GB2257458A

GB2257458A - Securing fixing clamp to support

Info

Publication number: GB2257458A
Application number: GB9114557A
Authority: GB
Inventors: Njal Underhaug
Original assignee: Holta & Haland As
Current assignee: Holta & Haland As
Priority date: 1990-03-19
Filing date: 1991-07-05
Publication date: 1993-01-13
Anticipated expiration: 2011-07-05
Also published as: NO170650C; NO901256L; NO901256D0; GB9114557D0; DE4125072C2; GB2257458B; DE4125072A1; NO170650B

Abstract

A fixing clamp is provided for securing a pipe or cable to a support formed with oblong holes. The clamp includes a jaw portion having a groove to receive the pipe or cable, and a top plate hold in place by two bolts to retain the pipe or cable in the groove. The bolts serve also to secure the clamp to the supports, and for this purpose each has a shank threaded to receive a securing nut and a head extending transversely to the head and connected to the head through a cranked portion. The cranked portion is received in a recess in the jaw portion and the recess provides reaction surfaces engageable by the cranked portion to limit rotation of the bolt about the axis of the shank. The heads of the bolts can be passed through the oblong holes in the support and can then be rotated by rotational movement of the jaw portion to position the heads transversely of the oblong holes. The axis of the groove is preferably at an angle other than 90 DEG to a common normal to the axes of the shanks of the bolts. <IMAGE>

Description

223 7433) m CLAMP FOR.FIXING A PIPE. OR OTHER ELONGATE ELEMENT TO A

PERFORATED SUPPORT This invention relates to a fixing clamp for the attachment of pipes, tubes, cables, conduits and like elongate elements to a perforated bearing member, for example in the form of a cable gate formed with oblong holes distributed over the longitudinal and lateral directions of the bearing member.

By way of example, on board offshore oil installations and within industrial plants, such cable gates in the form of paths and/or ladders may extend over several hundred metres in all. They serve as bearing members for holding and anchoring of pipes in the form of so-called instrument pipes or instrument tubes and cables of various kinds. Such cable gates are standardised to a certain degree and may consist of a flat steel plate or a steel plate bent along opposing longitudinal side edges to form a U-shaped profile chute. Cable gates, of the kind with which fixing clamps of the present invention are conveniently intended to be utilised, are formed with oblong through holes distributed in a suitable pattern in the longitudinal and lateral directions of the cable gate.

In view of the fact that two fixing bolts of the clamp are to be inserted through two adjacent oblong holes during the fixing operation, wherein the pipe or tube or cable is being attached to the cable gate by means of the fixing clamp, the spacing of the oblong holes in the cable gate, in the lateral direction of the cable gate, will substantially correspond to the distance between the axes of the bolts.

The jaw of such a fixing clamp may be formed with two or more parallel grooves, each adapted for the accommodation of e.g. an instrument pipe, said grooves then being distributed over the width of the fixing clamp, corresponding to the lateral direction of the cable gate, with the grooves extending in the longitudinal direction of the cable gate. Some known 2 clamps include two or more 'floors' wherein one or more instrument pipes, cables, etc. are accommodated at each 'floor' and, thus, are situated outwardly of each other in a direction of the clamp perpendicular to the 5 general plane of the cable gate.

A conventional fixing clamp of the kind in question comprises two identical plastic jaws formed with co-operating groove halves having a semi-circular cross-section as well as being provided with unthreaded bores for the bolts, the tightening nuts thereof being assigned a common underlying steel plate kept assembled with the jaws by means of the bolts. These conventional fixing clamps are very difficult to handle properly during the assembly operations. Thus, the two bolts together with the loose nuts must be held in one hand whilst the other jaw is being threaded onto the bolts, whereafter the instrument pipe or pipes are placed into the groove(s) of this jaw. Thereafter, the other jaw is placed upon the first-mentioned jaw, guided by the bolts, so that the pipe or pipes respectively are fitted within the groove half or halves thereof, whereafter said steel plate is brought into position. Thereafter, the nuts are placed on the bolts and finally tightened, and during this nuttightening operation the bolts must be prevented from rotating. The undesired rotation of the bolts is usually counteracted by keeping the bolt heads fixed by means of a suitable tool. Such an assembly operation requires the use of both hands of a very skilled assembler.

When mounting especially long and thin instrument pipes from a ladder or a scaffold in this manner, it appears to be obvious that such assembly operations not only are complicated to perform but also are very laborious and time-consuming, and thus very expensive.

3 - At larger installations wherein the cable gates may extend over several thousand metres, the mounting of pipes, tubes, cables and conduits will require tens of thousands of fixing clamps and it is, therefore, of great importance that the clamps not only are constructively simple and cheap but, additionally, as simple to mount as possible. Known fixing clamps allowing simple mounting comprise ordinarily a plurality of single parts, while fixing clamps consisting of fewer parts are often complex to mount.

A preferred embodiment of the clamp according to the invention is shown, by way of example, in the accompanying drawings, wherein:

Figure 1 is a perspective view, seen obliquely toward the general plane of a U-shaped cable gate subsequent to the fixing clamp's attachment.

Figure 2 illustrates in perspective side elevation view a fixing clamp placed upside down (in relation to the position according to Figure 1), the nuts on the threaded end portions of the bolts being omitted for clarity.

Figure 3 is a sectional view illustrating the fixing clamp during the insertion of the bolts into two adjacent oblong holes.

Figure 4 illustrates the same subsequent to a minor rotation of the clamp about the axial central line thereof, the bolt shafts thereby being rotated for the initial changing of the orientation of the bolt heads.

Figure 5 illustrates the same after a larger rotation of the clamps, bolt heads thereby being oriented in such a way that the withdrawal of the bolt shafts out of the oblong holes no longer can be effected (an intermediate hole is hidden behind the fixing clamp).

Figure 6 is identical to Figure 1 with regard to the positions of all parts except for the top plate, which here takes an open swungup position allowing the insertion of an instrument pipe without having to remove either the top plate or the nuts.

Referring now to the drawings, the fixing clamp comprises a bracket or jaw 1 of suitable material, e.g. flame-proof plastic. The jaw 1 is formed with a groove 2 for a pipe 3, or a tube, cable or like elongate element to be attached to a perforated bearing member, here in the form of a cable gate 4, which is formed with oblong holes 5 distributed over the cable gate in the longitudinal and lateral directions thereof.

For reasons to be further explained presently, the longitudinal direction of the chute shaped groove forms an angle with the width-wise dimension of the fixing clamp jaw 1 that differs from 0 The particular design and orientation of the groove 2 in relation to the pipe 3 to be accommodated will also be discussed presently.

It will be apparent that the jaw 1, instead of one groove 2,-may have two or more mutually parallel grooves. In such a case, one clamp can serve to attach several parallel pipes 3 or cables to the cable gate 4 at one point thereof.

Parallel to and symmetrically arranged about the axial central line 1' of the fixing clamp jaw 1, the jaw body is formed with two smooth bores 6, 6' for the accommodation of threaded bolts 7 and 7' respectively.

Each bolt 7, 7' has a threaded end portion 8, 8' for the screwing-on and tightening of a nut 9, 9', as shown in Figures 1 and 6. opposite its threaded end portion 8, 8', the bolt has a head in the form of an angled or lateral end 35 portion 10, 10' and, see especially Figure 2, an intermediate portion 11, 11' which extends in an open v 1 loop so as to be cranked and to extend eccentrically in relation to the bolt shaft axis over at least a portion of its length.

In the area of each intermediate or transition portion 11, 11' of the bolts 7, 7', the fixing clamp jaw 1 is formed with cavities 12, 12' defined by three surfaces 13, 14, 15 and 13', 14' and a surface hidden behind the jaw 1 in Figure 2, of which a first cavity-defining surface 13, 13' extends substantially parallel to the broad sides of the fixing clamp jaw 1, a second surface 14, 14' forming an angle of approximately 90 0 in relation to said first surface 13, 13', the third surface 15 extending substantially parallel to the narrow side faces of the jaw 1.

The portions of the jaw 1 forming said first surfaces 13, 13' can be omitted as they do not actually participate in the operation of the clamp.

Said second cavity-defining surfaces 14, 14' are intended to form abutment surface.s for at least part of the transition portions 11, 11', more particularly during the nut- tightening operation completing the assembly and mounting of the fixing clamps.

As shown in Figures 1 and 6, the fixing clamp comprises also a top plate 16 which prevents the pipe or pipes 3 from leaving the groove or grooves 2 of the jaw.

The top plate 16, instead of being formed with two holes for the bolts 7, 7', has one hole and a slot 16' which opens to a side edge of the plate. Thus, the hole in the plate 16 may be threaded onto the bolt 8' and form a pivot therewith, so that the top plate 16 can swing in a plane parallel to the narrow side surfaces of the jaw 1.

In this connection, reference is made to Figures 1 and 6. With the top plate 16 in its swung- 1 open position as in Figure 6, the pipe 3 to be mounted may be inserted into the groove 2 of the fixing clamp jaw 1 without having to dismount either the top plate 16 or the nuts 9, 9', all parts 1, 7, 7', 9, 9' 16 constituting the clamp being kept together at all times in an assembled condition, thus facilitating the assembly and mounting work substantially. When the pipe 3 is in place within the groove 2, the top plate 16 may be swung over to the position of Figure 1, whereby the slot 16' is brought into engagement with the threaded portion 8 of the bolt 7, and thereafter the two nuts 9, 9' may be tightened in order to complete the mounting operation.

The groove 2 of the fixing clamp jaw 1 for the accommodation of the pipe 3, cable or the like to be fixed and anchored to the cable gate 4, is formed such that the pipe 3 after insertion into the groove 2 is kept at least temporarily in place through friction against the surface of the groove. The material of the jaw 1 may thereby have certain inherent resilient deformation characteristics or, alternatively, flexible nodes, ribs or the like may be formed on the groovedefining surface of the jaw 1, slightly protruding from said surface and adapted to be brought into friction- retaining engagement with the pipe 3.

As the fixing clamp jaw 1 must be swung somewhat in order to take its mounting position on the cable gate 4, whereafter the width extension thereof will form an angle with the longitudinal as well as the lateral direction of the cable gate 4 differing from 0 as is shown in Figures 1 and 6, said angle is adapted to the angle formed by the groove 2 (or several mutually parallel grooves) in relation to the broad sides of the jaw 1. Conveniently, both these angles 0 may each be of the order of 45 ' so that the lengthwise dimension of the groove 2 after the rotation of the jaw k 1.

t.

i 1, in accordance with Figures 1, 5 and 6, will be in conformity with the longitudinal direction of the cable gate 4, see Figures 1 and 6.

When the fixing clamp jaw 1 is to be attached to the cable gate 4 prior to the actual mounting of the pipe 3 in the groove 2 and the top plate 16 thereafter is tightened by means of the nuts 9, 9', the head portions 10, 10' of the bolts 7, 7' are oriented such that they point towards each other, see Figure 2. With this orientation, the angled head-forming bolt end portions 10, 10' are inserted into two adjacent oblong holes 5 respectively, as shown in Figure 3. Thereafter, the fixing clamp jaw 1 is rotated about the axial centre line 1' thereof, for example in the direction indicated by the arrow 17 in Figure 3, whereby the guiding engagement between the bolts and the hole edges defining the oblong holes 5 causes the bolts 7, 7' to rotate about their axes 18, 18' in one and the same direction of rotation as indicated at 19, 19'.

With this 45 0 rotation of the fixing clamp jaw 1, it is desired to rotate each bolt 7, 7' 0 approximately 90 ' in order to orient the free end portions 10, 10' laterally of the longitudinal direction of the associated oblong hole 5, pointing in opposite directions, away from each other.

The fixing clamp jaw is now in its operative position, see Figures 1, 5 and 6, wherein the groove 2 is oriented such as to conform with the longitudinal direction of the cable gate 4. In this Position, the pipe 3 may be snapped into position within the groove 2 and there be retained through friction or press fit as previously stated. Thereafter, the top plate 16 is swung from its Figure 6 position into its Figure 1 position, whereupon the nuts 9, 9' are tightened. During the nut-tightening operation, the cavity- defining second surfaces 14, 14' act as reaction surfaces for at least some part of the eccentric portions 11, 11', thereby preventing rotation of the bolts 7, 7' during the rotation of the nuts 9, 9' on the threaded bolt portions 8, 8'. Such a fixing and anchoring device is much less dependent on exact width of the oblong holes 5 of the cable gate 4 than some prior art clamps intended for the same general purpose.

-7 n p J

Claims

1. A fixing clamp for the attachment of one or more pipes or like elongate elements to a perforated bearing member formed with oblong holes in the longitudinal and lateral directions thereof, said fixing clamp comprising a member having at least one groove for said elongate element, a top plate serving to retain the element in position within said groove, said jaw and top plate being connected by means of at least two bolts each formed with a threaded end portion for a nut and, at the opposite end, with a fixed bolt head, each bolt head being constituted by a transversely extending free end portion connected to the shank of the bolt by a cranked portion offset from the axis of the shank of the bolt, said member of the clamp having at least one reaction surface to engage the cranked portion to limit rotation of the bolt about the axis of the shank.

2. A fixing clamp as claimed in claim 1, wherein the groove or each groove of a plurality of mutually parallel grooves of the jaw extends in a direction forming an angle differing from 90 0 with a common normal to the axes of the shanks of the bolts.

3. A fixing clamp as claimed in claim 1 or claim 2, wherein the jaw surface defining the groove or each groove is formed with nodes, ribs or like projections capable of being deformed when the elongate element is pressed into the groove in order to retain the element through clamping.

4. A fixing clamp as claimed in any one of the preceding claims, wherein said top plate has a hole to be engaged by the threaded end of the shank of one of the bolts and an edge cavity for engagement by the threaded end of the shank of the other bolt, whereby said one bolt forms a pivot enabling the top plate to be rotated about said one bolt, the edge cavity being arranged to engage and co-operate with the other bolt - 10 when one or more said elements have been inserted into the groove or grooves of the fixing clamp jaw.

5. A fixing clamp substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.