US3823932A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vehicle seat suspension with variable spring rate
Assignee: Transamerica Business Credit Corp
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Filing: 1972-11-24
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Granted: 1974-07-16
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Expires: 1992-11-24
Abstract
Abstract Seat suspension system for tractors, trucks and other vehicles includes a pair of rubber torsion springs and a mechanism for selectively connecting or disconnecting one of the springs from operation with the other. In one embodiment the springs are selectively connectable in parallel to increase the total spring rate and in a second embodiment the springs are selectively connectable in series to decrease the spring rate. In both embodiments, one of the springs can be adjustably preloaded to adjust the seat''s ''''ride'''' position for a particular operator. The variable spring rate feature permits either light or heavy operators to experience a good ride. It also permits the suspension to be tailored to the terrain so as to provide a stiff suspension for bumpy terrain and a light suspension for smooth terrain. Either embodiment can be set to automatically become stiffer when seat movement reaches a predetermined level.
Inventors
- 👤 A Simons
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:24
CPC Classifications
B; B60; B60N; B60N2/00; B60N2/50; B60N2/502; B60N2/505; B60N2/506; B60N2/508; B60N2/54; B60N2/548
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
223 words
A suspension system for a vehicle seat, said suspension system comprising a linkage including a pivotal arm mounted on a base part and arranged to support a seat for upwards and downwards movement relative to the base part, spring means operative to bias the arm upwardly relative to the base part, said spring means comprising a continually operative first spring assembly and a selectively operative second spring assembly, the second spring assembly comprising two concentric members, and an elastic body interposed between the members and deformable upon relative rotation between the members, and means for connecting each member to a separate one of two elements of the system which move relatively to one another during upward and downward movement of the seat, so that the said members are rotated relatively to one another by said relative movement of the elements, one of the connecting means being operative to permanently connect one member to its associated element and the other connecting means being selectively operative and comprising means for locking the other member and its associated element in a predetermined relative angular position, and selectively operable means for continuously biasing the locking means towards its locking position, said locking means being urged by the biasing means into its locking position only when the said other member and element are in their predetermined angular position.
Claim 2
Dependent Claim
223 words
A suspension system for a vehicle seat, said suspension system comprising a linkage including a pivotal arm mounted on a base part and arranged to support a seat for upwards and downwards movement relative to the base part, spring means operative to bias the arm upwardly relative to the base part, said spring means comprising a continually operative first spring assembly and a selectively operative second spring assembly, the second spring assembly comprising two concentric members, and an elastic body interposed between the members and deformable upon relative rotation between the members, and means for connecting each member to a separate one of two elements of the system which move relatively to one another during upward and downward movement of the seat, so that the said members are rotated relatively to one another by said relative movement of the elements, one of the connecting means being operative to permanently connect one member to its associated element and the other connecting means being selectively operative and comprising means for locking the other member and its associated element in a predetermined relative angular position, and selectively operable means for continuously biasing the locking means towards its locking position, said locking means being urged by the biasing means into its locking position only when the said other member and element are in their predetermined angular position.
Claim 3
Dependent Claim
25 words
A suspension system as claimed in claim 1, wherein one of said elements is tHe arm and is permanently connected to the said one member.
Claim 4
Dependent Claim
92 words
A suspension system as claimed in claim 2, wherein the first and second spring assemblies are arranged in parallel, and the first spring assembly comprises an elastic body interposed between a pair of concentric members, and deformed by relative rotation between the members, one of the concentric members being pivotal with the arm and the other member being held against pivotal movement with the said one member, and means for rotating the said other member relative to the said one member whereby to vary the pre-load exerted by the first spring assembly.
Claim 5
Dependent Claim
34 words
A suspension system as claimed in claim 3, wherein the said one concentric member of the first and second spring assemblies is formed by a respective part of a shaft pivotal with the arm.
Claim 6
Dependent Claim
92 words
A suspension system as claimed in claim 3, wherein the locking means comprises an abutment pivotal between a pair of limit positions in which the abutment respectively lies out of contact with, and in locking engagement with, the said other member of the second spring assembly, and the biasing means comprises an over-center spring assembly operative to bias the abutment from an over-center position into the adjacent one of said limit positions, the abutment being rigid with a lever for moving the abutment from a said limit position into the over-center position.
Claim 7
Dependent Claim
15 words
A suspension system as claimed in claim 1, wherein the linkage comprises a crossed-arm linkage.
Claim 8
Dependent Claim
20 words
A suspension system as claimed in claim 1, wherein the said one member comprises a shaft pivotal with the arms.
Claim 9
Dependent Claim
47 words
A suspension system as claimed in claim 1, wherein in each said spring assembly the elastic body comprises an elastic sleeve arranged concentrically between the two said concentric members and anchored thereto whereby the sleeve is stressed in shear upon relative rotation between the two concentric members.
Claim 10
Dependent Claim
68 words
A suspension system as claimed in claim 1, wherein in at least one of said spring assemblies the two concentric members have opposed surfaces which are polygonal in section and wherein a respective elastic body is located between a face of the inner concentric member and a corner portion of the outer concentric member whereby the bodies are compressively stressed upon relative rotation between the two concentric members.
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) | 1977-07-15 | 1978-01-14 | 1978-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-15 | 1982-01-14 | 1982-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-15 | 1986-01-14 | 1986-07-16 | $7700.00 | Window Closed / Lapsed |