WO1995029311A1

WO1995029311A1 - Lift apparatus

Info

Publication number: WO1995029311A1
Application number: PCT/US1995/004845
Authority: WO
Inventors: Thomas J. Luedke; Richard C. Bue
Original assignee: Sico Incorporated
Priority date: 1994-04-22
Filing date: 1995-04-20
Publication date: 1995-11-02
Also published as: AU2359095A

Abstract

A stage (100) includes a lift mechanism (140). The lift mechanism includes a threaded shaft (160) which rotates to lengthen or shorten a vertical lift portion (142), thereby raising or lowering the stage (100). A gearbox (146) connects the vertical lift portion (142) to an actuator shaft (144) extending to an edge of the stage (100). In this position it can be easily actuated with a drill (148) or other tool for running a power lift.

Description

LIFT APPARATUS BACKGROUND OF THE INVENTION

1. Field of the Invention The present invention relates to an apparatus and method for raising and lowering elevationally adjustable stages and in particular to a power lift apparatus for elevationally adjustable stages.

2. Description of the Prior Art Elevationally adjustable stages are used for a variety of purposes to provide a temporary raised platform for use in schools, hotels, convention centers and other institutions where multiple use facilities require the capability of setting up temporary stages . When not in use, the individual stage structures typically fold to compact dimensions for storage. The stages typically have two stage surface members hinged together to provide for folding action and have legs which either fold out of the way or remain vertical while the stage panels fold. In addition, the stages typically have support legs which are telescoping so that the height of the stage may be adjusted for different uses in multipurpose facilities. The legs typically have several notches or holes formed therein so that the height of the stage may be changed between a lowest position and a highest position as well as several intermediate positions.

An example of such a folding stage is shown in U.S. Patent 4,949,649 to Terres et al. Although the stage shown in the '649 patent is very successful in providing efficient useful folding staging, further improvements are still possible, particularly with regard to raising and lowering the stage surface between the different heights. With the Terres stage as well as other stages, it is necessary to manually raise and lower the stage surface between the different heights . This often requires more than one person to adjust and requires raising one leg or one side of the stage at a time. When there are many stages moved together to form an extended stage surface, this process can be tiring for workers as well as time consuming. In addition, if the stages are loaded, it may be impossible to manually raise or lower the stage without first removing the items stored on the stage. This greatly adds to the time and effort required to raise and lower the stages.

It can be appreciated that if the elevationally adjustable stages could be mechanically raised and lowered, the utility of such stages would be greatly increased. In addition, if the raising and lowering of the stages could be done while the stage is loaded, the work involved would be greatly decreased. Furthermore, such an apparatus would have increased utility if it was accessible from an edge of the stage so that it could be actuated without having to move underneath the stage surface.

It can be seen then, that there is a need for a lift apparatus for elevationally adjustable stages which provides for mechanically raising and lowering elevationally adjustable stages. It can be seen that such an apparatus should be able to raise and lower the stage even when the stage is loaded and that such an apparatus should be able to lift and lower the stage by being actuated from an edge of the stage. The present invention addresses these as well as other problems associated with elevationally adjustable stages.

SUMMARY OF THE INVENTION The present invention is directed to a lift apparatus which is used with elevationally adjustable stages. Elevationally adjustable stages are commonly used and typically have telescoping legs or some other mechanism to adjust from one height to another. According to the present invention, the lift apparatus is mounted on the framework below the stage surface and extends downward to a cross member mounted to extendable portions of legs. In this manner, the lift mechanism extends between the portion contacting the floor and the stage portion which can be elevationally adjusted. A gearbox portion mounts to the frame below the stage with a vertical portion extending downward to the lower cross member. An actuator rod portion extends substantially horizontally from the gear box to an edge of the stage where it can be easily accessed. In the embodiment shown, a rotatable threaded member mounts to a gearbox and to a stationary member so that upon rotation of the threaded member, the telescoping vertical portion can be elongated or shortened, thereby raising or lowering the stage. To provide easy use, a shaft extends to an edge of the stage where it can be easily accessed. The shaft is actuated by a power drill or other tools so that the threaded portion can be quickly and easily rotated. The shaft extends to a horizontal extending gear which meshes with a vertically extending gear mounted to the threaded member. Therefore, rotation of the substantially horizontally extending rod portion will rotate the threaded member, thereby actuating the lift mechanism. These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, wherein like reference numerals designate corresponding elements throughout the several views : FIGURE 1 shows a perspective view of a folding stage having a power lift apparatus according to the principles of the present invention;

FIGURE 2 shows a side elevational view of the stage shown in FIGURE 1 with the stage in a lowered position;

FIGURE 3 shows a side elevational view of the stage shown in FIGURE 1 with the stage in a raised position;

FIGURE 4 shows a detail view of the power lift apparatus shown in FIGURE 1 with portions broken away; FIGURE 5 shows a partially exploded view of the lift apparatus shown in FIGURE 4; and,

FIGURE 6 shows a side elevational view of a second embodiment of a stage and power lift apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) Referring now to the drawings and in particular to Figure 1, there is shown an elevationally adjustable folding stage, generally designated 100. The stage 100 includes a framework 102 supporting stage panels 104, 106 which form an elevated stage surface. The height of the stage surface is elevationally adjustable with telescoping legs 108 which include a telescoping portion 110. The height of the stage 100 is determined by pins having releases 114. The pins insert into height adjustment orifices 112 located at different heights in the telescoping portions 110. The pins therefore support the main portion of the legs 108 to maintain the stage 100 at any of the heights corresponding to the adjustment orifices 112.

The frame 102 includes panel supports 116 which can also support bridging panels (not shown) to form an extended stage surface. The folding of the stage 100 is accomplished with cross links 122 in a spacing linkage 124. The stage shown folds from a use position which is shown in Figure 1 to a folded position wherein the panels 104, 106 are substantially vertical and opposed. However, it can be appreciated that the invention can be utilized with other stage embodiments which do not fold or fold in a different manner.

The stage 100 also includes roller assemblies 130 which include rolling casters 132. The casters 132 are connected to a mounting bar 136 which connects to a lower frame cross member 138 with pivoting links 134. The roller assembly 130 is lowered and raised between a rolling position, wherein the legs 108 are lifted from the floor, and a use position, wherein the roller assembly 130 is lifted so the support legs 108 engage the floor. The raising and lowering of the roller assemblies 130 is accomplished with a lift apparatus 128 as shown in U.S. Patent Application Serial No. 08/179,112 filed January 10, 1994, assigned to Sico

Incorporated, the assignee of the present application, and incorporated herein by reference.

To raise and lower the elevation of the stage 100, a lift apparatus 140 is utilized. The lift apparatus 140 includes a vertically extending portion 142 and a horizontal rod portion 144. The lift apparatus 140 mounts to the frame 102 below the stage panels 104, 106. At its lower end, the vertical lift portion 142 mounts to the lower frame cross member 138. It can be appreciated that for the folding stage 100 shown, two elevational power lift mechanisms 140 are utilized for the pair of legs 108 supporting each panel 104, 106. The vertical lift portion 142 attaches to a gear box 146 at its upper end which also connects to the horizontal shaft portion 144. The horizontal shaft portion extends to an outer edge of the stage below the panels 104, 106 and is adapted to be powered by a drill 148 or other actuator tool such as a ratchet or wrench. In the embodiment shown, the shaft 144 is configured to be held by a standard one half inch drill chuck. It can be appreciated that the shaft portions 144 may extend to the same side of the stage 100 or to opposite sides, depending on use and need.

As shown in Figure 4, the gear box 146 includes a vertical thrust bearing 152 mounted above a vertical gear 154. The vertical gear 154 and a horizontal gear 158 mesh to drive the vertical lift apparatus 140. The vertical lift portion 142 includes a screw member 160 having a helical thread mating with a nut 162. With this configuration, rotation of the horizontal shaft 144 rotates the horizontal gear 158 which actuates the vertical gear 154 connected to the screw member 160 in the vertical lift portion 142. Rotation of the screw member 160 mating with the nut 162 mounted in a sleeve 164 raises and lowers screw member 160 and the lift mechanism 140 as the horizontal rod 144 is rotated. The nut 162 is supported in a housing 172 to prevent the nut 162 from rotating in the sleeve 164 as the threaded screw member 160 is rotated.

The gear box 146 includes collars 176 and 178 which support the shafts 144 and 160 extending therefrom. The gear box 146 also includes an outer support wall 174 for providing additional support to the horizontal shaft member 144. The gear box 146 mounts to the frame 102 with a mounting bracket 170. In addition, the lower end of the vertical lift portion 142 mounts to a lower frame member 138 with a lower mounting bracket 168, as shown in Figure 6. It is appreciated that the sleeve 164 for the vertical lift portion 142 includes an outer sliding sleeve member 166 which telescopes with the sleeve 164 to cover the threaded member 160 as the stage is raised and lowered. The outer sleeve member 166 rests on the cross member 138 as the vertical lift portion 142 is extended and retracted. A front portion of the outer sleeve 166 is cut away at the bottom, as shown in Figure 6, so the rear and sides are covered. The sleeve member 166 is free floating and may be raised for accessing the screw member 160 and nut 162 for lubrication or other maintenance.

As shown in Figure 5, a second embodiment of the stage 200 is shown including a lift apparatus 202. It can be appreciated that the second embodiment of the stage 200 has a lower height than the embodiment shown in Figure 1. However, the stage 200 is still elevationally adjustable between a lowered position and a raised position. With the lower elevation, the extension still requires vertical distance in the lift mechanism 202. However, the stage has less vertical distance in which to place a lift mechanism. Therefore a gear box 206 is mounted above a frame cross member 212. A vertical portion 204 extends upward to the gear box mounted above the frame member 212. A horizontal member 208 still extends to a position below the stage panels. However, the horizontal member must extend slightly downward from the gear box 206 to the actuation position. To accomplish this, a universal joint 210 is inserted between the gear box 206 and the actuation point. This allows for actuating the shaft member 208 from an easily accessible edge of the stage 200 and still raising and lowering through the gear box 206 with a right angle drive.

In operation, to raise the stage 100 from a lowered position as shown in Figure 2 to a raised position as shown in Figure 3, the pin releases 114 must be actuated so that the telescoping portions 110 of the legs 108 can be free to move. The drill 148 or other tool is attached to the shaft member 144 at the edge of the stage 100. The drill 148 is then turned on, rotating the horizontal shaft 144. This in turn rotates the horizontal gear 158 which meshes with the vertical gear 154 to rotate the screw member 160. The screw member 160 rotates relative to the nut 162 and the sleeve 164 to raise the stage 100. When the desired height has been achieved, the pin release members 114 are released so that pins insert into the orifices 112 of the telescoping portions 110 of the legs 108 to secure the stage 100 at the desired height.

To lower the stage from a raised position as shown in Figure 3, to a lowered position shown in Figure 2, the same procedure is followed as for raising the stage. However, the drill 148 is rotated in the opposite direction to rotate the screw member 160 in an opposite direction to lower the vertical lift portion 142.

It can be appreciated with the present invention that physical labor is greatly reduced as the stage can be raised and lowered by simply actuating a tool from an easily accessible location at an edge of the stage. This labor and timesaving are especially important when a number of stages must be adjusted. In addition, it can be appreciated that with the present invention, a mechanical advantage is gained which provides for raising and lowering the stage even when loaded. This can account for great labor savings as it is not necessary to unload the stage before raising and lowering and then reload. In addition, this can account for great savings in time as well as the additional labor which is not required. Although the present embodiment shows a folding stage, it can be appreciated that other elevationally adjustable stages, including non-folding stages, may utilize the lift mechanism as well .

It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

Claims

WHAT IS CLAIMED IS:

1. An apparatus for raising and lowering an elevationally adjustable stage having a frame and a stage surface, comprising: a screw device for raising and lowering the stage surface, including a rotatable threaded member and a nut mating with the threaded member; actuation means located remote from the screw device; a gearbox connecting the actuation means to the screw device.

2. An apparatus according to claim 1, wherein the actuation means comprises a rotatable shaft extending substantially horizontally to an actuation location remote from the gearbox.

3. An apparatus according to claim 2, wherein the shaft includes a universal joint.

4. An apparatus according to claim 2, wherein a telescoping cover extends over the nut and threaded member.

5. An apparatus according to claim 2, wherein the gearbox includes a horizontally extending bevel gear mounted to the actuation means and a vertically extending bevel gear mounted to the screw device and located above the horizontally extending bevel gear.

6. An apparatus according to claim 2, wherein the gearbox includes a housing having support walls to support the rotatable shaft and wherein the gearbox includes a thrust bearing above the threaded member for supporting an upper end of the threaded member.

7. An elevationally adjustable stage, comprising: a support frame; panels forming a stage surface; one or more pairs of support legs; wherein each support leg includes a first portion and an telescoping portion adjustable relative to the first portion; lift means comprising a rotatable threaded screw mating with a nut for raising and lowering the stage surface; lift actuation means for actuating the lift means at a location remote from the lift means; and, a gearbox connecting the lift actuation means to the lift means.

8. A stage according to claim 7, wherein the actuation means extends from the lift means to an edge of the stage surface.

9. A stage according to claim 7, wherein the pair of support legs includes a first cross member extending between the first leg portions and wherein the frame includes a second cross member extending between the telescoping portions.

10. A stage according to claim 9, wherein the lift means mounts between the first and second cross members.

11. A stage according to claim 7, wherein the gearbox includes a housing with double support walls to support a horizontally extending member.

12. A stage according to claim 8, wherein a telescoping cover extends over the screw.

13. An apparatus according to claim 2, further comprising means for attaching a drill to an extended end of the rotatable shaft.

14. An apparatus according to claim 2, wherein the gearbox comprises : a vertical bevel gear enclosed in the gearbox and extending substantially downward coupled to the threaded member; a horizontal bevel gear enclosed in the gearbox below the vertical bevel gear and extending substantially horizontally coupled to the rotatable shaft, wherein the vertical bevel gear meshes with the horizontal bevel gear and a thrust bearing positioned above the vertical bevel gear for supporting the vertical bevel gear.

15. An apparatus according to claim 14, further comprising: a first support collar mounting to the gearbox and supporting the rotatable shaft; and, a second support collar mounting to the gearbox and supporting the threaded member.

16. A stage according to claim 7, wherein the actuation means comprises a rotatable shaft extending to a location proximate an edge of the stage surface.

17. An apparatus according to claim 4, wherein the telescoping cover comprises substantially rectangular telescoping sleeve members sliding vertically relative to one another.

18. An apparatus according to claim 12, further comprising: a vertical support collar mounting to the gearbox and supporting the rotatable shaft; a horizontal collar mounting to the gearbox and supporting the threaded member; and, a thrust bearing mounting in the gearbox above the vertical gear for supporting the vertical gear.

19. A stage according to claim 12, wherein the cover includes a housing within an inner sleeve, wherein the housing retains the nut and prevents the nut from freely spinning.

20. A stage according to claim 12, wherein the cover includes an upper inner sleeve and a lower outer sleeve, and wherein the outer sleeve rests on the support frame and is free floating, thereby providing for extending and retracting relative to an inner sleeve.