Dock leveler lip providing multi-position barrier
A dock leveler includes a lip that not only pivots between an extended operative position and a pendant position relative to a deck but also translates in its pendant position between blocking and non-blocking positions and does so at multiple deck elevations. In the blocking positions, the lip provides a safety barrier that helps prevent material and material handling equipment from accidentally falling off the front edge of the deck when a truck is not present at the dock. The lip can serve as the safety barrier when the deck is at its stored, cross-traffic position or when the deck is at a below-dock position for end loading operations. If required, the lip can be lowered below the top surface of the deck so as not to provide an obstacle during some below-dock end loading operations.
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1. Field of the Invention
The subject invention generally pertains to dock levelers and more specifically to a dock leveler whose pivotal lip can provide a barrier that helps prevent material handling equipment from accidentally driving off the front edge of the dock leveler's pivotal deck.
2. Description of Related Art
A typical truck loading dock of a building includes an exterior doorway with an elevated platform for loading and unloading vehicles such as trucks and trailers. Many loading docks have a dock leveler to compensate for a height difference that may exist between the floor of the loading dock platform and an adjacent bed of a truck or trailer. A typical dock leveler includes a deck that is hinged along its back edge at or near the elevation of the floor so that the deck can pivotally adjust the height of its front edge to an elevation that generally matches the height of the rear edge of the truck bed to provide a ramp for material handling equipment.
In addition, a front hinge may pivotally connect an extension plate or lip to the front edge of the deck. The front hinge allows the lip to pivot between a stored, pendant position and an extended, operative position. In the extended position, the lip can rest upon the truck bed to form a bridge between the deck and the bed. This allows personnel and material handling equipment, such as a forklift truck, to readily move on and off the truck during loading and unloading operations.
With some dock levelers, the lip is connected to the deck in such a way that the lip can also be used as a barrier to help prevent material handling equipment from accidentally driving off the edge of the deck when no truck is parked at the dock and the deck is at its stored, cross-traffic position (i.e., the deck is flush with the top surface or floor of the dock platform). An example of such a dock leveler is disclosed in U.S. Pat. No. 4,920,598. With the '598 dock leveler, the lip includes a series of slots through which a corresponding series of bolts extend to fasten the lip to a deck hinge. Sliding clearance between the bolts and the slots allow the lip to slide between a raised barrier position and a nonobstructing cleared position.
With the dock leveler of the '598 patent, when the lip is pendant with its front distal edge vertically supported by a stationary lip keeper, relative sliding motion between the lip and the deck allows the deck to descend to the cross-traffic position, while a back edge of the lip can protrude above the deck to create the runoff barrier.
The sliding connection between the deck and the lip also accommodates end-loading operations, where loads are added or removed from the very back end of the truck or trailer bed. To prevent the lip from interfering with the placement or removal of end loads, the deck can lift the lip up from the back edge of the truck and allow the lip to hang pendant between the lip keeper and the back end of the truck. With the lip unsupported by the trailer bed or the lip keeper, the deck can descend to a below-dock position without the lip creating a barrier, thereby facilitating below-dock, end-loading operations.
If, for example, the dock leveler were to remain in that position after a truck has departed from the dock position, a dockworker using a forklift could find himself exposed to the unprotected front edge of the dock leveler.
Thus, a need may exist for a dock leveler with an automatic barrier that can provide runoff protection during some below-dock end-loading operations, yet the barrier can be cleared if necessary.
SUMMARY OF THE INVENTIONIn some embodiments, a dock leveler includes a deck with a pivotal lip that automatically provides a runoff barrier when the deck is at a certain below-dock position.
In some embodiments, the lip provides a runoff barrier when the deck is at a cross-traffic position and certain below-dock positions.
In some embodiments, the deck can be moved to various below-dock positions, such that in one position the lip provides a runoff barrier and in another position the lip recedes to a nonobstructing position.
In some embodiments, it is the deck's weight that moves the deck to where a front edge of the deck is below a back edge of the lip, whereby the lip's higher back edge provides a runoff barrier.
In some embodiments, the lip can pivot and translate relative to the deck.
In some embodiments, a lip keeper of a dock leveler includes a plurality of vertically spaced apart resting points that can support the lip at different elevations.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring to
To perform various operations at the loading dock, deck 16 may be movable to a cross-traffic position (
In some embodiments, the various configurations or operating positions of dock leveler 14 can be achieved using a unique multi-step lip keeper 32 that can be attached to frame 24. Lip keeper 32 works in conjunction with a lip that can both pivot and translate linearly relative to the deck. Lip 30, for instance, can pivot between a pendant position (
In operation, truck 12 backs into the loading dock, adjacent to platform 10, as shown in
Next, in
Then, in
To add a load 50 to the very end of the truck bed, lip 30 can be lifted off the back end of the truck (to make room for the load), and deck 16 can be moved to one of its below-dock end loading position, such as the first below-dock end loading position of
If a barrier is desired in a below-dock end loading position, lip 30 could be allowed to lie pendant against the front face of lip keepers 32, and deck 16 could lift the pendant lip until its tip 40 falls into a desired rest point of lip keeper 32, such as a first rest point 52. Once tip 40 falls into first rest point 52, deck 16 can descend. While first rest point 52 supports tip 40, the sliding connection between lip 30 and deck 16 allows front edge 20 of deck 16 to descend below back edge 44 of lip 30, whereby below dock end-loading can be performed with lip 30 providing a runoff barrier as shown in
It should be noted that with deck 16 at the first below dock position of
It may also be beneficial to having a range of below dock loading positions with the barrier activated.
Referring to
To create the sliding connection between lip 30 and deck 16, lip 30 includes a series of slots 64 along which fasteners 66 can slide. In some embodiments, fastener 66 is a shoulder screw that screws into lip-hinge member 60 and slides within slot 64.
Although the invention is described with reference to a preferred embodiment, it should be appreciated by those of ordinary skill in the art that various modifications are well within the scope of the invention. Therefore, the scope of the invention is to be determined by reference to the following claims:
Claims
1. A dock leveler, comprising:
- a deck being movable to vertically move a front edge of the deck, wherein the deck is selectively movable to a cross-traffic position, a first below-dock position, and a second below-dock position, wherein the first below-dock position is between the cross-traffic position and the second below-dock position; and
- a lip coupled to the front edge of the deck, wherein the lip includes a back edge that protrudes farther above the front edge when the deck is resting at the first below-dock position than when the deck is resting at the second below-dock position.
2. The dock leveler of claim 1, wherein the back edge of the lip protrudes above the front edge of the deck when the deck is resting at the cross-traffic position.
3. The dock leveler of claim 1, wherein the lip supports more of the deck's weight when the deck is resting at the first below-dock position than when the deck is resting at the second below-dock position.
4. The dock leveler of claim 1, wherein the lip can translate linearly relative to the deck.
5. The dock leveler of claim 1, wherein the lip can pivot relative to the deck.
6. The dock leveler of claim 1, wherein the lip can both pivot and linearly translate relative to the deck.
7. The dock leveler of claim 1, wherein the deck is further selectively movable to an intermediate below-dock position that is between the cross-traffic position and the first below-dock position, and the back edge of the lip protrudes above the front edge of the deck when the deck is at the intermediate below-dock position.
8. The dock leveler of claim 1, further comprising a lip keeper that includes a plurality of rest points upon which the lip can rest, wherein the plurality of rest points are at a corresponding plurality of elevations that help determine the elevation of the front edge of the deck when the deck is resting at the cross-traffic position and the first below-dock position.
9. The dock leveler of claim 1, further comprising a lip keeper that includes a plurality of rest points upon which the lip can rest, wherein the plurality of rest points includes a storage rest point and a first rest point, wherein the storage rest point helps support the deck at the cross-traffic position when the lip is resting on the storage rest point, and the first rest point helps support the deck at the first below-dock position when the lip is resting on the first rest point.
10. The dock leveler of claim 9, wherein the plurality of rest points includes an intermediate rest point that helps support the deck at an intermediate position when the lip is resting on the intermediate rest point, wherein the intermediate position is between the cross-traffic position and the first below-dock position, and the intermediate rest point is between the storage rest point and the first rest point.
11. A dock leveler, comprising:
- a deck being pivotal to linearly move a front edge of the deck, wherein the deck is selectively movable to a cross-traffic position, a first below-dock position, and a second below-dock position, wherein the first below-dock position is between the cross-traffic position and the second below-dock position; and
- a lip coupled to the front edge of the deck such that the lip can both pivot and linearly translate relative thereto, wherein the lip includes a back edge that:
- i. protrudes above the front edge when the deck is resting at the cross-traffic position,
- ii. protrudes above the front edge when the deck is resting at the first below-dock position, and
- iii. protrudes farther above the front edge when the deck is resting at the first below-dock position than when the deck is resting at the second below-dock position.
12. The dock leveler of claim 11, wherein the lip supports more of the deck's weight when the deck is resting at the first below-dock position than when the deck is resting at the second below-dock position.
13. The dock leveler of claim 11, wherein the deck is further selectively movable to an intermediate below-dock position that is between the cross-traffic position and the first below-dock position, and the back edge of the lip protrudes above the front edge of the deck when the deck is at the intermediate below-dock position.
14. The dock leveler of claim 11, further comprising a lip keeper that includes a plurality of rest points upon which the lip can rest, wherein the plurality of rest points are at a corresponding plurality of elevations that help determine the elevation of the front edge of the deck when the deck is resting at the cross-traffic position and the first below-dock position.
15. The dock leveler of claim 11, further comprising a lip keeper that includes a plurality of rest points upon which the lip can rest, wherein the plurality of rest points includes a storage rest point and a first rest point, wherein the storage rest point helps support the deck at the cross-traffic position when the lip is resting on the storage rest point, and the first rest point helps support the deck at the first below-dock position when the lip is resting on the first rest point.
16. The dock leveler of claim 15, wherein the plurality of rest points includes an intermediate rest point that helps support the deck at an intermediate position when the lip is resting on the intermediate rest point, wherein the intermediate position is between the cross-traffic position and the first below-dock position, and the intermediate rest point is between the storage rest point and the first rest point.
17. A method of moving a dock leveler that includes a lip coupled to a deck, wherein the deck is movable above and below a cross-traffic position, the method comprising:
- lowering the deck below the cross-traffic position; and
- lowering the deck relative to the lip so that the lip protrudes above the deck when the deck is at a first below-dock position that is below the cross-traffic position.
18. The method of claim 17, further comprising:
- from the first below-dock position, raising the deck relative to the lip;
- raising the deck and lip together;
- partially extending the lip;
- lowering the deck and the lip so that the deck descends to a second below-dock position that is lower than the first below-dock position; and
- allowing the lip to retract.
19. The method of claim 17, further comprising pivoting and vertically sliding the lip relative to the deck.
20. The method of claim 17, further comprising pivoting the deck.
Type: Application
Filed: Dec 14, 2004
Publication Date: Jun 15, 2006
Applicant: RITE-HITE HOLDING CORPORATION (Milwaukee, WI)
Inventor: Michael Swessel (Menomonee Falls, WI)
Application Number: 11/011,546
International Classification: E01D 1/00 (20060101);