Dispensing – Axially rotary and longitudinally movable tubes – sleeves – or... – Axial discharge
Reexamination Certificate
2001-07-24
2003-12-30
Mancene, Gene (Department: 3754)
Dispensing
Axially rotary and longitudinally movable tubes, sleeves, or...
Axial discharge
C222S519000
Reexamination Certificate
active
06669063
ABSTRACT:
TECHNICAL FIELD
The invention relates to a system for fixing a cap on a container head on which there is a neck surrounding a distribution orifice. This system enables an irreversible attachment in the sense that the said cap cannot be detached from the assembly without deliberately applying large forces that could at least partially damage the head and/or the overcap. But this attachment is not a complete immobilization; when fixed, the overcap can be moved in a circular or helical movement with a limited amplitude with respect to the centreline of the neck in the head.
STATE OF THE ART
The use of this type of head is known for “quarter turn” or “centerlock” containers, which can be partially unscrewed to move the top of the cap away from the top of the head and thus release a central orifice through which the product can be distributed.
Thus, U.S. Pat. No. 5,199,605 registered by the applicant describes a distributor for cream or paste products comprising a rigid head fixed onto a body or a skirt and an overcap. The following description uses the same references used in the figures in U.S. Pat. No. 5,199,605. The head (
1
) and the overcap (
2
) comprise complementary screwing means (
9
and
19
) that rotate relative to each other to raise or lower the overcap with respect to the head. The overcap is provided with a central opening (
14
) and the top end of the head is in the form of a cylindrical neck (
5
) through which the product passes, closed by a closer (
3
) supported by tabs (
4
) fixed to the inside wall of the neck. The closer closes the central opening of the overcap when this overcap is in the down position.
Rotation is limited firstly by the end of the thread at the end of screwing in, and secondly by pads (
24
) located on the shoulder (
11
) of the distributor when screwing out and that work in cooperation with the ends (
26
and
25
) of axial reinforcing ribs (
260
and
250
) of the skirt (
16
) of the overcap. The shapes of the ends (
25
) and (
26
) are different. The end (
25
) is small but rigid, and stops in contact with a pad (
24
) that participates in blocking at the end of screwing in and protects the end of the thread. The end (
26
) is a circumferentially flexible plate that is fixed from above (
240
) by a pad (
24
) and is then suddenly released, and which vibrates and acts as a warning at the end of screwing out. The blocking means used are only efficient if the forces applied are small, particularly due to their size and the low stiffness of the assembly. Due to the warning, the user reduces and then stops applying a force when the overcap is close to a stop.
PROBLEM THAT ARISES
It is difficult to manufacture the distributor described above, particularly due to moulding of the central part of the head, namely the closer held in place at the end of the tabs fixed onto the internal wall of the neck. The tooling is complex, particularly to make the arms that hold the closer in place, which have to be as thin as possible so that the product can pass through easily—and consequently cannot be used as feed ducts for the plastic material leading from a central injection point. In this case, peripheral injection is necessary at several points around the wall of the neck, and the wall cannot be as thin as would have been desirable.
Furthermore, safety when screwing out remains uncertain despite the audible warning. The applicant considered replacing the “pad—end of grooves” device by a device such as that proposed in EP 0 633 197 in which, during screwing out, a flexible axial plate (
12
) fixed to the overcap reaches a stop in contact with a profiled axial portion (
14
) attached to the shoulder of the distributor. Another profiled axial portion (
15
) acts as a stop with a plate (
12
) that is flexible in the screwing in direction. In the case of EP 0 633 197, the objective is to make axial portions (
14
) and (
15
) as close to each other as possible to fix the overcap firmly in place. Moving the profiled axial portions (
15
) and (
14
) away from each other enables a limited relative rotation of the overcap and the head. But these profiled axial portions are thick and high which further increases the weight of plastic material to be injected on the head, which has a particularly negative effect on production rates, particularly when the head is directly insert moulded on the skirt or the body of the container, in other words when the head is fixed to the body or the skirt at the same time that it is injected.
Finally, the thick and heavy head makes the tube cumbersome to handle, which is not appreciated by the user of the container. The size of a device that cannot be unscrewed accidentally and with limited rotation such as any of the devices according to prior art is such that it is impossible to equip the head with other means that could perform other functions.
For example, it would be necessary to improve the stop at the end of screwing in since the flexibility of the plastic materials used for the neck and the overcap means that if the end of screwing in force is not controlled, the helical thickening forming the thread can easily skip from one helical groove to the next, with sudden movements of the overcap with respect to the head.
The seal provided by a system such as the “centerlock” is not excellent. For applications such as cosmetic or pharmaceutical products packaged in flexible tubes, it is usually necessary to use an outer cover to prevent unwanted leaks, particularly when these tubes are transported in a carry bag. Apart from the additional cost, the use of an outer cover further slightly increases the weight of the container at its distribution head. No solution based on the “centerlock” principle has been considered up to now for products sensitive to ambient air such as cyanoacrylate glues, due to the excessive risk of glue setting in the distribution orifice.
Therefore, the applicant attempted to develop a lightweight head+overcap assembly that is compact and easy-to-inject, in which the overcap is irreversibly fixed to the head in the axial direction and to which a limited rotation can be imposed, in other words by blocking the overcap in clearly defined positions when screwing in and screwing out. The weight reduction and the compactness of this fixing system not only makes containers according to prior art easier to use, they also make it possible to create new containers for more demanding applications, particularly for impermeability of the closure, by the addition of elements that perform other functions.
Purpose of the Invention
FIG. 1
diagrammatically shows the various attachment means to facilitate understanding of the description of the invention. It shows a top view of a head above a cylindrical wall (
50
) provided with attachment means (
11
,
12
,
15
) cooperating with the attachment means (
33
and
34
) on the overcap, the other parts of the said overcap not being shown.
The purpose of the invention is a container head and overcap assembly, the said head having one end open and designed to be fixed on the open ends of a container or flexible tube fitted with a cylindrical neck (
20
) and a shoulder (
3
) extending from the said open end to the base (
10
) of the neck, in which the cylindrical neck is provided with at least one helical screw thread (
21
) with pitch P and in which the overcap has a cylindrical skirt (
35
) provided with a screwing in means (
36
) on its inner wall complementary to the screwing in means on the neck. The overcap has a top wall (
46
) on which at least one radially flexible and circumferentially rigid axial plate (
33
) is fixed. The other end of this flexible plate is free. The plate is located at a distance from the centreline of the overcap that is slightly greater than the outside radius of the neck. The bottom of the neck is provided with at least one opening stop (
12
) with angular position &thgr;, and at least one closure stop (
11
) with angular position &phgr; that is not as high, the said opening stop being provided with a first wall (
14
) that gradually moves aw
Bodet Herve
Schneider Bernard
Vicchi Jean-Baptiste
Dennison, Schultz & Dougherty
Mancene Gene
Nicolas Frederick C.
Pechiney
LandOfFree
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