US3474504A - Buttons - Google Patents

Description

Oct. 28, 1969 J. F. HOLDSWORTH 3,474,504

su'rwons Filed April 20. 1967 United States Patent 3,474,504 BUTTONS John Frederick Holdsworth, Solihull, England, assignor to Scru-Fix Limited, Kings Heath, Birmingham, England, a British company Filed Apr. 20, 1967, Ser. No. 632,241 Int. Cl. A44b N30 US. Cl. 24-90 1 Claim ABSTRACT OF THE DISCLOSURE A button for use on a garment (e.g. a coat) comprising two main parts, namely: a button head which goes on one side of the material of the garment, and a base plate which goes on the other side of the material, the base plate having an axially projecting screw-threaded stern which is passed through the material and screwed into a plain passage in the button head so that the material is clamped between the button head and the base plate. The button head is formed of an inherently resilient plastics material (e.g. nylon) and the stem of the base is of metal and has a buttress thread which is oversize in relation to the plain passage in the button head so that an interference fit is obtained in which the plastics material surrounding the passage in the button head, due to its inherent resilience, first expands to allow the stem to be pushed or screwed in and then contracts to bind upon the threaded stern and prevent the button head and stem being separated by a straight axial pull, although the two can be intentionally separated, when desired, by unscrewing the stem from the head. To prevent accidental unscrewing, a lock washer may be provided between the button head and the material with interengaging serrations or ratchet teeth on the lock washer and the button head.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to buttons, for use on garments, and of the type comprising a button head which goes on one side of the material of the garment and a base plate which goes on the other side of the material, the base plate having an axially projecting stem which passes through the materail and engages in a passage in the button head to secure the two parts together and grip the material therebetween.

Description of the prior art Hitherto, in buttons of this type, such as in my prior Patent No. 2,902,735, the passage in the button head has been internally threaded for threaded engagement by an external thread on the button head and this arrangement has the drawback that accidental loosening of the two parts can take place, especially as many people have the habit of unintentionally or absent-miridedly twisting buttons on garments which they are wearing.

In British specification No. 795,600 it has been proposed to have the button head made of a heat-softenable plastics material and have a metal stern which is transversely ribbed or screw-threaded, heat being applied after the stern has been engaged in the button-head to soften the plastics material of the head causing it to enter into intimate contact with the stem and firmly adhere thereto after cooling. Such proposal does not however permit of subsequent intentional separation of the parts which is very often necessary when garments are cleaned, or when it is desired to change the style of buttons on a garment (e.g. a ladys coat or dress).

In British specification No. 842,779, the passage in the 3,474,504 Patented Oct. 28, 1969 button head has an entrance which is of smaller area than the remainder of the passage within the head so as to provide a shoulder within the passage, and the stem is made of resilient material and provided with annular ribs of buttress form so that when the stem is pushed into the passage, one of the ribs on the stem engages behind the shoulder in the passage to prevent withdrawal. In thil case also it is not possible to separate the parts of the button once they are engaged.

It is, therefore, the object of the invention to provide a button of the type in which the two parts, button head and base plate, are firmly locked together against separation by an axial pull, or accidental unscrewing, but may be intentionally separated when desired.

SUMMARY OF THE INVENTION The invention provides a button of the type hereinbefore described comprising a button head and a base plate having an axially projecting stern for engaging in a passage in the button head and wherein the button head is made of inherently resilient plastics material, the passage therein being plain and of constant internal diameter, the stem of the base plate being of metal and having an external screw thread of buttress form, the major diameter of which is greater than the internal diameter of the said passage so as to give an interference fit of the stem within the passage.

BRIEF DESCRIPTION OF THE DRAWINGS Two forms of the button in accordance with the invention will now be described with reference to the accompanying drawings wherein:

FIGURE 1 is a section through a two-part assembled on a piece of material.

FIGURE 2 is a similar section through a three-part button.

In FIGURE 1 the button head is indicated generally at 10 and the base plate at 11, the two parts being assembled upon a piece of material 12.

The button head is made of a suitable inherently resilient plastics material (e.g. nylon) and has an enlarged part 13, of domed shaped and on its underside an axially projecting shank 14 with an outwardly extending flange 15 at its lower end. An axial passage 19 extends axially through the shank 14 from the lower end thereof, the passage 19 being plain and of constant internal diameter from end to end.

The base plate 11 comprises a part 16, made of suitable plastics material and moulded around, or otherwise fixed to the head 17, of an externally threaded stem 18 which is made of metal.

The stem 18 is provided with a buttress-type screw thread 20 and, as will be observed from the drawing, the major diameter of the thread 20 is greater than the internal diameter of the passage 19, to ensure that the thread is an intereference fit in the passage.

The stem can be forced into the passage 19 as the resilience of the material of the head permits the wall of the passage to expand, but, after insertion, the material moves back into intimate engagement with the thread 20 and binds thereon and, due to the barbed nature of the buttress thread, the interference fit ensures that the button head is very firmly fixed upon the stem and cannot be removed as a result of a pull in the axial direction.

However, by rotating either the button head or the base plate in the appropriate direction, the button head can be unscrewed from the stern whenever removal is desired. However, this requires a deliberate and intentional act utilising an appreciable amount of torque and the button head remains firm against any relatively small button torque such as arises from absent-minded twisting of the button head by the wearer of a garment.

As shown, the opposed surfaces of the part 16 of the base plate and the flange 15 of the button head are pro vided with radially extending serrations 21 to improve the grip upon the material which is clamped therebetween and also providing additional resistance to accidental rotation of button head or base plate.

The three-part button shown in FIGURE 2 is similar in many respects to the two-part button of FIGURE 1 and to avoid duplication of description like reference numerals have been used in FIGURE 2 to refer to those parts which are the same as in FIGURE 1. The main difference is that the button of FIGURE 2 has a lock washer 22 mounted rotatably upon an axially projecting boss 23 at the lower end of the shank 24 of the button head. The upper and lower faces of this washer are provided with radially extending serrations 25, 26 respectively, the serrations 25 cooperating with similar radial serrations on the lower annular face of the shank and the serrations 26 gripping the material 12 in co-opeartion with serrations on the base plate 16. This lock washer functions in the manner described in my prior Patent No. 2,902,735.

The button formed in accordance with the invention is advantageous for use in an automatic machine for assembling the button and attaching it to a garment in which the button head 10 (assembled with washer 22, if provided) is pushed over the upwardly projecting stem 18 of the base plate in an automatic operation.

What I claim is:

1. A button for use on flexible material comprising the combination of a button head and a base member, said button head being formed of resilient plastic material having an enlarged upper portion connected to an axially extending shank of reduced diameter and terminating in an outwardly exteding flange, said flange having radially extending serrations on at least a portion of its lower surface and adapted to engage the flexible material to resist rotation of said button head, said button head having an axially extending internally plain passage of constant diameter extending substantially through the same from the underside thereof, said base member including an axially extending metal stem having an external screw thread of buttress form adapted to extend through said material and into engagement with said button head, the major diameter of said thread being greater than the internal diameter of said passage to provide an interference fit of the stem within the passage, a head fixed to one end of said stem, a base plate constructed of resilient plastic material molded about the shank head and being of a diameter substantially equal to the diameter of the flange of the button head, said base plate having radially extending serrations on at least a portion of its upper surface and adapted to engage the flexible material to resist rotation of said base member, said stem being adapted to be driven axially without rotation into said passage to secure the button head and base member against separation by direct axial pull while permitting normal separation of the button head and the base member by rotational unscrewing.

References Cited UNITED STATES PATENTS 2,896,285 7/1959 Morin. 3,141,211 7/1964 Blake. 2,247,522 7/1941 Purinton. 2,835,948 5/ 1958 Blake 24-108 26,776 1/ 1860 Meacham 24105 843,158 2/1907 Leger 24105 2,385,467 9/ 1945 Purinton. 2,902,735 9/ 1959 Holdsworth 24-105 3,028,646 4/ 1962 Janes.

FOREIGN PATENTS 200,130 3/ 1940 Switzerland. 76,235 1/ 1918 Switzerland.

DONALD A. GRIFFIN, Primary Examiner

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