Elevator – industrial lift truck – or stationary lift for vehicle – Stationary lift for roadway vehicle or required component... – Having specific drive means for support
Reexamination Certificate
2001-03-08
2003-01-07
Bratlie, Steven A. (Department: 3652)
Elevator, industrial lift truck, or stationary lift for vehicle
Stationary lift for roadway vehicle or required component...
Having specific drive means for support
C187S267000
Reexamination Certificate
active
06502667
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an ergonomic platform lift of the type that can be vertically adjusted while supporting a person thereon. More specifically, this lift combines rack and pinion units with at least one screw jack with self-locking thread so that a person can be solidly supported without any tilting in the lift and so that the height of the lift can be adjusted with great precision.
BACKGROUND OF THE INVENTION
In certain occupations, it is often necessary to use an apparatus to raise or lower a person to a desired height while having that person be solidly supported thereon.
Accordingly, platform lifts provide solid support and allow the placement of people, such as workers, at optimal heights to properly perform specified tasks. With a focus towards the workplace, proper height placement of workers on lifts providing solid support allows workers to safely perform tasks using proper body mechanics. As such, platform lifts can reduce worker injuries and increase work productivity.
The present platform lift differentiates from other types of lifting platforms in that this lift combines rack and pinion units with at least one screw jack to afford a person a solid support and give them the ability to adjust the height of the lift with great precision. This invention is most suitably adapted for use in connection with assembly lines used in food processing, material handling, manufacturing plants, such as automotive plants, and the like.
SUMMARY OF THE INVENTION
The present invention is directed to an ergonomic platform lift adapted to move vertically such that the height of a worker situated thereon can be adjusted to an optimum working height. The present invention further provides a worker with a solid support and the ability to adjust the height of the lift with great precision. The invention is best suited for use along an assembly line.
The platform lift includes a floor plate having a bottom surface and opposing longitudinal and lateral side edges. An upper movable frame supports the floor plate and is secured to the bottom surface of the floor plate.
The platform lift further comprises at least one jack screw supported by a lower stationary frame and operably connected with the floor plate to provide vertical movement or displacement of the floor plate thereof. A driving mechanism, preferably a motor, drives at least one screw jack to vertically move the floor plate. If more than one screw jack is used, the screw jacks are operably connected to each other by a drive shaft such that the driving mechanism drives at least one screwjack causing simultaneous movement of each due to the drive shaft connection therebetween. In a preferred embodiment, first and second screw jacks are operably connected therebetween by a drive shaft, are driven by a motor, and operably connected to the floor plate for vertical movement thereof.
The platform lift further includes first and second rack and pinion assemblies positioned apart and located below the floor plate for stabilization of the floor plate and to prevent tilting thereof. Each rack is fixedly mounted to the lower frame with the pinions carried and supported by an extension of the upper movable frame. The first and second rack and pinion assemblies are comprised of first and second rack and pinion units which also are positioned apart. In a preferred embodiment the first and second rack and pinion assemblies are positioned apart proximate opposing lateral side edges of the floor plate, and each of the first and second rack and pinion units of the first and second rack and pinion assemblies are positioned apart proximate opposing longitudinal side edges of the floor plate.
Each of the first and second rack and pinion units comprise a stationary rack securely supported vertically by the lower frame and a pinion supported by the upper frame for vertical movement with the floor plate. The pinion further is operably associated with the stationary rack for rotational movement therealong during vertical movement of the floor plate. Each pinion of the first rack and pinion assembly and each pinion of the second rack and pinion assembly further is operably connected therebetween by a cross shaft to allow simultaneous rotation of each pinion during vertical movement of the floor plate.
Additionally, multiple rollers are supported by the upper frame for vertical movement with the floor plate wherein one of each roller is located adjacent each stationary rack such that the rack is sandwiched between the roller and a pinion to increase the stability of the floor plate. During vertical movement of the floor plate, the roller moves along the rack in unison with the pinion.
To operate the lift, a worker activates the motor which, in turn, activates the screw jack system for vertical movement of the floor plate to a desired position. As the floor plate is raised or lowered by the screw jack(s), the pinions and associated rollers move in unison along their respective racks to provide stability to the floor plate. Notably, the use of a screw jack(s) allows precise adjustment of the floor plate when placing a worker at their optimum working height.
Accordingly, it is an object of the invention to provide a vertically adjustable platform lift that will provide a solid support for a worker so that the lift does not tilt.
It is another object of the invention to provide a vertically adjustable platform lift which can accommodate people having a wide range of heights.
Lastly, it is another object of the invention to provide a vertically adjustable platform lift that allows a worker the ability to adjust the height of the lift with great precision.
The invention will be further described in conjunction with the appended drawings and following detailed description.
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Mead Roy W.
Smoot Michael R.
Bratlie Steven A.
JoyceDayton Corporation
Wegman Hessler & Vanderburg
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