GB2165016A

GB2165016A - Pipe coupling accommodating expansion/contraction

Info

Publication number: GB2165016A
Application number: GB08523605A
Authority: GB
Inventors: Kunio Fukasawa; Toshiro Shimizutani
Original assignee: Victaulic Company of Japan Ltd
Current assignee: Victaulic Company of Japan Ltd
Priority date: 1984-09-28
Filing date: 1985-09-25
Publication date: 1986-04-03
Also published as: JPS6161390U; GB2165016B; JPH024311Y2; GB8523605D0; HK76588A

Abstract

A flange 20 is situated at one end of a sleeve 10, and an auxiliary ring 2 and a main ring 4 containing a U-shaped packing 5 are clamped together by bolts 6 and nuts 7. The auxiliary ring 2 is provided with a projection 3 adapted to be received in a tapered recess 12 formed at one end of the sleeve. When clamped, the U-shaped packing 5 is deformed such that its sharpened upper ends 5a slidably engage one side surface of the auxiliary ring 2 and the periphery of a pipe 1 to be connected whereby the pipe can expand and contract while maintaining a liquid tight seal. This makes it possible to construct a flexible pipe line. <IMAGE>

Description

SPECIFICATION Pipe connecting device This invention relates to a pipe connecting device, and more particularly a pipe connecting or coupling device which enables expansion and contraction of interconnected pipes.

It is usual to use a pipe coupling device for connecting a number of pipes of a given length to form a long pipe line.

Figure 4 of the accompanying drawings shows a prior art pipe coupler in which packings 11 having a wedge shaped cross-sectional configuration are interposed between the opposite ends of a sleeve 10 and pipes 1 to be interconnected, and the tail ends of the packings 11 are urged against the opposite ends of the sleeve 10 via push rings 24 by clamping means 6. With this construction since the packings 11 are strongly pressed into tapered receiving recesses 12 of the sleeve 10 it is possible to form a stable or rigid connection.

With this prior art construction, although it is possible to obtain a stable mechanical connection, since the pipes are locked by the coupling device the pipes cannot expand or contract during temperature variation, in response to variation in ground level or when vibrations are applied to the coupling device.

Moreover, the packings are severely damaged by the expansion or elongation and contraction of the pipes 1, thus shortening their useful life.

Although a coupling device enabling expansion and contraction of the pipes is known, the construction of such coupling device is basically different from that shown in Figure 4 so that, when this type of coupling device is used to form a pipe line, it is necessary to prepare a plurality of coupling devices having different constructions and to select suitable types of coupling device which makes troublesome the connecting operation.

The present invention seeks to provide an improved pipe connecting device capable of flexibly coupling together a pair of pipes, and which permits axial expansion and contraction of the pipes while maintaining a liquid tight seal.

According to the inventon, there is provided a pipe connecting device comprising: a sleeve formed with a recess at at least one end of said sleeve; at least one auxiliary ring having a projection adapted to be received in said recess; at least one main ring having an annular groove for receiving a U-shaped packing; and clamping means for clamping together said sleeve and said main and auxiliary rings, thus causing said U-shaped packing to slidably enaged one side surface of said auxiliary ring and a peripheral surface of a pipe to be coupled.

In order that the invention may be better understood, several embodiments thereof will now be described by way of example only and with reference to the accompanying drawings in which: Figure 1 is a side view, partially in section, showing one embodiment of a pipe connecting device embodying the invention; Figures 2 and 3 are side views, partly in section, showing modified pipe connecting devices of this invention and pipes interconnected thereby; and Figure 4 is a side view, partly in section, showing a prior art pipe connecting device.

Referring now to Figures 1 and 2, the pipe connecting device of this invention comprises an elongate sleeve 10 provided with tapered recesses 12 and flanges 20 with bolt openings 16 at both ends of the sleeve, clamping means in the form of bolts 6 and nuts 7, L-shaped auxiliary rings 2 each having a horizontal projection 3 adapted to be received in the recess 12, and main rings 4 each provided with an annular groove 14for receiving a U-shaped packing 5. The flange 20, and the main and auxiliary rings 4 and 2 are clamped together by bolts 6 and nuts 7.

When clamped in this manner, the packing 5 forms a cavity 15 as shown. The surface of the projection 3 confronting the inner surface of the recess 12 is formed with an annular groove 18 for receiving a sealing member 8, for example an O-ring.

The inner end 6a of each bolt 6 is flattened to make iteasierto hold with a tool.

As shown in Figure 4, in the prior art pipe connecting device packings 11 each having a wedge shaped sectional configuration are received in the recess 12. In the pipe connecting device of Figures 1 and 2, however, the wedge shaped packings 11 are substituted by the solid projections 3 of the auxiliary rings 2 and, since the inner surface of the recesses 12 and the outer surfaces of the projections 3 are inclined by the same angles with respect to the horizontal or the centre line, the projections 3 fit snugly into the recesses, thus automatically aligning the centre line of the auxiliary rings 2 and of the sleeve 10. For this reason, the auxiliary rings 2 and the sleeve 10 can be stably coupled together.

Since the upper ends of both legs of each Ushaped packing 5 is compressed in the groove 14 between the main and auxiliary rings 4 and 2, these sharpened ends 5a intimately and slidably contact with the side surface of the auxiliary ring 2 and the outer surface of the pipe 1, thereby forming efficient seals. Furthermore, as the pressure of the fluid in the pipe 1 is applied to the cavity 15 of the packing 5, a strong sealing action can be provided by the liquid pressure. This construction also permits relative sliding movement between the packing 5 and the pipe 1 while maintaining firm sealing therebetween without damaging their contact surfaces.

Since the advantageous effect of this invention can be afforded by providing the pipe connecting device either at one or both ends of the sleeve 10, one of the pipe connecting devices provided at both ends of the sleeve 10 may be substituted by the prior art construction shown in Figure 4. In this case, two types of pipe connecting devices can be obtained by using identical clamping means and a sleeve of the same construction. To obtain these two types of the pipe connecting device it is only necessary to change the auxiliary ring 2 and the main ring 4 provided with the U-shaped packing 5 (see Figure 3). Thus, either one or both of the pipes are slidably connected, whereas one of the pipes can be locked, that is connected to be not slidable. These two types of the pipe connecting devices of this invention and the prior art construction shown in Figure 4 can be used selectively or in combintion depending upon the conditions of the field of use where a pipe line is constructed where the pipe connecting devices of this invention are used at some points of the pipe line and the prior art pipe connecting devices shown in Figure 4 are used at other points, the pipe line as a whole can expand or contract. More particularly, by preparing main and auxiliary rings having different constructions, and U-shaped packings 5 and by suitably combining these parts, extremely flexible construction of the pipe line can be obtained.

Claims

1. A pipe connecting device comprising: a sleeve formed with a recess at at least one end of said sleeve; at least one auxiliary ring having a projection adapted to be received in said recess; at least one main ring having an annular groove for receiving a U-shaped packing; and clamping means for clamping together said sleeve and said main and auxiliary rings, thus causing said U-shaped packing to slidably engage one side surface of said auxiliary ring and a peripheral surface of a pipeto be coupled.

2. A pipe connecting device according to claim 1 wherein said sleeve is provided with said recesses at both ends thereof, and one of said auxiliary rings and one of said main rings is provided at each end of said sleeve.

3. A pipe connecting device according to claim 1 wherein said auxiliary ring and said main ring having said U-shaped packing are provided for one end of said sleeve, and wherein, at the other end of said sleeve, an annular ring and a wedge shaped packing are provided, said packing being pressed into the-recess by said annular ring.

4. A pipe connecting device according to any one of claims 1 to 3 which further comprises an O-ring packing received in a groove formed on an outer surface of said projection for sealing contacting surfaces of said recess and said projection.

5. A pipe connecting device according to any one of the preceding claims wherein the upper ends of both legs of said U-shaped packing are sharpened so that when said sleeve, and said main and auxiliary rings are clamped together, said sharpened upper ends of said U-shaped packing slidably enage one side surface of said auxiliary ring and the outer surface of a pipe to be coupled respectively.

6. A pipe connecting device substantially as hereinbefore described with reference to Figures 1 to 3 of the accompanying drawings.