GB2259530A

GB2259530A - Pivotal frame structure for buildings, e.g. tents

Info

Publication number: GB2259530A
Application number: GB9217817A
Authority: GB
Inventors: Rowland D Hunt
Original assignee: CLAMSHELL BUILDING Inc
Current assignee: CLAMSHELL BUILDING Inc
Priority date: 1991-09-09
Filing date: 1992-08-21
Publication date: 1993-03-17
Also published as: GB9217817D0; CA2076153A1

Abstract

Portal frames 10-14 with inclined side and roof members are pivotally mounted at ground level, at spaced intervals such that fabric panels 15-18, attached to the frames when lying flat on the ground, can be erected by pivotting the frames up around their pivot points 25, 26 without problems. <IMAGE>

Description

PIVOTAL FRAME STRUCTURE FOR BUILDINGS BACKGROUND OF THE INVENTION Field of the Invention This invention relates to pivotal frame structures for buildings, and in particular to buildings having spaced frames pivotally mounted on ground anchors and having fabric panels extending between adjacent pairs of frames.

Related Art US patent 4583331 describes buildings having a plurality of spaced parallel frames, pivotally attached to ground anchors, with fabric panels extending between frames. The frames have upwardly and inwardly inclined wall portions. The frames can readily be assembled on the ground, attached at their lower ends to the ground anchors, and can be pulled up into a vertical position. If desired, the frames can be pivoted over and down to the ground on the other side. The ends of the buildings are closed by various arrangements, as by vertical panels, inclined panels, or further frames extending at angles between the vertical and horizontal. Parallel frames require the fabric to be pulled in only after the frames are erected.

It is of considerable advantage to be able to assemble frames, with the fabric in position, on the ground, pivotally attached to ground anchors and moved to the erected position by pulling up of the frames.

SUMMARY OF THE INVENTION In accordance with the present invention, a building having opposed ends each comprised of a series of frames can be assembled at one end of a central position, with the frames assembled on the ground and pivotally attached to ground anchors. Fabric panels can be inserted and the frames pivoted up, with some frames pivoting over past the central portion.

This is obtained by providing particular dimension relationships to the frames when viewed in side view.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be readily understood by the following description in conjunction with the accompanying drawings, in which: Figure 1 is a plan view of one form of building, in erected condition; Figure 2 is a side elevation of the building of Figure 1; Figure 3 is a plan view of the frames of a building, as illustrated in Figures 1 and 2, assembled on the ground before erection; As illustrated in Figures 1 and 2, a building consists of five frames 10, 11, 12, 13 and 14. Fabric panels 15, 16, 17 and 18 extend between the frames. Further panels 1 9 and 20 extend from the lower or outer frames 12 and 14 and, in the example, are held down at their lower edges on to the ground surface. Other numbers of frames can be used, for example, 3, 4, 6 and 7. There may be no central, substantially vertical, frame.

In figures 1 and 2, the frames are shown in full, with the fabric panels in place. The frames may be of the same size, or have different wall heights. The frames are pivotally attached at their ends to ground anchors at 25 and 26. As seen in Figure 1, the ground anchors at 25 are in alignment, along a line parallel to the center axis of the building, spaced apart in a direction parallel to the axis of the building. If the frames are of the same size then the ground anchors at 26 are positioned outwardly of the ground anchors at 25.

In Figure 3 the frames are shown in an assembled condition and prior to putting the fabric panels in position. In this example, frames 10, 11 and 1 3 have each side wall composed of two straight sections 30 and the roof portions are each of four straight sections 31. Walls are joined to roof portions and the roof portions joined at the apex, by curved sections 32.

Frames 12 and 14 have the walls of two straight sections 30 and one shorter straight section 30a, roof portions of four straight portions 31, and joined by curved sections 32. However, the frames may be composed of a different number of sections, for example, in one extreme, of only three sections. The number of sections will be determined to some extent by frame size, and also by the desired maximum length of sections.

The frames are assembled, with the ground anchors 25 and 26 positioned and securely fastened to the ground. The panels are then installed. One particularly convenient way of installing panels is by forming a beaded or roped edge along each side of the panel and sliding the edges through grooves in the frames. One typical form of cross-section of a frame, with edges of panels in position, as illustrated in Figure 4.

Some distortion of the wall portions of the panels needs to be provided for, during lifting up of the frames. Zippers can be provided to join wall sections together after the frames are in position, or the wall sections can be pulled in after the frames are erected.

As illustrated in Figure 4, a frame has a box-shaped cross section, having two parallel spaced apart flanges 40 with webs 41 extending therebetween. Two circular cross-section grooves 42 are formed in each flange 40, at the center top edges, the grooves having openings 44. Panels 46 have their edges wrapped around ropes 47 and are a sliding fit in the grooves 42, near the openings 44.

The grooves extend along the frames and panels are attached by sliding the roped edge in and along the groove. The first panel 18 is installed by lifting the first frame - 1 4 - and supporting it up from the ground.

This provides access to the groove on the lower side of the frame. The edges of the panel are slid into the lower groove in frame 14 and also in the top groove of frame 1 3. Frame 13 can then be lifted up and panel 1 7 inserted.

This is repeated for frames 10 and 11. Panei 20 is readily inserted with the frame 14 on the ground or lifted up. Frame 12 will be lifted to insert panel 19.

The building or structure is now erected by pulling up on frame 12, as by a rope, the frame lifting up to the vertical and then over and down on the other side. The frames 13, 10, 11 and 12 follow until the positions of the frames are as in Figures 1 and 2.

It has been found that, with the panels in position, pulling up of the frames as described above can only be obtained if certain geometrical relationships occur. Otherwise panels of the correct shape for the erected configuration will not be able to be inserted near the ground as panels become taut at particular positions in a panel as frames are pivoting upward and then over. Considering Figure 5, a side elevation with frames being raised, in the direction of arrow X, panel 1 6 will become taut along a line indicated on a line between points 50a and 50b. As point 50a will move up and round on a longer circumference than point 50b, the distance between the points needs to increase as the frames move up. I However if the material is taut between these points, no increase in distance can occur.Therefore, movement of frame 12 is prevented. The same situation can occur for the other panels.

The desirable geometrical relationship is illustrated in Figure 6, which is a partial side view, to a larger scale for clarity. In Figure 6, the distance between points a and d when the frames are in a "lay flat" position, should be less than the distance between points a and d when in the erected condition, when a is the peak of the upper frame and d is the eave or junction of roof and wall, for the lower frame. For curves, at the junction between wall and roof, even large corners, the position d is the center of the curve.

As illustrated in the drawings, the straight wall portions are joined to the straight roof portions by curved sections. The radius of the corner sections will affect the equation to some extent. The smaller the radius - the sharper the corner - the more the equation is accurate. As the radius increases so the equation can be eased slightly.

Therefore, in accordance with the invention, the distance ad represented by the dotted line on Figure 6 - needs to have a distance substantially as defined above.

Thus the invention can be summarized as follows: It is desired to be able to build a structure "on the flat", that is, fiat on the ground, or substantially so. The structure should include all roof panels such that it can be erected by the pivoting up of the frames with one or more frames going up and over to the erected position from one side only.

The essential features for this are to chose geometry such that the individual frames can be built substantially laid flat on the ground without frames interfering with one another, and avoiding the risk of cutting the fabric of the panels. Also, the roof panels can be pulled into position in frames while the frames are laid flat or lifted to a slight degree for ease oi working. In practice, lifting a frame up by about 3 or 4 feet, at the peak, is sufficient.

To enable the frames to be built flat on the ground, the walls should be slightly inclined from vertical. This inclination increases with increasing depth of the beam forming the frames and decreasing frame base separation. For acceptable wall angles ( < 30 from vertical) and finite beam depths, base separations can become large, making it more difficult for roof panels to be pulled in while the frames are flat, or substantially so.

To enable roof panels to be pulled in while the frames are flat, or substantially so, the base pivots should be arranged so that all roof diagonals (eave to peak distances) when erected are greater than all eave to peak distances when laid flat, as described above. The particular problem generally occurs for those diagonals from the higher frame peak to lower frame eave or those frames which pass over the vertical.

Claims

What is claimed is:

1. A pivotal frame structure comprising a plurality of frames pivotally mounted at spaced ground anchoring means, each frame including an inclined wall portion at each side, an inclined roof portion at each side, said roof portions joined at a peak, and the wall portion and the roof at each side joined an an eave position, said frames including at least an upper frame and a lower frame, the ground anchoring means positioned so that the distance between the peak of said upper frame and the eave of said lower frame in the lay flat position is less than the distance from the peak of the upper frame to the eave of the lower frame in the erected position.

2. A frame structure as claimed in claim 1, said wall portion comprising at least one straight section.

3. A frame structure as claimed in claim 1, said roof portion comprising at least one straight section.

4. A frame structure as claimed in claim 1, said wall portion and said roof portion joined by an arcuate section.

5. A frame structure as claimed in claim 1, said roof portions of each frame joined by an arcuate section.

6. A frame structure as claimed in claim 1, said ground anchoring means spaced apart in a direction parallel to the longitudinal axis of the structure.

7. A frame structure as claimed in claim 1, comprising a central substantially vertical frame and at least one inclined frame at each side of said central frame.

8. A frame structure as claimed in claim 7, comprising said central substantially vertical frame and at least two additional, inclined frames at each side of said central frame.

9. A frame structure as claimed in claim 7, including further panels extending from the lower frame each side of said central frame.

10. A method of erecting a pivotal frame structure comprising a plurality of frames, comprising assembling said frames on a ground surface, towards one side of a central position, pivotally attaching said frames to ground anchoring means spaced apart in a direction parallel to the axis of the structure, each frame including an inclined wall portion at each side and an inclined roof portion each side, the roof portions joined at a peak and the wall and roof portions joined at an eave position, said frames including an upper frame and a lower frame; positioning said ground anchoring means so that the distance between the peak of said upper frame and the eave of said lower frame in the lay flat position is less than the distance from the peak of said upper frame to the eave of said lower frame in the erected position; pulling up said frames from a lay flat position to a fully erected position.

11. The method as claimed in claim 1, including installing fabric panels at least between roof portions of adjacent frames, before pulling up said frames.