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United States Patent Application	20080187410
Kind Code	A1
Young; Roland O.	August 7, 2008

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Claims

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1. A multi-stage drywall hydraulic lift system for efficiently and precisely lifting a drywall panel, comprising:a telescoping drywall lifter to lift and lower a drywall panel, wherein said telescoping drywall lifter includes a plurality of legs, a lower lifting member, a plurality of telescoping lifting members extending upwardly from said lower lifting member and an upper support;a hydraulic actuator mechanically connected to said telescoping drywall lifter to selectively extend and retract said lower lifting member and said plurality of telescoping lifting members;a hydraulic pump fluidly connected to said hydraulic actuator, wherein said hydraulic pump provides pressurized fluid to said hydraulic actuator;a valve unit fluidly positioned between said hydraulic pump and said hydraulic actuator to adjustably control a flow rate of said pressurized fluid to said hydraulic actuator based upon a desired vertical lift velocity; anda control unit in communication with said valve unit to control said flow of said pressurized fluid.

2. The multi-stage drywall hydraulic lift system of claim 1, wherein said valve unit has a normal state and an activated state, wherein said normal state allows a first flow rate of fluid and wherein said activated state allows a second flow rate of fluid that is different from said first flow rate.

3. The multi-stage drywall hydraulic lift system of claim 2, wherein said second flow rate is significantly less than said first flow rate.

4. The multi-stage drywall hydraulic lift system of claim 2, wherein said activated state is activated by closing an activation switch in said control unit.

5. The multi-stage drywall hydraulic lift system of claim 1, wherein said control unit communicates with said valve unit via wireless communications.

6. The multi-stage drywall hydraulic lift system of claim 1, wherein said control unit is attached to said telescoping drywall lifter.

7. The multi-stage drywall hydraulic lift system of claim 1, wherein said valve unit is comprised of a valve block.

8. The multi-stage drywall hydraulic lift system of claim 1, wherein said control unit is in communication with said hydraulic pump to control the operation of said hydraulic pump.

9. The multi-stage drywall hydraulic lift system of claim 1, wherein said hydraulic pump is electrically connected to a battery.

10. The multi-stage drywall hydraulic lift system of claim 1, including a reservoir fluidly connected between said hydraulic pump and said hydraulic actuator.

11. A multi-stage drywall hydraulic lift system for efficiently and precisely lifting a drywall panel, comprising:a telescoping drywall lifter to lift and lower a drywall panel, wherein said telescoping drywall lifter includes a plurality of legs, a lower lifting member, a plurality of telescoping lifting members extending upwardly from said lower lifting member and an upper support;a hydraulic actuator mechanically connected to said telescoping drywall lifter to selectively extend and retract said lower lifting member and said plurality of telescoping lifting members;a hydraulic pump fluidly connected to said hydraulic actuator, wherein said hydraulic pump provides pressurized fluid to said hydraulic actuator;a valve unit fluidly positioned between said hydraulic pump and said hydraulic actuator to adjustably control a flow rate of said pressurized fluid to said hydraulic actuator based upon a desired vertical lift velocity;wherein said valve unit is comprised of a first valve controlling flow of fluid through a first path and a second valve controlling a flow of fluid through a second path to said hydraulic actuator, wherein said first path has a first flow rate and wherein said second path has a second flow rate, wherein said first flow rate is greater than said second flow rate; anda control unit in communication with said valve unit to control said flow of said pressurized fluid.

12. The multi-stage drywall hydraulic lift system of claim 11, wherein said valve unit has a normal state and an activated state, wherein said normal state allows said first valve to remain open with said second valve closed and wherein said activated state includes said first valve closed with said second valve open.

13. The multi-stage drywall hydraulic lift system of claim 12, wherein said activated state is activated by closing an activation switch in said control unit.

14. The multi-stage drywall hydraulic lift system of claim 12, wherein said second flow rate is significantly less than said first flow rate.

15. The multi-stage drywall hydraulic lift system of claim 11, wherein said control unit communicates with said valve unit via wireless communications.

16. The multi-stage drywall hydraulic lift system of claim 11, wherein said control unit is attached to said telescoping drywall lifter.

17. The multi-stage drywall hydraulic lift system of claim 11, wherein said valve unit is comprised of a valve block.

18. The multi-stage drywall hydraulic lift system of claim 11, wherein said control unit is in communication with said hydraulic pump to control the operation of said hydraulic pump.

19. The multi-stage drywall hydraulic lift system of claim 11, wherein said hydraulic pump is electrically connected to a battery.

20. A multi-stage drywall hydraulic lift system for efficiently and precisely lifting a drywall panel, comprising:a telescoping drywall lifter to lift and lower a drywall panel, wherein said telescoping drywall lifter includes a plurality of legs, a lower lifting member, a plurality of telescoping lifting members extending upwardly from said lower lifting member and an upper support;a hydraulic actuator mechanically connected to said telescoping drywall lifter to selectively extend and retract said lower lifting member and said plurality of telescoping lifting members;a hydraulic pump fluidly connected to said hydraulic actuator, wherein said hydraulic pump provides pressurized fluid to said hydraulic actuator;a reservoir fluidly connected between said hydraulic pump and said hydraulic actuator;a valve unit fluidly positioned between said hydraulic pump and said hydraulic actuator to adjustably control a flow rate of said pressurized fluid to said hydraulic actuator based upon a desired vertical lift velocity;wherein said valve unit is comprised of a valve block;wherein said valve unit is comprised of a first valve controlling flow of fluid through a first path and a second valve controlling a flow of fluid through a second path to said hydraulic actuator, wherein said first path has a first flow rate and wherein said second path has a second flow rate, wherein said first flow rate is greater than said second flow rate;a control unit in communication with said valve unit to control said flow of said pressurized fluid and with said hydraulic pump to control the operation of said hydraulic pump;wherein said valve unit has a normal state and an activated state, wherein said normal state allows said first valve to remain open with said second valve closed and wherein said activated state includes said first valve closed with said second valve open;wherein said activated state is activated by closing an activation switch in said control unit;wherein said second flow rate is significantly less than said first flow rate;wherein said control unit communicates with said valve unit via wireless communications; anda battery electrically connected to said valve unit, said hydraulic pump and said control unit.

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Description

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CROSS REFERENCE TO RELATED APPLICATIONS

[0001]Not applicable to this application.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002]Not applicable to this application.

BACKGROUND OF THE INVENTION

[0003]1. Field of the Invention

[0004]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.

[0005]2. Description of the Related Art

[0006]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.

[0007]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.

[0008]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.

[0009]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.

BRIEF SUMMARY OF THE INVENTION

[0010]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.

[0011]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.

[0012]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.

[0013]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.

[0014]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.

[0015]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.

[0016]A further object is to provide a multi-stage drywall hydraulic lift system that expedites the process of installing drywall panels.

[0017]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.

[0018]A further object is to provide a multi-stage drywall hydraulic lift system that operates the hydraulic pump at a relative constant speed.

[0019]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.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]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:

[0021]FIG. 1 is a side view of the present invention in the retracted position.

[0022]FIG. 2 is a side view of the present invention in the extended position.

[0023]FIG. 3 is a block diagram illustrating the fluid connection of the various components of the present invention.

[0024]FIG. 4 is a block diagram illustrating the communications between the control unit, hydraulic pump and valve unit.

DETAILED DESCRIPTION OF THE INVENTION

A. Overview

[0025]Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views, FIGS. 1 through 4 illustrate a multi-stage drywall hydraulic lift system 10, which comprises a telescoping drywall lifter, a hydraulic actuator 60 connected to the telescoping drywall lifter to extend and retract the telescoping drywall lifter. A hydraulic pump 40 is fluidly connected to the hydraulic actuator 60. A valve unit 30 is fluidly positioned between the hydraulic pump 40 and the hydraulic actuators 60 to control the flow of fluid to the hydraulic actuator 60 based upon a desired vertical lift velocity.

B. Telescoping Drywall Lifter

[0026]FIGS. 1 and 2 illustrate an exemplary telescoping drywall lifter. The telescoping drywall lifter is capable of lifting and lowering a load such as but not limited to a drywall panel (e.g. plasterboard, paneling, wooden panels, composite panels and the like).

[0027]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 FIG. 2 of the drawings. The outer support 20 is comprised of a tubular vertical structure that receives a significant portion of the telescoping structure when retracted as shown in FIG. 1 of the drawings.

[0028]As shown in FIGS. 1 and 2 of the drawings, a hydraulic actuator 60 is positioned within the outer support 20 with a rotating sprocket attached to an extending arm thereof. The rotating sprocket engages a run of chain (or other elongated material) that is attached to a lower portion of the lower lifting member 22. When the hydraulic actuator 60 is extended, the run of chain is drawn upwardly thereby lifting the lower lifting member 22 which results in the telescoping of the plurality of telescoping members. When the hydraulic actuator 60 is retracted, the run of chain is extended downwardly thereby lowering the lower lifting member 22 which results in the retracting of the plurality of telescoping members. U.S. Pat. No. 5,586,619 to Young illustrates a lifting apparatus with a similar lifting structure and is hereby incorporated by reference herein.

[0029]A hydraulic pump 40 is fluidly connected to and provides pressurized fluid to the hydraulic actuator 60 as best illustrated in FIG. 3 of the drawings. The hydraulic pump 40 may be comprised of any pump capable of dispensing pressurized fluids. A reservoir 70 is preferably fluidly connected between the hydraulic pump 40 and the hydraulic actuator 60 to store a volume of the fluid to ensure proper operation of the hydraulic pump 40.

C. Valve Unit

[0030]The valve unit 30 is fluidly positioned between the hydraulic pump 40 and the hydraulic actuator 60 as illustrated in FIG. 3 of the drawings. As further shown in FIG. 3 of the drawings, a first supply line 50 is fluidly connected to the discharge port of the hydraulic pump 40 and an inlet port of the valve unit 30 to provide pressurized fluid to the valve unit 30. A second supply line 52 is fluidly connected to a discharge port of the valve unit 30 and to an inlet port of the hydraulic actuator 60 to provide a pressurized flow of fluid to the hydraulic actuator. The valve unit 30 is preferably comprised of a valve block, however various other valve technologies may be utilized to construct the valve unit 30.

[0031]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.

[0032]The valve unit 30 preferably includes a first valve 34 and a second valve 38 as shown in FIG. 3 of the drawings. The first valve 34 controls the flow of fluid through a first path 30 to the hydraulic actuator 60. The second valve 38 controls the flow of fluid through a second path 36 to the hydraulic actuator 60. The first path 30 has a first flow rate and the second path 36 has a second flow rate which is different than the first flow rate. The first flow rate is greater than the second flow rate to allow for increased vertical velocity during the initial lifting of a drywall panel and then decreased vertical velocity as the drywall panel approaches a desired location.

D. Control Unit

[0033]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).

[0034]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.

[0035]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.

[0036]As shown in FIG. 4 of the drawings, a battery 12 is electrically connected to the valve unit 30, the hydraulic pump 40 and the control unit 42. However, various other power sources may be utilized within the present invention such as but not limited to AC electrical power.

[0037]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.

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