US2705800A - Brassiere frame - Google Patents

Description

April 1955 M. SCHWARTZ 2,705,800

BRASSIERE FRAME Filed Oct. 20, 1954 FIGVZ lNVENTOR Marcus Schwanz ATTORNEY United States Patent BRASSIERE FRAME Marcus Schwartz, Flushing, N. assignor to S. & S. Industries, Inc., New York, N. Y., a corporation Application October 20, 1954, Serial No. 463,386

1 Claim. (Cl. 2-42) This invention relates to wire frames for brassieres.

Broadly, it is an object of the invention to provide an arcuate wire of substantially rectangular cross-section for use in a brassiere beneath the breast pockets for supporting the breasts.

With the advent of the strapless brassiere a means of support was necessary, since the brassiere was no longer supported by shoulder straps. The only successful method of supporting the brassiere was the use of arcuate wires. Presently, the brassiereis supported by the use of two arcuate wires of round cross-section beneath the breast pockets and supporting each breast, much on a suspension bridge principle, whereby a bridge is supported at both ends and properly engineered so that even though the span may be great and the weight which is carried is very heavy, the center can sufliciently support any given load. These arcuate wires, to function properly, must be of suflicient round cross-section as to withstand the pull of the weight of the individual bust. As can be readily seen, the weight of the bust of a large woman would necessitate the use of a Wire with a heavier round cross-section than the weight of a bust of a Woman which is small by size and weight. However, since the manufacturing of brassieres and of the arcuate wires of the round cross-section is a mass production item, it does not lend itself to the individual fitting of a diflerent thickness of a round crosssection for each particular weight by bust size. Therefore, one thickness of round cross-section arcuate wire has been developed, which does an adequate job for all sizes. Since this arcuate wire of round cross-section must be of sufficient rigidity to produce the required support in the vertical direction, it is also comparatively rigid in the transverse direction because in a wire with a round crosssection, the rigidity of the wire is the same in any direction. Heretofore, arcuate wires of round cross-section have been used in brassieres, but such wires have proven unsatisfacory, since an excess amount of pressure was exerted against the body in a transverse direction, that is, at right angles to the radii of the wire curvature. Wires for use in brassieres, to function properly, and withstand undue pressure against the body of the wearer, must be of sufhcient rigidity to produce the required support in the vertical direction, have a certain degree of flexibility in the vertical direction and have a greater flexibility and resiliency in the transverse direction, that is, to the plane of the curved wire. If a curved Wire of round crosssection is sufliciently resilient in the lateral direction, its use in brassieres is not sufficiently rigid in the vertical direction to properly support the bust when worn.

Being very conscious of the undue pressure against the womans body, which is caused by the rigidity of the wire, I have been trying for man many months to find a solution. I have conducted many experiments with the padding of brassieres with foam rubber, where the pressure of the wirev is located. After a great many experiments, I finally arrived at the answer. A wire must be developed which would have sufiicient rigidity in the longitudinal plane to take care of every size and yet have good flexibility in the transverse direction, so as to have little or no pressure against the body. By taking a special type of hypereutectoid steel wire of between .80 and 1.05 carbon content and treating it as hereinafter described, such wire has the proper rigidity and flexibility in the vertical direction and the desired degree of flexibility in the lateral direction, that is, the degree of flexibility in the lateral direction is greater than in the vertical direction. When this wire is used as a brassiere support beneath the breast, it will perform its required and proper function without undue pressure against the body of the wearer.

For a fuller understanding of the nature and objects of the invention, reference is had to the following detailed description in connection with the accompanying drawings, in which:

Fig. 1 is a plan view of one of a pair of brassiere wires comprising the framework of a brassiere; and

Fig. 2 is an enlarged sectional View taken along line 2-2 of Fig. 1.

Referring to the drawings, numeral 10 represents one of a pair of wires comprising a supporting frame for a brassiere. A special type of round cross-section hypereutectoid steel is selected for the manufacture of a substantially rectangular cross-sectional member for a brassiere frame and such steel member undergoes certain operations during its processing to change the inherent grain structure in order to produce the desired degree of flexibility and resilience. This steel member, in its annealed condition, has a crystal structure containing free ferrite and pearlite. The ferrite shows up as white areas surrounding the pearlite on polished and etched specimens. Under one hundred magnifications with a microscope, the structure shows equiaxed polyhedral grains.

This special wire, after further reduction of diameter, has an overlapping of the elongated grains which adds considerably to the strength of the wire material. The wire has a high tensile strength and high hardness due to the reduction of area caused by the wire drawing operations and is now in condition for further processing.

Further drawing operations of this wire causes a lengthening of the grain and a large amount of residual stress which is then relieved by a special operation consisting of a thermal treatment suflicient to refine the grain structure of the wire member and also prepare the wire member for additional drawings, which cause a more uniform sorbitic structure with a fine dispersion of ferrite.

The round wire is now ready for a special sequence of operations to make it a substantially rectangular crosssectional shape with round edges, as shown in Fig. 2, which is the desired shape for use in brassieres. We either flatten the round wire into cross-sections of rectangular shape with round edges, or into other shapes, by passing it through a rolling mill, flattening it in a power press or in a drop hammer. This can be done in two ways, that is, either in a continous coil or out into individual pieces of predetermined length. I have also produced a wire frame for brassieres and began with a flat Wire of the desired thickness from a continuous coil. This flat wire was then cut to the desired length, and then curved to the desired curve of arc, as shown in Fi 1, and as figured by the modulus of elasticity of material.

The other method of fabricating this wire is to have the round wire cut to the desired length'and then formed into an arcuate shape, as shown in Fig. 1, by bending the wire beyond its elastic limit, by previously determining the modulus of elasticity of the wire, which permits a certain amount of spring-back to occur. During this curving the grains actually slide over one another an infinitesimal amount Without destroying the bond of the amorphous cement holding them together. This over straining of the wire causes the grains to be compressed on the inside of the curve and elongated on the outside, thereby inducing additional residual stresses in the wire and causing it to be in an unstable condition. It now requires careful handling to prevent changing the desired shape until .astress equalizing heat treatment is provided, The wire is then baked for about one-half hour at temperature between 300 F. and 500 F. to stress relieve it. A certain amount of spring-back which occurs during stress relieving is allowed for during the manufacture. The sharp edges of the ends of the wire are taken care of by either the forming of spherical terminals, or the placing of a rounded part upon each end.

The round wire is then flattened into a rectangular shaped cross-section with rounded edges, as shown in Fig. 2, or into other shapes either by passing it through a rolling mill, flattening it in a power press, or drop hammer, forcing the grains to become more closely packed thereby reducing some of the bending stresses by reorienting the structure. This, however, sets up additional stresses due to the cold work of pressing. Th s cold working realigns the grains into the desirable condition for additional strength and higher hardness thereby permitting greater resilience. This is also due in part to the change in shape of the section in the transverse plane and this combination of effects imparts the desired mechanical properties. The unstable condition caused by residual stresses within the structure from cold working are then relieved by a low temperature thermal treatment, as hereinbefore stated. The special sequence of operations needed to produce the correct type of wire for the purpose described, combined with the unique forming operations and thermal treatments, permit manufacture of a product with a combination of flexibility and resilience heretofore unavailable and novel for use in brassiere framework;

The wire is treated so as to be completely rust-resistent. It may be electro-plated, metallic coated, or receive a baked enamel finish to provide a smooth finish coating. 1

Load and deflection tests were made to determine the flexibility and resilience of round sections of wire versus rectangular shaped wire, and such tests were conducted on a precision testing instrument commonly used for such tests in the following manner. In'making the longitudinal test, a brassiere wire frame of standard type round cross-section was placed on the hooks of a spring testing instrument and extended .625 in which condition it exerted a load of 28 ounces. A rectangular section was then placed on the same hooks (after removing the round section frame) and also extended .625" in which condition it exerted a load of 28 ounces. The loads exerted are exactly the same. The load placed upon the round Wire was exerted along the axis of the arc and it tended to further open the arc to the point of extension amounting to .625". This is the amount of extension required to fit the wire around the breast of the wearer.

Inasmuch as the stress. caused by the extension was less than the elastic limit for both sections, the frames returned to their normal free position. With this amount of deflection in both instances there was no distortion or twisting of either wire.

With the spreading of the brassiere wire to acccommodate fitting around the breast of the wearer, it is obvious that the pressure exerted by the wire when released or collapsed will be equal to the pressure required to open the wire. The rectangular cross-sectional wire will therefore have the same resistance of stretch and will free end. The loads are shown in the following table.

Round Wire, Flat Wire, Deflection Ounces Ounces (The round wire took a slight permanent set at 1% deflection indicating thesafe maximum deflection had been reached.)

The conclusion shown revealed that while both sections have the same longitudinal loads, a tremendous difference occurs in the transverse tests asshown in the above table.

The flat wire did not take a set even at-2 of deflection and could have been deflected more if desired.

It was found that 2" of lateral deflections was the maximum required to cause the rectangular cross-sectional Wire to fit a wide range of figures.

' before or after it is'curved.

The round and rectangular section ratio is 28 divided by 1.9 and equals 14.75, at /8" deflection in both planes. The ratio of the two wire sections is 64 divided by 4.8 and equals 13.3, for a transverse deflection of 1 For other conditions it varies between 12.5 to 14.2.

The conclusion with respect to the ratio of loads in the transverse plane shows the round wire to be quite stiff laterally. The round wire exerts about 13 times as much load against the body as does the flat wire. The flat wire, because of its greater flexibility (or less rigidity) requires only 7 /2% of the load to deflect it laterally, than does the round wire.

With respect to the flexibility of the round wire in comparison to the rectangular wire of my structure, the ability to be deflected in the longitudinal direction, parallel to the direction of the wire, for both round and rectangular sections is the same. This desired result is accomplished by correctly determining the size of the rectangular shape with respect to the round shape in such manner that the section modulus about the neutral bending axis is the same for both sections.

The increased ability for the rectangular section to be flexible in the transverse plane at a direction at right angles to the longitudinal direction is accomplished by the unique shaping of the rectangular wire so that the section modulus about the neutral bending axis in this plane is of a different value than it is about the other axis. The section modulus of the round section, however, is the same in both planes, therefore the flexibility in the transverse plane is not improved.

With respect to the resilience of the round wire in comparison to my rectangular wire structure, the ability to spring back to the original free position after deflection is the same for both round and rectangular sections when the deflection is in the longitudinal plane, a condition that can be easily made to exist by the proper temper or hardness placed in each material.

In the transverse plane of bending, however, a large difference in resilience exists between the round and rectangular sections. The rectangular section can be deflected much further than the round section and return to the normal free position without permanent set. This occurs because the change in shape changes the section modulus thereby lessening the fibre stress during deflection and permitting more resilience in this transbending direction. This desired condition cannot be obtained with a round section because the section modulus is the same in both planes.

The amount of temper is related to the hardness and tensile strength. The desired temper of the flattened section, to bring the elastic limit to the correct value for proper flexibility and resilience is accomplished by a correct determination of hardness in the wire before forming it into an arcuate shape, which is determined by the amount of cold work done in the flattening process and by a low temperature thermal treatment. The control of these operations can bring about the desired properties and temper. The proper amount of temper needed has been determined by actual test and is regulated by quality control methods verified by Rockwell Hardness Tests to maintain the proper condition. By actual tests, on sample parts and from records made, the hardness that provides the proper mechanical properties of tensile strength, temper, resilience and flexibility is. Rockwell C42C49.

When a pair of such wires are used or positioned into a slotted section of a brassiere, dress or undergarment, such as a brassiere slip, it is found to have ust the proper amount of lateral and vertical flexibility and vertical and lateral rigidity. Such wires provide the correct vertical support for the breasts and the proper resiliency and flexibility laterally so that there are no undue pressures against the body of the wearer and the brass iere can be worn comfortably the entire day and evening.

It is possible to form the thickness of the wire, either It is also desirable that the opposed longitudinal edges of the wire remain slightly curved for greater comfort to the wearer.

While I have described the cross-section of my wire as substantially rectangular, it is within the scope and spirit of the invention to have other cross-sections, such as oval, in the form of the figure 8, double concave, or other similar cross-sections, so ion as the arcuate wire is substantially rigid in its longitudinal plane andhas greater flexibility laterally than in its longitudinal plane.

I claim: a l I Asubstantially rigid arcuate wire brassiere frame of hypereutectoid steel of substantially rectangular cross section having its longer dimension extending radially of the curve, and having a greater degree of lateral flexibility than longitudinal extensibility, said lateral flexi 'lity being approximately fourteen times the lateral fiexi t ity of a round wire of the same cross sectional area under the same load and having the same longitudinal extensibility as the round wire, permitting lateral deflection of the Wire from the unstressed plane of the Wire to fit the contours of the body of the wearer With- 10 5 out causing a torsional twisting of the wire along the curve of the arc.

Reierenees Cited in the file of this patent UNITED STATES PATENTS 145,285 Dudley Dec. 9, 1873 1,989,303 Alberts Jan. 29, 1935 2,527,521 Bloom ct. 31, 1950

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