CA1135747A

CA1135747A - Contraction joint

Info

Publication number: CA1135747A
Application number: CA000370195A
Authority: CA
Inventors: James J. Bourassa; Guenther Ohnimus
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-02-05
Filing date: 1981-02-05
Publication date: 1982-11-16

Abstract

ABSTRACT OF THE DISCLOSURE
A contraction joint for aligned sections of pipe.
Inner and outer sleeves of the joint are separated by upper and lower guide members which allow the coaxial sleeves to slide and telescope one within the other. The space between the sleeves and the guide members provides a chamber in which O-rings are mounted. These sealing rings are slightly compressed between the opposing surfaces of the sleeves and roll therebetween as the sleeves telescope to compensate for settling of the building in which the pipe is installed.

Description

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This invention relates to means for interconnec-ting leng-ths of pipe and more particularly to a joint for vertically standing pipe used in buildings.
A building constructed mainly of wood has one great disadvantage which has proven troublesome over the years and that is the natural tendency of the structure to become compacted to a slight extent due to its own weight and the loads it is required to carry. A wood frame build-ing, for example, is known to settle as much as one half an inch for each storey of the structure and this presents problems particularly in the plumbing. The soil and other pipes which stand vertically and extend from the top floor to the basement of the building are usually formed of cast iron with the joint connecting the pipe sections between each floor. Because of the settling of the building, the pipe sections move relative to one another to such an extent that the joints will often fail and flooding occurs along with other attendant problems which require costly mainte- -nance to remedy.
Such a settling problem is solved by use of the present pipe joint which is designed to slip sufficiently to compensate for any reasonable amount of settling while still maintaining a fluidtight connection between the pipe sections.
More specifically, a device according to the present inven-tion may be defined as a contrac-tion joint for connecting aligned sections of pipe which joint comprises inner and outer sleevRs having opposite ends adapted to be secured to the pipe sections, a first guide member at a lower end of the inner sleeve, a second guide member at an upper end of 1~3~f ~

the outer sleeve, said first and second guide members slidably and telescopically supporting the inner and suter sleeve for coaxial movement between an expanded position and a contracted position, said inner and outer sleeves being radially spaced apart to provide an annular chamber between said sleeves and the first and second guide members, and sealing means contained within the annular chamber having rolling contact with opposing surfaces of the inner and outer sleeves between the first and second guide members as said sleeves move between the expanded position and the contracted position.
In drawings which illustrate a preferred embodi-ment of the invention, Figure 1 is an elevational view, part in section, showing the present contraction joint in an extended position, Figure 2 is an enlarged vertical section of the joint in a fully contracted position, and Figure 3 is a horizontal section taken on the line 3-3 of Figure 2.
Referring to the drawings, the numeral 10 in-dicates generally a contraction joint constructed in accor-dance with the present invention. The joint 10 is shown in Figure 1 used to provide a connection between two pipe sections 12 and 14. These pipe sections are assumed to be parts of a vertically standirlg soil pipe installed in an apartment building of wood frame construction since such buildings are subject to a considerable amount of settling which is the cause of failure in conventional joints. It should be noted that most building codes require that soil 5~7~

pipes and the jolnt itself be made of cast iron for dura-bility and strenyth.
The cast iron joint 10 is formed of outer and inner sleeves 20 and 21 which have lower and upper ends 22 and 23 respectively. Conventional flange couplings 24 and 25 or the like may be used to connect the ends 22 and 23 of the sleeves to the adjoining ends of the pipe sections.
This type of connection secures each sleeve against axial movement relative to the adjoining pipe sections and, of course, provides a fluidtight seal therebetween.
As shown in Figure 2, the cylindrical outer sleeve 20 is reduced in diameter near its lower end to provide an inwardly and downwardly tapering seat 26 on the inside of the sleeve. The inner sleeve 21 has an integral guide flange 28 at lower end 29 of the sleeve and this end is bevelled to provide a tapered shoulder 31 conforming to the tapered seat 26.
Upper end 33 of the outer sleeve is fitted with a guide ring 35. This guide ring is tapered in cross section so as to fit fairly snuggly between the two sleeves of the contraction joint. Set screws 36 (Figures 2 and 3) secure the guide ring to the upper end 33 of the outer sleeve.
The two sleeves of the joint 10 are thus spaced apart to provide an annular chamber 38 which extends between the guide flange 28 and the guide ring 35. It will be noted that the sleeves 20 and 21 have opposing surfaces 40 and 41 which are very rough as would be expected of cast iron so that an exceptionally tough and durable sealing arrangement is required for the chamber 38.

Such an arrangement is provided by means of rubber or Neoprene O-rings 45 which are sliyhtly oversize relative to the space which they must occupy between the opposing surfaces 40 and 41. The sealing rings 45 are forced into the chamber 38 before the guide 35 is fitted in place of course, and the O-rings must be compressed to some extent in order to enter the chamber whereupon they assume the oval shape which is shown in Figure 2. secause of this size and shape of the O-rings, these sealing members roll on the surfaces 40 and 41 whenever the telescopic sleeves are moved longitudinally with respect to one another. Thus, a tight and effective seal is provided by the O-rings 45 which have the capacity of moving lengthwise of the annular chamber 38.
Figure 1 shows the compression joint 10 fully extended or expanded as it would be when first installed in a building. As settling occurs in that building, the sleeves teiescope eventually to reach the fully compressed or contracted position shown in Figure 2 where the tapered shoulder 31 comes into contact with the tapered seat 26.

Water flowing down the pipe carries a certain amount of debris such as paper and rags which tends to hang up on any obstruction and eventually to clog the pipe~ However, the tapered shoulder and seat in the present joint prevents any such build up regardless of the position of the inner sleeve within the outer sleeve. The guide members 28 and 35 keep these sleeves coaxially aligned and sliding smoothly as the sleeves move longitudinally relative to one another and this is achieved even when the pipe sections 12 and 14 are not too accurately aligned as often is the case. Furthermore, the guide members maintain the spacing between the opposing A

~.3~7,~t7 surfaces 40 and 41 of the sleeves and this prevents damage to the O-rings 45 as they roll between the roughened surfaces of the cast iron joint. The rouyhened surfaces 40 and 41 impart a rolling action to the O-rings without wearing the surfaces of those sealing members to any appreciable extent and do so normally while maintaining the vertical spacing between the rings and, at the same time, the rings provide a long lasting and fluidtight sealing action between the relatively moving sleeves. Should the joint 10 be subjected to some unusual force tending to pull the sleeves apart, the O-rings are locked between the guide flange 28 and the guide ring 35 and those members co-operate to prevent the sleeves from separating completely.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:-

1. A contraction joint for connecting aligned sections of pipe comprising inner and outer sleeves having opposite ends adapted to be secured to the pipe sections, a first guide member at a lower end of the inner sleeve, a second guide member at an upper end of the outer sleeve, said first and second guide members slidably and teles-copically supporting the inner and outer sleeves for coaxial movement between an expanded position and a contracted position, said inner and outer sleeves being radially spaced apart to provide an annular chamber between said sleeves and the first and second guide members, and sealing means contained within the annular chamber having rolling contact with opposing surfaces of the inner and outer sleeves between the first and second guide members as said sleeves move between the expanded position and the contracted position.

2. A contraction joint as claimed in claim 1, and including a downwardly and inwardly tapering seat on the opposing surface of the outer sleeve, said inner sleeve having a correspondingly tapered shoulder between the lower end and the first guide member adapted to engage the seat when the inner and outer sleeves are in the contracted position.

3. A contraction joint as claimed in claim 2, in which said second guide member comprises a ring on the opposing surface of the outer sleeve, and fastening means releasably securing the ring to the upper end of the outer sleeve.

4. A contraction joint as claimed in claim 1, 2, or 3, in which said sealing means comprises a pair of flexible O-rings initially located near the first and second guide members when the inner and outer sleeves are in the expanded position and adapted to roll simultaneously along the opposing surfaces as said sleeves move to the contracted position.

5. A contraction joint as claimed in claims 1, 2 or 3, in which said inner and outer sleeves are formed mainly of cast iron.