Claims
- 1. A rolled edge can for accomodating a product under pressure, having a rim extending outwardly from the upper edge of the can in which the rim consists essentially of a straight end portion and a circular rolled portion joining the straight end portion with the upper edge of the can, said rolled portion defining a circular section of more than 180.degree., with the straight portion extending angularly from the circular rolled portion into the space within the circular section and dimensioned to have a length greater than the internal radius of the circular rolled portion in which it is confined so as to resist unrolling, and in which the profile of the straight end portion is along a plane which passes through the axis of the can.
- 2. A rolled edge can as claimed in claim 1 in which the straight end portion comprises a segment joined to the circular segment by a contiguous curvilinear band of about 65.degree..
- 3. A rolled edge can as claimed in claim 1 in which the straight end portion forms a frusto-conical section with respect to the axis of the can and from which the circular segment extends.
Priority Claims (1)
| Number |
Date |
Country |
Kind |
| 70.20123 |
Jun 1972 |
FR |
|
Parent Case Info
This is a continuation of application Ser. No. 595,772 filed July 14, 1975 (now abandoned), which is a continuation of application Ser. No. 366,492 filed June 4, 1973 (now abandoned).
This invention relates to an improvement in the formation of the rolled edge which, in aerosol type cans, surrounds the opening designed to receive the distribution valve.
The invention is addressed particularly to forming the edges of larger openings than those which are designed to receive conventional distribution valves standardized under the name "1 inch" in which the diameter at the base is 25.4 mm.
Valves of this kind are generally fixed by expansion, an operation which enables a cylindrical body to be fixed in a circular opening by increasing the diameter of the cylinder on either side of the edge of the opening.
In some cases, the valve has a more complex function to perform, which necessitates an increase in diameter at its base. This dimension has been standardized under the name "11/2 inch" in which the diameter corresponds to an opening of 38.1 mm.
This is the case, for example, with cans generally referred to as "double-flux" aerosol cans, in which two separate components are accommodated in one can, one being contained in a flexible bag fixed to the valve, while the other surrounds the bag. The two products are subjected to the same pressure and are intermixed within the valve at the time of use. The complexity of this system necessitates a more voluminous valve body.
Such valves are fixed by crimping to the edge of the can which has previously been rolled outwardly.
Unfortunately, this system is faced with a problem: the force, applied through the internal pressure at the base of the valve, increases with the square of the radius of the opening in which it is fixed. The 50% increase in the diameter of this opening exposes the base of the valve to a force more than twice that applied to the conventional valve. In many cases, this internal force results in more or less pronounced unrolling of the edge of the can and resultant loosening of the crimp fit, thus enabling escape of fluid from within the container.
The object of this invention is addressed to a resolution of the problem of unrolling of the edge by providing it with a particular form.
US Referenced Citations (4)
Foreign Referenced Citations (2)
| Number |
Date |
Country |
| 1,365,439 |
Feb 1964 |
FR |
| 915,642 |
Jan 1963 |
GB |
Continuations (2)
|
Number |
Date |
Country |
| Parent |
595772 |
Jul 1975 |
|
| Parent |
366492 |
Jun 1972 |
|
Patent Grant
4113133
