GB2272724A

GB2272724A - Exhaust clamp

Info

Publication number: GB2272724A
Application number: GB9224231A
Authority: GB
Inventors: Ian Hesp; Mark C Willey
Original assignee: TIMAX UK Ltd; Arvin UK Ltd
Current assignee: TIMAX UK Ltd; Arvin UK Ltd
Priority date: 1992-11-19
Filing date: 1992-11-19
Publication date: 1994-05-25
Anticipated expiration: 2012-11-19
Also published as: GB9224231D0; GB2272724B

Abstract

An exhaust clamp has a pair of part cylindrical shells (10, 11) each shell (10, 11) defining a V-section groove on its internal diameter, each shell (10, 11) having a lug (16, 17) extending from each end, the shells (10, 11) being interconnected lug (16) to lug (16) by means of a rivet (20), the rivet (20) being secured at one end to a lug (16) of one of the shells (10) and extending through an oversized aperture (21) in a lug (16) of the other shell (11), the rivet (20) having a head formation (22) at its other end, a clearance (C) being provided between the head formation (22) and the lug (16) on said other shell (11) and a means (26, 27) being provided for releasably tightening the other lugs (17) of the shells (10, 11) together. <IMAGE>

Description

EXHAUST CLAMP The present invention relates to an exhaust clamp by means of which a pair of tubular elements each with a flared end may be secured together.

In conventional exhaust clamps, a pair of semicylindrical shells define a "V"-section groove corresponding to the flared ends of the tubular elements, the semi-circular shells being adapted to be clamped together about the flared ends of the tubular elements, by means of a pair of diametrically opposed tangentially extending bolts. In order to assemble a joint using such a clamp, the two semi-circular shells must first be located about the flared ends of the tubular elements, bolts must then be inserted at the abutting ends of the shells, nuts engaged on the bolts and finally both bolts must be tightened to clamp the tubular elements together.

In accordance with British Patent Specification No BP 2,094,385A, in order to reduce the number of parts of the clamp and simplify its assembly, the bolt on one side of the semi-cylindrical shells was replaced by interengaging formations which hook together, so that the clamp could be secured together about the flanged ends of the tubular elements using a single bolt, located on the opposite side from the interengaging formations.

While this modification reduces the number of parts of the clamp and simplifies its fitting, the semicylindrical shells have to be of complimentary design, requiring separate press tools to produce them.

Furthermore, mating shells have to be selected which may be time consuming if the shells are transported and are stored together. Problems may also arise if odd numbers of each shell are supplied or shells are lost during transit or storage.

The present invention provides an exhaust clamp in which the two shells are based on the same pressing and may be permanently tied together so as to avoid the need to select mating shells.

According to one aspect of the present invention an exhaust clamp comprises a pair of part cylindrical shells, each shell defining a "V"-section groove on its internal diameter, each shell having a lug extending radially from each end, the shells being interconnected lug to lug by means of a rivet, the rivet being secured at one end to a lug of one of the shells and extending through an oversized aperture in a lug of the other shell, the rivet having a head formation at its other end, a clearance being provided between the head formation and the lug on said other shell, and means being provided for releasably tightening the other lugs of the shells together.

With the above exhaust clamp, the riveted connection permits the shells to be a pivoted apart in a plane normal to the axis of the tubular elements to permit the shells to be located about the tubular elements and locates the lugs at one end of the shells with respect to one another at one end while the lugs at the other end are tightened together to secure the clamp about the tubular elements.

It will be appreciated that the clearance between the head of the rivet and the lug of the shell located thereon, must be sufficient to permit adequate pivoting of the shells so that they may be located about the flared ends of the tubular elements, while allowing the clamp to be tightened sufficiently to clamp the tubular elements together. Typically, the rivet should allow the shells to be opened up by 250 to 300.

The means for releasably tightening the other lugs of the shells together may comprise a bolt which extends through apertures in the other lugs.

An embodiment of the invention is now described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a side elevation of an exhaust clamp in accordance with the present invention; Figure 2 is a section along the line II-II of Figure 1; Figure 3 is a partial plan view of the clamp illustrated in Figure 1; Figure 4 is a part sectional side elevation of the exhaust clamp illustrated in Figure 1, with the shells pivoted apart; and Figure 5 is a part sectional side elevation showing a modification to the exhaust clamp illustrated in Figure 1.

As illustrated in Figures 1 to 3, an exhaust clamp comprises a pair of part cylindrical shells 10 and 11, each defining a "V" -Section groove which corresponds to the flared ends 13 of a pair of tubular elements 14 and 15. The shells 10 and 11 each have radially extending lugs 16 and 17 one at each end. The longitudinal edges of the shells 10 and 11 are turned outwardly to provide reinforcing flanges 18.

A rivet 20 is secured by one end to lug 16 of shell 10.

The rivet 20 passes through a radially extending aperture 21 in the corresponding lug 16 of shell 11. A head formation 22 is provided at the other end of rivet 20 to locate the lug 16 of shell 11 thereon, so that there is a clearance C between the lugs 16, when the lug 16 of shell 11 abuts the head formation 22. As illustrated in Figure 4, the clearance C and elongate aperture 21 permit shell 11 to be pivoted with respect to shell 10 in an axial plane of the rivet 20, so that the lugs 17 at the other ends of the shells 10 and 11 may be moved apart.

The angle a by which the shells 10 and 11 may be moved apart may be of the order of 250 to 300. The rivet 20 also permits rotation of one shell 10,11 relative to the other shell 11,10, about the axis of the rivet 20.

Apertures 25 are provided in the other lug 17 of shells 10,11, through which a bolt 26 may be located. A nut 27 engages the bolt 26 on the side of the lug 17 remote from the head 28 of bolt 26.

In order to fit the exhaust clamp described above, with the bolt 26 removed, the shells 10 and 11 may be rotated relative to one another about the axis of the rivet 20, so that one shell may be engaged about the flared ends 13 of tubular elements 14,15. The other shell 11 may then be pivoted away from the shell 10 to clear the tubular elements 14,15 while it is rotated about the axis of the rivet 20 into alignment with shell 10 and engagement of the flared ends 13. The shells 10 and 11 may then be clamped together about the tubular elements 14 and 15, by tightening the lugs 17 together by means of bolt 26 and nut 27, the lug 16 of shell 11 abuting the head formation 22 as illustrated in Figure 1.

The clearance c must be such that it will allow sufficient opening of the shells 10 and 11 to permit them to be located about the tubular elements 14,15 while permitting sufficient tightening of the shells 10 and 11 to clamp the tubular elements. In order to achieve this, the faces of the head formation 22 engaged by lug 16 of shell 11 or the corresponding surface of lug 16 of shell 11 may be contoured so as to increase the opening of the shells 10 and 11 while minimising the clearance C when the clamp is tightened.For example, the inner edge 30 of the head formation 22 which is engaged by lug 16 of shell 11 when the shells 10 and 11 are opened, may be radiussed (as illustrated in broken line in Figure 3) in order to increase the degree of opening, while the outer edge 31 of the head formation 22 which is abutted by the lug 16 of shell 11 when the clamp is fastened, will maintain the clearance C. The clearance C may thus be reduced while permitting the required degree of opening of the shells 10 and 11.

In the above embodiment, the head formation 22 will permanently retain the two shells 10 and 11 together.

This is advantageous for transport and storage purposes.

However, in accordance with an alternative embodiment, the head formation 22 may be of elongate configuration corresponding to the elongate aperture 21 but disposed at 900 thereto when the shells 10 and 11 are aligned. In this manner, the shells 10 and 11 may be separated by rotating shell 11 so that it is at 900 to shell 10 when the head formation 22 will be aligned with aperture 21 and may pass therethrough.

In the above embodiment, the bolt 26 and nut 27 are separate from the shells 10 and 11. In the modification illustrated in Figure 5, a bolt 40 has a head in the form of a pivot pin 41. The lug 17 of shell 10 is bifurcated and the forks 42 are rolled around the pivot pin 41, so that the bolt 40 is hinged to the shell 10. The aperture 43 in lug 17 of shell 11 is opened to the end of lug 17, so that when the shells are located about the flared ends 13 of tubular members 14 and 15, the bolt may be swung into or out of engagement with the aperture 43 in lug 17.

The nut 44 on bolt 40 may then be tightened or loosened to fasten or release the clamp as required. A lip 46 is provided at the end of lug 17 on shell 11 to prevent the nut 44 from slipping off the lug 17.

Claims

1. An exhaust clamp comprising a pair of part cylindrical shells, each shell defining a "V"-section groove on its internal diameter, each shell having a lug extending radially from each end, the shells being interconnected lug to lug by means of a rivet, the rivet being secured at one end to a lug of one of the shells and extending through an oversized aperture in a lug of the other shell, the rivet having a head formation at its other end, a clearance being provided between the head formation and the lug on said other shell, and means being provided for releasably tightening the other lugs of the shells together.

2. An exhaust clamp according to Claim 1 in which the rivet engages through a radially extending elongate aperture in the lug on the other shell.

3. An exhaust clamp according to Claim 1 or 2 in which the clearance between the head formation of the rivet and the lug of said other shell permits the shells to be pivoted apart in a plane normal to the axis of the tubular elements by of the order of 250 to 300.

4. An exhaust clamp according to any one of the preceding claims in which the head formation or abutting surface of the lug on said other shell are contoured to provide the required degree of opening for a minimum clearance.

5. An exhaust clamp according to any one of the preceding claims in which the head formation of the rivet corresponds to the shape of the aperture but is offset angularly therefrom when the shells are aligned, so that the shells may be rotated relative to one another until the head formation is aligned with the aperture permitting detachment of one shell from the other.

6. An exhaust clamp according to any one of the preceding claims in which the means for releasably tightening the other lugs of the shells together comprises an aperture in each of the other lugs and releasable fastening means adapted to be located through said apertures.

7. An exhaust clamp according to Claim 6 in which the releasable fastening means comprises a nut and bolt.

8. An exhaust clamp according to any one of Claims 1 to 5 in which a bolt formation is pivotally attached to one of said other lugs, said bolt formation being movable between a position in which it is clear of the other of said other lugs and a position in which it extends through an aperture in said other of the other lugs.

9. An exhaust clamp comprising a pair of part cylindrical shells, each shell defining a "V"-section groove in its internal diameter, each shell having a lug extending radially from one end, the lugs being adapted to be interconnected lug to lug, a bolt being pivotally attached to the lug on one shell, said bolt being movable from a position in which it is clear of the lug on said other shell, to a position in which it engages in an aperture in the lug on said other shell.

10. An exhaust clamp according to Claim 8 or 9 in which a bolt has a head in the form of a pivot pin, the lug on one shell being bifurcated and the forks of the lug rolled around the pivot pin so that the bolt is hinged to the shell, an aperture being provided in a lug of the other shell, the aperture opening to the end of the lug so that the bolt may be swung from a position in which it is clear from said lug of the other shell to a position in which it is located through the aperture in the lug of said other shell.

11. An exhaust clamp substantially as described herein, with reference to and as shown in Figures 1 to 4 or 5 of the accompanying drawings.