filing: 1971-03-12
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Granted: 1973-04-24
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Expires: 1991-03-12
Abstract
Abstract A pneumatic suspension for a motorcar has a level indicator switch having a high load position and a low load position in which it is connected by first and second switches with an electric motor-compressor, and an electromagnetic relief valve, respectively. A third switch connects the motor-compressor parallel to the level indicator switch into the circuit. The three switches are part of a control switch means, and are operated by a spring biassed pressure responsive element having a piston portion in a pressure chamber communicating with the pneumatic cylinder and piston means by which the chassis is supported on a wheel shaft. By use of a strong spring for the pressure responsive element, the operation of the first switch takes place only at a predetermined high load.
Inventors
- 👤 O Engfer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:26
CPC Classifications
B; B60; B60G; B60G17/00; B60G17/02; B60G17/04; B60G17/052; B60G17/0523; B60G17/0525; B60G17/015; B60G17/019; B60G2204/00; B60G2204/10; B60G2204/11; B60G2400/00; B60G2400/05; B60G2400/051; B60G2400/0511; B60G2400/60; B60G2400/61; B60G2401/00; B60G2401/20
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
295 words
Pneumatic suspension for a motorcar, comprising a wheel shaft; a chassis; pneumatic cylinder and piston means for mounting said chassis on said wheel shaft; an electric motor compressor and an electromagnetic relief valve communicating with said cylinder and piston means for raising and lowering said chassis, respectively; level indicator switch means responsive to the relative position between said chassis and said wheel shaft to move to a first low-load position when said chassis is too low and to a second high-load position when said chassis is too high; and pressure responsive control switch means including a housing forming at one end a cylindrical pressure chamber communicating with said cylinder and piston means, first, second, and third switches mounted at the other end of said housing adjacent each other, a pressure responsive element having at one end a piston portion located in said cylindrical pressure chamber, and having at the other end an actuating portion for operating said first, second and third switches dependent on the pressure in said cylindrical pressure chamber and in said cylinder and piston means, and biassing means in said housing biassing said pressure responsive element against the pressure in said pressure chamber, said first switch connecting said level indicator switch means in said first position with said motor-compressor, and said second switch connecting said level indicator means in said second Position with said electromagnetic relief valve so that said motor-compressor is started when the load on said chassis is increased, and said relief valve is opened when the load on said chassis is reduced, and said third switch effecting energizing of said motor-compressor when the pressure in said cylinder and piston means and in said pressure chamber is too low, and being connected in parallel with said level indicator switch means.
Claim 2
Dependent Claim
295 words
Pneumatic suspension for a motorcar, comprising a wheel shaft; a chassis; pneumatic cylinder and piston means for mounting said chassis on said wheel shaft; an electric motor compressor and an electromagnetic relief valve communicating with said cylinder and piston means for raising and lowering said chassis, respectively; level indicator switch means responsive to the relative position between said chassis and said wheel shaft to move to a first low-load position when said chassis is too low and to a second high-load position when said chassis is too high; and pressure responsive control switch means including a housing forming at one end a cylindrical pressure chamber communicating with said cylinder and piston means, first, second, and third switches mounted at the other end of said housing adjacent each other, a pressure responsive element having at one end a piston portion located in said cylindrical pressure chamber, and having at the other end an actuating portion for operating said first, second and third switches dependent on the pressure in said cylindrical pressure chamber and in said cylinder and piston means, and biassing means in said housing biassing said pressure responsive element against the pressure in said pressure chamber, said first switch connecting said level indicator switch means in said first position with said motor-compressor, and said second switch connecting said level indicator means in said second Position with said electromagnetic relief valve so that said motor-compressor is started when the load on said chassis is increased, and said relief valve is opened when the load on said chassis is reduced, and said third switch effecting energizing of said motor-compressor when the pressure in said cylinder and piston means and in said pressure chamber is too low, and being connected in parallel with said level indicator switch means.
Claim 3
Dependent Claim
60 words
Pneumatic suspension as claimed in claim 1 wherein said switches are disposed in said housing staggered in the direction of movement of said pressure responsive element so that said first, second, and third switches are operated in different positions of said pressure responsive element depending on the pressure in said pressure chamber and on the force of said spring means.
Claim 4
Dependent Claim
25 words
Pneumatic suspension as claimed in claim 2 wherein said switches are parallel, and wherein said actuating portion of said pressure responsive element abuts said switches.
Claim 5
Dependent Claim
169 words
Pneumatic suspension as claimed in claim 2 wherein said spring means include a weak spring having one end abutting said housing and said pressure responsive element for urging the same in one direction against the pressure in said pressure chamber to a normal position if a predetermined normal pressure prevails in said pressure chamber, and beyond said normal position to a low pressure position if the pressure in said pressure chamber and in said cylinder and piston means drops below said normal pressure, and a strong spring abutting at both ends on portions of said housing, and being engaged by said pressure responsive element when the same moves in the opposite direction out of said normal position due to increased pressure in said pressure chamber so that a substantial increase of the pressure in said cylinder and piston means and of the load acting on said chassis is required for moving said pressure responsive element in said opposite direction against the action of both said weak and strong springs.
Claim 6
Dependent Claim
55 words
Pneumatic suspension as claimed in claim 4 wherein said pressure responsive element operate said third switch in said low pressure position so that said motor compressor is energized, and again in said normal position so that said motor compressor is deneergized at normal pressure in said cylinder and piston means, and in said pressure chamber.
Claim 7
Dependent Claim
63 words
Pneumatic suspension as claimed in claim 4 wherein said pressure responsive element operates said first switch to energize said motor-compressor when the load on said chassis is increased a predetermined amount, and thereby the pressure in said pressure chamber is increased to a predetermined pressure sufficient to move said pressure responsive element in said opposite direction against the action of said strong spring.
Claim 8
Dependent Claim
63 words
Pneumatic suspension as claimed in claim 4 wherein said pressure responsive element operates said second switch when the load on said chassis is reduced so that said relief valve is opened whereby the pressure in said cylinder and piston means is reduced to said normal pressure, whereupon said second switch is again operated by said pressure responsive element to close said relief valve.
Claim 9
Dependent Claim
168 words
Pneumatic suspension as claimed in claim 4 wherein said pressure responsive element operates said first switch to energize said motor-compressor when the load on said chassis is increased a predetermined amount, and thereby the pressure in said pressure chamber is increased to a predetermined pressure sufficient to move said pressure responsive element in said opposite direction against the action of said strong spring; wherein said pressure responsive element operates said second switch when the load on said chassis is reduced so that first said relief valve is opened whereby the pressure in said cylinder and piston means is reduced to said normal pressure, whereupon said second switch is again operated by said pressure responsive element to close said relief valve; wherein said pressure responsive element opErates said third switch in said low pressure position so that said motor compressor is energized, and again in said normal position so that said motor compressor is deenergized at normal pressure in said cylinder and piston means, and in said pressure chamber.
Claim 10
Dependent Claim
89 words
Pneumatic suspension as claimed in claim 8 wherein said pressure responsive element includes a stem having said actuating portion at said other end, a flexible membrane forming said piston portion mounted at said one end, and a flange on said one end abutting said membrane; and wherein said housing has an annular shoulder on which said flange abuts in an end position of said pressure responsive member when said weak and strong springs are deformed by said pressure responsive element to a predetermined degree at a predetermined high load.
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) | 1976-04-23 | 1976-10-23 | 1977-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-23 | 1980-10-23 | 1981-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-23 | 1984-10-23 | 1985-04-24 | $7700.00 | Window Closed / Lapsed |