Seal for range of pipe diameters with interlocking layers

Abstract

A pipe coupling includes a clamp housing and a seal assembly mounted in at least one end of the clamp housing. The seal assembly includes an outer sealing layer connected to an inner sealing layer with interlocking mating structures that abut against each other in radial and axial directions and prevent the inner and outer sealing layers from separating from each other in the radial and axial directions.

Claims

1. A pipe coupling comprising: a clamp housing comprising at least one end having two opposing clamp members and one or more tightening elements for tightening said clamp members towards each other in a direction transverse to an axial length of said clamp housing so as to apply a radially-inward clamping force on a pipe being clamped in said clamp housing; and a seal assembly mounted in said at least one end of said clamp housing; wherein said seal assembly comprises an outer sealing layer connected to an inner sealing layer with interlocking mating structures that abut against each other in radial and axial directions and prevent said inner and outer sealing layers from separating from each other in the radial and axial directions, wherein said interlocking mating structures comprise an at least partially annular lug that protrudes from one of said sealing layers and is received in an at least partially annular channel formed in the other sealing layer, and wherein said at least partially annular lug comprises first and second faces and is formed with a notch formed at a junction of a slanted face and a bulbous protrusion of said lug, and said slanted face extends at a slanted angle radially outwards from a contact surface of said inner sealing layer, said contact surface contacting an inner portion of said outer sealing layer, and said a bulbous portion bulges axially from said notch.

2. The pipe coupling according to claim 1, wherein said bulbous protrusion radially overlies said slanted face.

3. The pipe coupling according to claim 1, wherein said first and second faces are orthogonal to each other.

4. The pipe coupling according to claim 1, wherein said second face is parallel to a pipe interface surface and to a contact surface of said inner sealing layer, said contact surface being in contact with said outer sealing layer.

5. The pipe coupling according to claim 1, wherein said slanted face is opposite to said first face and is slanted with respect to said second face.

6. The pipe coupling according to claim 1, wherein said channel of said outer sealing layer is formed with a ridge that fits into said notch.

7. The pipe coupling according to claim 1, wherein said bulbous protrusion fits into a complementarily shaped crevice formed in said channel.

8. The pipe coupling according to claim 1, wherein said inner and outer sealing layers are constructed as one contiguous piece of an elastomer.

9. The pipe coupling according to claim 1, wherein said inner and outer sealing layers are not constructed as one contiguous piece of an elastomer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawing in which:

(2) FIG. 1 is a simplified sectional illustration of a prior art seal assembly;

(3) FIG. 2 is a simplified sectional illustration of a seal assembly, constructed and operative in accordance with a non-limiting embodiment of the present invention;

(4) FIG. 3 is a simplified pictorial illustration of a pipe coupling with the seal assembly of FIG. 2, in accordance with a non-limiting embodiment of the present invention;

(5) FIG. 4 is a simplified sectional illustration of the pipe coupling with the seal assembly, taken along lines IV-IV in FIG. 3; and

(6) FIG. 4A is an enlarged sectional illustration of the seal assembly in the pipe coupling.

DETAILED DESCRIPTION OF EMBODIMENTS

(7) Reference is now made to FIG. 3, which illustrate a pipe coupling 10 with a seal assembly 12, constructed and operative in accordance with a non-limiting embodiment of the present invention.

(8) Pipe coupling 10 includes a clamp housing 14 that has one or more ends 16 (two are shown in the illustrated embodiment). Clamp housing 14 may be cylindrical or partially cylindrical or of any other shape. Each end 16 is provided with two opposing clamp members 18 and one or more tightening elements 20 for tightening the clamp members 18 towards each other in a direction transverse to an axial length of the clamp housing 14 so as to apply a radially-inward clamping force on a pipe 22 (shown partially in broken lines in FIG. 2) being clamped in the clamp housing 14.

(9) Seal assembly 12 may be mounted in end 16 of clamp housing 14. Each seal assembly 12 is an at least partially annular seal, meaning it can be a full 360 sealing ring or it can be a partial ring spanning an angle less than 360, depending on the particular application.

(10) As seen in FIG. 2, seal assembly 12 includes an outer sealing layer 24 connected to an inner sealing layer 26 with at least one interlocking mating structure, such as an at least partially annular lug 28 that protrudes from one of the sealing layers (in the illustrated embodiment it protrudes from the inner sealing layer 26) and is received in an at least partially annular channel 30 formed in the other sealing layer (in the illustrated embodiment it is formed in the outer sealing layer 24). Lug 28 may include first and second (e.g., flat) faces 32 and 34, which are orthogonal to each other. Face 34 may be parallel to a pipe interface surface 36 and to a contact surface 38 of inner sealing layer 26 (contact surface 38 being the surface that contacts the inner portion of outer sealing layer 24). Opposite to first face 32, lug 28 is formed with a notch 40 formed at a junction of a slanted face 42 and a bulbous protrusion 44 of lug 28. Slanted face 42 is slanted with respect to the second face 34 and to the contact surface 38 of inner sealing layer 26.

(11) The channel 30 of outer sealing layer 24 is formed with a ridge 46 that fits into notch 40. The bulbous protrusion 44 of lug 28 fits into a complementarily shaped crevice 48 formed in channel 30 of outer sealing layer 24. The interlocking mating structures (such as the bulbous protrusion 44 of lug 28 abutting against channel 30; the ridge 46 abutting against notch 40 and slanted face 42) abut against each other in the radial and axial directions and prevent the inner and outer sealing layers from separating from each other in the radial and axial directions (indicated by arrows 37 and 39, and 41 and 43, respectively, in FIG. 2), even in the presence of forces during usage of the coupling.

(12) The interlocking mating structures may be provided in more than one place or in just one place. In the illustrated embodiment, the seal assembly includes an at least partially annular ridge 50 is received in an at least partially annular groove 52. Ridge 50 and groove 52 may have a trapezoidal or triangular cross-section.

(13) FIGS. 4 and 4A illustrate pipe coupling 10 with the seal assembly 12 installed therein.

(14) Seal assembly 12, without limitation, may be made of a rubber (e.g., EPDM (ethylene propylene diene monomer), butyl, styrene butadiene or neoprene) or a thermoplastic elastomer (e.g., polyurethane or olefin) compatible with the fluid to be carried in the pipe. For example, without limitation, seal assembly 12 may be made of EPDM rubber with 70-80 Shore A durometer.

(15) The inner sealing layer 26 is used together with the outer sealing layer 24 when clamping a pipe of relatively small diameter. If a relatively large pipe is to be clamped, inner sealing layer 26 may be removed from outer sealing layer 24, such as by simply removing inner sealing layer 26 (if the two layers are not one contiguous piece of elastomer) or by tearing or cutting inner sealing layer 26 (if the two layers are one contiguous piece of elastomer). Alternatively, if the two layers are one contiguous piece of elastomer as in the illustrated embodiment, inner sealing layer 26 may be folded away from outer sealing layer 26 (instead of being torn or cut).

(16) By one contiguous piece of elastomer it is meant that the two layers may be extruded or molded as one piece or may be joined to each other, such as by bonding, mechanical fastening or any other suitable method.

(17) Referring again to FIG. 2, outer sealing layer 24 may be constructed with an outer portion 54 folded over an inner portion 56 so as to define at least one inner annular space 58 between and bounded by the inner and outer portions 56 and 54. The inner annular space 58 is in fluid communication with a fluid (e.g., water, not shown) flowing in a pipe sealed by seal assembly 12. The fluid enters inner annular space 58 via one or more apertures (not shown) and applies pressure in inner annular space 58 to increase tightening of the seal.