US3654061A

US3654061A - Pipe wrap

Info

Publication number: US3654061A
Application number: US90909A
Authority: US
Inventors: John J Berwanger
Original assignee: Hood Sponge Rubber Co
Current assignee: Hood Sponge Rubber Co
Priority date: 1970-11-19
Filing date: 1970-11-19
Publication date: 1972-04-04
Anticipated expiration: 1989-04-04
Also published as: CA950818A; GB1306779A; DE2151614A1; FR2114872A5

Abstract

A pipe wrap comprises a strip of material that has a substantially moisture imprevious skin enclosing a sponge rubber core or interior. The longitudinal margins of the strip are rabbeted to provide short, opposed, outwardly directed flanges that are thinner than the remainder of the strip and are offset from each other such that the strip may be helically wrapped about a pipe with the flanges overlapping and fitting into the rabbets to form a helical seam at which the outer surface of the strip at each turn of the wrap is flush with the outer surface of an adjacent turn of the wrap so that a sheath with a smooth substantially continuous outer cylindrical surface is produced.

Description

April 4, 1972 J. J. BERWANGER PIPE WRAP Filed Nov. 19, 1970 Lo/m fa/wager ha 742;@ Wdwi s United States Patent O" U.S. Cl. 161--118 4 Claims ABSTRACT OF THE DISCLOSURE A pipe wrap comprises a strip of material that has a substantially moisture imprevious skin enclosing a sponge rubber core or interior. The longitudinal margins of the strip are rabbeted to provide short, opposed, outwardly directed flanges that are thinner than the remainder of the strip and are offset from each other such that the strip may be helically wrapped about a pipe with the flanges overlapping and fitting into the rabbets to form a helical seam at which the outer surface of the strip at each turn of the wrap is flush with the outer surface of an adjacent turn of the wrap so that a sheath with a smooth substantially continuous outer cylindrical surface is produced.

BACKGROUND OF THE INVENTION It is known to wrap a strip of fibrous material around a pipe in order to provide an insulation sheath for the pipe. Conventionally, these strips are wrapped in a helical fashion with the adjacent longitudinal edges of the strip forming a helical seam. A butt seam would tend to form a smooth exterior surface for the sheath, but butt seams are often not used since it is diflicult to assure, during the wrapping operation, that the edges are truly in abutting relationship throughout the helical seam. It will be appreciated that wherever gaps are present in the seam there is, in effect, a break in the insulation. Accordingly, it has been customery to wind these insulating strips with the edges of adjacent turns overlapping to provide a lap seam. However, the lap seam produces a lumpy exterior appearance. This may be undesirable for aesthetic reasons, and in addition the lump or ridge at the seam makes it difficult to apply and additional wrapping of insulation. In this regard it should also be noted that it is often desirable to wrap pipe with several layers of insulation of different materials. For example, a hot water pipe may be wrapped with an insulating layer of fibrous material and then overlaid by a metallic strip or tape to serve as a heat reflector and also to prevent ambient moisutre, dirt, or other contaminants from entering into the interstices of the insulation.

SUMMARY OF THE INVENTION The present invention comprises a pipe wrap comprising a unitary strip of rubbery material having an enveloping skin and a sponge core or interior, the skin having a resistance to the passage of moisture that is great as compared to that of the sponge interior. The relatively moisture imprevious skin is quite thin and completely envelops the highly porous sponge interior so that when the wrap is applied to a pipe, the skin serves as a moisture barrier for the porous sponge core to prevent deterioration of the insulating properties of the core. In many instances, this eliminates the need for applying a multiplicity of Wraps of different materials to the pipe. At the longitudinal margins of the wrap are outwardly extending flanges that are sized and are so offset from each other that when the strip is helically wrapped about a pipe the flanges overlap and form a helical seam which does not 3,654,061 Patented Apr. 4, 1972 ice produce a bulge or lump but, on the contarary, provides a wrapped sheath on the pipe in which the outer surface of the sheath is substantially smooth and continuous. Furthermore, a strip of a given size constituting the pipe wrap of he present invention is sufficiently flexible within its elastic limits to be helically wrapped around pipes within a range of diameters and still produce a sheath with a smooth erterior surface.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspective View, partially in section, and showing a pipe wrap constructed in accordance with and embodying the present invention;

FIG. 2 is a side elevational View, partly broken away and in section, and showing the wrap applied to a cylindrical pipe;

FIG. 3 is a side elevational view of the wrap partially broken away and in section along the longitudinal axis of the cylinder formed by the helically wound wrap; and FIG. 4 is an enlarged fragmentary sectional View of the setup.

DETAILED DESCRIPTION Referring now in more detail to the drawings, which illustrates a preferred embodiment of the present invention, 1 designates a pipe wrap that comprises a unitary strip of rubbery material having an enveloping skin 2 and a highly porous sponge core or interior 3 which has excellent insulating properties. The skin 2 is of considerably greater density than the sponge interior or core, 3 and as a result has a resistance to the passage of moisture that is relatively great as compared to that of the interior 3. Desirably, the skin 2 is substantially moisture impervious. The wrap 1 is produced in the strip form shown in FIG. 1 by known foam-extrusion techniques. By reason thereof, the dense skin 2 and the highly porous core 3 result.

The wrap 1 includes a generally rectilinear central body portion 4 that is defined by opposed

parallel surfaces

6, 7 and opposed parallel longitudinal margins 8, 49. Projecting outwardly from the margins :8, 9 are oppositely directedly

parallel flanges

11, 12. The flange 11 is flush with the surface 6 while the flange 12 is flush with the opposite surface 7. As will be seen, each

flange

11, 12 is thinner than the body portion 4, leaving grooves or

rabbets

13, 14 at the edges of the wrap 1. The combined thickness of the

flanges

11, 12 are substantially equal to the thickness of the strip measured between the surfaces 6 7. The

flanges

11, 12 may be of equal thickness.

The wrap 1 is applied to a cylindrical pipe 16 by helically winding over the exterior surface of the pipe 16, as shown in FIGS. 2 and 3 and represented by the arrow a. In the helical seam 17 formed by the wrapping operation, the Iflange 11 fits into the rabbet 14 while the flange 12 fits into the rabbet 13 and with the free edges of the

flanges

11, 12 abutting the adjacent longitudinal margins 8, 9. Since the combined thicknesses of the

flanges

11, 12 is equal to the thickness of the central body portion 4 and the

flanges

11, 12 are of eqjual width as measured from the margins 8, 9 from which they project, it will be apparent that each flange conforms to the shape of the rabbet in which it fits. As a result, the helical lap seam 17 is of the same thickness as the body portion 4 and a helical wrap over the pipe 16 is provided in which the portions of the exterior surface 6 at each turn of the wrap is flush with the portion of the exterior surface 6 at an adjacent turn of the wrap. A like result obtains with respect to the interior surface 7. Consequently, a smooth wrap around the pipe is provided. The width of the

flanges

11, 12 is only a minor fractional part of the width of the body portion 4 so that the degree of overlap need not be great.

The pipe wrap 1 has substantial flexibility within elastic limits and so for a given size of strip it may be applied to pipes of varying diameters within a relatively wide range.

lWhile a preferred embodiment of the present invention has herein been shown and described, it will be understood that various changes may be made, and all those falling within the scope of the appended claims are to be considered part of the invention.

The invention is claimed as follows:

1. A wrap for disposition around a pipe to constitute an insulation sheath for the pipe, said wrap comprising a yunitary strip of rubbery material having an enveloping skin and a sponge interior, said skin and interior being of the same material and said skin having a density that is great as compared to that of said interior, said strip including a central body portion formed by opposed parallel surfaces defining the thickness of said body portion and opposed longitudinal margins defining the width of said body portion, and a flange extending outwardly from each longitudinal margin and having a free edge, said anges being parallel and oppositely directed, one flange being flush with one of said opposed surfaces and the other flange being flush with the other surface, each flange being of a thickness measured along a line perpendicular to said opposed surfaces which is less than the thickness of the said body portion and the combined thickness of said flanges being substantially equal to the thickness of said body portion, said longitudinal margins and said anges defining opposed rabbets extending longitudinally of said strip, the width of each -iiange being substantially equal to the width of the opposite rabbet, said strip being suiciently flexible within its elastic limits to be helically wrapped around pipes within a range of external diameters and with one of the flanges overlapping the other flange and with said lianges lying in the rabbets and with said free edges of the flanges abutting respectively said longitudinal margins to form a helical seam the thickness of which is substantially the same as said thickness ofsaid body portion and at which seam the outer surfacein one helical turn of the wrap is ush with the outer surface of an adjacent helical turn of the wrap.

2. A wrap according to claim 1 in which said skin substantially moisture impervious.

3. A wrap according to claim 1 in which the anges are of a width which is a minor fractional part of the width of said body portion.

4. A wrap according to claim 1 in which said skin is thin as compared to the thickness of said body portion.

References Cited UNITED STATES PATENTS 2,111,113 3/1938 Fischer 161-161 x 3,563,825 2/1971 Segura et al 156-187 X FOREIGN PATENTS 1,055,619 10/1953 France 15e-'195 WILLIAM A. POWELL, Primary Examiner U.S. Cl. X.R.