US3488898A

US3488898A - Power-actuated telescoping platform assembly

Info

Publication number: US3488898A
Application number: US735870A
Authority: US
Inventors: Robert T Scaggs
Original assignee: American Seating Co
Current assignee: American Seating Co
Priority date: 1968-06-10
Filing date: 1968-06-10
Publication date: 1970-01-13
Anticipated expiration: 1987-01-13

Description

Jam. 13, 1970 R. T. SCAGGS POWER-ACTUATED TELESCOPING PLATFORM ASSEMBLY 2 Sheets-Sheet 1 Filed June 10, 1968 5 alias Jaw/ yway/112719, cZllZ'onp. 7011810,

ATTORNEYS Jan. 13, 1970 R. T. SCAYGG S 3,488,898

POWER-ACTUATED TELESCOPING PLATFORM ASSEMBLY Filed June 10, 1968 2 Sheets-Sheet 2 INVENTOR m Robert T. Scoggs web .6

W ATTORNEYS United States Patent 3,488,898 POWER-ACTUATED TELESCOPING PLATFORM ASSEMBLY Robert T. Scaggs, Urbana, Ill., assignor to American Seating Company, Grand Rapids, Mich., a corporation of Delaware Filed June 10, 1968, Ser. No. 735,870 Int. Cl. E04h 3/12 U.S. Cl. 52-10 9 Claims ABSTRACT OF TI-m DISCLOSURE Mobile platforms in a telescoping platform assembly are mounted for movement outwardly to an open position and inwardly to a closed position. A cable having one end secured to the outermost platform in the open position extends about pulleys mounted on the end of the other platforms and has its other end secured to a winch shaft or cylinder. A second cable having one end secured to the outermost platform in the open position extends about pulleys mounted on the rearmost platform and has its other end secured to the same winch shaft or cylinder in such a way that while one cable is being wound onto the winch shaft the other cable is being unwound from the winch shaft. Power means rotate the shaft to draw and play out the cable portions for moving the platforms inwardly and outwardly.

BACKGROUND AND SUMMARY Large platforms employed in telescoping relation to form bleachers present the problem of opening and closing the unwieldy structures and the problem of providing power for such closing and opening operations.

I have discovered that a winch provided with a cylinder or shaft may be employed to receive and play out cables the ends of which are secured to a forward part of the outermost platform when in the open position. By employing pulleys about which the cables are threaded, and preferably in connection with rails in the form of channels for supporting the cables, I find that power can be applied effectively and simultaneously to the end cable portions so that the heavy platform sections can be moved readily to inner and outer positions. By employing four cables, which can be conveniently operated by a cylinder of a winch, the power can be applied to the side portions of the platform sections simultaneously for the smooth and even operation of the sections.

DRAWINGS In the accompanying drawings, FIG. 1 is a side view of the plafiorm structure embodying my invention, the structure being shown in closed position; FIG. 2, a perspective view of the platforms in open or use position; FIG. 3, a broken perspective view of the winch and motor structure showing the cables attached to the shaft or cylinder of the winch; FIG. 4, a horizontal sectional view, the section being taken as indicated at line 44 of FIG. 5; FIG. 5, a broken side view in elevation of the platform sections opened to show the cables, pulley and winch; FIG. 6, a horizontal sectional view of the base portion with the sections opened to show the cable threading and pulley locations, the section being taken as indicated at line 6-6 of FIG. 5; and FIG. 7, a view similar to FIG. 3, showing a modified and preferred winch structure provided with four cables.

DETAILED DESCRIPTION As shown in the drawings, the platform assembly 10 consists of three sections, namely, a front section A, a

3,488,898 Patented Jan. 13, 1970 central section B, and a rear section C. It will be understood that the platform assembly may consist of any desired number of platform sections.

Each platform section has on each side thereof base channels 11, three casters 12, a post or mast 13, a supporting beam 14, and upon the section is mounted a platform 15. It will be understood that in addition to the foregoing, there may be employed cross members, brace members, guide members, and locking members, but in order to simplify the structure for the purpose of this invention, these parts are not included in the drawings.

The power-actuated mechanism consists of a base 16 at the rear of the structure 10 on which is mounted a winch 17 and a motor 18. As shown in FIG. 7, four

cables

19a, 19b, 20a and 20b each has one end attached to the cylinder of winch 17, and each cable has its forward ends connected by an automatic tension shock control 21 to the cross member or rail 22 of the outermost section A. The cable endings are attached to the front cross member 22 at 23 and to the side channels of platform A at 24. The winch base 16 is suspended from a cross member 25 on section C by means of two diagonal plates 26.

Pulleys are provided on each of the platforms for receiving the

cables

19 and 20. Pulleys 27 are mounted on a cross piece of the frame, as shown in FIG. 6, and recei-

ve cables

19 and 20 as shown in FIGS. 3 and 5, and

cables

19a, 19b and 20a and 20b as shown in FIG. 7. The channels 11 of platform C are provided with

pulleys

28 and 29, and the channel 11 of platform section B is provided at its ends with pulleys 30 and 31, and the outermost platform section A is provided at its rear with pulley 32, all as shown in FIG. 6.

In the specific illustration given, the cable on each side of the section C extends along the outer side of the channel and thence around pulley 29 and between the channels of sections B and C and around pulley 30. In the channel 11 of platform B, the cable extends diagonally within the channel in a sheltered position and then extends about the pulley 31 between the channels of sections A and B and thence over the pulley 32. With this structure, the pulley portions extending between the channels travel in the same direction as the channels in both the closing and opening operations.

In the operation of the structure, when it is desired to move the platform from the expanded position shown in FIG. 6 to the closed position shown in FIG. 4, the winch is operated in one direction so as to draw the cables attached to the cross piece 22 inwardly, while at the same time the winch plays out cable about the

pulleys

30, 31 and 32. In the opening operation, the winch cylinder is operated in the opposite direction so as to play forwardly the cable leading to the cross piece 22 while drawing inwardly the other cables extending around the pulleys and thus thrusting forwardly the mobile telescoping platform portions. Thus, as the winch turns to open the platforms, each cable is pulled so that there is less cable between the

pulleys

29 and 30 and between pulleys 31 and 32, while the amount of cable between the ending 23 and pulley 27 increases accordingly. In the closing operation, the reverse is true and there is relatively little cable extending between the ending at 23 and the pulley 27.

The cable ends may be secured to the forward section A by automatic tension shock controls or by any suitable means. In these connections, there are two disks, the forward disk being connected to the cross piece 22 and the rear disk connected to the cable end, and between the two disks extends a compression spring. Since such structure is well known, a detailed description herein is believed unnecessary.

In the modification shown in FIG. 3, there are two :

ables

19 and 20, each of the cables having an intermediate portion wound around the winch shaft. One portion of the cable 19 extends around the pulleys and is connected to the forward platform While the other end of cable 19 extends directly to the outermost platform. Similarly, the :able 20 has two portions, one extending directly to the outermost platform and the other extending about pulleys and with its outer end secured also to the outermost platform.

A preferred arrangement is shown in FIG. 7, in which there are four cables, each having its inner end secured to the winch shaft and each having its outer end secured to the outermost platform. As shown in FIG. 7, cable 19a extends from the winch shaft about the pulleys and is secured at its forward end to the outermost platform. Cable 19b, which has its inner end also secured to the Winch shaft extends directly to the outermost platform. Similarly, cable 20a extends about the pulleys of the several platforms and has its forward end connected to the outermost platform while cable 20b extends directly to the outermost platform.

From the foregoing, it will be apparent that any number of cables may be employed as long as one cable portion extends directly to the outermost platform for drawing the platforms inwardly while another cable portion extends about pulleys and thence to the outer platform so that upon being drawn, the latter cable portion will move the platforms outwardly to open position. Means for operating the cables so that one portion is being played out while another portion is being drawn inwardly, and vice versa, may be provided in various forms.

While in the foregoing specification, I have set out a specific structure in considerable detail for the purpose of illustrating the invention, it will be understood that such details may be varied widely by those skilled in the art without departing from the spirit of my invention.

I claim:

1. In a telescoping platform assembly, a plurality of telescoping platforms provided with pulleys and mounted for movement outwardly to open position and inwardly to closed position, a cable having one end secured to the outermost platform and its other end attached to a winch shaft, a second cable having one end also secured to said shaft and extending about pulleys on said platforms, said platforms having unobstructed spaces therebetween and pulley portions, extending into said spaces between said platforms, and power means for rotating said shaft to move said platforms outwardly and inwardly.

2. The structure of claim 1 in which four cables are employed and the ends of each cable is attached to said outermost platform near the sides thereof.

3. The structure of claim 1 in which each platform is provided with a base rail and said pulleys are mounted on said rail.

4. The structure of claim 3 in which said rails are channels and said pulleys are mounted in said channels at each end thereof.

5. The structure of claim 4 in which at least one channel is provided with pulleys at the ends of the channel and said cable extends diagonally between said pulleys and is housed within the channel.

6. The structure of claim 1 in which one end of each cable isattached to the outermost platform by springtensioned connections.

cable means carried by said winch shaft having cable portions secured to the outermost platform with one portion extending directly between said platform and said winch and the other portion extending about said pulleys, said platforms having unobstructed spaces therebetween and pulley portions extending into said spaces between said platforms.

8. The structure of claim 7 in which said cable means comprises a cable having an intermediate portion wound about said winchshaft.

9. The structure of claim 7 in which said cable means comprises four cables each of which is secured to said winch shaft at one end and to the outermost platform at the other end, two of the cables extending about said pulleys and two of the cables extending directly from said platform to said winch shaft.

References Cited UNITED STATES PATENTS 3,031,027 4/ 1962 Mitchell 182-223 3,107,398 10/1963 Murphy 5210 3,400,502 9/1968 Scaggs et a1. 529 3,429,081 2/ 1969 Robinson 529 REINALDO P. MACHADO, Primary Examiner U.S. 'Cl. X.R. I82-223, 132