US3662416A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dockboards
Assignee: SERCO ENG Ltd
•
Filing: 1970-12-29
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Granted: 1972-05-16
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Expires: 1990-12-29
Abstract
Abstract A dockboard comprises a main plate hinged at its rear edge to a frame and having a lip plate hinged at its front edge. Upwardly acting springs beneath the main plate are sufficiently strong to move the board upwards in the absence of a weight thereon. A cable is connected between the frame and the board, one end of the cable being wound around a ratchet-controlled reel which holds the board in any position to which it is set; a manually controlled release is provided for the ratchet. The lip plate is automatically elevated as the main plate rises by a snatch chain acting on one end of an articulated linkage which just reaches top dead center as the lip plate reaches the elevated position and locks it in that position. The linkage is mounted to move backward and thereby trip the latch upon an impact applied to the elevated lip, for example by a transport backing into the lip.
Inventors
- 👤 David Brooks
- 👤 Arthur L Reteff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:43
CPC Classifications
B; B65; B65G; B65G69/00; B65G69/28; B65G69/2805; B65G69/2811; B65G69/2835; B65G69/2841
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
234 words
A dockboard comprising frame means, a main plate having front and rear edges, means pivotally connecting the main plate with said frame means adjacent said rear edge for pivoting movement about a respective first pivot axis, a lip plate, means pivotally connecting the lip plate with the main plate front edge for pivoting movements relative to the main plate about a respective second pivot axis between a dependent position and an extended position, characterized by lip elevating and latching means comprising an extension arm movable with the lip plate, a lipelevating articulated linkage constituted by pivotally connected first and second latch arms, the first latch arm being pivotally connected to the extension arm and the second latch arm being pivotally connected to the underside of the main plate to have a portion thereof extending rearwardly from its pivotal connection with the main plate, the two latch arms having respective engaging latching faces operative when the arms reach a relative neutral position with the lip plate in said extended position to latch the arms against pivotal movement and thereby latch the lip plate in the extended position, and a snatch connection between the rearwardly extending portion of said second latch arm and the frame means and operative upon upward movement of the main plate beyond a predetermined position to move the said two latch arms into latching position with simultaneous elevation of the lip plate.
Claim 2
Dependent Claim
234 words
A dockboard comprising frame means, a main plate having front and rear edges, means pivotally connecting the main plate with said frame means adjacent said rear edge for pivoting movement about a respective first pivot axis, a lip plate, means pivotally connecting the lip plate with the main plate front edge for pivoting movements relative to the main plate about a respective second pivot axis between a dependent position and an extended position, characterized by lip elevating and latching means comprising an extension arm movable with the lip plate, a lipelevating articulated linkage constituted by pivotally connected first and second latch arms, the first latch arm being pivotally connected to the extension arm and the second latch arm being pivotally connected to the underside of the main plate to have a portion thereof extending rearwardly from its pivotal connection with the main plate, the two latch arms having respective engaging latching faces operative when the arms reach a relative neutral position with the lip plate in said extended position to latch the arms against pivotal movement and thereby latch the lip plate in the extended position, and a snatch connection between the rearwardly extending portion of said second latch arm and the frame means and operative upon upward movement of the main plate beyond a predetermined position to move the said two latch arms into latching position with simultaneous elevation of the lip plate.
Claim 3
Dependent Claim
44 words
A dockboard as claimed in claim 1, and comprising an assist spring means operatively connected between one latch arm and the main plate, the said pring means urging the latch arms toward the latched position and the lip plate away from its dependent position.
Claim 4
Dependent Claim
81 words
A dockboard as claimed in claim 2, wherein the assist spring means is connected between the main plate and the second latch arm and there is provided a lost-motion link connected between the spring means and the arm and permitting application of the spring force to the arm to urge latching movement of the latch arms only up to a predetermined position adjacent the fully latched position, the arms moving to the fully latched position without assist from the spring means.
Claim 5
Dependent Claim
113 words
A dockboard as claimed in claim 1, and comprising bracket means Pivotally mounting the second latch arm to the main plate for movement toward and away from the main plate front edge, spring means operative between the main plate and the bracket means and urging the said bracket means to a predetermined forward position, and cooperating cam means carried by the main plate and the articulated linkage and operative upon rearward movement of the bracket means upon application of a rearwardly operating force to the lip plate and thence to the bracket means through the articulated linkage to unlatch the latch arms and permit the lip plate to move to its dependent position.
Claim 6
Dependent Claim
87 words
A dockboard as claimed in claim 1, wherein the said rearwardly extending portion of the second latch arm is cranked to have its rear end extending downwards and means for unlatching the latch arms to permit the lip plate to move to its dependent position upon additional movement of the main plate below a predetermined position comprise a stop on the frame means engaging the said rear end to rotate the second latch arm out of latching engagement with the first latch arm upon said additional movement.
Claim 7
Dependent Claim
50 words
A dockboard as claimed in claim 1, and comprising spring means operatively connected between the frame means and the main plate and of sufficient strength to move the dockboard upward in the absence of additional weight thereon and to cause automatic elevation of the lip plate by said upward movement.
Claim 8
Dependent Claim
32 words
A dockboard as claimed in claim 6, and comprising an operator-controlled ratchet device operatively connected between the frame means and the main plate for control of the upward movement of the dockboard.
Claim 9
Dependent Claim
62 words
A dockboard as claimed in claim 7, wherein the said ratchet device comprises a spring wound ratchet-controlled drum mounted to the underside of the main plate, a buffer spring having one end connected to the frame means, and a flexible cable connected to the other end of the buffer spring and wound upon the drum by the action of the spring thereof.
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) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |