GB1565727A

GB1565727A - Collars for pipes

Info

Publication number: GB1565727A
Application number: GB3311677A
Authority: GB
Original assignee: ZANICHELLI G; RACI SpA
Current assignee: ZANICHELLI G; RACI SpA
Priority date: 1977-07-01
Filing date: 1977-08-08
Publication date: 1980-04-23
Also published as: ES230365Y; FR2396232A1; DE2737136A1; IT1114624B; ES230365U; DE2737136C2; FR2396232B1

Description

(54) COLLARS FOR PIPE (71) We, RACI S.p.A., a Body Corporate organised and existing under the laws of Italy, and GIANNI ZANICHELLI, a citizen of Italy, both of Milano P. za E. Duse, 2, Italy, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to collars for fitting onto a pipe for insertion into a bore of larger diameter. A possible use is to enable one pipe-end to be inserted into another without damaging the lagging on the pipe of smaller diameter as might arise where a gas pipeline has to pass through railway ballast. Another use is to isolate one pipe from another electrically as may be necessary in the case of metal pipes.

The invention provides a collar which comprises a flexible band provided externally with centring ribs normal to the axis of the band, one end of the band being provided with a row of teeth along each edge, and the other end of the band being provided with rows of teeth for receiving the rows of teeth on the first-mentioned end of the band.

Such a collar makes it possible for a pipe which is inserted to another pipe to be made coaxial therewith, so that in the case of gas leakage from the inner pipe the gas is able to flow freely into the space between the two pipes and so to be conveyed to a predetermined point.

A collar according to the invention may be from 1 to 1 Omm thick. The teeth in the rows at each end are preferably offset longitudmally with respect to each other to facilitate the introduction of the first-mentioned or male end into the female end and ensure good clamping. The collar may be of reinforced plastics material. In order to aid insertion, slots parallel to the rows of teeth may be provided in the male end.

To facilitate clamping of the collar about the pipe, the collar may be provided adjacent its ends with protusions by which a clamping action may be exerted. For this purpose, pliers are preferably provided with two arms, the ends of which engage in said protrusions. On closing the pliers, the male end is forced into the female end to clamp the collar.

The male end may be constructed in a single piece or in two pieces. In the first case the clamping protrusion may be disposed towards the extremity of the male end. This position is preferable because once the male end has entered the female end, traction rather than thrust may be exerted on the collar ends thus aiding rapid clamping.

The collar is also provided externally with ribs normal to the band axis, to enable the inner pipe to be centered relative to the outer pipe. The centring ribs may be of different height to vary the space between the tubes. These ribs may be three in number, and disposed at 1200 to each other. This number may evidently vary, such as when a number of collars are to be joined together. The ribs are advantageously inclined at their ends to provide a lead-in for facilitating introduction of the inner pipe.

The collar is also preferably provided on its inner face with longitudinal projections preferably of triangular profile to enable it to adhere better to the pipe to which it is fitted, so preventing it from sliding, especially during the insertion of one pipe into the other.

Instead of using one collar for each pipe diameter, it is possible and convenient to join together several collars according to the invention and fit the collar so obtained onto the pipe.

Thus, using for example only two types of collars, type B of length (development) 295 mm and type A of length 180 mm, these constituting elementary collars, it is possible to cover the entire range of nominal pipe diameters from 3" to 30". This is evident from the following Table. A collar may be formed by n elementary collars of type A and m elementary collars of type B, opportunely combined in function of the pipe diameter, wherein n may vary from 0 to 11 and m may assume the following values: 0, 1, 2, 3, 6 and 7.

TABLE Nominal pipe Number of collars diameter, inches Type A Type B 3 - 1 4 2 5 1 1 6 3 7 - 2 8 4 10 - 3 10 (alternative) 5 12 4 1 14 3 2 16 4 2 18 8 20 9 22 10 24 11 24 (alternative) 1 6 26 10 1 28 1 7 30 10 2 30 (alternative) 2 7 The invention is further illustrated by way of example in the drawings, of which: Figure 1 is a plan view of the outer surface of a collar according to the invention when extended; Figure 2 is a side view of the collar of Figure 1; Figure 3 is an elevation of the female end of the collar of Figure 1; Figure 4 is an elevation of the male end of the collar of Figure 1; Figure 5 is a plan view of the outer surface of a further collar according to the invention when extended; Figure 6 is a section through the collar of Figure 5 along A-A; Figure 7 is an elevation of the female end of the collar of Figure 5; Figure 8 is a side view of the collar of Figure 5; Figure 9 is a plan view of the inner surface of the collar of Figure 5; Figure 10 is a plan view of the teeth of the male end of the collar of Figure 5; and Figure 11 is a side view corresponding to Figure 10 along B-B.

As can be seen in Figures 1 to 4, a collar 20 comprises a flexible band having a male end 1 constructed in two equal parts provided with a row of teeth 4 along each edge. Slots 3 are disposed parallel to the rows of teeth 4 to facilitate introduction of the male end 1 into a female end 2. The end 2 is provided with guide plates 5 below which rows of teeth 11 are disposed, and with a bridge 9 provided with projections 6 for keeping the male end 1 lowered, in cooperation with the plates 5, while it is being inserted into the female end 2. The teeth 11 and the teeth 4, which mutually engage, are of acute angled profile and are oriented in such a manner that the ends 1 and 2 cannot be withdrawn from each other.

At the end 1 there are disposed two tongues 7 which may be easily removed, to allow further clamping of the collar on to the pipe. This is to take account of any variation in the thickness of the lagging on the pipe. The collar is provided with three transverse centring ribs 12, two corrugations 10 which help in wrapping the collar about the pipe, and longitudinal projections 8 which prevent the collar moving along the pipe once it has been positioned and tightened thereon. Clamping of the collar onto the pipe is facilitated by protrusions 13 and the bridge 9, to which force may be applied for example by pliers.

In Figures 5 to 9, a collar 30 has a male end 21 in a single piece and provided with two rows of mutually offset teeth 23 of acute angled profile. The male end 21 is also provided with lightening grooves 24 designed also to provide greater flexibility, and a rib 25 perforated at 31 which besides aiding centring also facilitates application of the collar clamping pliers by means of the holes 31.

The central part of the collar is provided with two resilient raised portions 33 partially hollow internally to give good flexibility to the collar, and centring ribs 26 and 26a, this latter provided with two holes 31 which, in cooperation with those of the rib 25, allow pliers to be applied. The ribs 26, 26a and the lugs 29, these latter also aiding centring are shaped with a lead-in 27 at their ends to allow the collar being mounted on the pipe to overcome any obstacles, e.g. weld seams, and to improve slidability.

The collar also has a female end 22 provided with two toothed guides 28 with internal teeth which recieve the male end 21 and prevent withdrawal, and two outwardly projecting tongues 32 to facilitate insertion of the male end 21 into the female end 22. The teeth of the two ends mutually engage and prevent separation. The guides 28 are lightened laterally at 34, to increase their resilience.

The inner surface of the collar is provided with longitudinal projections 30 of triangular cross-section to increase the grip on the pipe or on any lining thereof, and to prevent collar movement.

The teeth 25 on the male end 21 are specially shaped. The teeth on the female end 22 have a complementary profile but their height is about a half of the teeth 23. The optimal dimensions of the teeth 23, which have a pitch of 4mm, are:a = b; 4mm; c from 4.8 to 6.2mm; d = 2.5mm; e = 45 ; f = 10 ; g = 20 . As can be seen from c values, the end 21 is slightly tapered towards the external edge. This allows an easier insertion of the male end 21 into the female end 22. The teeth are staggered: 17 on one side and 18 on the other.

WHAT WE CLAIM IS: 1. A collar for fitting onto a pipe for insertion into a bore of larger diameter which comprises a flexible band is provided externally with centring ribs normal to the axis of the band, one end of the band being provided with a row of teeth along each edge, and the other end of the band being provided with rows of teeth for receiving the rows of teeth on the first-mentioned end of the band.

2. A collar according to claim 1 in which the teeth in the rows at each end are offset longitudinally with respect to each other.

3. A collar according to any preceding claim of which the ends are provided externally with protrusions for facilitating the clamping of the collar around pipe-ends.

4. A collar according to any preceding claim of which the first-mentioned end is provided with slots parallel to the rows of teeth.

5. A collar according to any preceding claim in which the first-mentioned end is provided with removable tongues.

6. A collar according to any preceding claim of which the centring ribs are provided inclined ends to provide lead-in.

7. A collar according to any of claims 1 to 3 or 6 which is provided on its inner surface with longitudinal projections to facilitate adherence to the pipes.

8. A collar according to any of claims 1 to 3, 6 or 7 of which the second-mentioned end is lightened to increase flexibility.

9. A collar as herein described with reference to Figures 1 to 4 of the drawings.

10. A collar as herein described with reference to Figures 5 to 11 of the drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. As can be seen in Figures 1 to 4, a collar 20 comprises a flexible band having a male end 1 constructed in two equal parts provided with a row of teeth 4 along each edge. Slots 3 are disposed parallel to the rows of teeth 4 to facilitate introduction of the male end 1 into a female end 2. The end 2 is provided with guide plates 5 below which rows of teeth 11 are disposed, and with a bridge 9 provided with projections 6 for keeping the male end 1 lowered, in cooperation with the plates 5, while it is being inserted into the female end 2. The teeth 11 and the teeth 4, which mutually engage, are of acute angled profile and are oriented in such a manner that the ends 1 and 2 cannot be withdrawn from each other. At the end 1 there are disposed two tongues 7 which may be easily removed, to allow further clamping of the collar on to the pipe. This is to take account of any variation in the thickness of the lagging on the pipe. The collar is provided with three transverse centring ribs 12, two corrugations 10 which help in wrapping the collar about the pipe, and longitudinal projections 8 which prevent the collar moving along the pipe once it has been positioned and tightened thereon. Clamping of the collar onto the pipe is facilitated by protrusions 13 and the bridge 9, to which force may be applied for example by pliers. In Figures 5 to 9, a collar 30 has a male end 21 in a single piece and provided with two rows of mutually offset teeth 23 of acute angled profile. The male end 21 is also provided with lightening grooves 24 designed also to provide greater flexibility, and a rib 25 perforated at 31 which besides aiding centring also facilitates application of the collar clamping pliers by means of the holes 31. The central part of the collar is provided with two resilient raised portions 33 partially hollow internally to give good flexibility to the collar, and centring ribs 26 and 26a, this latter provided with two holes 31 which, in cooperation with those of the rib 25, allow pliers to be applied. The ribs 26, 26a and the lugs 29, these latter also aiding centring are shaped with a lead-in 27 at their ends to allow the collar being mounted on the pipe to overcome any obstacles, e.g. weld seams, and to improve slidability. The collar also has a female end 22 provided with two toothed guides 28 with internal teeth which recieve the male end 21 and prevent withdrawal, and two outwardly projecting tongues 32 to facilitate insertion of the male end 21 into the female end 22. The teeth of the two ends mutually engage and prevent separation. The guides 28 are lightened laterally at 34, to increase their resilience. The inner surface of the collar is provided with longitudinal projections 30 of triangular cross-section to increase the grip on the pipe or on any lining thereof, and to prevent collar movement. The teeth 25 on the male end 21 are specially shaped. The teeth on the female end 22 have a complementary profile but their height is about a half of the teeth 23. The optimal dimensions of the teeth 23, which have a pitch of 4mm, are:a = b; 4mm; c from 4.8 to 6.2mm; d = 2.5mm; e = 45 ; f = 10 ; g = 20 . As can be seen from c values, the end 21 is slightly tapered towards the external edge. This allows an easier insertion of the male end 21 into the female end 22. The teeth are staggered: 17 on one side and 18 on the other. WHAT WE CLAIM IS:

1. A collar for fitting onto a pipe for insertion into a bore of larger diameter which comprises a flexible band is provided externally with centring ribs normal to the axis of the band, one end of the band being provided with a row of teeth along each edge, and the other end of the band being provided with rows of teeth for receiving the rows of teeth on the first-mentioned end of the band.