GB1575295A - Below ground clamp unit - Google Patents

Description

(54) BELOW GROUND CLAMP UNIT (718) We, STAINES METAL PRO DUCTS (GROUP) Limited, a British Company, of Ferry Lane, Hythe End, Wraysbury, Staines, Middlesex TW19 6HH, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:: In the complete specification of our copending patent application No. 51011/75 Serial No. 1526769 there is described and claimed on installation for anchoring a member to the ground, comprising a support structure including a tube having an upper end portion which is slotted to render the mouth of the tube resilienty contractible, and clamping the tube mouth about the member inserted into the tube, a major part of the tube, including the lower end thereof, being embedded in set material to such a depth that the clamping means is located above the surface of said set material.

The present invention relates to improvements in and modifications to such an installation which is referred to herein for convenience as an 'installation as defined".

With an installation as defined it may be possible for water, e.g. rain water to run down the member inserted into the tube and collect in the tube. The presence of water within the support structure is undesirable since it will accelerate corrosion both of the structure and the member supported by it.

The invention aims at eliminating the above drawback and according to one aspect. provides an installation as defined further comprising a sealing element having a portion to fit tightly around the member being supported and another portion for enclosing the upper end. including the clamping means, of the support structure.

The sealing element serves to preclude water from entering the tube and has the additional advantage that it can prevent surface materials, such as tarmacadam, from coming into direct contact with the supported member, for example a steel upright of a climbing frame or a steel leg of a playground item support frame. It is well known that a mixture of water, oxygen and an electrolyte causes rapid corrosion of steel and it is apparently true that acids are dissolved out of tarmac by soft rainwater.

Therefore the sealing element may form an effective barrier preventing the corrosive mixture from contacting the supported column or leg or the upper end of the support structure.

The sealing element is preferably made of nitrile rubber which is resistant to deterioration by ultraviolet radiation and contact with tarmacadam.

When an installation as defined is used for supporting a climbing frame or other unit having a single column support, the clamping force exerted by the clamping means may not be great enough to prevent rotation of the column in the support structure.

To overcome the above disadvantage it is proposed in accordance with a second aspect of the invention to provide an installation as defined including a member inserted in the support structure and keying means keying the member to the support structure against rotation relative thereto.

The keying means may be a radial projection fixed to the member and received in a slot in the tube.

The projection, preferably a bead or a lug welded to the column, keys the column to the tube against rotation. The tube is preferably provided with a plurality of slots spaced apart around its mouth, the projection being selectively engagable in any of the slots for varying the angular position of the column and climbing frame supported on it.

By way of example, an installation embodying the invention will now be de scribed in greater details with reference to the accompanying drawings, in which: Figure 1 is a side view of a single column climbing frame supported by the installation; Figure 2 is an exploded view of the installation shown in Figure 1: and Figures 3 and 4 are horizontal and vertical cross-sections through the sealing gaiter.

Except for the differences and modifications specifically described below the illustrated support structure is constructed exactly as described in the complete specification of application No. 51011/75 Serial No.

1526769.

The steel tube C welded to the square steel base plate A has three axially directed slots 1 extending downwardly from its upper end, each slot terminating in a hole 2 to prevent the tube splitting further. The slots are uniformly spaced apart arpund the tube at 120 from each other. The column 10 of the climbing frame has a radial projection in the form of a vertical weld bead 11 applied to it.

When the climbing frame is being erected the lower end of the column is inserted into the tube C so that the bead 11 enters a selected one of the slots 1 to fix the angular position of the climbing frame. The nut and bolt are then tightened to draw together the flanges 3 of the clamping ring B to clamp the column firmly in the mouth of the tube C.

The clamping action of the ring B secures the climbing frame against vertical displacement and the keying action of the bead 11 in one of the slots 1 prevents rotation of the frame. It will of course be appreciated that the support structure is embedded in concrete 7 to a depth just below the clamping ring B as a preliminary step before erecting the frame.

The provision of three slots in the tube allows some choice as to the angular position of the climbing frame. More or less slots could be provided in the tube C as required, but if there is only one slot the projection on the column must be positioned near the bottom of the slot so that it does not interfere with the clamping action at the tube mouth.

The installation includes a sealing gaiter 12 which as a sleeve portion 13 is arranged to fit closely around the column 10 and a base portion 14 shaped to fit closely over the clamping ring B at the upper end of the tube C. The sleeve portion has several internal, annular lips 15, which bear and seal against the column to prevent water running down the column into the support structure. The exterior shape of the sleeve portion is frusto conical so it serves to direct the water away from the column. The base portion includes a circular part below the sleeve portion 13 for enclosing the sealing ring and another laterally protruding part arranged to receive the flanges 3 as well as the nut and bolt. The result is a skirt shaped to follow the periphery of the clamping device, as seen in Figure 4.When the clamping ring B has been tightened the gaiter 12 which is located on the column before it is inserted into the tube, is pushed down into position as shown in Figures 1 and 3. The gaiter 12 serves to prevent water running into the support structure and also prevents the surface material M of the playground in which the climbing frame is installed coming into contact with the column 10 and the clamping device. As a result corrosion is impeded and a longer useful lifetime of the climbing frame and support structure can be expected.

It will be recognised that the sealing gaiter can readily be pulled up the column 10 to allow the clamping ring to be slackened for routine inspection of the underground length of the column, as required by safety standards.

The gaiter is preferably moulded from nitrile rubber or other material which is resistant to deterioration by ultra-violet radiation and tarmac.

To protect the gaiter itselg against deterioration by contact with the elements, it could be provided with an outer casing, for example in the form of a stainless steel pressing to the inside of which the gaiter could be bonded.

WHAT WE CLAIM IS: 1. An installation as claimed in any one of claims 1 to 8 of co-pending application No. 51011/75 Serial No. 1526769, further comprising a sealing element positionable on the support structure to cover the upper end of the tube and the clamping means and to closely surround the member inserted into the tube.

2. An installation according to claim 1, wherein the sealing element has an upstanding sleeve portion for surrounding said member, and a base portion for enclosing the upper end of the tube and clamping means.

3. An installation according to claim 2, wherein the sleeve portion has a plurality of internal, annular sealing lips for bearing and sealing against the said member.

4. An installation according to claim 2 or 3, wherein the sleeve portion has a frusto-conical outer surface.

5. An installation to claim 2, 3 or 4, wherein the base portion includes a skirt shaped to follow the periphery of the clamping means.

6. An installation according to any one of claims 1 to 5, wherein the sealing element is moulded from nitrile rubber.

7. An installation as claimed in any one of claims 1 to 8 of application No. 51011/75

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (10)

**WARNING** start of CLMS field may overlap end of DESC **. scribed in greater details with reference to the accompanying drawings, in which: Figure 1 is a side view of a single column climbing frame supported by the installation; Figure 2 is an exploded view of the installation shown in Figure 1: and Figures 3 and 4 are horizontal and vertical cross-sections through the sealing gaiter. Except for the differences and modifications specifically described below the illustrated support structure is constructed exactly as described in the complete specification of application No. 51011/75 Serial No. 1526769. The steel tube C welded to the square steel base plate A has three axially directed slots 1 extending downwardly from its upper end, each slot terminating in a hole 2 to prevent the tube splitting further. The slots are uniformly spaced apart arpund the tube at 120 from each other. The column 10 of the climbing frame has a radial projection in the form of a vertical weld bead 11 applied to it. When the climbing frame is being erected the lower end of the column is inserted into the tube C so that the bead 11 enters a selected one of the slots 1 to fix the angular position of the climbing frame. The nut and bolt are then tightened to draw together the flanges 3 of the clamping ring B to clamp the column firmly in the mouth of the tube C. The clamping action of the ring B secures the climbing frame against vertical displacement and the keying action of the bead 11 in one of the slots 1 prevents rotation of the frame. It will of course be appreciated that the support structure is embedded in concrete 7 to a depth just below the clamping ring B as a preliminary step before erecting the frame. The provision of three slots in the tube allows some choice as to the angular position of the climbing frame. More or less slots could be provided in the tube C as required, but if there is only one slot the projection on the column must be positioned near the bottom of the slot so that it does not interfere with the clamping action at the tube mouth. The installation includes a sealing gaiter 12 which as a sleeve portion 13 is arranged to fit closely around the column 10 and a base portion 14 shaped to fit closely over the clamping ring B at the upper end of the tube C. The sleeve portion has several internal, annular lips 15, which bear and seal against the column to prevent water running down the column into the support structure. The exterior shape of the sleeve portion is frusto conical so it serves to direct the water away from the column. The base portion includes a circular part below the sleeve portion 13 for enclosing the sealing ring and another laterally protruding part arranged to receive the flanges 3 as well as the nut and bolt. The result is a skirt shaped to follow the periphery of the clamping device, as seen in Figure 4.When the clamping ring B has been tightened the gaiter 12 which is located on the column before it is inserted into the tube, is pushed down into position as shown in Figures 1 and 3. The gaiter 12 serves to prevent water running into the support structure and also prevents the surface material M of the playground in which the climbing frame is installed coming into contact with the column 10 and the clamping device. As a result corrosion is impeded and a longer useful lifetime of the climbing frame and support structure can be expected. It will be recognised that the sealing gaiter can readily be pulled up the column 10 to allow the clamping ring to be slackened for routine inspection of the underground length of the column, as required by safety standards. The gaiter is preferably moulded from nitrile rubber or other material which is resistant to deterioration by ultra-violet radiation and tarmac. To protect the gaiter itselg against deterioration by contact with the elements, it could be provided with an outer casing, for example in the form of a stainless steel pressing to the inside of which the gaiter could be bonded. WHAT WE CLAIM IS:

1. An installation as claimed in any one of claims 1 to 8 of co-pending application No. 51011/75 Serial No. 1526769, further comprising a sealing element positionable on the support structure to cover the upper end of the tube and the clamping means and to closely surround the member inserted into the tube.

2. An installation according to claim 1, wherein the sealing element has an upstanding sleeve portion for surrounding said member, and a base portion for enclosing the upper end of the tube and clamping means.

3. An installation according to claim 2, wherein the sleeve portion has a plurality of internal, annular sealing lips for bearing and sealing against the said member.

4. An installation according to claim 2 or 3, wherein the sleeve portion has a frusto-conical outer surface.

5. An installation to claim 2, 3 or 4, wherein the base portion includes a skirt shaped to follow the periphery of the clamping means.

6. An installation according to any one of claims 1 to 5, wherein the sealing element is moulded from nitrile rubber.

7. An installation as claimed in any one of claims 1 to 8 of application No. 51011/75

Serial No. 1526769 or any one of the preceding claims, including a member inserted in the support structure and keying the member to the socket structure against rotation relative thereto.

8. An installation as claimed in claim 7, wherein the keying means comprises a radial projection on the member, the projection being engaged in a slot in the upper end of the tube.

9. An installation as claimed in claim 8, wherein the tube has a plurality of slots spaced apart around the tube, and the projection is selectively engageable in any of the slots.

10. An installation for anchoring a member to the ground substantially as herein described with reference to the accompanying drawings.