Patent Application
20080187410
Not applicable to this application.
Not applicable to this application.
1. Field of the Invention
The present invention relates generally to drywall lifters and more specifically it relates to a multi-stage drywall hydraulic lift system for efficiently lifting a drywall panel while providing increased precision in positioning of the drywall panel.
2. Description of the Related Art
Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.
Drywall lifters have been in use for years. A conventional drywall lifter is comprised of a telescoping structure attached to a base, an upper support attached to an upper portion of the telescoping structure and a drive unit mechanically connected to the telescoping structure to selectively lift and lower the telescoping structure. The drive unit may be manual or hydraulic. A drywall panel is positioned upon the upper support and is thereby raised to a desired position on a ceiling for securing by workers with conventional fasteners and then removed after fastening. U.S. Pat. No. 5,586,619 (hydraulic lifter) to Roland Young, U.S. Pat. No. 5,368,429 (manual lifter) to Roland Young and U.S. Pat. No. 3,828,942 (manual lifter) illustrate examples of conventional drywall lifters.
While manual drywall lifters can be very precise in the positioning of a drywall panel, they are relatively slow, labor intensive, cumbersome and require the operator to be positioned beneath the drywall panel during lifting. While hydraulic drywall lifters are able to lift a drywall panel in a fast manner, they are not very precise in the positioning of a drywall panel.
Hence, there is a need for a hydraulically powered drywall lifter that is able to provide for an efficient lifting speed while providing increased precision in positioning of the drywall panel in a desired position.
The general purpose of the present invention is to provide a multi-stage drywall hydraulic lift system that has many of the advantages of the drywall lifters mentioned heretofore. The invention generally relates to a drywall lifter which includes a telescoping drywall lifter, a hydraulic actuator connected to the telescoping drywall lifter to extend and retract the telescoping drywall lifter. A hydraulic pump is fluidly connected to the hydraulic actuator. A valve unit is fluidly positioned between the hydraulic pump and the hydraulic actuator to control the flow of fluid to the hydraulic actuator based upon a desired vertical lift velocity.
There has thus been outlined, rather broadly, some of the features of the invention in order that the detailed description thereof may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and that will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction or to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting.
An object is to provide a multi-stage drywall hydraulic lift system for precisely positioning a drywall panel into a desired position for securing within a building structure.
Another object is to provide a multi-stage drywall hydraulic lift system that may be utilized to lift various types of drywall panels including but not limited to plasterboard, paneling, wooden panels, composite panels and the like.
An additional object is to provide a multi-stage drywall hydraulic lift system that may be utilized to lift and lower various types of loads.
A further object is to provide a multi-stage drywall hydraulic lift system that expedites the process of installing drywall panels.
Another object is to provide a multi-stage drywall hydraulic lift system that reduces damage to the drywall panel, surrounding material or structures during positioning of a drywall panels.
A further object is to provide a multi-stage drywall hydraulic lift system that operates the hydraulic pump at a relative constant speed.
Other objects and advantages of the present invention will become obvious to the reader and it is intended that these objects and advantages are within the scope of the present invention. To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated and described within the scope of the appended claims.
Various other objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views,
The telescoping drywall lifter includes a plurality of legs 21, a lower lifting member 22, a plurality of telescoping lifting members 24′, 24″ extending upwardly from the lower lifting member 22 and an upper support 26. The lower lifting member 22 is vertically movable within an outer support 20 attached to the legs 21 as illustrated in
As shown in
A hydraulic pump 40 is fluidly connected to and provides pressurized fluid to the hydraulic actuator 60 as best illustrated in
The valve unit 30 is fluidly positioned between the hydraulic pump 40 and the hydraulic actuator 60 as illustrated in
The valve unit 30 is designed to adjustably control a flow rate of the pressurized fluid to the hydraulic actuator 60 based upon a desired vertical lift velocity. The flow rate may be adjustable via a few select flow rates or adjustable in a variable manner.
The valve unit 30 preferably includes a first valve 34 and a second valve 38 as shown in
The control unit 42 is in communication with the valve unit 30 to control the flow of the pressurized fluid to the hydraulic actuator 60. The control unit 42 is further preferably in communication with the hydraulic pump 40 to control the operation of the hydraulic pump 40. The control unit 42 may be comprised of a manually operated structure directly connected to the valve block to control the flow of fluid or an electrically operated device (wireless or wired).
In the preferred embodiment of the present invention, the valve unit 30 has a normal state and an activated state. The normal state allows the first valve 34 to remain open with the second valve 38 closed to provide a normal flow rate of fluid to the hydraulic actuator 60 resulting in a first vertical velocity of the upper support 26. The activated state includes the first valve 34 closed with the second valve 38 open to provide a reduced flow rate of fluid to the hydraulic actuator 60 resulting in a second vertical velocity of the upper support 26 that is less than the first vertical velocity. The reduced flow rate is significantly less than the normal flow rate resulting in significant decrease in vertical velocity when in the activated state. The reduced vertical velocity allows for the user to more precisely position the drywall panel (or other load) in a desired position.
The activated state is preferably activated by closing an activation switch in the control unit 42 and deactivated by releasing the activation switch. The control unit 42 preferably also has a power switch to control the flow of electrical power to the motor of the hydraulic pump 40.
As shown in
What has been described and illustrated herein is a preferred embodiment of the invention along with some of its variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations are possible within the spirit and scope of the invention, which is intended to be defined by the following claims (and their equivalents) in which all terms are meant in their broadest reasonable sense unless otherwise indicated. Any headings utilized within the description are for convenience only and have no legal or limiting effect.
