Bridges – Gangway – ramp – or dock leveler
Reexamination Certificate
2000-03-09
2001-06-05
Bagnell, David (Department: 3673)
Bridges
Gangway, ramp, or dock leveler
C014S071300
Reexamination Certificate
active
06240587
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to edge-of-dock levelers.
BACKGROUND
Dock levelers are used to bridge the gap between a vehicle (e.g., a truck or a trailer) and a loading dock at which the vehicle is parked for unloading or loading. Dock levelers include pit-type dock levelers, which are mounted within a pit in the loading dock, and edge-of-dock levelers, which are mounted on the front edge of the loading dock.
Prior art edge-of-dock levelers include manual levelers wherein an operator uses a lever to raise the edge-of-dock leveler above the level of a vehicle bed parked adjacent to the dock. The leveler is then lowered and a lip extends to engage the vehicle bed. These edge-of-dock levelers commonly include a spring that biases the edge-of-dock leveler upwardly to assist the operator when raising the leveler.
Other prior art edge-of-dock levelers include powered levelers. For example, one type of powered edge-of-dock leveler utilizes a hydraulic actuator to raise and lower the leveler. Another type of edge-of-dock leveler includes a fan or blower and an air bag. The air bag is inflated with the blower, raising the edge-of-dock leveler through a linkage. Examples of powered edge-of-dock levelers utilizing a blower and air bag are disclosed in U.S. Pat. Nos. 5,450,643 and 5,621,938.
SUMMARY
Several disadvantages have been identified in prior art dock levelers and edge-of-dock levelers. Hydraulic dock levelers are generally very expensive, and can require significant modification to the loading dock. Manual edge-of-dock levelers are controlled by an operator, and usually have an upwardly-biased spring mechanism. The upward spring-bias utilized in manual edge-of-dock levelers often causes the edge-of-dock leveler to bounce as material handling devices are moved across them, creating a less stable device. Prior art fan-powered edge-of-dock levelers include relatively complex linkages, and therefore can be more difficult to service.
The present invention provides an edge-of-dock leveler adapted to be mounted to the face of a loading dock. The leveler of the present invention includes a deck plate, a lip plate, and a removable air pan. A retaining member is mounted on the dock face, and a portion of the air pan is received in the retaining member. The air pan is therefore removably mounted on the face of the loading dock for rotation with respect to the dock face.
Mounted on the air pan is a blower. An air bag having a plurality of air lobes is mounted on one of the dock face and the air pan, and includes apertures through which the blower forces air into the bag. When the air bag is deflated, it hangs pendant between the loading dock face and the air pan. As the lobes are inflated by the blower, the lobes abut against the dock face and against the air pan, causing the air pan to pivot about the retaining member away from the face of the dock. The air pan includes at least one deck plate bearing that abuts the underside of the deck plate of the leveler. As the air pan is raised or lowered in response to inflation or deflation of the air bag, the air pan raises and lowers the deck plate through the deck plate bearing. One or more biasing members are provided to bias the deck plate and the air pan down toward the dock face.
The edge-of-dock leveler of the present invention also includes a lip lifter arm. The lip lifter arm hangs pendant from the lip plate as the deck plate is raised. When the deck plate has been raised to a predetermined level, a notch in the lip lifter arm engages a bearing mounted on the loading dock. The blower is then turned off, allowing the deck to settle downwardly under the influence of gravity and the biasing members, and forcing air out of the air lobes and through the blower. The blower fan provides resistance to the flow of air out of the air lobes, thereby causing the deck plate to settle at a controlled rate. As the deck plate is lowered, the lip lifter arm causes the lip plate to extend and come to rest on a portion of the vehicle.
REFERENCES:
patent: 3685077 (1972-08-01), Wiener et al.
patent: 3786530 (1974-01-01), Le Clear
patent: 4665579 (1987-05-01), Bennett et al.
patent: 5042103 (1991-08-01), Megens
patent: 5088143 (1992-02-01), Alexander
patent: 5274867 (1994-01-01), Hageman
patent: 5446938 (1995-09-01), Warner et al.
patent: 5450643 (1995-09-01), Warner
patent: 5471693 (1995-12-01), Hodges
patent: 5475888 (1995-12-01), Massey
patent: 5481774 (1996-01-01), Hodges et al.
patent: 5500968 (1996-03-01), Hodges
patent: 5522107 (1996-06-01), Hageman et al.
patent: 5522108 (1996-06-01), Massey et al.
patent: 5600859 (1997-02-01), Hodges et al.
patent: 5621938 (1997-04-01), Warner
patent: 5651155 (1997-07-01), Hodges et al.
patent: 5774920 (1998-07-01), Alexander
patent: 6098227 (2000-08-01), Meichtry et al.
Meichtry Michael M.
Roth Donald G.
Addie Raymond W
Bagnell David
Kelley Company Inc.
Michael & Best & Friedrich LLP
LandOfFree
Fan-powered edge-of-dock leveler does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fan-powered edge-of-dock leveler, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fan-powered edge-of-dock leveler will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2455246