Device for delivering a composition, the device including a membrane forming a check valve
The device includes a membrane slidably mounted in a metering chamber, the membrane including a first sealing element forming a check valve, and a second sealing element enabling the membrane to slide in a leaktight manner relative to the metering chamber. The first and second sealing elements are made of a material that is relatively flexible, the membrane also including a rigid portion made of a material that is more rigid than the material of the first and second sealing elements.
1. A device for delivering a composition, the device comprising a piston having a support and a membrane, the support including a feed channel opening out via one or more feed orifices provided in the top end of the support, the membrane being mounted to slide in a metering chamber and comprising:
a first sealing means forming a check valve, the first sealing means being capable of taking a liquid-blocking configuration by being pressed against the support; and
a second sealing means enabling the membrane to slide in leaktight manner relative to the metering chamber;
the first and second sealing means being made of a material that is relatively flexible, the membrane also including a rigid portion made of a material that is more rigid than the material of the first and second sealing means, the rigid portion being distinct from the support.
2. The device according to claim 1 , wherein the rigid portion and the first and second sealing means are obtained by co-injection, bi-injection, or overmolding.
3. The device according to claim 1 , wherein the rigid portion is made of a material selected from a polymer or metal.
4. The device according to claim 1 , wherein the rigid portion is substantially in the form of a ring.
5. The device according to claim 1 , wherein the second sealing means include at least one lip forming a body of revolution.
6. The device according to claim 1 , wherein the membrane includes a transverse wall carrying the first sealing means, and a cylindrical skirt carrying the second sealing means, the rigid portion extending mainly in the cylindrical skirt.
7. The device according to claim 1 , wherein the membrane is assembled on the support and includes a base bearing against the support, the bearing base forming a portion of the rigid portion of the membrane.
8. The device according to claim 1 , wherein the rigid portion includes a bearing surface for a tool for assembling the membrane in the device.
9. The device according to claim 1 , including third sealing means providing permanent sealing between the membrane and the support.
10. The device according to claim 1 , wherein the membrane is used in a pump.
11. The device according to claim 1 , wherein the membrane is fitted on the support, and the support includes a bearing seat for the first sealing means, which first sealing means are pressed against the seat when they are in a blocking configuration, and are spaced apart therefrom when they are in a composition-release configuration.
12. The device according to claim 11 , wherein the seat is integrally molded with the support.
13. The device according to claim 1 , wherein the support includes a tubular portion defining the feed channel and the membrane includes a cylindrical skirt mounted stationary around said tubular portion.
14. The device according to claim 3 , wherein the material is one of polypropylene, polyethylene, polyester, polyacetal, and polyamide.
15. The device according to claim 3 , wherein the material is poly-butylene-terephthalate (PBT).
16. The device according to claim 3 , wherein the material is stainless steel.