US2401990A

US2401990A - Structure

Info

Publication number: US2401990A
Application number: US505093A
Authority: US
Inventors: Ward T Van Orman
Original assignee: Wingfoot Corp
Current assignee: Wingfoot Corp
Priority date: 1943-10-06
Filing date: 1943-10-06
Publication date: 1946-06-11
Anticipated expiration: 1963-06-11

Description

A Jue l1, 1946. vw. T. VAN ORM-AN S TRUC TUBE Filed oct'. e, 1943 Ward 77 Via/7 @rma/r Patented June 41v1, 1946 yPrice STRUCTURE Ward T. Van Orman, Akron, Ohio, assigner to Wingfoot Corporation, Akron, h10, a corporation of Delaware Application ctober 6, 1943, Serial No. 505,093

y is claims; (cl2-2.1i

sections with gently sloping sides, etc., which are.

adapted to be lled with a fluid under pressure. The fluid may be a gas or a liquid. uAccording to this invention, the fabric used in such cylin drical structures may be formed from squarewoven fabric by racking it, or two-ply, pickless fabric may be used. Whatever the fabric, the textile elements-i. e., threads if basket-weave and cords if two-ply pickless--rneet one another in an obtuse angle, preferably oi about 109 28', with the projection of the anis of the cylinder approximately bisecting this obtuse angle.

When a cylindrical structure in which the textile elements meet one another at an angle of approidmately 109 28 is placed under pressure, the longitudinal tension in the fabric is balanced by the radial tension. There is, therefore, no tendency for the cylinder to grow in either direction at the expense of the other. Also, in a fabric structure of this type, one obtains maximum strength with the minimum weight of material.

There is an advantage in using this type oi cylindrical structure in many fabric products. The advantages may be due chiefly to the sav' ing in material and consequent saving in weight, as in the construction of lighter-than-air craft, or they may lie in the improvement in the physical properties inherent in such structures, as will be more fully explained in what follows.

scribed in connection with the construction oi' a pressure garment, such as a suit for an aviator or diver. The garment its'loosely on the wearer, and the space between the garment and the wearer is iilled with a gas under pressure. air or oxygen is normally used, and this, is breathed by the wearer. Fresh gas is supplied continually, and the spent gas is continually bled from the suit. The space within the suit is lrept under a pressure' of two or three or four or more pounds greater than the pressure on the outside. A diver will maintain the suit under a pressure of one or two pounds above that of the depth of water at 4which he is working. .An aviator who illes at very high altitudes will maintain the pressure within the suit at a pressure several pounds greater than that found at these high altitudes. If the suit is to be used by a diver, it, of course, must be waterproof. This is not essential in an aviators suit. However, the fabric must be gas tight for both types of suits.

According to this invention, the cylindrical members of the suit, such as the arms and legs and trunk, are made of woven abric or two-ply pickless in which the textile elements meet at an obtuse angle. Although in the preferred form of` the invention the angle is substantially 7109 (or more exactly, 109 28'), there are advantages in using a substantially larger or smaller obtuse in lighter-than-air construction the sections of a ship near its center are generally cylindrical. When made of a balanced fabric, i. e., when constructed according to this invention, the amount of material employed may be kept at a minimum. The necessary strength may be obtained with the lightest weight cloth. This means an increase in the carrying power or pay load of the ship.

Many types of hose are now usually braided. A wrapped hose of two-ply or woven fabric is, much cheaper to construct. If an unbalanced structure is used, such as that produced by using conven\ tional, square-woven fabric on the bias, one of two things will happen when pressure is created within the hose by the passage of water or other fluid through it: either the hose will increase in .diameter and decrease in length, or it will decrease in diameter and increase in length. This will depend upon whether the radial or longitudinal tension is the greater. Any such tendency oi' the fabric to grow in one direction at the expense of the other is overcome by constructing the hose according to this invention.

The invention will be more particularly deangle. This will be explained in lwlciat follows.

The suit' may be designed to be worn in the sitting position or to be worn in the standing posil tion, or by designing it for an intermediate position as shown in the drawing, its shape can most conveniently be changed to accommodate a person whether in the sitting or standing position. The arms may be designed to hang at the side or rest in the lap or may be designed to normally assume any other desired position, preferably a position 'which approaches a mean of the positions the wearer will be required to assume while wearing the suit. The head piece may be of fabric,

'with transparent eyes, although a transparent dome is preferably used. The dome may be fastened to the balance of the suit in any usual or suitable manner.

The invention will be further described in connection with the accompanying drawing, in which Fig. 1 is a side view of a suit in perspective. Fig. 2 is a front view of the suit in perspective; Fig. 3 is an enlarged section on the line 3-3 of Fig. 2; Fig. 4 is an enlarged section on the line 4-8'of Fig. 1; Fig. 5 illustrates the relation of the textile elements to one another and to the axis of the suit member. Fig. 6 illustrates the exing of a I member. l

question is a knee or arm. Fig. 6 illustrates the not be flexed without placing a strain on the n warp on one side of the member and retracting the warp threads on the opposite side of the For example, suppose the member in warp 5 in any such member running parallel with its axis. The ll t is perpendicularto this. in the bent :.3 member. it is obvious that on the outer side of the bend the *1I-larp is placed underv tension, and on the under side of the bend the warp members are compressed.

If the fabric is placed on the bias, pantographic action of the warp and fill or cords gives greater iexibiity to the fabric. of course, that the bers are not too tightly Woven to preclude such movement during 'flexing The flexibility of the garment. however, is not solely dependent on the Warp and lill or cords being placed on the bias.

The most exible structure is that in which the threads or cords are under the least tension. If some threads or cords are taut and others are not under tension, the flexibility is not as great as when none of the threads or cords are taut; i. e., when all of the threads or cords are under equal stress. This is true in a balanced structure; e. g., in a cylinder in which the radial tension balances the longitudinal tension. The determination of the angle required between the textile elements to produce such a balanced, cylindrical structure will be explained by reference to Fig. 8 and the following calculations:

If P is the unit pressure and D is the diameter of the cylinder, We know that for a cylinder:

2 Longitudinal force h: 1rD4 P Length 1rD X tan 0 new` that t is the angle which produces h and cesnnonents which exactly balance the stress in the cylinder, referring to Fig. 8 and using the above values, we see that:

Angle e=35 1e' d This is the acute angle between the textile elements and a plane passed through the cylinder at right angles to its axis. The angle between the textile elements and a projection of the axis is, therefore, 54 44'. The obtuse angle between the vtextile elements is twice this or 109 28'. For

practical piu'poses, an angle of approximately 109? is satisfactory. This is illustrated in Fig. 5.

Although the greatest flexibility is obtained by using fabric with the textile elements at an angle of 109 428' to one another, the use of fabric in which they meet at any obtuse angle (either larger or smaller than 109 28') gives a more exible suit member under pressure than can be obtained from square-woven fabric. This is because the obtuse angle allows greater elongation than square-woven fabric. For instance, in one fabric which was tested the fabric was racked to 109 28', and the elongation measured along an axis bisecting this angle was approximately twice that of the conventional square-woven fabric placed on the The elongation of the racked fabric along an axis perpendicular to that mentioned was only about one-half that of the conventional square-woven fabric. The elongation of fabric racked to different angles varies ac-` flexible than if the member is made of squarewoven fabric.

The warp and fill of woven fabric may be originally woven at an obtuse angie. but it will generally be preferable .to produce the desired fabric by racking square-woven fabric, such as basketweave. This may be done as described in U. S. Patent 1,763,569.' The preferred methodl of obtaining the desired angle between the warp and the fill is to use square-woven fabric and distort it on a preparation table before it is coated. Further distortion of smaller magnitude may be done by using a spreading machine equipped with off-angle let-ofi' bars, guides or drags so that the fabric is drawn to one side as it leaves the spreader, and the fill will no longer lie transverse across the sheet at a angle, but at an angle of about 109 28' to the warp. The fabric distortion need not all-begaccomplished in a single passage through the spreader, but may be increased in each successive passage through the spreader until the desired racking is obtained.

The fabric is preferably made of high tenacity material, such as Sea Island, Sak or Pima cotton, or a. high tenacity rayon, such as the double Fortisan type, or other high, strength, continuous,

filament yarn, such as nylon, etc. With such high strength materials a fabric of low gauge may be employed, and this, in itself, lends ilexibility to the fabric structure.

A loosely woven, sleazy fabric lends itself to racking more readily than a tightly woven fabric.

A basket-weave fabric, such as that with 3 x 3 woven groups illustrated in Fig. '7, or one with 5 x 5 woven groups or the like, may advantageously be used. l I

The 'fabric is made gas impervious by treatment with rubber or another plastic, preferably applied in the form of a thick cement. It is desirable not to impregnate the fabric as this will increase its stiffness. .Strongly adherent coatings of methylene diphenyl diisocyanate to ten parts of the rubber or other plastic, may be desirable to obtain the adhesion required.

A cylinder formed of the racked fabric, when inflated, may show a marked tendency to twist due to the difference in the elongation of the Warp and ll or to certain stresses set up in the fabric. To nullify such distortion, the various cylindrical members of the suit or other structure are preferably made up by reversing circumferentially adjacent pieces of fabric. For example, as shown in Fig. 2, the lower leg portion I0 is made as a different unit from the boot '6 clearly. The twoparts of the zipper 20 are united to fabric tapes 50, which are sewn by the stitches 5I to the reinforcing strips 52, which are cemented to the pieces 23 and 24 of coated fabric. .A cushion ,63, which may be rubberized fabric, is provided to insure an airtight seal between the flap 22 and the section .23 of the coated fabric to which one section of the zipper is attached.v The .member 54 is a stiifening member. such as a metal strip, which prevents the suit Yfrom buckling when the wearer bends forward. It in- II to which it is later attached. Also, the thigh I2 is made as a separate member. These are united by the knee I3. Each of these members I0, I2, and I3 is made of racked fabric with the warp and fill forming an obtuse angle, which in each member is approximately bisected by a projection of the axis of that member on it. The members I0, I2, and I3 are each made up of two sections--a front and back. This is illustrated by Fig. 3, which shows an enlarged section of the lower leg member. The front and back portions of the leg member are indicated by the numerals I4 and I5, respectively. In assembling these members, the two halves of the pattern are reversed; that is, the coating A on the outside of the front half of the leg member is placed on the inside of the back half of this member. The side coated B, which is the inner side of the front member I4, then becomes the outside of the back member I5. By reversing adjoining pieces which make up the members I0, i2, and i3, the tendency of any one piece to distort the member is practically nulliiied by the opposite tendency of the adjoining piece. Similarly, each arm member is made up of two pieces which are likewise reversed.

The upper and lower trunk members are each advantageously made of four sections, as illustrated. Each is made from racked fabric with the obtuse angle of each member substantially symmetrical with respect to the projection of its axis. Fig. 4 shows an enlarged section through the lower trunk member. The front of the garment is shown as being closed with the `zipper 20. Any suitable closing me'ans may be employed.

Fig. t shows flaps 2i and 22 adjoined to different sections 23 and 26 of the lower trunk member overlapping behind the zipper to prevent the escape of air through the zipper when the suit is inflated. The rear sections of the trunk memoer are indicated by the numerals f5 and 25. As indicated by the letters A and B', which refer to opposite sides of the uncut fabric, the alternate, adjoining pieces which make up the lower trunk member are reversed. 2t is reversed with respectto both 20 and 25. 25 is reversed with respect to both 26 and 25. 25 is reversed with respect to both 25 and 23, and 23 is reversed with respect to both 20 and 2d. This gives a -balanced structure which shows minimum distortion on inflation.

lf two-ply, pickless cord fabric is used, the plies coated with uncured rubber or other curn able, plastic are placed on one another so that the angle between them is the desired obtuse angie. As shown in Fig. 10, the cords it in one ply make an angle of 109 28' with the cords dit in the other ply. The rubber coating is cured with the plies in this relation.

Fig. 9 gives details of the zipper-closing device shown in Fig. 4, with the diiferent parts spaced from one another to show the construction most sures an airtight seal between the two flaps 2land 22.

Fig. 4 shows in section the front and back of reinforcing straps 28 and 23 which pass over the shoulders and under the crotch of the suit.

' Attachments for supplying air and for bleeding the waste air may be provided in any desired manner. These are illustrated by the feed hose 35 and the spring-balanced pressure-relief valve 31. i

The helmet 40 is of transparent plastic, such as Plexiglas, although any suitable helmet may be used, and it may be fastened to the balance of the suit in any desired manner. The gloves may be made as desired. Various attachments, such as heating pads, etc., may be supplied as desired.

This application is in part a continuatlonof vmy application Serial No. 458,515, filed September 16, 1942.

What I claim is: l l. A generally cylindrical structure of woven fabric which is adapted to be inflated and in which the warp and fill form an angle of substantially 109 which is substantially bisected by a projection of the axis of the structure thereon.

2. A generally cylindrical structure of two-ply, pickless cord fabric which is adapted to be inflated, in which the cords of one ply form an angle of substantially 109 with the cords of the other ply, the angle between the cords being substantially bisected by a projection of the axis of the structure thereon.

3. A generally cylindrical structure of woven fabric which is adapted to be inflated and in which the warp and ll form an angle of substantially 109 which is substantially bisected by a projection of the axis of the structure thereon, circumferentially adjacent pieces of the fabric being reversed.

s. A generally cylindrical fabric structure which is adapted to be inflated and in which the textile elements, such as cords, threads and the like, form. an angle of substantially 109 to one another, which angle is substantially bisected by a projection of the axis of the cylinder thereon, circumferentially adjacent pieces of the fabric being reversed.

5. A generally cylindrical structure of racked, Woven fabric which is adapted to be inflated and in which the warp and lill form an angle of sub- 13 7. A pressure garment with a generally cylinsections of the fabric being reversed with re.

spect to the section on each side oi it.

8. A pressure garment formed with a member which is generally cylindrical in shape and made of Woven fabric in which the warp and fill form an obtuse angle, which member is so placed in the garment that a projection of the axis of the member substantially bisects the obtuse angle.

9. A pressure garment formed with a .member which is generally cylindrical in shape and made of a plurality of pieces of racked woven fabric in which the warp and the fill form an obtuse angle, in which member circumferentially adjacent pieces of fabric are reversed, which member is so placed in the garment that a projection of the axis of the member at least approximately bisects the obtuse angle.

l0. A pressure garment formed with a. member which is generally cylindrical ln shape and made of a plurality of pieces of two-ply, pickless cord fabric with the cords in one ply at an obtuse angle to the cords in the other ply, in which member circumferentially adjacent pieces of fabric are reversed, which member is so placed in the garment that a projection of the axis of the member atleast approximately bisects the ob angle.

ll. A pressure garment comprising a generally cylindrical member fabricated from racked fabric in which the textile elements such as cords.

threads and the like forming the fabric are disv prising the member being reversed to balance.

said member upon inflation thereof. l

l2. A pressure garment certain parts of which are fabricated in generallytubular form vIroxn at least two superposed coextensive plies of pickless cord fabric, the cords in one4 ply being disposed in angular relation to the corresponding cords of the other plies for producing a substantial bal? ance between radial and longitudinal tension introduced to the part by the inflation thereof.

13. An inflatable generally tubular body formed of at least one ply of cord fabric inwhich one set of generally parallel cords is disposed in angular relation to another set of generally parallel cords for producing a substantial balance between radial and longitudinal tension introduced to the body by the inflation thereof, said angular relation being of the order of substantially 109 with the angle being substantially bisected by the projection of the longitudinal axis of the body in the plane of the fabric.

WARD T. VAN ORMAN.