US3837947A

US3837947A - Method of forming an inflatable member

Info

Publication number: US3837947A
Application number: US00820966A
Authority: US
Inventors: B Malone
Original assignee: Lynes Inc
Current assignee: Lynes Inc
Priority date: 1969-05-01
Filing date: 1969-05-01
Publication date: 1974-09-24
Anticipated expiration: 1991-09-24

Abstract

A method of forming or building up a reinforced inflatable member on a body wherein one end may be secured to the body with the other end movable relative to the body as the member is inflated, or wherein both ends of the inflatable member may be moved relative to the body as the member inflates. Also, the invention contemplates a relatively uncomplicated method of fabricating or forming an end anchorage for the ends of an inflatable member that is reinforced by a sheath within a minimum of space without sacrificing strength and which is able to withstand somewhat substantial stress or loads that may tend to try to pull out or shear the ends of the reinforced inflatable member.

Description

l ited States atent 1 1 3,837,947 alone Sept. 24, 1974 METHOD OF FORMING AN INFLATABLE Primary Examiner-Benjamin A. Borchelt MEMBER Assistant ExaminerJ. V. Doramus [75] Inventor: Billy C. Malone, Houston, Tex. Attorney Agent or Firm-Jack Hayden [73] Assrgnee: Lynes, llnc., Houston, Tex. [57] ABSTRACT [22] Filed May 1969 A method of forming or building up a reinforced in- [21] Appl. No.: 820,966 flatable member on a body wherein one end may be secured to the body with the other end movable relative to the bo'cly as the member is inflated, or wherein both ends of the inflatable member may be moved re]. [58] Fieid 156/73 277/34 ative to the body as the member inflates. Also, the invention contemplates a relatively uncomplicated 113/111 287/20 method of fabricating or forming an end anchorage for the ends of an inflatable member that is reinforced by a sheath within a minimum of space without sacri- [56] References Cited ficing strength and which is able to withstand some- UNITED STATES PATENTS what substantial stress or loads that may tend to try to 2,778,432 1/1957 Allen 277/34 pull out or shear the ends of the reinforced inflatable 3,003,798 10/1961 Sandlin ..287/20R member,

18 Claims, 7 Drawing Figures msmmu SHEET 10? Z 5/76/ C Mar/One INVENTOR Magda/u m/e! & MaHLewA ATTORNEYS METHOD OF FORMING AN INFLATABLE 1 MEMBER CROSS-REFERENCE TO RELATED APPLICATION The present method relates to construction and structural arrangement disclosed and claimed in my cpending application for Inflatable Element filed May 12, 1969 and bearing Ser. No. 823,880, now US. Pat. No. 3,604,732.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the method of forming an inflatable member which may be used as a forming mandrel, closure in a conduit, mine shaft or lateral, well bore, or other opening. Specifically, the invention relates to a method for forming or building up a reinforced inflatable member on a body as well as a method of forming an end anchorage for the inflatable member which utilizes a minimum of space but which is able to withstand substantial stress tending to pull or shear the ends of the reinforced inflatable member. Also, the method of the present invention relates to forming an inflatable member wherein both ends of the inflatable element forming part of the inflatable member may be fixed on a body while one end of the inflatable member may be fixed on the body and the other end movable relative to the body or wherein both ends of the inflatable member may be movable relative to the body.

2. DESCRIPTION OF THE PRIOR ART While there may be other art, the prior art with which applicant is familiar is the patent to H. L. Sandlin, US. Pat. No. 3,003,798, and the patent to G. H. Allen, US. Pat. No. 2,778,432. In the Sandlin patent, there is disclosed a reinforcing employing either circumferentially spaced cables or a braided sheath within a resilient member; the reinforcing is anchored at its ends by a potting slurry comprising a resinous material, preferably an epoxy resin, a filler, and heat responsive polymerizing (or hardening) agent for the resin. While the Sandlin patent discloses the use of a resin and a catalyst for hardening the resin to anchor the reinforcing ends of an inflatable member, the roughened surface of the cavity receiving the reinforcing, the hardened resin, and the filler comprises primarily the arrangement for securing the reinforcing at its ends. Also, Sandlin does not show an inflatable member including an inflatable element which may be secured at both ends to a body with a surrounding reinforcing sheath that may have either one or both of its ends movable relative to the body.

In the Allen patent, a reinforcing sheath is disclosed comprising a plurality of strips of braided wire which is coated with rubber or nylon, and in the Allen patent, the reinforcing sheath thus formed by the overlapping strips is retained in position against the stresses tending to tear or pull the ends of the reinforcing position by means of the wedge cones 20 at each end of the inflatable member.

Thus, it can be seen from the Sandlin patent that since the primary force tending to retain the reinforcing sheath or cables of the inflatable member at each end is the hardened epoxy, filler, and cooperating roughened surface, the strength of the inflatable member is somewhat limited. Also, in larger diameter sizes, the Allen construction is difficult to manufacture and expensive because of the necessity for close tolerance machining on large diameter parts. Furthermore, in the Allen patent, the space required for the wedge cones to retain the circumferentially arranged, longitudinally overlapping strips of reinforcing in position to form the sheath can become cumbersome where the inflatable member increases in diameter while the space within which it is to be used may be limited or restricted.

SUMMARY OF THE INVENTION The present invention relates to a method of forming an inflatable member with a reinforcing sheath on a body as well as a method of forming an end anchorage for the reinforcing sheath which utilizes a minimum of space.

The method of the present invention employs an adhesive such as by way of example only, a resin and catalyst, such as an epoxy resin, and a suitable catalyst or hardening agent therefor; an acrylic adhesive, or other suitable adhesives, as a method of aiding in locking the ends of a reinforcing sheath of an inflatable member in position along with a method of forming the ends of the sheath to aid in locking the ends of the sheath within the hardened adhesive to retain the reinforcing ends in position notwithstanding substantial loads or stresses that may be applied thereto upon inflation of the inflatable member.

Another object of the present invention is to provide a method of building up an inflatable member utilizing a void forming substance such as by way of example only, a closed cell foam such as a closed cell urethane foam whereby a void is formed in the adhesive so that one or both ends of the inflatable member may, after fabrication and upon inflation, move readily relative to the body upon which the inflatable member is formed.

Another object of the present invention is to provide a method of forming a reinforced inflatable member wherein a shield is provided to aid in relative movement of portions of the inflatable member relative to other portions as it inflates.

Still another object of the present invention is to provide a method of forming a reinforcing sheath for an inflatable member wherein the ends are anchored by an adhesive, which hardened adhesive along with the arrangement of the ends of the reinforcing sheath is able to withstand substantially greater-stresses and forces than the forces or stresses necessary for shearing or pulling of the reinforcing when it is potted at its ends in hardened resin and filler material.

A further object of the present invention is to provide a method of fabricating an inflatable member on a body wherein an inflatable element forming part of the member may be secured at both ends to the body with a surrounding reinforcing sheath that is movable at one or both ends relative to the body upon inflation.

Other objects and advantages of the present invention will become apparent from a consideration of the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a one-quarter sectional view of a body which has already been formed with bands secured thereto illustrating the first step of the method;

FIG. 2 illustrates the next steps and is a quarter sectional view of one end of the body with parts cut away showing a resilient element surrounding the body and abutting against one of the back-up rings, along with means for securing or sealing the resilient element adjacent the ring and a wrap temporarily positioned over the resilient element to confine it for vulcanizing. It can be appreciated that the method of forming the other end of the inflatable member on the body is similar to that shown in FIG. 2 whereby both ends of the resilient element are secured adjacent the spaced back-up rings;

FIG. 3 is in part a quarter sectional view showing the inflatable member after it has been formed to the point where a shield for the end or ends of the inflatable member which are to be moved is provided between the resilient element and the reinforcing sheath, which in this figure is shown in half section. A sleeve is shown positioned over one end of the reinforcing sheath with the reinforcing extending beyond the back-up ring;

FIG. 4 is a sectional view showing the inflatable member as having been provided with an additional shield applied adjacent the body on which the member is being formed with a void forming substance or material such as a closed cell urethane foam positioned between the back-up ring and the second shield. Also, the sleeve is illustrated in a position whereby the shield and void forming substance may be inserted beneath the reinforcing sheath;

FIG. 5 is a perspective view of one end of the body upon which the inflatable element is being formed showing, in this embodiment, the exposed ends of the reinforcing sheath and a member or anchor plate inserted between each of the overlapping circumferentially extending reinforcing strips at their ends. It can be appreciated that such members are inserted in each end of the sheath between the reinforcing strips;

FIG. 6 is a sectional view, partly in elevation, of one end showing the sleeve in its final position surrounding the end of the reinforcing sheath formed by the strips with the member between and at the end of each strip and a closure member or seal between one end of the sleeve and the body; and

FIG. 7 is a sectional view, partly in elevation and partly cut away, illustrating one configuration of an inflatable member which has been built up on a body of a desired configuration and illustrates an arrangement of an inflatable member wherein one end is secured to the body and the other end is movable relative thereto, with the inflatable element sealably secured at each end to the body. An outer cover is shown as positioned between the sleeves and secured thereto and to the reinforcing sheath in the FIG. 7 illustration.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention will be described in detail wherein the inflatable element is formed or built up on a tubular member such as a pipe. However, it can be appreciated that the body upon which the inflatable element is formed may be of any desired configuration and that the body may be formed in any suitable manner to any size or diameter.

Attention is first directed to FIG. 1 wherein a body is represented generally by the numeral 20. It will be noted that the body is tubular in form and is of any desired longitudinal extent and diameter. The steps of forming the inflatable member on the body 20 will vary somewhat, depending upon the materials employed. For example, where the resilient element 27 which extends between the back-up rings 21 is to be formed from elastomer sheets or strips which are applied between the metal rings 21 by suitable means well known in the art, such as by a calendar machine, then the rings 21 will be secured to the body 20 in longitudinal spaced relation as illustrated in FIG. 1, depending upon the length of inflatable member desired. The rings 21 are illustrated as being welded on one side as at 23 to secure them in position to the body 20 as shown. Since the rings 21 aid in anchoring the end portions of the reinforcing sheath to inhibit shear as will be described, in those instances where the inflatable member is to be used at relatively high pressures, it is desirable that the means of securing the bands or rings 21 to the body 20 be by welding; however, in some circumstances the rings 21 could be secured to the body 20 by any suitable adhesive such as by an epoxy resin and hardening agent by means well known in the art.

Where the resilient element 27 is preformed and precured to the desired diameter of the outer surface of the body 20, such resilient element 27 may be initially positioned on the body and thereafter the rings 21 abutted against each end of the resilient element 27 and secured in position. Where the resilient element 27 is prefermed and then positioned on the body 20 and the rings 21 thereafter positioned adjacent each end of the resilient element 27, suitable metal bands (not shown) or suitable strips of material of sufficient strength could be placed on the outer surface of the resilient element 27 at each end thereof adjacent the bands 21 to clamp or seal the ends of the resilient element 27 in position against the body 20.

Where the resilient element 27 is formed of elastomer and vulcanized in position on the body 20, the tu bular body 20 may be cleaned adjacent each ring for a suitable distance, by way of example, such as two or three inches in width as illustrated at 22. The cleaning of the surface of the body 20 adjacent each ring 21 may be effected by sandblasting or by rough grinding or machining the surface to clean off all grease and foreign materials such as mill scale and other material so that a suitable bonding agent may be thereupon applied to the surface 22. The bonding agent is any bonding agent well known to those skilled in the art so that when the elastomer sheet or strip forming the resilient element 27 is vulcanized, the ends thereof will adhere and seal to the portion 22 of the body 20 adjacent each of the rings 21. After the bonding agent has been applied, then that portion of the body between the cleaned surfaces 22 is prepared so that the raw elastomer will not adhere thereto during the vulcanizing step and to accomplish this a suitable mold release agent is employed, if necessary, which mold release agent is well known to those skilled in the art of handling and vulcanizing elastomer and forms no part of the present invention. After the mold release agent has been applied thereto, then the temporary plug 24 may be positioned within the threaded opening 25 which is formed in the body 20 between the rings 21 as shown in FIG. 1 of the drawings, and mold release agent is applied thereto to prevent the resilient element from bonding therewith. It can be appreciated that the plug 24 can be secured in position initially before the rings 21 are secured to the body 20.

After the moldrelease agent has been applied to the outer surface of the body between the cleaned portions 22, the elastomer sheet or strips are applied between the metal bands to the desired thickness, which in some instances will be rolled onto the pipe to build the resilient element up to a desired thickness such as one-quarter of an inch to one-half inch thick; however, in some instances, this thickness will vary and the foregoing is given by way of example only and is not intended as a limitation. It is desired that the thickness of the resilient element 27 approximate the width of the metal rings 21, and if necessary, the elastomer can be trimmed after it has been applied to the outer surface between the metal rings 21 to obtain uniform thicknes throughout its longitudinal extent.

Where elastomer sheets or strips are used to form the resilient element 27 on the body 20, suitable confining material such as nylon tape as represented at 28 is then wrapped on the exterior of the elastomer sheet or strip to confine it during the vulcanizing step. It can be appreciated that any tape or wrapping material normally employed to confine the elastomer such as rubber during vulcanization may be employed, and such material forms no part of the present invention.

Thereafter, the wrapped resilient element is subjected to vulcanizing either by steam or dry heat, or any other suitable vulcanizing process to form or vulcanize the elastomer to the desired physical properties.

FIG. 3 diagrammatically illustrates the next step, or steps, of the present method which will be varied, depending upon whether both ends of the inflatable member are to be formed so that they are movable relative to the body upon which the inflatable member is formed or whether only one end of the inflatable member is to be movable relative to the body upon which the inflatable member is formed with the other end being fixed or secured to the body.

.If one or both ends of the element is to move, then it may be desirable, or in some circumstances necessary to position a shield 30 adjacent the movable end, or movable ends. After vulcanizing, the plastic wrap 28 is removed from the outer surface of the resilient element 27, and the shield 30 then fixed in position. The shield 30 may be formed of any suitable material to accomplish the results desired and which will withstand the temperatures encountered during curing of the adhesive or vulcanizing when an outer cover 60 is employed, as will be described. It may be formed of a metal strip which may be, by way of example only, approximately 0.010 to 0.040 inch in thickness and may be wrapped over the ring 21 and extended around and along the end portion of the element 27 as shown in FIG. 3. The end 31 of the shield 30 may be bent down as shown in FIG. 3 over the ring 21 which it covers so as to retain it in the position and inhibit movement thereof. Where the shield 30 is formed of a strip of material, the end 32 may overlap the end 33 and the ends secured together by solder, spot welding, epoxy resin, or other adhesive. If the ends 32 and 33 do not overlap, but merely-abut, they may still be secured in the same manner. If desired, the shield 30 may abut the end of ring 21 and be compressed into resilient element 27 so that the surface 21a of ring 21 and the surface 30a of shield 30 are in substantially the same plane.

As shown in FIG. 3, the edge 31 is bent down continuously over the ring 21; however, it could be bent down merely at spaced circumferential intervals. As noted before, it is desirable that the shield retain its position as relative movement occurs between the reinforcing and the end of the resilient element 27 which is anchored or secured to the body 20, as will be described in greater detail hereinafter. The length of the shield 30 is preferably shorter than the over-all length of the sleeve 42 which surrounds each end of the reinforcing sheath 34 as will be described hereinafter.

As noted, if the inflatable member is to'be formed so that both of its ends are movable, then a shield 30 will be provided adjacent each of the spaced rings 21 whereas if only one of the ends of the inflatable member is to be movable, then a shield 30 is positioned adjacent the ring 21 on the end of the inflatable member which is movable.

If the smooth exposed surface of shield 30 is such that the adhesive employed, as will be described, might stick to it, then a mold release agent of any suitable type well known to those skilled in the art may be employed to prevent the adhesive from sticking to the exposed surface of the shield 30.

The reinforcing sheath referred to generally by the numeral 34 in FIG. 3 is next formed, and it can be noted that the reinforcing sheath 34 is preferably formed of longitudinally extending strips 35 which are of a suitable length so that they extend beyond each of the rings 21, at each end of the inflatable member--with only one of such ends being illustrated in FIG. 3 and showingthe strips 35 extending beyond the ring 21 secured to the body 20. It will be noted that each of the longitudinally extending strips 35 circumferentially overlapan adjacent strip. The width of the strips'and their arrangement in forming the sheath 34 is such that each of the strips will overlap the next adjacent strip when the inflatable member is deflated and each strip will overlap the next adjacent strip when the inflatable member is inflated, thus forming a reinforcing sheath for the inflatable element at all times.

Depending upon the use for which the inflatable member is constructed, the base material of the strips may be of flat braided wire impregnated with elastomer or plastic, strips of plain woven fiberglass which may or may not be impregnated with elastomer or plastic, strips of plain or woven nylon, strips of spring steel, strips of metal such as ordinary mild steel or other permanently deformable material (where a permanent set is desired in the inflatable member), strips of other plain or woven material, such as teflon or other plastics, depending upon the pressure to which the inflatable member is to be inflated.

As a practical matter, the strips 35 which form the reinforcing sheath 34 may be laid or placed on the outer surface of the inflatable element 27 in any suitable manner, and one suitable manner is to position at least one rubber band or O-ring on the inflatable element 27 to retain the strips 35 in position as they are applied one by one. After all of the strips 35 have been placed on the inflatable element 27, temporary metal bands held in place by any suitable clamp means may be employed to retain the strips in position and prevent shifting thereof during subsequent forming of other portions of the inflatable member.

After the reinforcing sheath 34 has been formed, then the sleeves 42 may be slipped over the ends of the body 20 and preferably moved to a position as illustrated in FIG. 4 to expose not only the ends of the strips 35 but also the metal bands or rings 21. FIG. 4 also illustrates one end of an inflatable member and the method of forming thereof, which end is formed so that it may move relative to the body upon which the inflatable member is being formed, and it can be appreciated that if both ends of the inflatable member are to be movable, they will be formed in a manner similar to that described with regard to FIG. 4.

Where the end of the inflatable member is to be formed so that it is movable, a void forming substance or material such as by way of example, a closed cell foam, such as closed cell urethane foam may be positioned to form ring 44 which abuts metal ring 21. To accomplish this, it can be appreciated that the ends of the reinforcing strips 35 may be flared outwardly and a strip or ring of void forming substance positioned as shown at 44 in FIG. 4. The void forming substance may be balsa wood, styrofoam, heavy grease which resists deterioration under high temperatures (i.e., above the curing temperature of the adhesive or vulcanizing temperatures employed which are both well known to those skilled in the art), a thin shell of plastic, wood, metal, or other material which will collapse under pressure, but which will effectively form a void on one side of the ring 21 so that adhesive will be prevented from filling it and thereby provide a space to accommodate movement of the end of the inflatable member.

Where the surface 20 of body 20 is such that it will accommodate movement of the inflatable member end, then a mold release agent can be applied thereto to inhibit adhesive from sticking to the surface 20'. If necessary, an additional shield 45 formed of a strip of material such as teflon which has a smooth surface, or metal, can be inserted beneath the reinforcing and against the outer surface 20 of the body 20. Its ends 46 and 47 may be overlapped and secured as described with regard to the shield 30, or they may be abutted and setained commercially and forms no part of the present invention.

It will be noted that the second shield 45 is in spaced relation to the metal ring 21, and if desired, the void forming substance or material may overlap the second shield 45 as shown in FIG. 4.

As noted previously, the void forming substance 44 is compressible and collapses under pressure to accommodate movement of the inflatable member end relative to the body on which is is formed.

It can be appreciated that if desired the void forming substance or material 44 and the second shield 45 could be first positioned on the body 20 and then the reinforcing strips laid over the inflatable element 27 which would avoid flaring the ends of the strips 35 as previously mentioned. Actually, whether the second shield 45 is employed or not, the void forming substance 44 may be positioned anytime before members 38 are inserted in the sheath 34 as will be described.

Attention is now directed to FIG. 5 of the drawings wherein it will be noted that members or anchor plates 38 are inserted in the sheath between the ends of the strips 35.

As shown in FIG. 5, a member or anchor plate 38 may be inserted between each of the strips 35 at each end of the sheath 34; however, such method and arrangement is only the preferred form, and if desired, the anchor plates or members 38 may be inserted in any staggered relationship such as between every other strip 35, or even between every third or every sixth strip, or otherwise, depending upon the strength desired in the end anchorage for the inflatable member. The arrangement shown in FIG. 5 provides the strongest end anchorage for the inflatable member.

When the anchor plates 28 are inserted in the ends of the sheath, they are loose. That is, a void is formed between the anchor plates 38 and ends of strips 35 so that the adhesive employed will have intimate contact with the exposed surfaces of members 38 and adjacent exposed ends of strips 35.

Where the strips 35 are formed of a base material such as braided fibers or wire coated with elastomer or plastic, then the elastomer or plastic is preferably removed therefrom. Stripping the coating exposes the base material of the strips 35 so as to form a better bond with the adhesive substance as will be described.

Where nylon or other plastic is employed as the base material of strips 35, the members 38 could be formed of nylon or other plastic. It is generally desirable that the strength of the members 38 approach the strength of the base material of the strips 35 to achieve the most effective anchorage. As a practical matter, the members 38 are approximately two to three inches in length, but this length may vary as desired. Also, the members 38 may be flat or arcuate.

After the members 38 have been positioned as shown in FIG. 5 of the drawings, then the sleeve 42 is slipped along the sheath 34 until the counterbore 42' formed therein abuts the innermost end 38' of the members 38 as shown in FIG. 6. If desired, the sleeves 42 can be positioned in their final position and the members 38 then inserted in the ends of the sheath 34. After the members 38 are inserted and the sleeve 42 properly positioned, one of the ends between the sleeves 42 and the body 20 is closed off by any suitable means such as a closure or seal 50. As shown in FIG. 6, the closure 50 is a metal ring which is inserted within the counterbore 42 and thereafter may be secured to the sleeve 42 by suitable means such as welding 51. It will be noted that the inner edge 53 of the ring 50 rides on the shield 45, where such shield is employed, as more clearly illustrated in FIG. 7 of the drawings. Where no shield 45 is employed, the ring will ride on surface 20' of body 20.

After the space between the sleeves 42 and the body 20 has been closed off at one end of the sleeves 42, each end of the member may be supplied with a suitable adhesive for bonding the members 38 and ends of strips 35. It will be noted that the sleeves 42 are each provided with a hole 42a, and after the closure 50 has been secured in position, the body 20 may be suspended or supported in substantially a vertical position. It should be noted at this point that the ring 50 at the other end of the inflatable member will either ride on a shield 45 or on the surface 20 of body 20 where both ends are to be movable, or if one end is to be fixed as the inflatable member is illustrated in FIG. 7 of the drawings, the ring 50' will be secured to the body 20 by a weld 54. If only one end of the inflatable member is to be movable relative to the body upon which it is being formed, then the inflatable member will assume the configuration as shown in FIG. 7 wherein one end is completely sealed off and the other end is partially sealed off. In order to seal off the end which is partially sealed off, that is, the movable end-suitable means such as the seal element represented in dotted line at 56 may be employed to seal off between the ring 50, the shield 45, and the outer surface 20 of the body 20. Thereupon, the adhesive may be poured in the other end 42b of the sleeve, whereupon it will flow downwardly into the sleeve 42 and fill it up to the hole 42a. The adhesive may then be precured to a partially hardened condition, whereupon the other end of the inflatable member is positioned so as to receive the adhesive through the end 42b of the outer sleeve 42. Again the sleeve is filled until the adhesive leaks out the hole 42a, and thereupon precured to partially harden the adhesive. Thereafter, the adhesive can be fully hardened or cured by heating for a suitable length of time if desired and if necessary.

The adhesive employed may be of any suitable type, one which cures at room temperature, or one which cures more readily with applied heat. For example, it may be any suitable epoxy resin and catalyst, the catalyst being well known to those skilled in the art. One suitable adhesive is sold under the trademark EPON by Shell Chemical Corporation. A suitable acrylic adhesive is sold under the trademark CHEMLOK by Hughson Chemical Company, Division of Lord Corporation, and another suitable adhesive is sold under the trademark SOLlTl-IANE by Thiokol Chemical Corporation.

It is desirable that the adhesive when fully cured provide an intimate bond with the plates 38 and ends of strips as well as being hard and remaining hard at elevated temperatures.

Where an adhesive is used that cures at room temperature, wax may be employed as the void forming substance 44, and after the adhesive has cured, the wax could be melted and poured out the end 42b of sleeve 42.

In those situations where it is desired, an outer cover as represented at 60 of resilient or plastic material may beapplied to the reinforcing sheath 34. This is accomplished by cleaning the exposed portions of the reinforcing strips 35 to remove. grease, or other foreign material, one suitable cleaning agent being methyl ethyl ketone, or if desired, a light sandblasting may be employed to clean the exposed surfaces and then a bonding agent is applied to the cleaned surfaces. The temporary metal bands on the sheath 34 are then removed.

The elastomer is then applied in sheets or strips to the reinforcing sheath 34. If desired, the elastomer may be trimmed to provide a uniform thickness. Thereafter, a

wrap (not shown) or the like is applied to the elastomer in a manner previously described with regard to the resilient element 27 to confine it during vulcanizing. After the outer cover has been vulcanized, the tape or wrap is removed so that the inflatable member may expand when it is inflated.

Thereafter, the plug 24 is removed, leaving the opening 25 for receiving fluid internally of the inflatable member. If desired, the inflatable member may be inflated so as to break the movable end or ends free to collapse the ring or rings 44 and to assure proper functioning of the inflatable member.

The foregoing disclosure and description of. theinvention are illustrative and explanatory thereof, and various changes in the size, shape, and materials as well as in'the details of the illustrated construction may be made without departing from the spirit of the invention.

What is claimed is: j

1. A method of fabricating an inflatable member on a body comprising the steps of:

a. positioning a resilient tubular element to surround the body;

b. bonding the element adjacent each end to the body;

c. securing back-up rings on the body adjacent each end of the resilient element;

cl. positioning reinforcing strips over the resilient element to form a sheath wherein the strips forming the sheath overlap adjacent strips throughout their length;

e. positioning a sleeve over each end of the sheath;

f. inserting anchor plates between the ends of the reinforcing strips;

g. sealing off one end of each sleeve with closure means; and I h. pouring an adhesive mixture into the other end of each of the sleeves to bond the anchor plates and ends of the reinforcing strips.

2. A method of fabricating an inflatable member on a body comprising the steps of:

a. positioning a resilient tubular element to surround the body;

b. bonding the element adjacent each end to the body;

(1. securing a shield in position over at least one end portion of the resilient tubular element;

e. positioning a void forming substance adjacent at least one of the back-up rings and the end portion of the element having a shield thereon;

f. positioning reinforcing strips over the resilient element to form a sheath wherein the strips forming the sheath overlap adjacent strips throughout their length;

g. positioning a sleeve over each end of the sheath;

h. inserting anchor plates between the ends of the reinforcing strips;

i. sealing off one end of each sleeve with closure means; and

j. pouring an adhesive mixture into the other end of each of the sleeves to bond the anchor plates and ends of the reinforcing strips.

3. The method of claim 1 including the additional step of applying a resilient cover to the sheath and the sleeves.

4. The method of claim 2 including the additional step of applying a resilient cover to the sheath and the sleeves.

5. The method of claim 1 including the step of securing the end of one of the sleeves to the body.

6. The method of claim 2 including the step of securing the end of one of the sleeves to the body.

7. A method of fabricating an inflatable member on a tubular body comprising the steps of:

a. welding back-up rings on the tubular body in spaced relationship;

b. cleaning the tubular body adjacent each ring for receiving a bonding agent and applying the bonding agent to the cleaned surface;

c. applying an elastomer to the tubular body between the rings to a desired thickness;

d. applying a confining means to the elastomer on the tubular body to confine it;

e. vulcanizing the elastomer on the body to secure it at each end adjacent the metal rings and to form a resilient element;

f. removing the confining means from the vulcanized elastomer;

g. positioning reinforcing strips over the resilient element to form a sheath wherein the strips forming the sheath overlap adjacent strips throughout their length;

h. positioning a sleeve over each end of the sheath;

i. inserting anchor plates between the ends of the reinforcing strips;

j. sealing off one end of each sleeve with closure means; and

k. pouring an adhesive mixture into the other end of each of the sleeves to bond the anchor plates and ends of the reinforcing strips.

8. The invention of claim 7 including the steps of:

a. applying an elastomer to the sheath to a desired thickness;

b. applying a confining means to the sheath to confine it;

c. vulcanizing the elastomer on the sheath and to the sleeves; and

d. removing the confining means from the vulcanized elastomer.

9. The invention of claim 7 including the step of securing the end of one of the sleeves to the body.

10. The method of claim 7 including the additional step of applying a resilient cover to the sheath and the sleeves.

11. The method of claim 7 wherein the tubular body has an opening therethrough between said rings which are welded in position in spaced relation, the additional step of plugging the opening before vulcanizing the rubber to form the resilient element.

12. A method of fabricating an inflatable member on a body comprising the steps of:

a. welding back-up rings on the tubular body in spaced relationship;

0. applying an elastomer to the tubular body between the rings to a desired thickness;

f. removing the confining means from the vulcanized elastomer;

' g. securing a shield in position over at least one end portion of the resilient element;

h. positioning a void forming substance adjacent at least one of the back-up rings and the end portion of the element having a shield thereon;

i. positioning reinforcing strips over the resilient element to form a sheath wherein the strips forming the sheath overlap adjacent strips throughout their length;

j j. positioning a sleeve over each end of the sheath;

k. inserting anchor plates between the ends of the reinforcing strips;

1. sealing off one end of each sleeve with closure means; and

m. pouring an adhesive mixture into the other end of each of the sleeves to bond the anchor plates and ends of the reinforcing strips.

13. The invention of claim 12 including the step of securing the end of one of the sleeves to the body.

14. The method of claim 12 wherein the tubular body has an opening therethrough between saidrings which are welded in position in spaced relation, the additional step of plugging the opening before vulcanizing the rubber to form the resilient element.

15. The method of claim 12 including the additional step of applying a resilient cover to the sheath and the sleeves.

16. The invention of claim 12 including the steps of:

a. applying an elastomer to the sheath to a desired thickness;

b. applying a confining means to the sheath to conc. vulcanizing the elastomer on the sheath and to the sleeves; and

d. removing the confining means from the vulcanized elastomer.

17. A method of fabricating an end anchorage for an inflatable member that is reinforced by a surrounding sheath formed of strip material with sleeves surrounding each end of the sheath comprising the steps of:

a. inserting plate members in the sheath between ends of the strips;

b. sealing off one end of the sleeves with closure means; and

c. pouring an adhesive mixture into the other end of each of the sleeves for bonding the members and the sheath.

18. A method of fabricating an end anchorage for an inflatable member that is reinforced by a surrounding sheath formed of strip material with at least one sleeve surrounding an end of the sheath comprising the steps of:

a. inserting plate members in the sheath between ends of the strips adjacent a surrounding sleeve;

b. sealing off one end of the sleeve with closure means; and c. pouring an adhesive mixture into the other end of the sleeve for bonding the members and the sheath.

Claims

1. A method of fabricating an inflatable member on a body comprising the steps of: a. positioning a resilient tubular element to surround the body; b. bonding the element adjacent each end to the body; c. securing back-up rings on the body adjacent each end of the resilient element; d. positioning reinforcing strips over the resilient element to form a sheath wherein the strips forming the sheath overlap adjacent strips throughout their length; e. positioning a sleeve over each end of the sheath; f. inserting anchor plates between the ends of the reinforcing strips; g. sealing off one end of each sleeve with closure means; and h. pouring an adhesive mixture into the other end of each of the sleeves to bond the anchor plates and ends of the reinforcing strips.

2. A method of fabricating an inflatable member on a body comprising the steps of: a. positioning a resilient tubular element to surround the body; b. bonding the element adjacent each end to the body; c. securing back-up rings on the body adjacent each end of the resilient element; d. securing a shield in position over at least one end portion of the resilient tubular element; e. positioning a void forming substance adjacent at least one of the back-up rings and the end portion of the element having a shield thereon; f. positioning reinforcing strips over the resilient element to form a sheath wherein the strips forming the sheath overlap adjacent strips throughout their length; g. positioning a sleeve over each end of the sheath; h. inserting anchor plates between the ends of the reinforcing strips; i. sealing off one end of each sleeve with closure means; and j. pouring an adhesive mixture into the other end of each of the sleeves to bond the anchor plates and ends of the reinforcing strips.

7. A method of fabricating an inflatable member on a tubular body comprising the steps of: a. welding back-up rings on the tubular body in spaced relationship; b. cleaning the tubular body adjacent each ring for receiving a bonding agent and applying the bonding agent to the cleaned surface; c. applying an elastomer to the tubular body between the rings to a desired thickness; d. applying a confining means to the elastomer on the tubular body to confine it; e. vulcanizing the elastomer on the body to secure it at each end adjacent the metal rings and to form a resilient element; f. removing the confining means from the vulcanized elastomer; g. positioning reinforcing strips over the resilient element to form a sheath wherein the strips forming the sheath overlap adjacent strips throughout their length; h. positioning a sleeve over each end of the sheath; i. inserting anchor plates between the ends of the reinforcing strips; j. sealing off one end of each sleeve with closure means; and k. pouring an adhesive mixture into the other end of each of the sleeves to bond the anchor plates and ends of the reinforcing strips.

8. The invention of claim 7 including the steps of: a. applying an elastomer to the sheath to a desired thickness; b. applying a confining means to the sheath to confine it; c. vulcanizing the elastomer on the sheath and to the sleeves; and d. removing the confining means from the Vulcanized elastomer.

12. A method of fabricating an inflatable member on a body comprising the steps of: a. welding back-up rings on the tubular body in spaced relationship; b. cleaning the tubular body adjacent each ring for receiving a bonding agent and applying the bonding agent to the cleaned surface; c. applying an elastomer to the tubular body between the rings to a desired thickness; d. applying a confining means to the elastomer on the tubular body to confine it; e. vulcanizing the elastomer on the body to secure it at each end adjacent the metal rings and to form a resilient element; f. removing the confining means from the vulcanized elastomer; g. securing a shield in position over at least one end portion of the resilient element; h. positioning a void forming substance adjacent at least one of the back-up rings and the end portion of the element having a shield thereon; i. positioning reinforcing strips over the resilient element to form a sheath wherein the strips forming the sheath overlap adjacent strips throughout their length; j. positioning a sleeve over each end of the sheath; k. inserting anchor plates between the ends of the reinforcing strips; l. sealing off one end of each sleeve with closure means; and m. pouring an adhesive mixture into the other end of each of the sleeves to bond the anchor plates and ends of the reinforcing strips.

14. The method of claim 12 wherein the tubular body has an opening therethrough between said rings which are welded in position in spaced relation, the additional step of plugging the opening before vulcanizing the rubber to form the resilient element.

16. The invention of claim 12 including the steps of: a. applying an elastomer to the sheath to a desired thickness; b. applying a confining means to the sheath to confine it; c. vulcanizing the elastomer on the sheath and to the sleeves; and d. removing the confining means from the vulcanized elastomer.

17. A method of fabricating an end anchorage for an inflatable member that is reinforced by a surrounding sheath formed of strip material with sleeves surrounding each end of the sheath comprising the steps of: a. inserting plate members in the sheath between ends of the strips; b. sealing off one end of the sleeves with closure means; and c. pouring an adhesive mixture into the other end of each of the sleeves for bonding the members and the sheath.

18. A method of fabricating an end anchorage for an inflatable member that is reinforced by a surrounding sheath formed of strip material with at least one sleeve surrounding an end of the sheath comprising the steps of: a. inserting plate members in the sheath between ends of the strips adjacent a surrounding sleeve; b. sealing off one end of the sleeve with closure means; and c. pouring an adhesive mixture into the other end of the sleeve for bonding the members and the sheath.