IE43774B1 - Clamp for fixing an elongate object - Google Patents

Abstract

The present invention relates to a clamp or fixing device, made of a semi-rigid plastics material having an elastic memory, for tubes, cables and the like. The object of the present invention is a clamp which is adaptable to tubes, etc. within a range of sizes.

Description

The present invention relates to a clamp or fixing device, made of a semi-rigid plastics material having an elastic memory, for tubes, cables and the like.

The object of the present invention is a clamp which is adaptable to tubes, etc. within a range of sizes.

The present invention provides a clamp for fixing an elongate object to a surface against which the elongate object is layed, the clamp comprising a member of semirigid plastics material having an elastic memory cast in the form of a support column having a base end, or free end longitudinally opposite to the base end, a longitudinal bore for receiving a fastening element and a resilient hook projecting laterally from the column at or near its free end and then curving round towards the base end with the concave side of the hook facing a bearing surface of the column, wherein the hook is shaped to so resiliently embrace elongate objects in a range of diameters and hold them against the bearing surface of the column that the clamp can be clipped onto the object, and wherein the base is so inclined to the bearing surface of the column, that when the clamp is used for fixing, to a laying surface, an object having a diameter near to the small end of the range of diameters embraoeable by the clamp, the bearing surface of the column is substantially normal to the laying surface but the column only touches the laying surface along that edge of its base which is nearest to - 3 the bearing surface, and that when the clamp is used for fixing, to a laying surface, an object having a diameter near to the large end of the range of diameters embraceable by the clamp, the bearing surface of the column leans back away from the object with the base of the column flush with the laying surface.

The said clamp can have, moreover, at least one of the following characteristics: The column has, internally, two blind frusto-conioal recesses whose axes are substantially parallel to the bearing flank of the said column and having a crosssection which widens out towards its base, the said frusto-conical recesses being disposed one on each side of the bore provided for passing a fastening element, imparting to this latter a clamping elasticity during the passage of the said fastening element.

The base intended to come in contact with the laying plane forms an angle to at least 5°, with the said plane, when clamping an object of the minimum diameter which the clamp can hold.

The hook has an inside diameter a little smaller than the smallest diameter which the clamp can resiliently embrace and an outside diameter which does not have the same centre as the inside diameter; The thickest cross-section of the hook is extended by a shank whose other end is connected to the column at an acute angle; The outside surface of the shank forms, with the laying plane, an angle at least egual to 10° when the clamp is used in conjunction with the smallest diameter object it can hold.

An embodiemnt of the present invention is described by way of example with reference to the accompanying drawing, in which: £l & '{7 & - 4 Figure 1 is a perspective view of a clamp with a fastening connected therethrough; Figure 2 is a cross-section through a vertical plane in Figure 1 ; Figure 3 is a side view showing schematically the fixing of a tube having the minimum diameter which the clamp can clamp; Figure 4 is a similar view to that in figure 3, with a tube having a large diameter; and Figure 5 is a similar view showing schematically the fixing of a tube whose diameter is the maximum diameter which the clamp can clamp. in figure 1, a clamp 1 embodying the invention is formed of a single casting of plastics material. A slightly tapered support column 3 has a base 7 at one end and supports a hook 2 which projects laterally from near the top of the column 3 before curving down and round to form a partially enclosed region adjacent a bearing surface 6 of the column 3. A fastening element 5 passes ) through a longitudinal bore 4 Of the column 3 and projects through the base 7 for fastening in a support surface 15 (figures 3, 4, and 5) on which the clamp 1 is to be mounted. The fastening element 5 shown is a nail with a milled head that is received in a countersunk portion at : the top of the bore 4. For ease of casting the column has two blind frusto-conical recesses 8 and 9 opening in the base 7 and disposed one on each side of the bore 4.

The axis of the bore 4, i.e. the driving direction of the nail 5, is referenced. 11.

The clamp 1 is described as though standing on a horizontal support surface 15 such as a floor. It will be appreciated that it can equally well be fixed to a wall or to a ceiling or to a surface at any other angle. - 5 However, for ease of visualisation and consistency with the drawings, this description continues to use the support surface 15 as a reference plane 10 and defines its orientation as horizontal. The clamp 1 stands on this reference horizontal plane.

The hook 2 is in the form of a tapering strip of plastics material. It has a shank 14 which is solid at its root with the top of the column 3 and projects laterally therefrom at a slightly descending angle β (i.e. the shank 14 is at an angleof slightly less than 90° to the bearing surface 6) . The tapering strip of plastics material then curves round to form the hook shaped part of the hook 2 having an outside surface 13 which is not quite coaxial with its inside surface 12 because of the taper. As can be seen in figures 3 to 5, the clamp 1 is suitable for clamping tubes of various different diameters and in all cases the clamped tube is held by contact with the inner surface 12 of the hook 2, the bearing surface 6 of the column 3 and the support surface 15 itself.

The base 7 is not perpendicular to the bearing surface 6 but is inclined at a small angle a from the perpendicular to the bearing surface 6 so that when the base 7 is pressed firmly against the support surface 15 then the bearing surface 6 is at an obtuse angle to the support surface 15 and has the appearance of leaning back away from an object to be clamped. The base 7 and the bearing surface 6 meet at an edge 17.

The particular shape of the clamp in accordance with the invention and its adaptability to several different diameters will be better understood with reference to figures 3 to 5.

In figure 3, the clamp is used for fixing against a wall 15 a cylindrical tube 16 whose diameter corresponds to the smallest diameter for which the clamp 1 is intended. i377 - 6 The clamp 1 is snapped onto the tube before laying and holds onto it elastically. If the tube 16 were of smaller diameter the clamp 1 could not apply elastic pressure to it, and would be loose and free to slide along the tube. On laying, the contact on the support surface 15 is effected along a tangent of the tube 16 and against the edge 17 of the base 7 of the column 3. In this position corresponding to the smallest clampable diameter, the base 7 forms an acute angle a'with the support surface . When the fastening element is driven into the support surface 15, in this case, it remains vertical, i.e. substantially perpendicular to the support surface 15.

For larger tube diameters, the angle between the base 7 and the surface 15 will progressively decrease and, the driving direction 11 will become correspondingly inclined. Thus, to accommodate various diameters, there ia a combination of the elasticity of the hook 2 with the variable inclination of the base 7 to the support surface .

In figure 4, the clamp 1 is used to fix a cylindrical tube 18 whose diameter corresponds to the minimum diameter which can be fitted with face to face contact between the base 7 and the support surface 15. That is with contact Which is no longer partial along the ridge j 17, but which extends over the whole surface of the base; the driving direction 11, then being substantially at the angle a to the support 15.

In figure 5, the clamp according to the invention can be used to fix a cylindrical tube 19 whose diameter i exceeds a little the diameter of the tube 18. The inclination of the base 7 is not increased further and the shank 14 deforms to accammodate the extra diameter. The clamp thus still holds the tube 19 elastically. In practice, it is not desirable to thus deform the shank 14 too much and it is preferable to choose a larger clamp. - 7 The clamp 1 thus caters for a range of sizes 16 to 18 with possible slight extension of the range at the large end to the size of the tube 19 or thereabouts: The angle a should preferably be at least equal to 5°, measured in the case of the smallest diameter to be clamped, i.e. the range of inclinations possible should be at least 5°.

The angle β of connection between the outside surface of the shank 14 and the column 3 gives an extra reserve of deformation and enables the range of the clamp to be widened. It is advantageous to provide an angle β at least equal to 10°.

It is advantageous to provide the blind frustoconical recesses 8 and 9, having an axis substantially parallel to the bearing surface 6 of the column 3 and having a cross-section which widens towards the base 7.

These recesses 8 and 9 reduce the total amount of plastics material used in the casting, but their principal function is to ensure there are no unduly thick portions of the casting which could shrink on cooling. Mechanically a slightly shrunken column 3 would be sound enough but it would look ill-formed and therefore be unsuitable for use where it could be seen.

An advantage is that a set of clamps can be clipped onto a cable or pipe in their approximate final positions, the cable or pipe then layed in the desired position and the clamps adjusted and their nails hammered home. The advantage in their holding onto the cable or pipe is that only one hand is needed for adjusting the final position of the clamp and then hammering while the other hand can hold the pipe in place.

Claims (7)

1. A clamp for fixing an elongate object to a surface against which the elongate object is layed, the clamp comprising a member of semi-rigid plastics material having an elastic memory cast in the form of a support column having a base end, a free end longitudinally opposite to the base end, a longitudinal bore for receiving a fastening element and a resilient hook projecting laterally from the column at or near its free end and then curving round towards the base end with the concave side of the hook facing a bearing surface of the column, wherein the hook is shaped to so resiliently embrace elongate objects in a range of diameters and hold them against the bearing surface of the column that the clamp can be clipped onto the object, and wherein the base is so inclined to the bearing surface of the column, that when the clamp is used for fixing, to a laying surface, an object having a diameter near to the small end of the range of diameters embraceable by the clamp, the bearing surface of the column is substantially normal to the laying surface but the column only touches the laying surface along that edge of its base which is nearest to the bearing surface, and that when the clamp is used for fixing, to a laying surface, an object having a diameter near to the large end of the range of diameters embraceable by the clamp, the bearing surface of the column leans back away from the object with the base of the column flush with the laying surface.

2. A clamp according to claim 1 including two blind frusto-conical recesses disposed in the column substantially parallel to and one on each side of the bore, the recesses having their wider ends opening in the base.

3. A clamp according to claim 1 or 2 wherein the base is inclined at an angle of at least 5° from the plane 4. Ί , 9 “ of the laying surface when the clamp is used in conjunction with an object having the minimum diameter resiliently embraceable by the clamp.

4. A clamp according to any preceding claim 5. Wherein the hook tapers from a root where it joins the column to a tip at the end of its curved part.

5. A clamp according to any previous claim wherein the angle between the bearing surface of the column and the shank of the hook is less than 90°. 10

6. A clamp according to claim 5, wherein the said angle is not more than 80°.

7. A clamp substantially as herein described with reference to and as illustrated in the figures of the accompanying drawing.