US3019936A

US3019936A - Unbreakable and impervious ring of moulded synthetic material for package tins

Info

Publication number: US3019936A
Application number: US72233A
Authority: US
Inventors: Maulaz Georges
Original assignee: Satrametal S A
Current assignee: Satrametal S A
Priority date: 1959-12-02
Filing date: 1960-11-28
Publication date: 1962-02-06
Anticipated expiration: 1979-02-06
Also published as: CH358711A

Description

Feb. 6, 1962 G. MAULAZ 3,019,936

UNBREAKABLE AND IMPERVIOUS RING OF MOULDED SYNTHETIC MATERIAL FOR PACKAGE TINS Filed Nov. 28, 1960 /n /emor GEORGES MAULAZ United States Patent 3019 936 UNBREAKABLE ANli llVIPERVIOUS RING OF MOULDED SYNTHETIC MATERIAL FOR PACK- AGE TINS Unbreakable and impervious rings of moulded synthetic material are already known, which are designed to be fixed, for example by setting, on the one hand on the body of a package tin and, on the other hand, on a lid'closing this tin, to unite this tin and its lid and ensure a vacuumtight closure. These rings are provided, on the one hand, with two peripheral grooves defining between them a strip designed to be torn away when the tin is opened for the first time and, on the other hand, a tongue integral with the portion included between the two grooves, this tongue serving to tear this strip.

The moulding of such a ring with its tongue presents the following difficulties:

The moulding must be effected by means of a slide mould and the problem is to give the tongue such a shape that once the ring and the tongue have been moulded into a single element, the mould may be opened, that is to say that the slides may be separated from the core of the mould. Up to the present, these difiiculties have not been solved.

The invention aims at providing a ring of such shape that these difliculties disappear. It has for object an unbreakable and impervious ring, of the type indicated, which is characterized in that the above mentioned strip is provided, in its part adjacent to the base of the tongue, over its whole width, with a thickness which diminishes progressively up to this base, in order to facilitate the initial stage of the tearing, the outer surface of the strip in the part thus thinned being tangential, at the point of minimum thickness of this strip, to a cylinder coaxial to the ring.

The accompanying drawing shows, by way of example, one embodiment of the ring according to the invention and of the mould serving for its manufacture.

FIG. 1 is a perspective view showing a part of a cylindrical metallic tin provided with its lid and with this embodiment of the ring.

FIG. 2 is a partial longitudinal view in section, on a large scale, of the tin, its lid and the ring.

FIG. 3 is a partial cross sectional view of the slide mould employed in the manufacture of the ring according to FIGS. 1 and 2 showing the closed mould and the ring which has just been moulded therein.

FIG. 4 shows the same members as FIG. 3 but in the open position of the mould, while the ring is still on the core of the mould.

FIG. 5 is a view along 5-5 of FIG. 4.

FIG. 6 is a partial cross sectional view of'the ring visible in FIGS. 3 and 4 but after deformation of the tongue.

The ring 1 is of moulded synthetic material and it is designed to be fixed, by a setting 2, on the body 3 of a cylindrical metallic tin. It is designed to be fixed, on the other hand, by a setting 4, on a lid 5, also metallic and closing this tin. This ring has for function to join as one the tin body 3 and the lid 5, to ensure a vacuumtight closure of the tin and moreover to guarantee the unbreakability of the tin. By unbreakability is to be understood, according to custom, that the tin cannot be opened without destruction of the entirety of the ring, thus preventing any fraudulent opening and reclosing of the tin.

The ring 1 is provided, as is known, with two peripheral 3,619,936 Patented Feb. 6, 1962

tearing grooves

6, 7, parallel, defining between them a strip 8 designed to be torn when the tin is opened for the first time. It is obvious that, at the time of this tearing, the ring is torn along the

grooves

6 and 7. A tongue 9, of a piece with the ring 1 and integral with the strip 8, serves to tear this strip.

The ring shown differs from known constructions by the following characteristics:

The strip 8, which is seen in cross section in FIGS. 3 and 4, is provided, in its part adjacent to the base 10 of the tongue 9, over its whole width, with a thickness diminishing progressively up to this base, in order to facilitate the initial stage of the tearing. The outer surface 110i the strip 8, in the part thus thinned, is tangential, at the point 12 of minimum thickness of the strip, to a geometrical cylinder coaxial to the ring.

The junction-line of the base 10 of the tongue 9 with I the strip 8, on the side where the latter is thinned, has

the shape of a chevron 13 the point of which is in the middle of the strip 8, where it is the thinnest. The ends 14 and 15 of the chevron each coincide with the bottom of one of the

tearing grooves

6, 7. The thinning of the strip 8 at 12 and the obliqueness of the line 13 facilitate the beginning of the tearing from 12, along 13. The fact that the ends 14, 15 of the line 13 coincide with the bottom of the

grooves

6, 7 facilitates the continuation of the tearing along these grooves. In order to manufacture the ring described, use is made of a slide-mould, of which one sees the core at 16, one of the slides at 17 and the other slide at 18.

In order to form'the tongue 9 and the thinned part (19 in FIG. 3) of the ring, during moulding, the slide 17 forming an outer element of the mould, comprises a bladeshaped part 2% having two

surfaces

21, 22 of general flat form and parallel. These surfaces are further parallel to the direction of the reciprocating motion of this slide. When the slide 17 is in the operative position (FIG. 3),

. these

surfaces

21, 22 are tangential to geometrical cylinders coaxial to the core of the mould. The surface 21 is provided to form the surface 11, that is to say the thinned part of the tearing strip 8, whereas the surface 22 is provided to form the inner surface 23 of the tongue 9. Due to this tangential arrangement of the

surfaces

21 and 22, it is ohviousthat the slide 17 may be separated from the core after moulding, without any difficulty. This arrangement givesa particularly simple and reliable solution of the moulding problem not solved up to the present to which reference was made in the beginning.

The slide 18 comprises a part having a generally flatshaped surface 24, provided to form the outer surface 25 of the tongue 9. In this example, the surface 24 is parallel to the

surfaces

21 and 22 and to the direction of the reciprocating motion of the slide 18 which is the same as for the slide 17.

In the example shown, the surfaces 23 and 25 of the tongue are provided with slight roughnesses designed to facilitate the tearing operation of the strip. The presence of these roughnesses permits of holding this tongue more easily between the fingers during this operation.

In FIG. 6, there is shown the tongue 9 folded flat against the inner surface of the ring 1. This folding operation is effected after moulding, for example by heat softening the base 10 of the tongue and then exerting a radial pressure on the latter. This deformation of the tongue aims simply at avoiding damage thereto during package or transport of the tins.

According to modifications, the ring could be fixed to the tin and to the lid not by settings, but by gluing or by soldering; the tin and the lid could not be of cylindrical shape; they could also be of another material than metal, for example of plastic material.

'3 What I claim is: 1. In an unbreakable and impervious ring of moulded synthetic material fixed at one edge on the body of a package tin and at the other edge on a lid closing said tin for surface of said strip in the portion of diminishing thickness being tangential to a cylinder coaxial to said ring.

2. vA strip as claimed in claim 1, further comprising a junction line between the base of the tongue and the portion of the strip having a thickness diminishing progressively up to the .base of said tongue, said junction line being oblique relative to the parallel edges of said strip to facilitate the beginning of the tearing.

3. In an unbreakable and impervious ring of moulded synthetic material fixed at one edge on the body of a package tin and at the other edge on a lid closing said tin and said lid and ensuring an airtight closuretherebetween,

a strip, two peripheral and parallel tearing grooves defining the width of said strip, a tongue integral with said strip and serving to tear said strip along said grooves, said strip having a thickness diminishing progressively up to the base of said tongue to facilitate the initial stage of tearing, the outer surface of said strip in the portion of diminishing thickness being tangential to a cylinder coaxial to said ring, and a junction line between the base of the tongue and the portion of the strip having a thickness diminishing progressively up to the base of said tongue, said junction line having the shape of a chevron, the center point of said chevron beingin the middle of said strip at the end of the portion of diminishing thickness of said strip.

4. A strip as claimed in claim 3, wherein the end points of said chevron coincide with the bottoms of said tearing grooves.

References Cited in the tile of this patent UNITED STATES PATENTS 424,982 Hidden Apr. 8, 1890 2,433,683 Coyle Dec. 30, '1947 2,747,345 Plastino May 29, 1956