SCREW CAP FOR CAN.

Abstract

A screw cap, comprising an annular groove (48) which is open in the opposite direction to the bottom of the cap (37) and comprising at least one air passage orifice (50) which, from the annular groove (48), passes through the bottom of the cap (32), comprising a tapped hole (19) adapting to the thread (18) of a pouring spout (16) of a can, the screw cap (32) having, at the end of its screwing operation, a certain angular position relative to the pouring spout (16), and comprising a passage orifice (24) in the pouring spout (16), according to claim 1 of the main patent application, characterized in that at least two air passage orifices (50, 63, 64) are provided which are arranged angularly offset from each other.

Description

The present addition relates to a screw cap, comprising an annular groove which is open in the opposite direction to the bottom of the cap and comprising at least one air passage orifice which, from the annular groove, passes through the bottom of the cap, comprising a tapping which adapts to the thread of a pouring tube of a can, the screw cap having, at the end of its screwing operation, a certain angular position relative to the pouring tube, and comprising a passage orifice in the pouring tube. These containers are mass-produced, and due to their manufacturing process, high tolerances cannot be expected. They are used in very different environments, where temperatures can vary, for example, from -400°C to +75°C. The force required to tighten the screw cap also varies considerably. When people are very tired and it's very cold, they have little strength. It's not always important that the contents be emptied quickly. However, there are emergency situations where emptying the container rapidly is crucial, and sometimes even vital. Consider, for example, transferring fuel from a jerrycan into the tank on a rocking boat. If the operation takes too long, even a strong person cannot keep the container aloft for long. When the transfer takes a very long time, the spout may slip out of the inlet tube into the tank, and fuel may spill, with all the associated risks, such as the risk of explosion. It is also sometimes important to minimize waste, especially when the can is the last one in the reserve, and so on. A single air passage opening with the annular groove 48 is normally sufficient. However, if this air passage opening 50 is totally or partially blocked and / or if the annular groove is totally or partially closed, the air no longer flows back properly and the consequences mentioned above may occur. In practice, and for various reasons, the annular groove 48 can decrease in cross-section or close completely: for example, at very low temperatures, a sufficient quantity of viscous liquid can reach it. It can also simply become clogged, or crushed in its cross-section for one reason or another. The invention aims to ensure good air reflux, even in extreme situations. This aim is achieved according to the invention by providing at least two air passage orifices which are arranged at an angular offset from each other. Given that the annular spacing is greater than two air orifice diameters but less than five air orifice diameters, under the conditions mentioned above, it is possible to maintain optimal proximity between air passage 50 and air passage 24. Furthermore, the air passage 50s are not too close together, which would weaken the plug and create a breaking point. Moreover, they are sufficiently far apart that the clogging of one air passage does not affect the other. These conditions can be further optimized when the angular spacing is between two and four air orifice diameters. By providing three air passage orifices, including a central orifice, in normal position after a screwing operation, this central orifice aligns, in the alignment zone, with the passage orifice of the pouring tube, it is obtained that an air passage orifice is practically always opposite the passage orifice of the pouring tube, and that the air passage orifices, located to the right and left of this one, produce their effects, in one direction or the other, only in the case of extreme tolerance. Various other features of the invention will become apparent from the detailed description that follows. An embodiment of the invention is shown by way of non-limiting example in the attached drawings. Fig. 1 is a 1:1 scale top view of a screw cap without a pouring spout which, otherwise, is similar to the screw cap of the main patent application. Fig. 2 is a side view, partly in cross-section, of the pouring tube area of ​​a can. A can 11, made of blow-molded plastic, has a nominal capacity of twenty liters. It includes a spout 16 which is practically symmetrical in rotation, with respect to a geometric longitudinal axis 17. The spout has a screw thread 18 which is relatively coarse. In the wall 23, approximately one centimeter thick, of the pouring spout 16, there is a passage 24 located at the upper part, when the container 11 is being poured. This passage opens into the front face 21 and extends, on the inner face of an oblique surface 14 of the container 11, into a bung 26. A rigid vent tube 27 is attached to this bung, the inner end of which opens into the highest volume when the container is being poured. If a container 11 of this type is poured, liquid flows outwards through the opening 29 of the pouring spout 16. Air is drawn in through the orifice 31 of the pouring tube 16 and flows, through the passage orifice 24, through the ventilation tube 27 to its end, into the highest air volume in the container 11. A screw cap 32 has, on its underside as shown in Fig. 1, an annular groove 48 open towards the front face 21 in the operating position. Three air passage orifices 50, 63, 64 open into this groove. Their diameter corresponds approximately to the width of the annular groove 48. The air passage holes 63, 64 are angularly spaced 30° apart, relative to the air passage hole 50, viewed from the geometric longitudinal axis 17. Under normal conditions, i.e., within the central range of manufacturing tolerances, at normal temperatures, and with normal sliding forces, the air passage hole 50 is aligned with the hole 31. This is explained by the fact that the single-pitch thread 18 has a thread starter 66 that coincides with the thread starter 67 of a tapped hole 19. The tapped hole 19 is also single-pitch, so that the air passage holes 50, 63, 64 are, in all cases, located in the area of ​​the hole 31 when the screw cap 32 is screwed in.

Claims

DEMANDS 1. Screw cap, comprising an annular groove (48) which is open in the opposite direction to the bottom of the cap (37) and comprising at least one air passage orifice (50) which, from the annular groove (48), passes through the bottom of the cap (32), comprising a tapped hole (19) adapting to the thread (18) of a pouring spout (16) of a can, the screw cap (32) having, at the end of its screwing operation, a certain angular position relative to the pouring spout (16), and comprising a passage orifice (24) in the pouring spout (16), according to claim 1 of the main patent application, characterized in that at least two air passage orifices (50, 63, 64) are provided which are arranged angularly offset from each other.

2. Device according to claim 1, characterized in that the angular spacing is greater than two air orifice diameters, but less than five air orifice diameters.

3. Device according to claim 2, characterized in that the annular spacing is between two and four air orifice diameters.

4. Device according to claims 1 to 3, characterized in that three air passage orifices (50, 63, 64) are provided, the central orifice of which, in normal position after a screwing operation, is aligned, in the alignment zone, with the passage orifice (24) of the pouring tube (16).

5. Device according to claim 1, characterized in that the tapping (19) and the threading (18) are simple pitch, with starters (66, 67) adapting angularly to the air passage orifices (50, 63, 64).