US3648312A

US3648312A - Expansible collar

Info

Publication number: US3648312A
Application number: US25150A
Authority: US
Inventors: Gerald L May
Original assignee: BF Goodrich Corp
Current assignee: SMR Technologies Inc
Priority date: 1970-04-02
Filing date: 1970-04-02
Publication date: 1972-03-14
Anticipated expiration: 1989-03-14
Also published as: CA919514A

Abstract

A double wall inflatable cylinder of elastomeric material having a pair of overlapping layers of cords extending in intersecting relationship at an angle to a line extending axially of the cylinder for compact storage in the retracted position, maximum expansion of the outer wall and gripping of a core by the inner wall in the inflated condition. A layer of circumferentially extending cords at one edge of the cylinder limits expansion of the cylinder at that edge and the walls are invaginated at the other edge to provide a double fold for compact stowage.

Description

it] States May [151 fimdfill [45] Mar. M, 1972 [54] EXPANSTBLE CULLA [21] Appl. No.: 25,150

Mosshart et a1. ..l52/356 1,367,225 2/1921 Barker ..9/340 X 2,309,256 1/1943 Rekersdres 1,998,805 4/1935 Driggs ..1 14/20 Primary Examiner-Milton Buchler Assistant ExaminerGregory W. OConmor Attorney-John D. Haney and Harold S. Meyer [57] AESTMRACT A double wall inflatable cylinder of elastomeric material having a pair of overlapping layers of cords extending in intersecting relationship at an angle to a line extending axially of the cylinder for compact storage in the retracted position, max imum expansion of the outer wall and gripping of a core by the inner wall in the inflated condition. A layer of circumferentially extending cords at one edge of the cylinder limits expansion of the cylinder at that edge and the walls are invaginated at the other edge to provide a double fold for compact stowage.

7 Claims, 7 Drawing Figures Fuel INVENTOR.

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EXPANSIBLE Cort/tn BACKGROUND OF THE INVENTION This invention relates to an expansible collar of the type which is carried by a projectile such as a torpedo and is inflatable to provide sufficient buoyancy so that the projectile will float and therefore be in a position to be recovered and used again. Collars of this type are also used as a brake to reduce the speed of the projectile through the water after it has been used so that it may be more easily recovered.

It is possible to use practice torpedoes at less than tactical gross weight to insure they will float after their run; however, it is desirable that these practice torpedoes be operated under normal tactical conditions and therefore expansible collars of this type are needed.

Inflatable bags have been used to float torpedoes; however, these bags have presented certain problems. In order to provide the volume necessary for buoyancy, the bags were folded and had many pleats which had to be laid in position so that the bags would fit in the limited space provided and not have wrinkles at the surface which would interfere with the opera tion of the torpedo. To reuse the bags, they had to be refolded and the proper stowage of the bags was an exacting and tedious time-consuming operation. Another problem with the folded bags was that during expansion, one side would expand before the other in a random manner which would turn the torpedo if it was still moving through the water. The moving torpedo would also exert high stresses on the bags causing rupture of the walls. These bags also had a low bursting strength and it was necessary to provide precise control of the gas pressure withing the bags.

The high cost of torpedoes used for practice and in development makes it imperative that they be recovered with dispatch and be ready for reuse in the shortest possible time. It is evident from the above that the folded bag type gear which has been used heretofore has not met these requirements.

SUMMARY OF THE INVENTION The expansible collar of this invention provides a collar of elastomeric material which presents a smooth outer surface, fits in a small space in the surface of the torpedo, expands to a large volume to provide the necessary buoyancy to float the torpedo and automatically retracts to the original position when deflated without requiring any restowing of the gear. During expansion the collar assumes a streamline shape and the expansion is concentric resulting in braking action which does not turn the torpedo or generate excessive forces in the walls of the collar.

Inflation of the collar requires a relatively low gas pressure; however, the construction is such that it will withstand high pressures and therefore the pressure controls for this equipment need not be of a highly sophisticated and expensive construction to regulate gas pressure.

Control of the expansion of the collar during inflation is provided through the use of layers of high strength cord fabric embedded in a body of the elastomeric material with the cords of overlapping layers having opposite bias angles. The space required to stow the collar is kept at a minimum by making use of a construction in which the wall of the collar is invaginated at one edge and whereby a double fold produces four thicknesses of the wall for stowage in the recess provided. Preferably, this invagjnated edge is at the aft end so that as the collar expands, the forward edge will expand at a slower rate than the aft edge. A layer of cord fabric with cords extending in the circumferential direction may be built into the forward edge of the collar to further reduce initial expansion of that portion of the collar.

The resilient nature of the collar permits it to be stretched over the torpedo during installation and snapped into place in the recess provided. The collar may have a flange at the forward end to secure the body of the collar in the recess of the torpedo. The construction of the collar is such that it will not roll over on itself during expansion and therefore has the necessary stability.

The accompanying drawings show one preferred form of expansible collar made in accordance with and embodying this invention and which is representative of how this invention may be practiced.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. l is a plan view of a torpedo showing the expansible flotation collar in the inflated condition.

FIG. 2 is an enlarged fragmentary view of the apparatus shown in FIG. 1 with the expansible flotation collar shown in half section to illustrate the position of the walls in the inflated condition.

FIG. 3 is a view like FIG. 2 showing the expansible collar in the partially inflated condition.

FIG. 4 is a view like FIG. 3 showing the expansible collar in the deflated condition and stowed away in the recess on the torpedo surface.

FIG. 5 is an enlarged fragmentary sectional view of the forward end of the expansible collar shown in FIG. 4i illustrating the layers of cord fabric in detail.

FIG. 6 is a fragmentary plan view of the forward end of the expansible collar in the deflated condition with parts being broken away to show the disposition of the cords in the overlapping layers of cord fabric.

FIG. 7 is a view like FIG. 5 but showing the inflation port in the collar.

DETAILED DESCRIPTION Referring to FIG. 11, a schematic view of a torpedo I0 is shown on which a flotation collar 11 is mounted and is shown in the full inflated condition. As shown in FIG. 2 in more detail, the collar III is a hollow annular body or double wall cylinder seated in a circumferential recess 12 in the torpedo surface. The collar 11 has an inner wall 13 which abuts the surface of the recess, and an outer wall M which expands during inflation and contracts during deflation of the collar.

As described heretofore, FIG. 2 shows the collar III in the full inflated condition providing the maximum buoyancy with the maximum volume. FIG. 3 shows a view of the collar II in the partially inflated condition in which the outer wall M has a tapered contour presenting a streamline surface for braking of the torpedo. It will be noted that forward edge 15 of the collar ll 1 has not expanded as much as aft edge In and this provides the tapered contour in this partially inflated condition. The completely deflated and retracted position of the collar 1111 is shown in FIG. 4. The inner wall 13 and the outer wall Ml have been invaginated at the aft edge providing a double fold and a circumferential folded portion 17 which extends forwardly of the collar 11 and reduces the length of the recess which is required for stowage of the collar.

Referring to FIG. 5, l5 and 7, a more detailed construction of the flotation collar III is shown. The collar Ill may be made of an elastomeric material which preferably is highly elastic and has high elongation properties. A material which will provide good adhesion to cord fabric is also desirable and in the present embodiment, natural rubber is used. Within the body of the collar 11 of the elastomeric material are overlapping layers of cord fabric which are laid on the bias. The number of layers depends on the strength requirement; however, they should be in multiples of two and in the present embodiment two layers are shown. The cords are of a high strength type and may be of rayon, nylon or other material. Stretch cord may also be used if desired. In the present embodiment, nylon having a strength of 1,600 pounds per square inch of width is used.

As shown in FIG. 5, an inner layer Id of cord fabric overlaps an outer layer 119 of cord fabric and these layers extend through the inner wall 113 and outer wall M of the collar ll forming an airtight chamber 22 which may be inflated. At the forward edge 15 a retaining layer 23 of cord fabric is interposed between the inner layer llfl and the outer layer 19 of the inner wall 13 for restricting the expansion of the forward edge and holding the collar 11 in the recess 12 of the torpedo.

Referring to FIG. 6, outer wall 14 is cut away to show cords 24 of outer layer 19 which are disposed at a relatively small bias angle to a line extending axially of the collar which is represented by center line XX shown in the drawing. This bias angle a may be in the range of 14 to 26 degrees and is approximately l8 degrees in this embodiment. The inner layer 18 has cords 25 which extend at a small bias angle to the center XX with the angle being represented on the drawing by b. It is preferable that the bias angle a equals bias angle b" and that the

cords

24 and 25 intersect or cross. As the collar 11 expands the

cords

24 and 25 will pantograph and the bias angles a and b will increase to a point where they are approximately 55 degrees to the center line XX whereupon the cords will lockup and fix the outer diameter of the inflated collar.

The retaining layer 23 has cords 26 extending substantially circumferentially of the collar to limit the expansion of the retaining layer during inflation and deflation of the collar 11. At the radially inner surface of the forward edge 15 of the collar, a folded edge or flange 27 extends under the retaining layer 23 and with the retaining layer, helps to secure the collar 11 in the recess 12. Referring to FIG. 7, a valve spud 28 having an opening 29 and secondary orifices 32 through which inflating gas may be injected into the collar 11 from gas producing means within the torpedo is shown. This valve spud 28 has a flange 33 which may be interposed between the inner layer 18 and outer layer 19 and adhered thereto by a suitable adhesive. The valve spud 28 may extend through an opening 34 in the wall of the torpedo 10 and have a threaded surface for receiving a threaded retaining ring 35.

To install the collar 11, it may be slipped over the end of the torpedo l and to the recess 12 in a stretched condition. This is possible due to the resiliency of the elastomeric material and the disposition of the

cords

24 and 25 in the layer of

fabric

18 and 19. The valve spud 28 is fitted in the opening 34 in the wall of the torpedo and secured by the retaining ring 35. The torpedo is then ready for operation with the collar 11 in the position shown in FIG. 4.

When the torpedo 10 is launched as in target practice or in tests, a gas producing device within the torpedo which is connected to the valve spud 28 is actuated after a predetermined time or at a certain signal. The gasis then injected into the chamber 22 of the collar 11 and expands the outer wall to the shape shown in FIG. 3. The operating pressure may be in the range of five p.s.i. to 30 p.s.i. The angular disposition of the

cords

24 and 25 of the outer layer 19 and inner layer 18 respectively permits this expansion and the circumferential disposition of the cords 26 of the retaining layer 23 retard the expansion of the forward edge to provide the tapered or cone-shaped contour shown in FIG. 3. In this position the collar 11 provides a smooth surface which is equally resistant to water flow along the torpedo and provides braking without turning the torpedo or damaging the collar itself. This braking action also limits the travel of the torpedo and therefore makes recovery easier.

Finally, in the fully inflated condition of the collar shown in FIG. 1 and FIG. 2, the inner wall 13 and outer wall 14 are stretched to the limit permitted by the cords 24 and to provide a maximum volume of the chamber 22. The disposition of the cords at the angles a" and b shown in FIG. 6 also provide for gripping of the surface of the torpedo at recess 12 by the inner wall 13 during expansion so that the collar 11 will have the necessary stability and stay in place.

After the torpedo has been recovered, the gas is released from the collar 11 and because of the construction of the collar as described heretofore, it will retract to the position shown in FIG. 4 and be ready for another use. Removal of the collar is also accomplished with ease simply by disconnecting the valve spud 28 and pulling the collar over the torpedo and off the end.

What is claimed is:

1. An inflatable expansible collar occupying a small space in a deflated retracted condition and expanding to contain a substantially large volume of gas in the inflated condition comtubular annular body of elastomenc material having prising a an inner wall, and outer wall and overlapping layers of cords adhered to said material and extending through said inner wall and said outer wall, an inner layer, an outer layer and a means for inflating and deflating said body, said inner layer having cords disposed at an angle to a line extending axially of said collar, said outer layer having cords extending at an angle to said line on the opposite side of said line for controlled expansion and complete return to the deflated condition of said body, a retaining layer of substantially circumferentially extending cords embedded in and adhered to said elastomeric material of said inner wall providing for limited stretching of said retaining layer and resilient gripping of a supporting body within said collar and said retaining layer being disposed at one edge of said inner wall to deter the inflation of that edge and the adjoining edge of said outer wall during expansion to provide a tapered contour of said body when partially inflated.

2. An inflatable expansible collar according to claim 1 wherein an opening is provided in said inner wall at a position adjacent said retaining layer and connected to said means for inflating and deflating said body.

3. An inflatable expansible collar according to claim 1 wherein a flange extends outwardly from said inner wall outwardly from said inner wall and under said retaining layer for securing the collar to another object.

4. An inflatable expansible collar according to claim 1 wherein said body has a circumferential folded portion opening in a double fold at a second edge of said collar spaced from said one edge of said collar providing for maximum expansion of said body, a small stowage volume in the retracted condition and a tapered contour of said body when partially inflated.

5. A torpedo brake and flotation collar comprising an annular, tubular, inflatable, expansible double wall cylinder for disposition in a circumferential recess in the outer surface of a torpedo, an inner wall and an outer wall having a diameter substantially the same as the outer surface of the torpedo, said inner wall and said outer wall of said cylinder having at least two overlapping layers of reinforcing cord embedded in and adhered to a highly elastic material, said overlapping layers having cords extending on the bias at opposite but equal angles to a line extending axially of said cylinder, gas producing means within the torpedo connected to said cylinder through an opening in said inner wall of said cylinder for inflating and expanding the cylinder to brake movement through the water during partial expansion and provide the necessary buoyancy to float the torpedo when fully expanded, a retaining layer of substantially circumferentially extending cords embedded in an adhered to said elastomeric material at the forward edge of said inner wall to provide a tapered contour of said outer wall of said cylinder during expansion and braking of the torpedo with a streamline surface.

6. A torpedo brake and flotation collar according to claim 5 wherein said cylinder has a flange extending outwardly from the forward edge of said inner wall and under said retaining layer for securing said collar to the walls of said recess of said torpedo.

7. A torpedo brake and flotation collar according to claim 6 wherein said inner wall and said outer wall of said cylinder are invaginated at the aft edge to provide for stowing said cylinder in a recess in the torpedo of less width than the length of the inner and outer walls of said cylinder and provide for expansion of the aft edge at a faster rate than the forward edge of the collar.

TED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 15485312 Dated March 1i, 1972 Inventor(s) GERALQ L. MAY

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

' Column 3, line 3 "layer"v should read .1

--layers---.

Column 4,

lines

28 and 29, (claim 3), cancel "outwardly from said inner wall".

Column 1, line 5 4, (claim 5), "an" should read -and---.

Signed and sealed this 15th day of August 1972.

(SEAL) Attest:

EDWARD M.,FLETCHER,JR. ROBERT GOTTSGHALK Attesting Officer Commissioner of Patents

Claims

1. An inflatable expansible collar occupying a small space in a deflated retracted condition and expanding to contain a substantially large volume of gas in the inflated condition comprising a tubular annular body of elastomeric material having an inner wall, an outer wall and overlapping layers of cords adhered to said material and extending through said inner wall and said outer wall, an inner layer, an outer layer and a means for inflating and deflating said body, said inner layer having cords disposed at an angle to a line extending axially of said collar, said outer layer having cords extending at an angle to said line on the opposite side of said line for controlled expansion and complete return to the deflated condition of said body, a retaining layer of substantially circumferentially extending cords embedded in and adhered to said elastomeric material of said inner wall providing for limited stretching of said retaining layer and resilient gripping of a supporting body within said collar and said retaining layer being disposed at one edge of said inner wall to deter the inflation of that edge and the adjoining edge of said outer wall during expansion to provide a tapered contour of said body when partially inflated.