GB1570036A - Joint for pipes and the like - Google Patents

Description

(54) A JOINT FOR PIPES AND THE LIKE (71) I, GÖRAN SUNDHOLM, a Finnish citizen of Postbox 11, 01511 Vanda 51, Finland, do hereby declare the invention for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a joint for pipes and the like, in which one of the pipes at its end is provided with a muff for receiving the end of the other pipe. Onto the muff is screwed a nut which at the same time presses a so-called cutting ring into engagement with the surface of the pipe end received by the muff thereby keeping the joint together.

Sometimes a leakage tends to occur between the cutting ring and the pipe and in order to overcome this problem it has been suggested, e.g. in the German published application No. 2 323 085, to form a groove in the surface of the cutting ring adjacent to the pipe surface and to insert a sealing member in that preformed groove. In many cases this sealing member is made of a resilient material, such as in the case of an ordinary so-called ring. in other cases where very great strength is required from the pipe joint, the sealing member is a ring of solder, which after mounting is melted by heating up the whole joint and thus at the same time prevents leakage and gives a considerable additional strength to the joint.

Both these solutions using a preformed groove in the cutting ring with a sealing member inserted therein present, however, a serious problem relating to the mounting of the joint. In the case where the sealing member is an ordinary 0-ring it protrudes out of the groove and as the pipe end to be inserted generally has a very sharp and often uneven edge, due to the fact that pipes are mostly cut plainly by sawing, the 0-ring is often torn to such an extent that it becomes useless. which renders the mounting operation very time-wasting. The problem with a ring of solder is the same, it tends to protrude out of the preformed groove and makes the mounting difficult.

The object of the present invention is to overcome the above mentioned difficulties.

According to the present invention there is provided a joint for pipes and the like, comprising a muff provided at the end of one of the pipes to be joined, for receiving the end of the other pipe, and having an outer thread, a nut to be screwed on said muff, a cutting ring inserted between the muff and the nut, for cutting into rhe surface of the pipe received by the muff and thereby retaining said pipe in the joint, and a sealing member inserted between the cutting ring and the respective pipe, for preventing leakage between the cutting ring and the pipe, said cutting ring being provided at at least one of its ends with a recess open to the end of the cutting ring for receiving said sealing member, the edge of said recess being arranged to be bent to close the recess around said sealing member when the nut is screwed on said muff.

With an arrangement of the invention it is possible to place the sealing member, e.g. an 0-ring, around the pipe end thereafter to insert the pipe end into the cutting ring whereby the open recess in the end of the latter without difficulty receives the sealing member. If a ring of solder is used as the sealing member the open recess at the end of the cutting ring often makes it possible to alternatively preinsert the ring of solder into the recess in such a way that it does not protrude out of the recess and thus does not provide an obstacle when inserting the pipe end. The nut to be screwed on the muff may be provided with a shoulder inclined to the longitudinal axis of the pipe end which upon tightening the joint closes the recess around the sealing member by pressing down the edge of the recess, preferably to cut into the surface of the pipe, especially when the sealing member is a ring of solder. In the case of an 0-ring of a resilient material an additional advantage is achieved in that the 0-ring is compressed and the whole joint is resiliently pre-stressed. Such a pre-stressed joint can take pressure shocks without causing separation, contrary to conventional joints employing cutting rings.

In a further embodiment the receiving muff itself may be used to press the edge of the recess into the surface of the received pipe end. Such a joint is generally, however, weaker as a joint employing a cutting ring where the forward edge cuts into the received pipe.

The invention shall now be described in more detail with reference to the accompanying drawing.

Figure 1 illustrates the assembling of a joint according to the invention.

Figure 2 shows the joint of Figure 1 assembled.

Figures 3 to 6 show two other embodiments of the invention.

In Figures 1 and 2 reference numeral 1 indicates a muff provided at the end of a pipe. 2 is a nut which is screwed on the muff, 3 is a pipe end to be received by said muff, 4 is a cutting ring having an open recess at its end facing pipe 3, the edge of said open recess is indicated 6 and 5 is an 0-ring. The open recess at the end of the cutting ring 4 makes it possible to first place the 0-ring 5 around the end of pipe 3 after which the cutting ring 4 is pushed over the pipe end whereat the open recess receives the O-ring without tearing it. The pipe 3 with cutting ring 4 and O-ring 5 is then inserted in the receiving muff 1 and the joint is tightened by means of the nut 2. As the nut 2 is tightened the conical part of the receiving muff forces the front edge of the cutting ring 4 into the surface of the pipe 3 and a shoulder of the nut 2, which is inclined to the longitudinal axis of the pipe 3, bends down the edge 6 of the recess around the 0-ring. Figure 2 shows the joint assembled. The 0-ring 5 may be replaced by a ring of solder.

In Figures 3 and i the conical muff of the pipe 8 presses down the edge 11 of the recess at the end of the cutting ring 9 around the sealing member 10 into the surface of the pipe 12 when the nut 7 is tightened on the muff 8.

Figures 5 and 6 show an alternative embodiment where a recess has been formed at both ends of a cutting ring 16.

When the nut 13 is tightened on the muff 14 the inclined shoulder of the nut pressed down the edge 19 around the tightening member 17 into the surface of the pipe 15 and in a similar manner the conical receiving part of the muff 14 presses down the edge 20 around the tightening member 18.

WHAT I CLAIM IS: 1. A joint for pipes and the like, comprising a muff provided at the end of one of the pipes to be joined, for receiving the end of the other pipe, and having an outer thread, a nut to be screwed on said muff, a cutting ring inserted between the muff and the nut, for cutting into the surface of the pipe received by the muff and thereby retaining said pipe in the joint, and a sealing member inserted between the cutting ring and the respective pipe, for preventing leakage between the cutting ring and the pipe, said cutting ring being provided at at least one of its ends with a recess open to the end of the cutting ring for receiving said sealing member, the edge of said recess being arranged to be bent to close the recess around said sealing member when the nut is screwed on said muff.

2. A pipe joint as claimed in claim 1, wherein the nut is provided with a shoulder inclined to the longitudinal axis of the pipe end, said shoulder being arranged to engage the edge of said recess and bend said edge to close the recess upon being screwed on said muff.

3. A pipe joint as claimed in claim 1, wherein the muff has a conical receiving surface which is arranged to engage the edge of said recess and bend said edge to close the recess when the nut is screwed on the muff.

4. A pipe joint as claimed in any preceding claim, wherein said sealing member is a resilient 0-ring.

5. A pipe joint as claimed in any of claims 1 to 3, wherein said sealing member is a ring of solder for giving additional strength to the joint.

6. A joint for pipes and the like substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

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

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. the sealing member by pressing down the edge of the recess, preferably to cut into the surface of the pipe, especially when the sealing member is a ring of solder. In the case of an 0-ring of a resilient material an additional advantage is achieved in that the 0-ring is compressed and the whole joint is resiliently pre-stressed. Such a pre-stressed joint can take pressure shocks without causing separation, contrary to conventional joints employing cutting rings. In a further embodiment the receiving muff itself may be used to press the edge of the recess into the surface of the received pipe end. Such a joint is generally, however, weaker as a joint employing a cutting ring where the forward edge cuts into the received pipe. The invention shall now be described in more detail with reference to the accompanying drawing. Figure 1 illustrates the assembling of a joint according to the invention. Figure 2 shows the joint of Figure 1 assembled. Figures 3 to 6 show two other embodiments of the invention. In Figures 1 and 2 reference numeral 1 indicates a muff provided at the end of a pipe. 2 is a nut which is screwed on the muff, 3 is a pipe end to be received by said muff, 4 is a cutting ring having an open recess at its end facing pipe 3, the edge of said open recess is indicated 6 and 5 is an 0-ring. The open recess at the end of the cutting ring 4 makes it possible to first place the 0-ring 5 around the end of pipe 3 after which the cutting ring 4 is pushed over the pipe end whereat the open recess receives the O-ring without tearing it. The pipe 3 with cutting ring 4 and O-ring 5 is then inserted in the receiving muff 1 and the joint is tightened by means of the nut 2. As the nut 2 is tightened the conical part of the receiving muff forces the front edge of the cutting ring 4 into the surface of the pipe 3 and a shoulder of the nut 2, which is inclined to the longitudinal axis of the pipe 3, bends down the edge 6 of the recess around the 0-ring. Figure 2 shows the joint assembled. The 0-ring 5 may be replaced by a ring of solder. In Figures 3 and i the conical muff of the pipe 8 presses down the edge 11 of the recess at the end of the cutting ring 9 around the sealing member 10 into the surface of the pipe 12 when the nut 7 is tightened on the muff 8. Figures 5 and 6 show an alternative embodiment where a recess has been formed at both ends of a cutting ring 16. When the nut 13 is tightened on the muff 14 the inclined shoulder of the nut pressed down the edge 19 around the tightening member 17 into the surface of the pipe 15 and in a similar manner the conical receiving part of the muff 14 presses down the edge 20 around the tightening member 18. WHAT I CLAIM IS:

1. A joint for pipes and the like, comprising a muff provided at the end of one of the pipes to be joined, for receiving the end of the other pipe, and having an outer thread, a nut to be screwed on said muff, a cutting ring inserted between the muff and the nut, for cutting into the surface of the pipe received by the muff and thereby retaining said pipe in the joint, and a sealing member inserted between the cutting ring and the respective pipe, for preventing leakage between the cutting ring and the pipe, said cutting ring being provided at at least one of its ends with a recess open to the end of the cutting ring for receiving said sealing member, the edge of said recess being arranged to be bent to close the recess around said sealing member when the nut is screwed on said muff.

2. A pipe joint as claimed in claim 1, wherein the nut is provided with a shoulder inclined to the longitudinal axis of the pipe end, said shoulder being arranged to engage the edge of said recess and bend said edge to close the recess upon being screwed on said muff.

3. A pipe joint as claimed in claim 1, wherein the muff has a conical receiving surface which is arranged to engage the edge of said recess and bend said edge to close the recess when the nut is screwed on the muff.

4. A pipe joint as claimed in any preceding claim, wherein said sealing member is a resilient 0-ring.

5. A pipe joint as claimed in any of claims 1 to 3, wherein said sealing member is a ring of solder for giving additional strength to the joint.

6. A joint for pipes and the like substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.