Patent US3877102A successfully refreshed from Google Patents.
US3877102A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Safety leg support for a dockboard
Assignee: KELLEY CO Inc
•
Filing: 1974-05-20
•
Granted: 1975-04-15
•
Expires: 1994-05-20
Abstract
Abstract A safety leg construction for a dockboard which acts to limit normal slow descent of the ramp, as well as rapid descent of the ramp, after a truck pulls away from the dock. Safety legs are hinged to the undersurface of the forward edge of the ramp and are biased to a forward supporting position and are pivotable to a retracted non-supporting position. The legs are coupled to the lip of the dockboard through a releasible latch mechanism which includes an acceleration responsive element. In normal operation when a truck pulls away from the dock after the loading operation is completed, the ramp descends slowly, and the lip pivots downwardly toward the pendant position and the legs pivot toward the forward supporting position to engage fixed supports and support the ramp against further descent. Under a rapid gravitational descent of the ramp caused by an added load on the ramp when the truck pulls away from the dock, the increased acceleration of the ramp will actuate the acceleration responsive element to release the latch mechanism and enable the legs to return, under the force of the biasing means, to the supporting position independently of the position of the lip, to thereby support the ramp against further descent.
Inventors
- 👤 Thomas G Artzberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:02
CPC Classifications
B; B65; B65G; B65G69/00; B65G69/28; B65G69/287; B65G69/2876; B65G69/2894; B65G69/2805; B65G69/2811; B65G69/2835; B65G69/2841
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
137 words
In a dockboard, a supporting structure, a ramp structure hinged at its rear edge to the supporting structure and movable from a generally horizontal position to an upwardly inclined position, a fixed support connected to one of said structures, a movable support secured to the other of said structures and movable between an operable ramp-supporting position and an inoperable position, biasing means to bias the Movable support to the operable position, means for moving the movable support to the inoperable position, latch means for retaining the movable support in the inoperable position, and means responsive to a predetermined rapid downward acceleration of the ramp structure caused by descent of the ramp structure with an added load thereon for releasing said latch means whereby the movable support will be moved to the supporting position by said biasing means.
Claim 2
Dependent Claim
137 words
In a dockboard, a supporting structure, a ramp structure hinged at its rear edge to the supporting structure and movable from a generally horizontal position to an upwardly inclined position, a fixed support connected to one of said structures, a movable support secured to the other of said structures and movable between an operable ramp-supporting position and an inoperable position, biasing means to bias the Movable support to the operable position, means for moving the movable support to the inoperable position, latch means for retaining the movable support in the inoperable position, and means responsive to a predetermined rapid downward acceleration of the ramp structure caused by descent of the ramp structure with an added load thereon for releasing said latch means whereby the movable support will be moved to the supporting position by said biasing means.
Claim 3
Dependent Claim
37 words
The dockboard of claim 1, wherein said latch means comprises a first latch member connected to the other of said structures and a second latch member on said movable support and engageable with said first latch member.
Claim 4
Dependent Claim
43 words
The dockboard of claim 2, wherein said first latch member is mounted for pivotal movement with respect to said other structure about a pivot axis and includes a latching element disposed to engage said second latch member and spaced from the pivot axis.
Claim 5
Dependent Claim
27 words
The dockboard of claim 3, wherein the means responsive to predetermined rapid downward acceleration of the ramp structure comprises a weight connected to the first latch member.
Claim 6
Dependent Claim
45 words
The dockboard of claim 4, wherein said weight is positioned with respect to the pivot axis so that on rapid downward acceleration of the ramp structure the weight will swing in a direction to release the latching element from engagement with said second latch member.
Claim 7
Dependent Claim
24 words
The dockboard of claim 1, wherein said movable support is hinged to the ramp structure and the fixed support is on the supporting structure.
Claim 8
Dependent Claim
19 words
The dockboard of claim 2, and including linkage means pivotally interconnecting the first latch member and said other structure.
Claim 9
Dependent Claim
26 words
The dockboard of claim 3, wherein said latching element comprises a hook and said second latch member comprises an abutment to be engaged by said hook.
Claim 10
Dependent Claim
28 words
The dockboard of claim 1, and including means for automatically returning the latch means to the latched position after the movable support is moved to the supporting position.
Claim 11
Dependent Claim
83 words
The dockboard of claim 1, wherein said dockboard includes a lip hinged to the forward edge of the ramp and movable between a downwardly hanging pendant position and an extended position where the lip forms an extension to the ramp, said means for moving the movable support comprising coupling means interconnecting the lip and said movable support whereby movement of the lip from the pendant to the extended position will move the movable support from the operable supporting position to the inoperable position.
Claim 12
Dependent Claim
224 words
In a dockboard, a supporting structure, a ramp structure hinged at its near edge to the supporting structure and movable from a generally horizontal position to an upwardly inclined position, a lip hinged to the front edge of the ramp and pivotable from a downwardly hanging pendant position to an extended position where the lip forms an extension to the ramp structure, a fixed support connected to one of said structures, a leg hinged to the other of said structures and pivotable between an upright ramp supporting position and a retracted inoperable position, biasing means to bias the leg to the ramp supporting position, coupling means for interconnecting the lip and the leg whereby movement of the lip from the pendant to the extended position will move the leg from the supporting position to the retracted position, latch means associated with the coupling means and movable between a latched position and a released position, said latch means when in the latched positionn serving to latch the coupling means and interconnect the lip and the leg, and means responsive to a predetermined rapid downward acceleration of the ramp structure caused by descent of the ramp structure with an added load thereon for releasing said latch means and disconnecting said coupling means whereby the leg will be pivoted to the supporting position by said biasing means.
Claim 13
Dependent Claim
224 words
In a dockboard, a supporting structure, a ramp structure hinged at its near edge to the supporting structure and movable from a generally horizontal position to an upwardly inclined position, a lip hinged to the front edge of the ramp and pivotable from a downwardly hanging pendant position to an extended position where the lip forms an extension to the ramp structure, a fixed support connected to one of said structures, a leg hinged to the other of said structures and pivotable between an upright ramp supporting position and a retracted inoperable position, biasing means to bias the leg to the ramp supporting position, coupling means for interconnecting the lip and the leg whereby movement of the lip from the pendant to the extended position will move the leg from the supporting position to the retracted position, latch means associated with the coupling means and movable between a latched position and a released position, said latch means when in the latched positionn serving to latch the coupling means and interconnect the lip and the leg, and means responsive to a predetermined rapid downward acceleration of the ramp structure caused by descent of the ramp structure with an added load thereon for releasing said latch means and disconnecting said coupling means whereby the leg will be pivoted to the supporting position by said biasing means.
Claim 14
Dependent Claim
41 words
The dockboard of claim 11, wherein said coupling means includes an arm, and said latch means includes a first latch element coNnected to said arm and a second latch element engageable with the first latch element and connected to said leg.
Claim 15
Dependent Claim
61 words
The dockboard of claim 12, wherein one of said latch elements is mounted for pivotal movement about a pivot axis, said means responsive to a predetermined rapid downward acceleration comprises a weight on the pivotally mounted latch element and spaced from the pivot axis, whereby said rapid downward acceleration will pivot said pivotally mounted latch element to release the latch means.
Claim 16
Dependent Claim
200 words
In a dockboard, a supporting structure, a ramp structure hinged at its rear edge to the supporting structure and movable from a generally horizontal position to an upwardly inclined position, a lip hinged to the front edge of the ramp and pivotable from a downwardly hanging pendant position to an extended position where the lip forms an extension to the ramp, a fixed support connected to one of said structures, a leg hinged to the other of said structures and pivotable between an upright ramp supporting position and a retracted inoperable position, biasing means to bias the leg to the ramp supporting position, releasible coupling means having an engaged position wherein movement of the lip from the pendant position to the extended position will move the leg from the supporting position to the retracted position, and said coupling means having a released position wherein the leg is movable independent of lip movement, and means responsive to a predetermined rapid downward acceleration of the ramp structure caused by descent of the ramp structure with an added load thereon for moving the coupling means to the released position whereby the leg will be pivoted to the supporting position by said biasing means.
Claim 17
Dependent Claim
200 words
In a dockboard, a supporting structure, a ramp structure hinged at its rear edge to the supporting structure and movable from a generally horizontal position to an upwardly inclined position, a lip hinged to the front edge of the ramp and pivotable from a downwardly hanging pendant position to an extended position where the lip forms an extension to the ramp, a fixed support connected to one of said structures, a leg hinged to the other of said structures and pivotable between an upright ramp supporting position and a retracted inoperable position, biasing means to bias the leg to the ramp supporting position, releasible coupling means having an engaged position wherein movement of the lip from the pendant position to the extended position will move the leg from the supporting position to the retracted position, and said coupling means having a released position wherein the leg is movable independent of lip movement, and means responsive to a predetermined rapid downward acceleration of the ramp structure caused by descent of the ramp structure with an added load thereon for moving the coupling means to the released position whereby the leg will be pivoted to the supporting position by said biasing means.
References Cited (Backward Citations)
US3117332A
Cited
US3137017A
Cited
US3368229A
Cited
US3606627A
Cited
US3646627A
Cited
US3728753A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-14 | 1978-10-14 | 1979-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-14 | 1982-10-14 | 1983-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-14 | 1986-10-14 | 1987-04-15 | $7700.00 | Window Closed / Lapsed |