US2127268A - Cap and tube assembly - Google Patents

Description

Aug 16, 1938 R. PALMER J271258 CAP AND TUBE ASSEMBLY Filed July 9, 1937 12 Z 9 J2 9 J0 7 I a "1-1 F I i' I i i l 1 l l i I i I 2 i I g I z- Z I i Z i i l I 1 i I I 1 1 i I I I I INVENTOR Patented Aug. 16, 1938 UNlTED STATES PATENT OFF'lflE Wheeling Stamping Company,

Wheeling,

W. Va., a corporation of West Virginia Application July 9, 1937, Serial No. 152,723

1 Claim.

This invention relates to a collapsible tube and a cap therefor, and more particularly to an assembly of a cap and tube having means for restraining the cap against accidental removal.

Collapsible tubes of the character used for toothpaste .and various cosmetics and pharmaceutical and other preparations comprise a collapsible body having a neck with a removable cap on the neck. The caps are applied to the collapsible tubes in the plant where the tubes are made, and the tubes are filled at the end opposite the cap end after which this end is sealed. The caps are generally made of a synthetic resinous material, although they may be made of metal, After the caps have been put on the tubes by the manufacturer of the tubes, it is desirable that they remain very tight on the tubes until the cap is removed by the customer who purchases the filled tubes. As now commonly 52o constructed, the caps will sometimes become loose either from the handling of the tubes and caps or from the fact that some shrinkage of the synthetic resinous material from which the.

caps are formed takes place after the caps are ,5 put on the tubes. This looseness is objectionable because the cap may come off the tube while the tube is being filled, requiring that the filling machine be stopped to clean up the material which has thus escaped from an uncapped or an im- 1Q properly capped tube. This looseness is undesirable after the tube has been filled and before it is acquired by the customer, because oils and volatile ingredients may escape therefrom.

The present invention provides a cap and tube 5 assembly wherein there is a retention between the neck and cap of the tube other than the threaded retention which will insure the cap being retained against accidental removal and keep the tube tightly sealed until the cap is rotated with force to remove it.

The invention may be readily understood by reference to the accompanying drawing, in which Figure 1 shows a cap and tube assembly embodying my invention, with the cap in the position about to be applied to the neck of the tube, the drawing being on an enlarged scale, the cap and the neck of the tube being illustrated in section; and

Figure 2 is a view similar to Figure 1, showing the cap screwed onto the neck of the tube.

In the drawing, 2 designates the body of the collapsible tube. It is provided with the usual shoulder 3 and with a neck 4. The neck has a threaded portion 5 .and an unthreaded extension 5. Except for the unthreaded extension 6 beyond the threaded portion 5 the tube is otherwise of conventional form.

The cap, designated generally as 1, comprises a main base portion 8 having a fiange or skirt 9 thereon. The flange or skirt 9 is provided with 5 internal threads ii] for cooperation with the threaded portion 5 of the neck of the tube. Formed on the base of the cap on the inside thereof is an integral projection ll having sloping or tapered sides. The projection II is 10 surrounded by an annular outwardly flaring recess l2, this recess being formed between the side walls of the projection II and an outwardly flaring or sloped surface l3 inside the cap extending inwardly from the threaded portion thereof. 15

The cap is applied to the tube in the usual manner. It is first fitted over the end of the tube and then screwed onto the tube, the cooperating threads of the cap and the neck serving to pull the cap down on the neck of the tube. When the projection ll engages the unthreaded extension 6 of the neck, the sloping walls thereof tend to expand the neck into the flared recess or space l2 and against the sloping surface Hi. When the cap is fully screwed on, the unthreaded extension of the tube will substantially fill the recess l2 and be tightly wedged against the projection II and against the sloping surface l3. This not only forms a fluid-tight seal, but in order to remove the cap it is necessary to apply a rotating force thereto sufiicient to contract the neck enough to enable the cap to be removed from the tube.

It will be seen that the walls of the neck beyond the threaded portion must be forced by the unscrewing of the tube inwardly until the outside diameter of the unthreaded portion is such as to clear the threads on the interior of the cap. The positive force required to accomplish this purpose is such as to effectively hold the cap against accidental removal and against removal due to shrinkage of the plastic material of which the cap is made. At the same time, the metal of which the tube is formed is a soft metal and the amount of force required to remove the cap is not 4 such as to render the use of the tube and cap assembly inconvenient. The inclined wall l3 around the recess l2, of course, serves to bend or contract the unthreaded extension of the neck inwardly when the tube is unscrewed to the diameter where this portion of the neck will clear the threads on the inside of the cap.

I have illustrated a preferred embodiment of my invention, but it will be understood that var ious changes may be made therein and that the contour of the projection ll may be varied to the unthreaded portion of the neck of the tube, meet the requirements. said cap having an outwardly flared interior wall I claim: around said space positioned to engage the ex- A tube and cap assembly comprising a tube terior of the neck of the tube when it is ex- 5 having a neck with a threaded portion and an panded by said projection, said annular recess unthreaded terminal extension beyond the formed between the projection and said outthreaded portion, and a cooperating cap having wardly flared wall also being outwardly flared, a flange and a base, the flange being provided said recess being of a thickness only suificient to with interior threads to engage the threads on receive the unthreaded portion of the tube neck, 10 the neck of the tube, the inside of the base of the whereby said unthreaded neck portion is excap having a sloping neck-engaging projection panded outwardly upon entering said recess therein adapted to be forced into the unthreaded when the cap is screwed home and is contracted extension of the neck of the tube, there being an with the initial turning of the cap to unscrew it. annular recess around the projection to receive ROBERT PALMER.

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