GB2226851A

GB2226851A - A clamp for cross-wise elongate members

Info

Publication number: GB2226851A
Application number: GB9000172A
Authority: GB
Inventors: Christopher Anthony Budd
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-01-05
Filing date: 1990-01-04
Publication date: 1990-07-11
Also published as: GB9000172D0; GB8900181D0

Abstract

With reference to Figure 2, a clamp 10 for securing a pair of tubular members 4 and 5 together, comprises a saddle- shaped structure 11 formed from a metal blank 12 bent over so as to have a middle portion 13 of part-circular form, flanked by a pair of laterally-shaped outer portions 14. The blank is also bent so as to form a pair of inwardly-extending flange portions 15, disposed substantially normal to the outer portions 14. The outer portions 14 are identical and have cutaway portions 20, formed so as to receive the tubular member 5. The cutaway portions 20 each comprise a part-circular part 20a, and a sloping, ramp-like part 20b merging with the part-circular part 20a. A pinch nut and bolt assembly 22 is provided for drawing the lower end of the outer portions 14 together. When the nut of the assembly 22 is tightened, the outer portions 20 are drawn together, causing the clamp to be rotated about contact point C between structure 11 and the member 4. This causes the middle portion 13 to be brought into hard, biting engagement with the member 4, and the member 5 to be forced into hard contact with the member 4. The clamp 5 can also secure a tie 6 to the tubular members 4 and 5. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO CLAMPS This invention relates to clamps and provides a clamp particularly suitable for securing together elongated hoop, purlin, and tie members of tunnels, the tunnels comprising metal frame structures covered with plastics sheet material.

The tunnels have a variety of purposes, for example, the growing of flowers and/or plants and the housing of animals.

The tunnel frame structures each comprise a plurality of hoops of inverted US form held in place by interconnected purl ins extending crosswise from hoop to hoop and tie members extending crosswise within the upper portion of each hoop.

According to the invention, a clamp for securing together at least a pair of elongated members disposed crosswise together comprises a saddle-shaped structure for straddling one of the members, the structure having a middle portion flanked by a pair of laterally-spaced outer portions cut away so as to receive the other of the members, and means for drawing the outer portions together.

When used in the building of tunnels, a third elongate member may be secured in place, held between the drawn together outer portions.

The invention also resides in a frame structure comprising a plurality of elongate members secured together by a plurality of said clamps.

The invention further resides in a tunnel comprising a frame structure as set forth in the preceding paragraph, covered with plastics sheet material.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein: Figure 1 is a fragmentary end view, in section, of a tunnel, Figure 2 is a fragmentary side view which illustrates a clamp according to the invention in use, Figure 3 is a view looking in the direction of arrow III of Figure 2, Figure 4 is an end view of the clamp, seen in the direction of arrow IV of Figure 3, and Figure 5 is a plan view of a blank from which the clamp is formed.

Referring first to Figure 1, a tunnel 1 comprises a metal frame structure 2 covered with plastics sheet material 3.

The frame structure 2 comprises hoop 4, purl in 5 and tie 6 members, all of tubular, elongated form, secured together. The tubular components 4 and 5 are of hollow (circular) cross-section. The tie member 6 is of generally circular cross-section with flattened (oval) ends. The frame structure 2 further comprises tubular pillars 7. End doors 8 provide access to the interior of the tunnel. The bottom ends of the hoops 4 and pillars 7 extend into the ground 9.

The hoops 4 are of inverted U form, held in place by the purl ins 5 which extend crosswise, from hoop 4 to hoop 4, along the length of the tunnel 1, as well as by the tie members 6 which extend crosswise (relative to the purlins 5) within the upper portion of each hoop.

With additional reference now to Figures 2 to 5, the clamp 10 illustrated thereby is used to demountably secure a hoop 4, purlin 5 and tie member 6 together at point X (Figure 1 only). Thus a plurality of clamps 10 is employed.

The clamp 10 comprises a saddle-shaped structure 11 for straddling the hoop 4. The structure 11 is formed from a metal blank 12 (Figure 5) bent over so as to become of "U"-like form (Figure 4), having a middle portion 13 of part-circular form, flanked by a pair of laterally-spaced outer portions 14. The blank 12 is also bent so as to form a pair of inwardly-extending flange portions 15, disposed opposite to each other as well as substantially normal to the outer portions 14. The flange portions 15 have ramp-like sloping parts 15a.

The outer portions 14, which are formed with aligned holes 16, are identical and have cutaway portions 20, formed so as to receive the purl in 5. The cutaway portions 20 each comprise (see Figure 5) a part-circular part 20a, and a sloping, ramp-like part 20b merging with the part-circular part 20a.

Means comprising a pinch nut and bolt assembly 22 are provided for drawing ie pressing the lower ends of the outer portions 14 together.

The tie member 6 is formed with a hole (not shown) for alignment with holes 16 in the clamp structure 11.

The clamp 10 is fitted in the following manner: 1. Conveniently, a structure 11 is slid over a hoop 4 before the hoop is disposed in the operative position shown in Figure 1.

Otherwise, the pinch nut and bolt assembly 22 is removed, and the outer portions 14 of the structure 11 moved apart momentarily so as to allow the structure to straddle the hoop 4. The outer portions 14 are then restored to their original positions.

2. The purl in 5 is then slid under the hoop 4, in a direction substantially normal thereto. However, to enable this to be done, the structure 11 has first to be tilted upwards at an angle to the hoop, about point C. The direction of tilt is opposite to that of arrow A.

Tilting the structure 11 upwardly causes the outer portions 14 to be forced apart, due to sliding contact between the outer surface of the hoop 4 and the ramp-like parts 15a. This action enlarges the distance D (Figure 2) between the hoop 4 and the bottoms of the cutaway portions 20, allowing the purlin 5 to be slid into place.

The tilting action also forms a gap 25 between the upper surface of the hoop 4 and the middle portion 13 of the structure 11.

3. A flattened end of the tie member 6 is disposed between the outer portions 14 of the structure 11 and the bolt of the assembly 22 passed through the holes 16 in the structure 11, as well as the hole in the tie member 6. The nut of the assembly 22 is then fitted on to the bolt end.

4. The nut of the assembly 22 is tightened, pulling the outer portions 14 of the structure 11 towards each other and thus forcing the tapered parts 15a of the flange portions 15 (Figure 4) downwardly over the outer surface of the hoop 4. At the same time, the clamp structure 11 is caused to be rotated, about contact point C between the structure 11 and hoop 4, and in the direction of arrow A,so as to close the gap 25.

5. As the gap 25 closes, rotation of the structure 11 about point C causes the cutaway portions 20 of the clamp structure 11 to push the purl in 5 up hard against the hoop 4, reducing distance D. This results in the middle portion 13 of the structure 11 being brought into hard, biting and positive engagement with the hoop 4 along substantially the full width of the middle portion. Simultaneously, the sloping parts 15a of the flange portions 15 are brought into hard, biting and positive engagement with the hoop 4. This hard, metal to metal, positive engagement prevents the clamp 10 from sliding along the hoop 4. The tie member 6 which is disposed in substantially the same vertical plane as the hoop 4 is, of course, held tightly in place by the assembly 22. The harder the pinch bolt assembly 22 is tightened, the more positive and rigid the lock between the clamp 10, hoop 4, purl in 5 and tie member 6.

Use of the clamp 10 to build the tunnel 1 results in a strong structure well-suited to prevent deformation of the hoops 4 under high snow weight or wind force loads which would tend to cause a clamp to slip along a hoop.

Use of the clamp 10 also provides the frame structure 2 with strong resistance against structural loading caused by high winds and/or weight of snow, as well as a positive anchorage for the tie members 6.

The clamp 10 is easy to manufacture and simple to fit.

The clamp 10 can be used in circumstances where a tie member 6 is not present. That is to say, the clamp 10 can be used to secure only two members (such as components 4 and 5) together.

The tie member 6, when present, need not be disposed at an angle.

It could, for example, be disposed substantially horizontally.

Claims

1. A clamp for securing together at least a pair of elongated members disposed crosswise together comprising a saddle-shaped structure for straddling one or the members, the structure having a middle portion flanked by a pair of laterally-spaced outer portions cut away so as to receive the other of the members, and means for drawing the outer portions together.

2. A clamp as claimed in claim 1 wherein, when the outer portions are drawn ' together, the middle portion of the clamp rotates, about said one member, so that said cutaway outer portions are moved towards said one member.

3. A clamp as claimed in claim 2 provided with a pair of flange portions extending inwardly from the said outer portions, towards each other, the flange portions being formed with sloping parts so that when the middle portion of the clamp is rotated, the flange portions are brought into engagement with said one member.

4. A clamp as claimed in any of claims 1, 2 or 3, formed to secure together a pair of elongated members of circular cross-section.

5. A clamp as claimed in claim 4 where each outer portion comprises a part-circular part and a sloping, ramp-like part merging with the part-circular part.

6. A clamp as claimed in any one of claims 1 to 4 wherein the means for drawing the outer portions together comprises a nut and bolt assembly.

7. A frame structure comprising a plurality of elongate members secured together by a plurality of clamps, each as claimed in any one of claims 1 to 6.

8. A tunnel comprising a frame structure as claimed in claim 7, covered with plastics sheet material.

9. A clamp, substantially as hereinbefore described, with reference to Figures 2,3, 4 and 5 of the accompanying drawings.

10. A tunnel, substantially as hereinbefore described, with reference to Figures 1 to 5 of the accompanying drawings.

11. A frame structure, substantially as hereinbefore described, with reference to Figures 1 to 5 of the accompanying drawings.