GB2200401A

GB2200401A - Support clamp

Info

Publication number: GB2200401A
Application number: GB08800690A
Authority: GB
Inventors: Christopher Greenaway
Original assignee: GREENAWAY AND SON Ltd M
Current assignee: GREENAWAY AND SON Ltd M
Priority date: 1987-01-24
Filing date: 1988-01-13
Publication date: 1988-08-03
Anticipated expiration: 2008-01-13
Also published as: GB2200401B; GB8800690D0; GB8701563D0

Abstract

A support clamp for elongate members, e.g. steel water supply pipes, has a pair of rigid, semi-circular arms (11, 12) arranged to cooperate to define an annulus for receiving the member to be supported, each arm(11, 12) having an integral boss portion (11c, 12c) at one end, the boss portions defining, in use, a boss having therein a re-entrant recess (15) open at a face of the boss presented away from the annulus. A screw threaded support rod (17) has a head (18) at one end which is received in the recess (15) of the boss, the rod extending substantially radially outwardly with respect to the annulus in use. A clamping sleeve (22) is moveable axially along said support rod and receives the boss therein, the inner surface of the sleeve and the outer surface of the boss cooperating to define a tapering interface whereby axial movement of the sleeve (22) towards the annulus drives the boss portions (11c, 12c) towards one another thus clamping the arms (11, 12) together to define the annulus. <IMAGE>

Description

SUPPORT DEVICE This invention relates to a device for supporting an elongate member, such for example as a steel, water supply pipe, in spaced relationship from a mounting surface,- such for example as a wall or ceiling or a structural member such as a girder or rolled steel joist of a building.

Although for convenience, the invention will be described herein in relation to supporting a water supply pipe it is to be understood that the invention may find use in supporting other elongate members of circular cross-section, for example, other fluid flow conducting pipes and tub'es, electrical conduit, and solid rods.

There exists a widely known supporting device, usually referred to as a pipe clip", which comprises a pair of semi-circular members secured together to define an annulus through which the pipe to be supported extends.

Each semi-circular member has an outwardly extending lug at each of its ends, the lugs of both members being drilled to receive fastening devices whereby the members are secured together to clamp the members around#the pipe. The fastening devices may be in the form of a nut and bolt wherein the bolt shanks each pass through clearance holes in a pair of mutually presented lugs, or, the fastening devices may be machine screws wherein the shanks extend through a clearance hole in one lug of each mutually presented pair and engage in a screw thread in the bore of the other lug of each pair. One of the semi-circular members includes an integral boss adjacent its mid-point whereby the member is secured to a screw threaded metal rod through which in use the clip is secured to the building ceiling, wall, or structural member.

Such known clips have existed for many years, and have proved satisfactory in a wide variety of applications.

Such clips are however not aesthetically pleasing, and in some confined locations the fitting of the fastening devices may prove problematic, and it is an object of the present invention to provide a support device wherein these disadvantages are minimised.

In accordance with the present invention there is provided a support device comprising first and second rigid, semi-circular arms arranged to cooperate to define an annulus for receiving the member to be supported, each arm having at one end an integral boss portion, said boss portions defining, in use, a boss having therein a re-entrant recess open at a face of the boss presented away from said annulus, a screw-threaded support ro having a head at one end received in said recess of the boss, said rod extending substantially radially outwardly with respect to the annulus in use, and, a clamping sleeve movable axially along said support rod and receiving the boss therein, the inner surface of said sleeve and the outer surface of said boss co-operating to define a tapering interface whereby axial movement of the sleeve towards the annulus drives said boss portions towards one another thus clamping the arms together to define said annulus.

Preferably, a nut in screw threaded engagement with the support rod bears against the end of the sleeve to drive the sleeve towards the annulus.

Desirably at their ends remote from the boss portions said arms are pivotally interconnected.

Preferably the inner surface of the sleeve and the outer surface of the boss are frusto-conical.

Conveniently the head at said one end of the screw threaded support rod is defined by a component in screw-threaded engagement with the rod.

Alternatively the head at said one end of the support rod is intergral therewith.

One example of the invention is illustrated in the accompanying drawings wherein Figure 1 is a perspective view of an assembled support device, Figure 2 is an exploded perspective view of the device of Figure 1, Figure 3 is a side elevational view, partly in section of the device of Figure 1, and Figure 4 is a view similar of Figure 2 of a modification.

Referring to the drawings, the support device, which is primarily but not exclusively intended for use as a pipe clip, for supporting a cold water supply pipe in a building sprinkler system, comprises first and second identical cast metal arms 11, 12, each of which is semi-circular and has a part cylindrical inner surface and a circumferential rib (indicated in the drawings by the suffix a) on its outer surface. Conveniently the arms 11, 12 are cast in malleable cast iron and their rigidity is enhanced by the presence of the ribs lla, 12a. Although the arms 11, 12 are intended to be positioned opposite one another to define an annulus, they are identical, and can thus be produced from common moulds thereby minimising production costs.

At one end of each arm, the rib is extended to form a lug (indicated in the drawings by the suffix b) which is offset from the centre line of its respective arm so that when the two arms are positioned to define the annulus their lugs overlap. The overlapping portions of the lugs are formed with respective apertures through which extends a pivot pin 13 whereby the arms 11, 12 are pivotally interconnected for movement about an axis parallel to the axis of the annulus.

Conveniently the pivot pin is a phosphor bronze or mild steel rivet.

At their ends remote from the lugs llb, 12b the arms 11, 12 each define a half portion llc, 12c of a boss.

When the arms are positioned to define an annulus the portions llc, 12define the boss which has a frusto-conical outer surface 14 and an internal re-entrant recess 15. The re-entrant recess 15 is open at the face of the boss which is presented away from the annulus, the end face of the boss in effect having a circular aperture 16 giving access to a void within the boss of larger diameter than the aperture 16.

The support device further includes a screw-threaded mild steel support rod 17 carrying a head member 18 at one end. The head member 18 is cast from the same material as the arms 11, 12 and includes a body 18a of generally rectangular transverse cross-section having an axially extending screw threaded bore in one end face, in which the rod 17 is engaged. Extending axially from the opposite end face of the body 18a is a narrow neck 19 of circular, transverse, cross-section terminating in an integral, enlarged head 21 also of circular, transverse, cross-section. The dimensions of the head 21 correspond with the internal dimensions of the recess 15 of the boss of the arms 11, 12 and the neck 19 is so dimensioned that it can lie within the circular aperture 16.Thus the two arms 11, 12 can be moved to the position in which they define the annulus, with the head 21 and neck 19 being received within the boss as the two parts of the boss come together.

Slidable on the rod 17 is a clamping sleeve 22 also cast in the same material as the arms 11, 12. The clamping sleeve is of frusto-conical form having its wider end open, and presented towards the annulus defined by the arms 11, 12, and its narrower end partially closed by a flange defining a circular aperture 23 through which the rod 17 extends. The taper angle and dimensions of the inner surface of the sleeve 22 are matched to those of the outer surface of the boss defined by the boss portions llc, 12c so that as the sleeve 22 is driven along the rod 17 towards the annulus, cooperation between the inner surface of the sleeve 22 and the outer surface of the boss presses the two halves of the boss towards one another thus pressing the arms 11, 12 towards one another to define the annulus. Desirably, the sleeve 22 is driven along the length of the rod 17 by rotation of a nut 24 on the rod 17, the nut 24 bearing against the end of the sleeve 22, or (as shown in Figure 3) against a washer 25 which in turn abuts the end of the sleeve 22.

It will be noted from the drawings that the open end of the sleeve 22 is formed with a diametrically opposed pair of notches 26 within which the ribs lla, 12a are received in the clamping position of the sleeve 22.

The presence of the notches 26 is desirable, but not essential, and it will be understood that if desired the dimensions of the interior of the sleeve and the exterior of the boss can be so arranged that full clamping takes place before the open end of the sleeve reaches the ribs Ila, 12a in which case the notches are not needed.

Moreover, it is not necessary for the head 21 and neck 19 to fit tightly within the recess 15 and aperture 16 of the boss. Indeed, in order that the two parts of the boss can be pressed firmly against one another it is desirable that the head and neck are a loose fit within the boss, it being recognised that when the sleeve is moved to its clamping position by the nut 24 then the rod 17 and head member 18 are placed in tension, and the head 21 will be pulled tightly against the undercut surface within the boss. Thus, even though there may be play between the head 21 and the recess 15, this play will be taken up in the clamping action and a rigid construction will be produced.

Although the presence of the pivot pin 13 is desirable so that the user of the device can handle the arms 11, 12 as a single unit for assembly around the member to be supported, it is to be understood that the pivot pin 13 is not essential in mechanical terms. Indeed, provided the arms 11, 12 can be conveniently held in position around the member to be supported during tightening of the nut 24 to position the sleeve 22, then the pivot pin 13 can be dispensed since the clamping action of the sleeve 22 on the boss llc, 12c, together with the rigidity of the arms 11, 12, is sufficient to ensure that the member to be supported is adequately clamped between the arms.

It will be understood that the flat surfaces on the body 18a of the head member 18 enable the head member 18 to be screwed tightly onto the rod 17 during assembly. Moreover, it will be recognised that where the sleeve 22 does not have notches 26 then if desired the nut 24 could be dispensed with and the sleeve 22 could itself be in screw-threaded engagement with the rod 17, and flats could be provided on the outer surface of the sleeve 22 to facilitate rotation of the sleeve 22 relative to the rod 17 to produce the axial movement of the sleeve 22 necessary for clamping.

Naturally a range of arms of different dimensions will be produced to suit the range of water supply pipes, or other elongate members with which the support devices are to be used. It is probable that throughout a substantial part of the range of the sizes, if not the whole of the range, the dimensions of the boss portions of the arms can be constant, thus facilitating the use of common rods 17, head members 18, and sleeves 22.

In use the rod 17 will be anchored to a wall or ceiling, or other structural member in the conventional manner adjacent the location of the water pipe or other elongate member to be supported. The sleeve 22 and nut 24 will be engaged with the rod 17 and then the head member 18 will be screwed onto the free end of the rod 17. Thereafter the arms 11, 12 will be positioned around the pipe and will be pivotted towards one another to define the annulus gripping the pipe and to close the boss around the head member 18. Thereafter the nut 24 will be used to move the sleeve 22 axially to engage the boss and to effect clamping.

Since the clip described above is intended, inter alia, for use in supporting the steel pipes of a building water sprinkler system, it is, by design, fire resistant. However, where fire resistance is not needed, for example where the device is to support domestic water supply pipes of copper or plastic construction, then a similar design or support device could be manufactured in plastics material rather than metal. Manufacture of the arms 11, 12 in a plastics material might permit the arms to be moulded as one component with an integral hinge replacing the pivot pin 13. If necessary filled or fibre reinforced plastics materials may be utilized to obtain the required strength and/or rigidity.

Figure 4 illustrates a modification applicable to all of the variants of the clip described above, in that the separate rod 17 and head member 18 are replaced by a rod 17a having an integral head 18a. The rod 17a with integral head 18a may be constituted by a conventional bolt or as shown by a conventional machine screw having a transverse slot, a cruciform slot or an "Allen-Key" recess in the head to facilitate the use of a conventional screw driver or Allen-Key in screwengaging the shank of the screw with the supporting structure.

Claims

CLAIMS.

1. A support device, for supporting an elongate member, comprising first and second rigid, semi-circular arms arranged to cooperate to define an annulus for receiving the member to be supported, each arm having at one end an integral boss portion, said boss portions defining, in use, a boss having therein a re-entrant recess open at a face of the boss presented away from said annulus, a screw-threaded support rod having a head at one end received in said recess of the boss, said rod extending substantially radially outwardly with respect to the annulus in use, and, a clamping sleeve movable axially along said support rod and receiving the boss therein, the inner surface of said sleeve and the outer surface of said boss co-operating to define a tapering interface whereby axial movement of the sleeve towards the annulus drives said boss portions towards one another thus clamping the arms together to define said annulus.

2. A device as claimed in claim 1 including a nut in screw threaded engagement with the support rod which bears against the end of the sleeve to drive the sleeve towards the annulus.

3. A device as claimed in claim 1 or claim 2 wherein said arms are pivotally interconnected at their ends remote from the boss portion.

4. A device as claimed in any one of the preceding claims wherein the inner surface of the sleeve and the outer surface of the boss are frusto-conical.

5. A device as claimed in any one of the preceding claims wherein the head at said one end of the screw threaded support rod is defined by a component in screw-threaded engagement with the rod.

6. A device as claimed in any one of claims 1 to 4 wherein the head at said one end of the screw threaded support rod is integral therewith.

7. A support device substantially as hereinbefore described with reference to Figures 1 to 3 of the accompanying drawings.

8. A support device substantially as hereinbefore described with reference to Figure 4 of the accompanying drawings.