US3866935A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Suspension for utility trailer
Assignee: Individual
•
Filing: 1973-01-30
•
Granted: 1975-02-18
•
Expires: 1993-01-30
Abstract
Abstract The running gear for a towed trailer includes a single wheel on each side of the trailer, mounted on a bell crank pivotally supported on the trailer frame. The wheel is rotatably supported at one end of the bell crank remote from its pivot, and the other end of the crank is coupled to the frame by means of an extensible fluid motor which functions to rotate the crank and thereby raise and lower the wheels relative to the frame, or, conversely, raise and lower the trailer frame relative to the wheels and the ground. The extensible fluid motor may take the form of an air lift-hydraulic shock absorber with an air cushion chamber, an extensible air motor with an air cushion chamber, or an extensible hydraulic motor with an associated air cushion chamber. The extensible fluid motor and the associated air cushion chamber functions as an air spring suspension for the trailer running gear.
Inventors
- 👤 Charles C Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:50
CPC Classifications
B; B60; B60P; B60P1/00; B60P1/04; B60P1/16; B60P1/18
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
248 words
A trailer comprising a frame having means at its front end for coupling to a towing vehicle; suspension means comprising a ground engaging wheel mounted at each side of said frame intermediate the ends thereof; mounting means for each wheel comprising a crank arm mounted to oscillate about a transverse axis, and coacting rotatable support means on said frame and crank arm defining said transverse axis; said crank arm defining first arm means carrying a wheel spindle in spaced relation to said transverse axis, and defining second arm means carrying an operating pivot in spaced relation to said transverse axis; an extensible fluid motor, having an expansible chamber, moUnted between said frame and said crank arm operating pivot, operable in extended condition to position said crank arm and wheel to support said frame in elevated transport condition, and operable in retracted condition to lower said frame relative to said wheel; said motor expansible chamber defining, at least in part, a cushioning air chamber providing an air spring suspension between said frame and said crank arm; and control means mounted on said frame, for said extensible fluid motors; said control means comprising a reservoir for operating fluid for said extensible fluid motors; conduit means communicating said reservoir with said fluid motors, and flow control means associated with said reservoir and said conduit for directing fluid under pressure to said extensible fluid motors to extend said motors, and for releasing fluid from said motors to effect retraction of said motors.
Claim 2
Dependent Claim
248 words
A trailer comprising a frame having means at its front end for coupling to a towing vehicle; suspension means comprising a ground engaging wheel mounted at each side of said frame intermediate the ends thereof; mounting means for each wheel comprising a crank arm mounted to oscillate about a transverse axis, and coacting rotatable support means on said frame and crank arm defining said transverse axis; said crank arm defining first arm means carrying a wheel spindle in spaced relation to said transverse axis, and defining second arm means carrying an operating pivot in spaced relation to said transverse axis; an extensible fluid motor, having an expansible chamber, moUnted between said frame and said crank arm operating pivot, operable in extended condition to position said crank arm and wheel to support said frame in elevated transport condition, and operable in retracted condition to lower said frame relative to said wheel; said motor expansible chamber defining, at least in part, a cushioning air chamber providing an air spring suspension between said frame and said crank arm; and control means mounted on said frame, for said extensible fluid motors; said control means comprising a reservoir for operating fluid for said extensible fluid motors; conduit means communicating said reservoir with said fluid motors, and flow control means associated with said reservoir and said conduit for directing fluid under pressure to said extensible fluid motors to extend said motors, and for releasing fluid from said motors to effect retraction of said motors.
Claim 3
Dependent Claim
92 words
The trailer of claim 1 said extensible fluid motor comprising an air lift-hydraulic shock absorber unit; said cushioning air chamber being defined by the air lift chamber of said air lift-hydraulic shock absorber unit; said reservoir for operating fluid comprising a reservoir for pressurized air; and said flow control means comprising first valve means for controlling the flow of pressurized air from said reservoir to said extensible motor chamber to effect extension thereof, and second valve means for controlling the flow of air from said extensible motor chamber to effect retraction thereof.
Claim 4
Dependent Claim
105 words
The trailer of claim 1 said extensible fluid motor comprising a hydraulic cylinder unit; said cushioning air chamber means comprising an accumulator chamber for hydraulic fluid communicating with said hydraulic motor, and a chamber for pressurized air acting on the hydraulic fluid in said chamber; said reservoir for operating fluid comprising a reservoir for hydraulic fluid communicating with said accumulator and said extensible fluid motor; said flow control means comprising a pump and check valve for effecting the flow of hydraulic fluid under pressure to said extensible fluid motor, and a valve and conduit means for releasing fluid from said fluid motor to said reservoir.
Claim 5
Dependent Claim
107 words
The trailer of claim 1 said extensible fluid motor comprising an air cylinder unit; air chamber means comprising an auxiliary air chamber communicating with the air chamber of said air cylinder unit; said auxiliary air chamber and said air cylinder unit together defining said cushioning air chamber; said reservoir comprising a pressurized air supply tank communicated with said auxiliary air chamber means by suitable conduits; and said flow control means comprising first valve means for controlling the flow of air from said supply tank to said auxiliary chamber, and second valve means for effecting the discharge of air from said auxiliary chamber and said extensible air cylinder.
Claim 6
Dependent Claim
44 words
The trailer of claim 1 said suspension means comprising a single ground engaging wheel mounted on each side of said frame; and each ground engaging wheel being supported independently on said frame by one assembly of said crank arm and said extensible fluid motor.
Claim 7
Dependent Claim
84 words
A trailer as set forth in claim 5 said frame having generally parallel side frame members; a bearing member mounted on each of said side frame members, each bearing member defining a transverse axis, with the axes of the two bearing members being aligned; each of said crank arms carrying a relatively short spindle shaft parallel to said wheel spindle, and disposed to be rotatably supported in said bearing member; and said bearing member and said spindle shaft defining said coacting rotatable support means.
Claim 8
Dependent Claim
74 words
The trailer of claim 1 said flow control means comprising first and second throttling valves connected in said conduit means; said first valve being a normally closed valve, openable to permit the flow of fluid from said reservoir to said fluid motors; and said second valve means being a normally closed valVe positioned in said conduit means between said first valve and said fluid motors and openable to vent fluid from said fluid motors.
Claim 9
Dependent Claim
84 words
The trailer of claim 1 a coupling link connected between said crank arm and said frame for limiting rotation of said crank arm in one direction relative to said frame to limit the lowering of said frame relative to said ground engaging wheels; said coupling link permitting limited oscillation of said arm relative to said frame in the transport condition of said trailer; and means for uncoupling said link to permit additional rotation of said arm to lower said frame relative to said wheels.
Claim 10
Dependent Claim
51 words
The trailer of claim 2 booster spring means associated with said extensible fluid motor and said crank arm; said booster spring means comprising a tension spring connected between said crank arm and said frame and urging rotation of said arm in a direction to lift said frame relative to said wheel.
Claim 11
Dependent Claim
105 words
The trailer of claim 9 an elongated lever having a pivot for pivotally mounting the lever on said frame; means for latching said lever in a predetermined position on said frame; said lever having coupling means spaced from said pivot for attachment to said tension spring; said lever comprising said means for attaching said spring to said frame; said lever in said predetermined latched position tensioning said spring to provide maximum spring assist for said air motor; and said lever being swingable from said predetermined latched position to release the tension of said spring, thereby permitting the lowering of said frame relative to said wheel.
Claim 12
Dependent Claim
161 words
The trailer of claim 2 said air lift-hydraulic shock absorber unit comprising a first casing defining an elongated closed cylinder chamber; means at one end of said first casing for coupling said unit to said frame; a piston disposed within said casing having an attached piston rod extending from the other end of said casing and including means for coupling said unit to said crank arm; said first casing and said piston defining two chambers for containing hydraulic fluid; and valved passage means associated with said piston for permitting predetermined flow of fluid past said piston in either direction to control the rate of movement of said piston within said first casing; a second elongated cup-shaped casing associated with said piston rod and disposed in telescoping relation with said first casing; flexible sealing means between said first and second casing; and said first and second casings and said flexible sealing means providing an expansible air chamber defining said air lift chamber.
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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) | 1978-02-17 | 1978-08-19 | 1979-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-17 | 1982-08-19 | 1983-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-17 | 1986-08-19 | 1987-02-18 | $7700.00 | Window Closed / Lapsed |