SPRING COUNTERBALANCED COMPACT DOCKBOARD

• US 3,636,578 A
• Filed: 06/20/1969
• Issued: 01/25/1972
• Est. Priority Date: 06/20/1969
• Status: Expired due to Term

• Current Assignee: Donald P. Dieter
• Original Assignee: Donald P. Dieter
• Inventors: Dieter, Donald P.
• Primary Examiner(s): Nackenoff, Jacob L.
• Application Number:
  US04/834,987
• Time in Patent Office: 949 Days
• Field of Search: 14/71
• US Class Current: 14/71.3
• CPC Class Codes: B65G 69/2841 extensible by pivoting parts

Abstract

A folding dockboard includes a deck plate hingedly mounted to a loading dock and a lip plate which is hingedly mounted to the deck plate and adapted to be positioned on the bed of a lading carrying vehicle. The lip plate is rotatable from a position in which the lip plate is positioned at a substantial angle to the deck plate to a position in which the deck and lip plates lie in substantially the same plane and counterbalancing springs exert a force on the deck plate in a direction so as to urge the deck plate toward a substantially upright position. A latching assembly rigidly latches the deck and lip plates to each other when the lip plate is positioned in the same plane as the deck plate. The counterbalancing springs maintain the latched deck and lip plates in the substantially upright disposition, but the force exerted by the springs is overcome by the extended lip plate when the latched plates are tilted from their upright disposition, causing movement of the latched plates to a horizontal disposition on the truck bed. The latching assembly may be either manually disengaged to enable storage of the dockboard or automatically disengaged when the truck bed is withdrawn.

Claims

1. A folding dockboard for transferring lading between a loading dock and a lading carrying vehicle, comprising:

swingable deck means for transferring lading between the loading dock and the vehicle, the deck means including a deck plate adapted to have one edge Thereof hingedly mounted to the loading dock, the deck means also including a lip plate adapted to be positioned on the bed of the vehicle, the lip plate being hingedly connected to said deck plate adjacent the other edge thereof and being angularly swingable relative to the deck plate between a first position in which the deck and lip plates lie in substantially the same plane and a second position in which the deck and lip plates are positioned at a substantial angle relative to one another, said deck means being angularly movable relative to said loading dock between a substantially upright storage position and a substantially horizontal use position;

counterbalancing means for continuously exerting a substantial force on said deck plate for urging the deck plate toward said upright position, said counterbalancing means including;

a. cam means mounted on said deck plate adjacent the lower surface thereof, b. lever means adapted to be pivotally mounted on said loading dock for swinging movement in a substantially vertical plane about a pivot axis, c. said lever means including follower means thereon disposed in engagement with said cam means, said follower means being spaced a substantial distance from said pivot axis, and d. movable force exerting means interconnected between said dock and said lever means for applying a substantially vertically directed force on said lever means irrespective of the position of said deck means, said vertically directed force being applied to said lever means at a point which is horizontally laterally spaced from both said pivot axis and said follower means for swingably urging said lever means in a direction whereby said follower means is maintained in engagement with said cam means, e. said counterbalancing means exerting sufficient force on said deck plate so as to maintain said deck means in said storage position, said deck means having sufficient weight and creating sufficient torque when said lip plate is in said first position to overcome the force created by said counterbalancing means after said deck means has been tilted slightly from said storage position, whereupon the weight of the deck means causes the aligned deck and lip plates to continuously move downwardly into said horizontal use position; and

latch means for rigidly latching said lip plate to said deck plate in said first position.

2. A dockboard according to claim 1, wherein said latch means includes a latch lever pivotally mounted on one of said deck and lip plates adjacent the underside thereof, and a latch member fixedly mounted on the other of said deck and lip plates and positioned for latching engagement with said latch lever when said lip plate is in said first position.

3. A dockboard according to claim 2, further including means for causing said latch lever to automatically engage said latch member when said lip plate is in said first position.

4. A dockboard according to claim 3, wherein said last-mentioned means includes spring means for resiliently urging said latch lever in a pivotal direction whereby same is pivotally moved so as to automatically engage said latch member when said lip plate is in said first position.

5. A dockboard according to claim 1, wherein said force-exerting means comprises substantially vertically oriented spring means disposed for exerting a substantially vertical force on said lever means in all positions of said deck means, said spring means having one end thereof connected to said lever means at a location which is horizontally laterally spaced from said pivot axis by a distance less than the spacing between said follower means and said pivot axis.

6. A dockboard according to claim 5, wherein said spring means comprises a vertically disposed compression spring having the upper end thereof interconnected to said lever means, the lower end of said compression spring being fixedly interconnected relative to said loading dock.

7. A dockboard according to claim 5, wherein Said latch means includes a latch lever pivotally mounted to one of said deck and lip plates and a latch member fixedly secured to the other of said deck and lip plates and disposed for latching engagement with said latch lever when said lip plate is in said first position, said latch means also including means for causing said latch lever to automatically engage said latch member when said lip plate is moved into said first position.

8. A dockboard according to claim 1, wherein said force-exerting means comprises spring means disposed in a substantially vertical position irrespective of the position of said deck means for continuously imposing a substantially vertically directed force on said lever means, said lever means comprising a lever member having one end thereof connected to said spring means, said follower means including a cam roller rotatably mounted on said lever means adjacent the other end thereof, and said lever member being pivotally mounted on said loading dock about a pivot axis located between and horizontally laterally spaced from a line joining the axis of said cam roller to the point of connection of said spring means.

9. A folding dockboard for transferring lading between a loading dock and a lading carrying vehicle, comprising:

swingable deck means for transferring lading between the loading dock and the vehicle, the deck means including a deck plate adapted to have one edge thereof hingedly mounted to the loading dock, the deck means also including a lip plate adapted to be positioned on the bed of the vehicle, the lip plate being hingedly connected to said deck plate adjacent the other edge thereof and being angularly swingable relative to the deck plate between a first position in which the deck and lip plates lie in substantially the same plane and a second position in which the deck and lip plates are positioned at a substantial angle relative to one another, said deck means being angularly movable relative to said loading dock between a substantially upright storage position and a substantially horizontal use position;

counterbalancing means for continuously exerting a substantial force on said deck plate for urging the deck plate toward said upright position, said counterbalancing means including;

a. cam means mounted on said deck plate adjacent the lower surface thereof, b. lever means adapted to be pivotally mounted on said loading dock for swinging movement in a substantially vertical plane about a pivot axis, c. said lever means including follower means thereon disposed in engagement with said cam means, said follower means being spaced a substantial distance from said pivot axis, and d. movable force-exerting means interconnected to said lever means for applying a torque thereto for swingably urging said lever means in a direction whereby said follower means is maintained in engagement with said cam means, said force-exerting means applying a force to said lever means at a point which is laterally spaced from both said pivot axis and said follower means, e. said counterbalancing means exerting sufficient force on said deck plate so as to maintain said deck means in said storage position, said deck means having sufficient weight and creating sufficient torque when said lip plate is in said first position to overcome the force created by said counterbalancing means after said deck means has been tilted slightly from said storage position, whereupon the weight of the deck means causes the aligned deck and lip plates to continuously move downwardly into said horizontal use position;

latch means for rigidly latching said lip plate to said deck plate in said first position, said latch means including a latch lever pivotally mounted on said lip plate adjacent the underside thereof and a latch member fixedly mounted on the underside of said deck plate and positioned for latching engagement with said latch lever when said lip plate is in said first position; and

means for causing said latch lever to automatically engage said latch member when said lip plate is in said first position, said last-mentioned means including spring means resiliently urging said latch lever in a pivotal direction whereby said latch lever is pivotally moved so as to automatically engage said latch member when said lip plate is in said first position.

10. A dockboard according to claim 9, further including means for automatically unlatching said latch means to permit said lip plate to swing downwardly from said first position to said second position when the deck means is in the horizontal use position and the vehicle bed is withdrawn from beneath the lip plate.

11. A dockboard according to claim 10, wherein said unlatching means includes abutment means mounted on said loading dock and disposed for contacting and causing disengagement of said latch lever from said latch member when the deck means swings downwardly a predetermined amount below the use position.