GB2119057A - Pipe insulation - Google Patents

Abstract

A slotted insulating shell for covering a pipe consists of polyolefin foam and can be non-destructably applied and removed by means of a slide fastener consisting of two identical fastener strips which is adapted to be opened and closed by a slider. Each strip comprises a thin fixing flange and a backing, which is parallel to and offset from the flange, and at least two ribs which extend at right angles from the backing. The ribs are hook-shaped in cross-section and between them define grooves, which are complementary in cross-section to the ribs. A slideway (26) for the slider is left free below one of the fixing flanges. <IMAGE>

Description

SPECIFICATION Insulation for covering pipes This invention relates to an insulation for covering pipes, which insulation can be non-destructably applied and removed by means of a slide fastener, which is adapted to be closed and opened by a slider.

Such insulation is known from German Patent Specification 1,001,070. That known insulation consists of a backing sheet of plastics material and a soft, deformable insulating mat. The insulating mat may be attached to one side of the backing sheet by sticking, stitching with threads, fixing by means of clips or the like means. If the insulation is applied to a pipeline by a single person, the insulation surrounding the pipeline is secured at points spaced about 50 cm apart by means of cords or ribbons surrounding the pipeline. If the insulation is applied to a pipeline by two persons, one of them holds the and aligns the insulation and the second closes the slide fastener by means of a tool. Relatively long pipelines can also be insulated without difficulty in this manner, as is apparent from a prospectus issued by Schneider + Co.Gmbh, Isoliermaterialien, Dichtungen, of Holzstrasse 4, D-7000 Stuttgart N. That tool consists of a composite, hand-size handle, which is made of various materials and is linked to the slider by a connecting member. The slide fastener which is employed may be of any desired type.

At that time, slide fasteners as disclosed in German Patent Specifications 836,931 and 856,882 had been known in the art.

A different insulation of the kind in question here has been disclosed in U.S. Patent Specification 2,758,172. That known insulation consists of glass fibers. The slide fastener strips are in accordance with U.S. Patent Specification 2,558,367,2,613,421, 2,637,085 or 2,637,086. The slider is in accordance with U.S. Patent Specification 2,613,421. The actuating handle is linked to the slider and has a length of about 2.5 to 3.75 cm.

German Utility Model 6601 735 discloses a device which serves to close slide fasteners and in which the closing tool is bipartite and the confronting top and bottom plates are carried by tong arms. At least two hook-shaped longitudinal ribs on one slideway interengage with two complementary ribs on the other slideway. The tongs can be adjusted to a desired opening width and can be fixed in the adjusted position. The bottom plate is provided with spaced apart longitudinal ribs, which flare at that end that is near the tong arm. The tong arm tapers in cross-section to a point at its free end.In the use of that device for closing slide fasteners, the slide fastener can be threaded into the device from either side and contrary to other known devices that device can be operated also by persons having no manual dexterity and can be used to close even relatively long fasteners without difficulty.

Another slider for closing and opening fasteners having profiled strips is known from German Patent Specification 1,922,985.

The two devices mentioned last for closing and opening slide fasteners have the disadvantage that a composite tonglike tool is required which is complicated and relatively large.

German Patent Publication 2,512,755 discloses a pipe-insulating shell which consists of a slotted tube of closed-cell foam. The main purpose of such insulating shells is to ensure a specified heatinsulating effect regardless of the proficiency of the workers so that the insulation can be applied in the field in a minimum of time. Because the closed-cell foam is impermeable to water vapour, it can be used also on cold pipelines so that such foam has a much wider field of application than open-cell foamed plastics. On the other hand, a uniform heatinsulating effect cannot be achieved unless the initially opened insulating shell is vapour-tightly sealed as it is applied.It has been attempted first to accomplish this by cementing the insulating shells together at abutting faces defining the slot (e.g., with "Porophin" insulating shells of Grunzweig & BR< Hartmann). But that practice has the disadvantagethat cemented joints which have not been made properly may permit a condensation of water in the insulating shell so that the heat-insulating effect will be impaired, and that the need for the additional cementing work substantially reduces the rate at which insulation can be applied.

According to another proposal the insulating shell which has been applied to the pipe is surrounded by a vapour-impermeable web of plastics material and said web is subsequently mechanically closed. For this purpose, hooklike bars are welded to the edges of the plastics webs and are interengaged. That arrangement has the disadvantage that the vapour seal is not perfect. Besides, the application of the insulation is difficult because the insulating shell and the loose covering are not firmly connected.For this reason, the object to provide a closed-cell insulating shell which can be applied in a very simple manner and without need for a tool and can be closed so as to be absolutely gastight is accomplished in accordance with German Patent Publication 2,512,755 by the provision of an insulating shell which consists of polyolefin foam and can be gastightly closed and re-opened by means of a slide fastener of plastics, which is welded to the shell along the slot and comprises a plurality of interengaging sealing lips.

Such insulations for covering pipes have proved quite satisfactory in practice. But it has been found that it is difficult to apply the insulation without a tool to relatively long pipelines, particularly in commercial operations, so that the high application rates which are desired cannot be achieved for the duration because the worker's hand is fatigued or even his health may be adversely affected.

For this reason it is an object of the invention to provide an insulation which is of the kind described first hereinbefore and which regardless of the proficiency of the workers applying the insulation ensures that the pipes will be provided with an absolutely gastight, insulating covering, which can be applied even to long pipelines at high rates for the duration, particularly in commercial operations, without a fatigue of the worker and without a danger of health damage to the worker's hand.

In an insulation of the kind described first hereinbefore, this object is accomplished by the combination of the features residing in that an insulating shell consisting in known manner of polyolefin foam and constitutes a slotted tube is provided with a slide fastener which is made of plastics material and extends along the slot and is welded to the shell and consists of two identical fastener strips, each of which comprises a thin fixing flange and a backing which is parallel to and offset from the flange and comprises at least two ribs, which extend longitudinally and at right angles from the inside surface of the body of the backing and are hook-shaped in crosssection and between them define grooves which are complementary to the cross-section of the ribs, a slideway for the slider is left free below one of the fixing flanges, the backings have specially shaped outer edge portions for guiding the slider, which is applied to the backings, and a handle is rigid with an integral with the slider.

The following advantages are afforded bythe insulation according to the invention: The closedcell insulating shell can be made in one piece and can be closed to provide an absolutely gastight seal.

The slide fastener resists high tensile stresses and can be made at low cost. The slider consists of a removable tool, which may be used for a large number of insulating shells, if desired, and as it is rigid with the handle can easily be handled and reliably be controlled. The handle can be made in one piece with the slider by a stamping operation at low cost. In the known insulating shell, the fact that the slide fastener is welded to the shell has been a prejudice to the closing and opening of the slide fastener by means of a slider.

Desirable developments of the invention are recited in the dependent claims. Various embodiments will be explained more fully in the following description with reference to the drawings, in which Figure 1 is a transverse sectional view showing an insulation according to one embodiment of the invention; Figure 2 is a fragmentary similar cross-sectional view showing a different embodiment; Figure 3 is a similar view showing a third embodiment; Figure 4 is a transverse sectional view showing a slide fastener which has been functionally adapted in accordance with the invention; Figure 5 shows a particularly advantageous embodiment of a slider for the insulation according to the invention; Figure 6 shows another embodiment of a slider; and Figure 7 a third embodiment of a slider.

The general structure of the insulation provided by the invention for covering pipes, with the exception of the slider, is shown in Figure 1. The slider can be removed when the pipe has been covered. An insulating shell 1 consisting of a slotted tube of polyolefin foam is provided with a slide fastener 3, which extends along the slot 2 and has been welded to the shell. Such slide fastener consists of plastics material and is shown in Figure 4. The slide fastener consists of two identical fastener strips 4,5. Each fastener strip 4 or 5 comprises a thin fixing flange 6, 7 and a backing 8, 9, which extends parallel to the flange and is provided with two ribs 10, 11 which extend longitudinally and at right angles to the inside surface of the body of the backing.The ribs 10, 11 are hook-shaped in cross-section and between them define grooves which are complementary in cross-section to the ribs. As is apparent from Figures 1 to 3, a slideway 12 for the slider 15 is left free below one of the fixing flanges 6 and 7. Figures 1 to 3 show three different embodiments of that feature of the insulation. In the embodiment shown in Figure 1, the backing of one fastener strip 4, which backing is provided with the groove and ribs, protrudes beyond the slot-defining surface 28 of the insulating shell 1.

The other slot-defining surface 29 is provided with a groove 26 for receiving the slider 15. That groove 26 is disposed below the backing of the other fastener strip 5, which backing is also provided with a groove and ribs.

In the embodiment shown in Figure 2, the two slot-defining surfaces 28,29 constitute a butt joint and the seam weld 30 joining one fastener strip to the shell terminates short of the slot-defining surface 29.

In the embodiment shown in Figure 3, the surfaces 28, 29 define a V-shaped slot and engage in the inner portion of the insulating shell 1 whereas on the outside periphery of the insulating shell 1 the surfaces 28, 29 define a gap 30 corresponding to the width of the backings 8,9 of the fastener strips 4,5, which backings are provided with the grooves and ribs.

Figure 4 shows an example of a slide fastener which generally corresponds to the teachings of German Patent Specification 836,931 and has been functionally adapted in accordance with the invention. The slide fastener shown in Figure 4 affords all advantages of that known slide fastener, which has proved satisfactory, and particularly comprises the specially designed outer guiding edges 13, 14. The fastener strips 4,5 have guiding edges 13, 14, which are reinforced in wedge shape so that the fasteners will resist substantial tensile stresses. An unintended separation of the fastener strips from each other under the action of heat is also prevented. Each of the guiding edge portions 13, 14 cover the outer rib 10 or 11" of the respective other fastener strip 4 or 5 throughout the height of said rib. The surface which is engageable by the slider is increased in that the fixing flange 6 or 7 of each fastener strip 4,5 terminates at the free end rather than at the centre of a reinforced guiding edge portion 13, 14.

Figures 5a and 5b, Figures 6a to 6d, and Figures 7a to 7f, respectively show three different embodiments of sliders for use with the insulation according to the invention in different views. All sliders embody the structural features which will be described hereinafter. In other respects, the designs of the sliders may differ widely, as will readily be apparent from the drawings.

The preferred embodiment of a slider for use with the insulation according to the invention is shown in Figure 5 and consists of a stamping made from a simple metal strip 19. The slider comprises an angled and curved handle portion 20 and a slider portion 21. The slider portion 21 is provided with a parting member 22, which is downwardly offset by the height of the backings 8,9 of the fastener strips, and with guiding webs 23 to 25, which are spaced apart to match the width of the backings 8,9 and extend at right angles to the metal strip 19 and the parting member 22. The guiding web 23 connects the parting member 22 to the slider portion 21 of the metal strip 19. The guiding web 24 is also provided on the metal strip 19 and depends therefrom at right angles thereto.The opposite guiding web 25 is provided at the free end of the parting member 22 and extends parallel to the guiding web 23. During the closing and opening movements of the slider 15, the backings 8,9 of the fastener strips 4,5 are guided and held between the guiding webs 23,24 on one side and 25 on the other side. The lower fastener strip 4 or 5 is guided between the metal strip 19 and the parting member 22. The upper fastener strip 4 or 5 is introduced through the groovelike opening 31 formed in the metal strip 19. As a result, a closing movement imparted to the slider will cause the ribs 10, 11 of the backings 8,9 to be forced into the grooves of the respective opposite fastener strip.

During the oppositely directed opening movement, the two fastener strips 4, 5 are forced apart by the parting member 22.

In all embodiments, the slider has a handle 16, which is rigid and integral with the slider.

In Figure 6, like reference numbers designate the same structural elements as in the embodiment shown in Figure 5. Figure 6a shows the slider 15 having a handle portion 20 and a slider portion 21 in position on a partly open insulating shell 1. The parting member is designated 22. Figure 6b is a longitudinal sectional view showing that slider in a position in which the fastener strips are closed in the right-hand part of the Figure and still open in the left-hand part. A special advantage afforded by that embodiment is apparent from Figure 6c, which shows that the receiving side of the sliderflares like a funnel so that the two fastener strips 4, can easily be introduced.

Athird embodiment of a slider is shown in Figure 7. In Figure 7a the slider is shown with the inserted fastener strips. In Figure 7b the slider is shown alone. Figures 7d and 7e show the slider portion 21 viewed from above and below, respectively.

Claims (7)

1. An insulation for covering pipes, which insulation can be non-destructably applied and removed by means of a slide fastener, which is adapted to be closed and opened by a slider, characterized in that an insulating shell consisting in known manner of polyolefin foam and constitutes a slotted tube is provided with a slide fastener which is made of plastics material and extends along the slot and is welded to the shell and consists of two identical fastener strips, each of which comprises a thin fixing flange and a backing which is parallel to and offset from the flange and comprises at least two ribs, which extend longitudinally and at right angles from the inside surface of the body of the backing and are hook-shaped in cross-section and between them define grooves which are complementary to the cross-section of the ribs, a slideway for the slider is left free below one of the fixing flanges, the backings have specially shaped outer edge portions for guiding the slider, which is applied to the backings, and a handle is rigid with and integral with the slider.

2. An insulation according to claim 1, characterized in that the fixing flange of each fastener strip engages the free end of a reinforced guiding edge, by which the outer rib of the respective other fastener strip is covered throughout the height of said rib.

3. An insulation according to claim 1 or 2, characterized in that the slider serving to join and separate the two fastener strips consists of a stamping in the form of a metal strip, which has an angled and curved handle portion and a slider portion, and the latter comprises a parting member, which is downwardly offset to an extent corresponding to the height of the backings of the fastener strips, and guiding webs, which are spaced apart by the width of the backings and extend at right angles to the metal strip and the parting member and are adapted to force the fastener strps into each other during the closing movement of the slider and to force them apart during the opening movement of the slider.

4. An insulation according to any of claims 1 to 3, characterized in that the backing of one fastener strip, which backing is provided with the groove and the ribs, protrudes over one of the slot-defining surfaces of the insulating shell and the other slotdefining surface is formed with a groove, which is disposed below the backing provided with the ribs and the groove and serves to receive the slider.

5. An insulation according to any of claims 1 to 4, characterized in that the two slot-defining surfaces engage to form a butt joint and the seam weld joining one fastener strip to the shell terminates short of the slot-defining surface.

6. An insulation according to any of claims 1 to 3, characterized in that the slot-defining surfaces define a V-shaped slot and engage each other in the inner portion of the insulating shell whereas at the outside periphery of the insulating shell they are spaced apart by a distance corresponding to the width of the backings of the fastener strips, which backings are provided with the grooves and ribs.

7. An insulation for covering pipes, substantially as hereinbefore described and as illustrated in the accompanying drawings.