GB2146280A

GB2146280A - Pipe clamp

Info

Publication number: GB2146280A
Application number: GB08324085A
Authority: GB
Inventors: David Michael Moss
Original assignee: S S E PIPEFITTINGS Ltd
Current assignee: S S E PIPEFITTINGS Ltd
Priority date: 1983-09-08
Filing date: 1983-09-08
Publication date: 1985-04-17
Also published as: GB8324085D0

Abstract

An apparatus for clamping two members in a predetermined relationship comprises first and second locating means (10a, 10b) respectively provided on first and second body portions (11a, 11b). The body portions (11a, 11b) are interconnected by an integrally cast cross member (M) of generally cylindrical configuration and which serves to maintain said body portions in fixed relationship and the respective members are clamped through over dead centre linkages (20a, 20b). The relationship between the first and second clamping means can be other than in strict side-by-side relationship, and the shape of the co-operating surfaces of the locating means and of the clamping means may be varied as desired, for example, to suit the shape of members to be clamped. The apparatus may be used to clamp together two pipes to enable them to be welded together in end-to-end relationship. <IMAGE>

Description

SPECIFICATION Holding apparatus This invention relates to an apparatus for holding two members in predetermined relationship. The invention is particularly, but not exclusively concerned with holding the ends of two pipes in a predetermined relationship and in particular a coaxial abutting or closely spaced relationship to permit of the ends to be welded together.

An object of the invention is to provide an improved apparatus for holding two members in predetermined relationship and a further object is to provide a new and improved method of making a welded connection between the ends of pipes.

According to one aspect of the invention, we provide an apparatus for holding two members in predetermined relationship comprising a first clamp means adapted releasably to clamp a first member to a first locating means, and a second clamp means adapted releasably to clamp a second member to a second locating means, the first and second locating means being held in fixed relationship.

The clamping means may each comprise a clamp element to engage the member to be clamped thereby and an over-dead centre linkage to hold the clamp element in clamping relationship.

Each clamp element may be pivotally mounted relative to the locating means and the linkage may comprise a first link pivotally connected at one end to the clamping element, and pivotally connected at the other end to one end of a second link, the second link being pivotally connected at its other end to a part fixed relative to the associated locating means.

The first link may be provided with a handengageable portion, for example, as an extension beyond said other end, to permit of movement of the pivotal connection between the links through a deadcentre position in which said positions of pivotal connection of the first link to the clamping element, of the second link to the part fixed relative to the locating means and of the pivotal connection between the links are co-planar.

The position of pivotal connection of the second link to the part fixed relative to the clamping means may be adjustable towards and away from the position of pivotal connection of the clamping element to the locating means to permit of adjustment of the size of gap between the locating means and clamping element when said parts are in clamping relationship.

The first and second clamp means may be held in said fixed relationship so that the respective gaps between the clamping means and locating means are disposed in side-byside spaced relationship, preferably the axes of pivotal connection of the first and second clamp elements to the first and second locating means respectively are coaxial.

According to another aspect of the present invention, we provide a method of making a welded connection between adjacent ends of coaxially disposed pipes comprising the steps of clamping the pipes with an end of each pipe in adjacent coaxial relationship, using an apparatus according to the first aspect of the invention and then performing a welding operation to weld together said ends.

An example of the invention will now be described, with reference to the accompanying drawings wherein: Figure 1 is a side elevation of a clamping apparatus embodying the invention; and Figure 2 is a section on the line 2-2 of Fig.

1.

Referring to the figures, a clamping apparatus comprises first and second locating means 1 Oa, 1 orb respectively provided on first and second body portions 11 a, 11 b. The body portions 11 a, 11 b are interconnected by an integrally cast cross member M which is of generally cylindrical configuration and which serves to maintain the body portions 11 a, 11 b in a fixed relationship. Each clamping means 1 ova has a clamping recess 12a, 12b formed therein of truncated triangular configuration providing opposed sides 13a, 13b which are inclined inwardly and downwardly and an intermediate base part 14a, 14b.

Pivotally mounted on each body portion 11 a, 11 b by a pivot pin 15a, 1 Sb is a clamping element 16a, 16b, having a clamping recess 17 a, 17 b of part-cylindrical configuration.

The body portions ii a, 11 b are each provided with a slotted portion 18 a, 18 b to accommodate the part of the clamping element 16a, 16b receiving the pivot pin 15a, 15b.

A first link 19a, 1 9b of an over-dead centre linkage 20a, 20b is pivotally connected at one end to the clamping element 16a, 16b by means of a pivot pin 21 a, 21b and at its other end to one end of a second link 22a, 22b by a pivot pin 23a, 23b. The first link 19a, 19b has a manually engageable extension part 24a, 24b beyond said other end (having the pivot pin 23a, 23b).

The second link 22a, 22b at its other end, extends through a slot 25a, 25b formed in the body portion 11 a, 11 b. The slot 25a, 25b communicates with a cylindrical bore 26a, 26b formed in the body portion and the slot 25a, 25b has an enlarged width portion 27a.

The second link 22a, 22b at the end passing through the slot 25a, 25b has a laterally extending pivot pin 28a, 28b which is passed through the enlarged diameter part 27a, 27b to enter the bore 26a, 26b and thus retains said other end of the link 22a, 22b within the slot 25a, 25b.

A coil compression spring 30a, 30b is provided within the bore 26a, 26b at the end thereof adjacent the pivot pin 15a, 1 5b to engage an abutment surface 31 a, 31 b provided on the link 22a, 22b to bias the link to the right in Fig. 1 towards an abutment surface 32a, 32b provided on an adjustment member 33a, 33b which is in screw-threaded engagement with a threaded portion 34a, 34b of the bore 26a, 26b.

The adjustment member 33a, 33b is provided with a knurled head 35a to facilitate manual rotation of the member 33a, 33b and thus to permit of axial adjustment of the abutment surface 32a and hence of the position of pivotal connection (provided by the pivot pin 28a, 28b) of the other end of the link 22a, 22b to the body portions, towards and away from the pivot pin 15a, 15b thereby permitting of adjustment of the gap between the surfaces 12a, 12 b and 17a, 17 b of the locating means and clamping element respectively.

The manually engageable extension 24a, 24b of the first link 19a, 19b is provided with a cut-away portion 36a, 36b to facilitate manual lifting of the extension 24a, 24b from a clamping position in which the extension 24a, 24b is closely adjacent to the body portion 11 a, 11 b and in which position with pivot pins 21 a, 21 b, 23a, 23b and 28a 28b are nearly co-planar but with the pivot pin 23a, 23b displaced below the plane containing the pivot pins 21a, 21 b, 28a, 28b thereby providing an over-dead centre action to retain the surface 12a, 12b, 17a, 176in clamping relationship with a member engaged therebetween, such as the pipes P1 and P2 illustrated in Fig. 2.

In use, the extensions 24a, 24b are lifted manually to the position shown in Fig. 1 thereby opening the clamping elements 16a, 16b away from the associated locating means 12a, 12boo permit of the pipes P1 and P2 being introduced in the respective gaps.The extensions 24a, 24b are then pivoted, downwardly in Fig. 1, to move the links 19a, 19b, 22a, 22b into the above mentioned overdeadcentre relationship thereby moving the clamping elements 16 a, 1 6b into clamping engagement with the associated pipes P1 and P2 and thus clamping the pipes in a predetermined relationship in which end surfaces S1 and S2 are maintained in coaxial abutting relationship, thereby permitting a welding operation to be performed to weld the ends together.

After the welding operation has been completed, the extensions 24a, 24b are raised to the position shown in Fig. 1 thereby releasing the clamping action on the pipes.

Although in the present example the apparatus described has identical body portions and clamping means which are disposed strictly in side-by-side relationship with the axes of pivots 1 spa, 15b coaxial, if desired, the apparatus could be modified so that the relationship between the first and second clamping means is other than in strict side-byside relationship depending upon the shape of articles to be clamped together and the juxtaposition desired between the articles to be clamped together. Moreover, the shape of the co-operating surfaces of the locating means and of the clamping means may be varied as desired, for example, to suit the shape of members to be clamped.

Claims

1. An apparatus for holding two members in predetermined relationship comprising a first clamp means adapted releasably to clamp a first member to a first locating means, and a second clamp means adapted releasably to clamp a second member to a second locating means, the first and second locating means being held in fixed relationship.

2. An apparatus according to Claim 1 wherein each clamp means comprise of a clamp element to engage the member to be clamped thereby and an over-dead centre linkage to hold the clamp element in clamping relationship.

3. An apparatus according to Claim 2 wherein each clamp element is pivotally mounted relative to the locating means and the linkage comprises a first link pivotally connected at one end to the clamp element, and povitally connected at the other end to one end of a second link, the second link being pivotally connected at its other end to a part fixed relative to the associated locating means.

4. An apparatus according to Claim 3 wherein the first link is provided with a handengageable portion, to permit of movement of the pivotal connection between the links through a dead-centre position in which said positions of pivotal connection of the first link to the clamp element, of the second link to the part fixed relative to the locating means and of the pivotal connection between the links are co-planar.

5. An apparatus according to Claim 4 wherein the hand-engageable portion is an extension beyond said other end.

6. An apparatus according to any one of Claims 3 to 5 wherein the position of pivotal connection of the second link to the part fixed relative to the clamp means is adjustable towards and away from the position of pivotal connection of the clamping element to the locating means to permit of adjustment of the size of gap between the locating means and clamp element when said parts are in clamping relationship.

7. An apparatus according to any one of the preceding claims wherein the first and second clamp means are held in said fixed relationship so that the respective gaps between the clamping means and locating means are disposed in side-by-side spaced relationship.

8. An apparatus according to claim 7 wherein the first and second locating means are held in said fixed relationship by a member extending therebetween.

9. An apparatus according to Claim 8 wherein the member is integral with said locating means.

10. An apparatus according to any one of Claims 7 to 9 wherein the axes of pivotal connection of the first and second clamp elements to the first and second locating means respectively are coaxial.

11. An apparatus substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

12. A method of making a welded connection between adjacent ends of coaxially disposed pipes comprising the steps of clamping the pipes with an end of each pipe in adjacent coaxial relationship, using an apparatus according to any of the preceding claims and then performing a welding operation to weld together said ends.

13. A method of making a welded connection substantially as hereinbefore desdribed with reference to the accompanying drawings.

14. Any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.