GB2301640A

GB2301640A - Elastomeric sleeve for coupling pipe ends

Info

Publication number: GB2301640A
Application number: GB9610772A
Authority: GB
Inventors: Robert James Pritchatt
Original assignee: Flex Seal Couplings Ltd
Current assignee: Flex Seal Couplings Ltd
Priority date: 1995-06-01
Filing date: 1996-05-23
Publication date: 1996-12-11
Anticipated expiration: 2016-05-23
Also published as: GB2301640B; GB9610772D0

Abstract

The outside of the sleeve (10) is formed with circumferential ribs (11, 12) between which are located band clamps (13, 14) with screw tightening devices (15), and in order to prevent the sleeve (10) from collapsing and becoming separated from the band clamps (13, 14), stakes (16) are driven through the ribs (11, 12) to overlie portions of the band clamps (13, 14).

Description

PIPE COUPLINGS This invention relates to pipe couplings of the type comprising an elastomeric sleeve adapted to receive internally a pair of abutting pipe ends, the outside of the sleeve being formed with a plurality of circumferential ribs between which are located band clamps with screw tightening devices, to enable the sleeve to be sealingly secured round inserted pipe ends.

However, until the sleeve receives a pair of pipe ends there is the possibility of the elastomeric sleeve collapsing and becoming separated from the band clamps, so time is lost in having to re-assemble the coupling before it can be used.

The object of the present invention is to provide simple means whereby the elastomeric sleeve is prevented from collapsing.

According to the present invention, a pipe coupling of the type referred to is provided at spaced intervals externally with a plurality of stakes passing through the ribs and overlying portions of the band clamps, thereby preventing the elastomeric sleeve collapsing from that location.

Each stake preferably consists of a strip having a point at one end (which may be round in plan and/or may be bevelled to provide a cutting edge) and an abutment at the other end for engagement by a plunger in tooling for pushing the point through a rib or ribs. The length of the strip between the point and the abutment is preferably such as to be able to pass through an adjacent end pair of ribs, thus spanning the band clamp between the ribs, and to overlie a portion of the adjacent band clamp. The length may even be such as to pass through all the ribs.

Each stake may be formed from metal strip (e.g., stainless steel) with the abutment bent up from the end remote from the point; the bent-up end is preferably bent again back over the strip, so as to overlie the endmost rib and the bentback end deformed upon completion of insertion of the stake through the ribs (by means of an anvil in the tooling cooperating with the plunger, or by a secondary operation) to nip or entrap the endmost rib locally, thus securing the stake in place, as well as ensuring that no injurious end of the strip remains exposed.

Alternatively, each stake may be formed of metal or rigid plastics with the abutment constituted by part of a clip portion snapping over the endmost rib as insertion of the stake through the ribs reaches completion.

It is generally sufficient to provide stakes as aforesaid at diametrically opposed locations at each end of each coupling, but on larger sizes of pipe couplings of this type it may be prudent to provide three or more stakes as aforesaid spaced equally around each coupling or around each end of each coupling.

An embodiment of the invention and the problem that it overcomes will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a half-scale end elevation of a pipe coupling of the type initially described showing the elastomeric sleeve collapsing and becoming separated from the band clamps; Figure 2 is an elevation of the pipe coupling of Figure 1 as seen from the left hand side; Figure 3 corresponds to Figure 2 but shows a pipe coupling in accordance with the invention; Figure 4 is a full scale fragmentary view in the direction of the arrow IV in Figure 3 showing one of the stakes used to overcome the problem illustrated by Figures 1 and 2; Figure 5 is a fragementary section on the line V-V of Figure 4;; Figure 6 is a side view of a stake as in Figures 4 and 5 but shown in the preferred condition before application to the pipe coupling; Figure 7 is a fragmentary plan view of tooling for applying the stakes to couplings; Figure 8 is a fragmentary vertical section through the tooling taken from the line VIII-VIII in Figure 7.

In Figures 1 and 2, a pipe coupling of the type comprising an elastomeric sleeve 10 adapted to receive internally a pair of abutting pipe ends (not shown) has the outside of the sleeve formed with a plurality of circumferential ribs 11, 12 between which are located band clamps 13, 14 with screw tightening devices 15 to enable the sleeve to be sealingly secured round the inserted pipe ends.

Until the sleeve 10 receives a pair of pipe ends there is the possibility of the elastomeric sleeve collapsing, as illustrated by Figures 1 and 2, and becoming separated from the band clamps 13, 14 so time is lost in having to reassemble the coupling before it can be used.

To prevent the elastomeric sleeve from collapsing, and as illustrated by the embodiment of the invention shown in Figures 3 to 5, a plurality of stakes 16 are provided at spaced intervals externally of the coupling, each stake passing through a pair of ribs 11, 12 and overlying portions of the band clamps 13, 14.

Each stake 16 consists of a strip having a point 17 at one end and an abutment 18 at the other for engagement by a plunger 19 in tooling as shown in Figures 7 and 8 for pushing the point through the ribs 11, 12. It will be evident that the length of the strip between the point 17 and the abutment 18 is such as to be able to pass through an adjacent end pair of ribs 11, 12, thus spanning the band clamp 13 between the ribs and overlying a portion of the adjacent (middle) band clamp 14.

Each stake is formed from stainless steel with the abutment 18 bent up from the end remote from the point 17, and the bent-up end is bent again back over the strip at 20, as shown in Figure 6, so as to overlie the endmost rib 11. The bent-back end 20 is deformed upon completion of insertion of the stake 16 through the ribs 11, 12, by means of an anvil 21 in the tooling co-operating with the plunger, to nip the endmost rib 11 locally, as shown in Figures 4 and 5, thus securing the stake 16 in place, as well as ensuring that no injurious end of the strip remains exposed.

It will be seen from Figure 3 that it is generally sufficient to provide stakes 16 as aforesaid at diametrically opposed locations at each end of each coupling 10, but on larger sizes of pipe couplings of this type it may be prudent to provide three or more stakes as aforesaid spaced equally around each end of each coupling.

In Figures 7 and 8 stakes 16 are fed along a guide 22 to a chamber 23 from whence they are directed, by a pusher 24 connected to the piston (not shown) of a pneumatic cylinder 25, through a throat 26 into a breech 27 aligned with the plunger 19 which is connected to the piston (not shown) of a pneumatic cylinder 28 in the main body 29 of the tooling. A coupling 10 to be "staked" is supported locally on a block 30 adjoining the base 29, and the anvil 21 is mounted on a lever 31 (Figure 8 only) for raising the lowering the anvil, which is provided with grooves 32, 33 to fit over the ribs 11, 12 of the coupling 10 to enable the anvil 21 to clamp the coupling on the support block 30.

A pawl 34 is lightly urged by a spring 35 to project into the breech 27 to overlie each stake 16 to restrain it from lifting as its point 17 is driven by the plunger 19 through the endmost rib 11 of the coupling 10, and the anvil 21 has a groove 36 to guide the stake as its point is driven through the adjacent rib 12. The pawl 34 is swung out of the way by a stake entering the breech 27, and again by the bentback end 20 of a stake being driven out of the breech by the plunger 19.

The groove 32 (in the anvil 21) for fitting over the rib 11 of the coupling 10 is provided with an inclined surface 37 which deflects and deforms the bent-back end 20 of a stake during completion of its insertion through the ribs 11, 12, to nip the endmost rib 11 locally, as described previously with reference to Figures 4 and 5.

Claims

1. A a pipe coupling of the type comprising an elastomeric sleeve adapted to receive internally a pair of abutting pipe ends, the outside of the sleeve being formed with a plurality of circumferential ribs between which are located band clamps with screw tightening devices, to enable the sleeve to be sealingly secured round inserted pipe ends, characterised in that the coupling is provided at spaced intervals externally with a plurality of stakes passing through the ribs and overlying portions of the band clamps, thereby preventing the elastomeric sleeve collapsing from that location.

2. A pipe coupling as in Claim 1, characterised in that each stake consists of a strip having a point at one end and an abutment at the other end for engagement by a plunger in tooling for pushing the point through a rib or ribs.

3. A pipe coupling as in Claim 2, characterised in that the point of each stake is round in plan.

4. A pipe coupling as in Claim 2 or Claim 3, characterised in that the point of each stake is bevelled to provide a cutting edge.

5. A pipe coupling as in any one of Claims 2 to 4, characterised in that the length of the strip between the point and the abutment is such as to be able to pass through an adjacent end pair of ribs, thus spanning the band clamp between the ribs, and to overlie a portion of the adjacent band clamp.

6. A pipe coupling as in any one of Claims 2 to 4, characterised in that the length of the strip between the point and the abutment is such as to pass through all the ribs.

7. A pipe coupling as in any one of Claims 2 to 6, characterised in that each stake is formed from metal strip with the abutment bent up from the end remote from the point.

8. A pipe coupling as in Claim 7, characterised in that the bent-up end is bent again back over the strip, so as to overlie the endmost rib and the bent-back end deformed upon completion of insertion of the stake through the ribs to nip or entrap the endmost rib locally, thus securing the stake in place, as well as ensuring that no injurious end of the strip remains exposed.

9. A pipe coupling as in any one of Claims 2 to 6, characterised in that each stake is formed of metal or rigid plastics with the abutment constituted by part of a clip portion snapping over the endmost rib as insertion of the stake through the ribs reaches completion.

10. A pipe coupling as in any one of the preceding Claims characterized by stakes as aforesaid at diametrically opposed locations at each end of each coupling.

11. A pipe coupling as in any one of Claims 1 to 9, characterized by three or more stakes as aforesaid spaced equally around each coupling or around each end of each coupling.

12. A pipe coupling substantially as hereinbefore described with reference to Figures 3 to 5 of the accompanying drawings.