US3901398A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semi-trailer having a hinged ramp member
Assignee: Bunch Bellcrank Systems Inc
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Filing: 1974-02-22
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Granted: 1975-08-26
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Expires: 1994-02-22
Abstract
Abstract A semi-trailer consisting of a wheeled supporting truck having a transverse axle on which a main load-carrying bed member is pivotally supported. A depending box structure surrounding the axle is pivoted to the main bed member. A forwardly extending hitch frame is pivoted beneath the forward portion of the main bed member. Front link bars connect the box structure to the hitch frame. A ramp member is hinged to the rear edge of the main bed member. Rear link bars connect the ramp member to the box structure. A spring-biased telescopic strut assembly is provided between the box structure and the forward margin of the ramp member, biasing the ramp member toward alignment with the main bed member. An elevating jack is provided on the front end of the main bed member, acting against the hitch frame. When the elevating jack is operated, the linkage thus defined acts to lower the ramp member relative to the main bed member into ground contact as the front end of the main bed member is elevated.
Inventors
- 👤 Harry J Bunch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 00:41
CPC Classifications
B; B60; B60P; B60P1/00; B60P1/43; B60P1/433; B62; B62D; B62D53/00; B62D53/04; B62D53/06; B62D53/061; B62D53/062
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
199 words
A semi-trailer comprising a wheeled truck assembly having a transverse axle, a main load-carrying bed member pivotally mounted at its rear portion on said transverse axle, a forwardly extending hitch frame beneath the forward portion of said bed member, means pivotally connecting the intermediate portion of said hitch frame to the bed member for rotation on a transverse axis, a ramp platform hinged to the rear transverse edge of said bed member, jack means acting between said bed member and hitch frame to at times vary the angle therebetween, and linkage means interconnecting the rear end of the hitch frame, the rear portion of the bed member and said ramp platform to control the angular position of the ramp platform relative to the bed member in accordance with the angular position of the bed member relative to the hitch frame, said linkage means including a box-like frame member surrounding said axle and pivoted at its upper portion to said bed member, first link means connecting the front portion of said box-like frame member to the rear end portion of said hitch frame, and second link means connecting the ramp platform to the rear portion of said box-like frame member.
Claim 2
Dependent Claim
199 words
A semi-trailer comprising a wheeled truck assembly having a transverse axle, a main load-carrying bed member pivotally mounted at its rear portion on said transverse axle, a forwardly extending hitch frame beneath the forward portion of said bed member, means pivotally connecting the intermediate portion of said hitch frame to the bed member for rotation on a transverse axis, a ramp platform hinged to the rear transverse edge of said bed member, jack means acting between said bed member and hitch frame to at times vary the angle therebetween, and linkage means interconnecting the rear end of the hitch frame, the rear portion of the bed member and said ramp platform to control the angular position of the ramp platform relative to the bed member in accordance with the angular position of the bed member relative to the hitch frame, said linkage means including a box-like frame member surrounding said axle and pivoted at its upper portion to said bed member, first link means connecting the front portion of said box-like frame member to the rear end portion of said hitch frame, and second link means connecting the ramp platform to the rear portion of said box-like frame member.
Claim 3
Dependent Claim
36 words
The semi-trailer of claim 1, and wherein said bed member is provided with depending bracket means over said transverse axle, and wherein the top portion of said box-like frame member is pivoted to said bracket means.
Claim 4
Dependent Claim
23 words
The semi-trailer of claim 1, and resilient support means acting between the forward margin of said ramp platform and said box-like frame member.
Claim 5
Dependent Claim
65 words
The semi-trailer of claim 1, and wherein the rear end portion of the hitch frame is angled downwardly relative to the forward portion thereof sufficiently so that said ramp platform can be lowered into ground contact responsive to the elevation of the front end of the bed member before the hitch frame rear end portion comes into contact with the underside of the bed member.
Claim 6
Dependent Claim
37 words
The semi-trailer of claim 4, and wherein said jack means comprises a jack assembly secured to the front transverse edge portion of the bed member and having a downwardly extensible portion drivingly engaged with said hitch frame.
Claim 7
Dependent Claim
21 words
The semi-trailer of claim 5, and resilient strut means acting between said ramp platform and a portion of said linkage means.
Claim 8
Dependent Claim
31 words
The semi-trailer of claim 6, and wherein said resilient strut means is connected between the forward marginal portion of said ramp platform and the rear portion of said box-like frame member.
Claim 9
Dependent Claim
114 words
The semi-trailer of claim 7 wherein said resilient strut means biases the ramp platform into substantial alignment with the main bedmember when the latter is in horizontal position, said strut means comprising a first sleeve pivoted at one end to said box-like frame member, a second sleeve pivoted at one end to the ramp member, a threaded rod slidably received in the free ends of the first and second sleeves, a pair of nuts threaded on said threaded rod, one of said nuts abutting a free end of one of said sleeves; and a coil spring surrounding the threaded rod and held between the free end of the other sleeve and the other nut.
Claim 10
Dependent Claim
159 words
A semi-trailer comprising a wheeled truck assembly having a transverse axle, a main load-carrying bed member pivotally mounted at its rear portion on said transverse axle, a forwardly extending hitch frame beneath the forward portion of said bed member, means pivotally connecting the intermediate portion of said hitch frame to the bed member for rotation on a transverse axis, a ramp platform hinged to the rear transverse edge of said bed member, a fulcrum member at least partially surrounding said axle and pivoted to said bed member, first link means pivotally connecting a forward portion of said fulcrum member to the rear end portion of said hitch frame, and second link means pivotally connecting the ramp platform to a rear portion of said fulcrum member, said fulcrum member and first and second link means being so constructed and arranged as to automatically rotate the ramp platform relative to the bed member as the hitch frame is raised or lowered.
Claim 11
Dependent Claim
159 words
A semi-trailer comprising a wheeled truck assembly having a transverse axle, a main load-carrying bed member pivotally mounted at its rear portion on said transverse axle, a forwardly extending hitch frame beneath the forward portion of said bed member, means pivotally connecting the intermediate portion of said hitch frame to the bed member for rotation on a transverse axis, a ramp platform hinged to the rear transverse edge of said bed member, a fulcrum member at least partially surrounding said axle and pivoted to said bed member, first link means pivotally connecting a forward portion of said fulcrum member to the rear end portion of said hitch frame, and second link means pivotally connecting the ramp platform to a rear portion of said fulcrum member, said fulcrum member and first and second link means being so constructed and arranged as to automatically rotate the ramp platform relative to the bed member as the hitch frame is raised or lowered.
Claim 12
Dependent Claim
39 words
A semi-trailer according to claim 9, and resilient strut means acting between sAid ramp platform and said fulcrum member to bias the ramp platform into substantial alignment with the main bed member when the latter is in horizontal position.
Claim 13
Dependent Claim
23 words
The semi-trailer of claim 9, and jack means acting between said bed member and hitch frame to at times vary the angle between.
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) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |