WO1996022163A1

WO1996022163A1 - Pump with a single-piece inlet valve and assembly for moulding said valve

Info

Publication number: WO1996022163A1
Application number: PCT/FR1996/000068
Authority: WO
Inventors: Miroslav Pavlata; Claude Jouillat
Original assignee: Valois S.A.
Priority date: 1995-01-18
Filing date: 1996-01-16
Publication date: 1996-07-25
Also published as: DE69600760D1; FR2729436B1; EP0805719A1; DE69600760T2; EP0805719B1; JPH10512488A; FR2729436A1

Abstract

A fluid dispensing pump including a pump chamber (5) communicating with a fluid supply via an inlet channel (41), said pump chamber (5) being provided with an inlet valve for cutting off the pump chamber (5) from the supply when the fluid is dispensed. Said inlet valve is made in a single piece and incorporates the following members: a base ring (1) fixedly mounted in the pump chamber (5) and circumjacent to said inlet channel (41), a valve seat (111), a needle member (2) resiliently movable between a rest position in which said needle member (2) sealingly engages the valve seat (111), and an open position in which the supply is in communication with the pump chamber (5), and resilient means (21) connecting the base ring (1) to the needle member (2) and biasing said member by resilient preloading towards the rest position in which it engages the valve seat (111).

Description

One-piece inlet valve pump and molding assembly for such a valve.

The present invention relates to a pump for dispensing fluids, comprising a pump chamber in communication with a fluid reservoir via an intake channel, said chamber being provided with an adapted intake valve. isolating the pump chamber from said reservoir during the distribution of the fluid. The invention relates more particularly to said intake valve.

There are many types of inlet valves for use in small pumps. A conventional form consists in trapping a ball or a washer in a housing formed at the outlet of the intake channel. When the pressure increases in the pump chamber, the ball or washer is pressed against a valve seat formed at the mouth of the intake channel. Thus, the pump chamber is isolated from the reservoir during the distribution of the fluid. On the other hand, during the aspiration phase of fluid product coming from the reservoir, the ball or the washer is detached from its seat, undergoes the turbulence of the flow and floats inside the housing provided for this purpose. It is a very simple design technique, but which has the disadvantage of having to make a housing to retain the ball or the washer in a defined volume which ensures that the ball or the washer is repositioned, after each suction phase, tightly on its valve seat. The housing can be an integral part of the pump body, in which case it is necessary to provide a mold with a complex imprint. The housing can also be formed by an insert in the pump body. Again, a specific mold is required. It can be seen that the need for housing to confine the ball or the washer in a limited volume generates complexity in terms of molding. In addition, a subsequent mounting operation is necessary to introduce the ball or the washer into said housing.

One of the objects of the present invention is to provide an inlet valve which does not require the formation of a housing capable of accommodating a free valve member such as a ball or a washer. The inlet valve must be able to be mounted in a simple pump body without any particular structure.

Another type of intake valve implements a needle located at the lower end of the actuating rod and which is intended to close the intake channel when the actuating rod is pressed. This is a very specific type of valve, since there is interaction between the pump body and the actuating rod to perform the function of intake valve. Indeed, this valve can only exist in a precompression pump in which the piston is slidably mounted on the actuating rod. This valve cannot therefore be used universally on any type of pump. Another particular type of intake valve is implemented in precompression pumps using the overpressure prevailing in the pump chamber to detach a needle from its seat and thus create an outlet passage for the fluid. The needle is in sealed support in the fluid delivery channel under the action of a spring. The needle extends downward and forms a skirt which is intended to be fitted onto a sleeve integral with the pump body. The engagement of the skirt and the sleeve fulfills the role of intake valve. Again, this is a special valve for specific use.

Another object of the present invention is to provide an intake valve capable of being mounted in most pumps and which does not involve a dynamic member thereof.

There is yet another type of valve in which the valve member is applied with a certain preload on its seat. This isolates the reservoir from the pump chamber even when the pump is at rest. European patent EP-0 377 536 discloses such an intake valve. This comprises a flexible flat seal and a valve holder with an internal relief which presses on the edge of the seal and tends to position it in the sealing position with prestress. During the fluid suction phase, the flat seal flexes and clears a passage for the fluid. As soon as the suction is finished, the seal returns to the initial position of support on its seat. This variant of valve is somewhat similar to that using a washer, except that the seal is constrained by the valve valve and therefore cannot float freely in the housing defined by the valve valve. However, this valve has the disadvantage that its installation in a pump body is difficult since the valve holder must perfectly cover the seal without crushing it too much and without leaving it free. There is also a problem of centering of the seal during assembly, because the valve valve must surround the seal with its base intended to come into abutment at the bottom of the pump body. These mounting difficulties arise from the fact that the valve is made in two separate parts requiring relative positioning in the pump body.

Another object of the present invention is to provide a one-piece intake valve in which the valve member is prestressed on its valve seat.

To respond to these problems, the invention provides a pump for the distribution of fluid products, comprising a pump chamber in communication with a fluid reservoir through an intake channel, said pump chamber being provided an intake valve adapted to isolate the pump chamber from said reservoir during the distribution of the fluid product, said intake valve being formed in one piece integrating at least the following members: - a base crown fixedly mounted in the pump chamber circumferentially to said intake channel, - a valve seat, - a needle member movable elastically between a rest position in which said needle member is in sealed contact with the valve seat and an intake position in which a passage is established between the reservoir and the pump chamber, and - elastic means connecting the base crown to the needle member and urging the latter by elastic prestressing in the rest position against the valve seat.

Thanks to this arrangement, the valve forms a whole which is easily insertable into a pump body. Prestressing is provided by the valve itself and no longer in cooperation with another member of the pump.

According to another embodiment, the valve seat is formed by the base crown. Here, the valve is completely autonomous and no longer depends on the surrounding structure. Advantageously, the base crown is fixedly held in the pump chamber by a return spring which bears on the latter.

According to another characteristic of the invention, the base crown is formed with a ring on which said elastic means are fixed, said ring being connected to the rest of the crown only by a bridge of material so that the ring and its needle body elastically connected are articulated by rappoπ to the rest of the base crown.

Preferably, the elastic means are elastic tabs extending substantially helically between the base crown and the needle member.

The invention also defines a molding assembly for molding an inlet valve according to claim 6, characterized in that it comprises two different mold halves, a first mold half having an imprint corresponding to the negative of the lower part of the base crown and the upper part of the needle member and the ring, and a second mold half having an imprint corresponding to the negative of the upper part of the base crown and the lower part of the member needle and ring, the base crown and the ring to which the needle member is fixed being molded head to tail side by side with the material bridge defining a communication channel between them. The first set makes it possible to mold a valve in the final form, ready for use, while the second set makes it possible to mold a valve flat which must then be folded back on itself. The first set implements more than three pieces while the second set implements only two pieces.

The invention will now be described in more detail with reference to the accompanying drawings which give by way of nonlimiting example an embodiment of the invention. In the drawings:

FIG. 1 is a sectional view of a second embodiment of an intake valve, and

- Figure 2 shows both a plan view and in section of the valve of Figure 1 in the not yet folded state.

Referring to Figures 1 and 2, an embodiment of a valve according to the invention will be described. Figure 1 shows the valve in its final state of use, while Figure 2 shows the valve seen from above in its initial state just at the end of the mold. A base ring 1 is formed of a substantially cylindrical part at the lower end of which extends a collar 10 inwards. The collar has a reinforced inner periphery 11 defining a surface 1 11 preferably rounded. We will see below that this surface 1 1 1 acts as a seat for the needle member 2. The upper end of the part of the cylinder of the crown has a substantially uniform periphery, except for one of the diametrically opposite points. At one of these points, said crown 1 is connected to a ring 12 via a material bridge 13. At the other point, the crown defines a housing 14 adapted to receive a tooth 14 'formed at the periphery outside of the ring 12. Advantageously, the housing 14 is formed on a part of the periphery of the base ring by a peripheral buttress 15 in which part of the external periphery of the ring 12 is inserted. The tooth 14 'is then more in the form of a peripheral protuberance which extends over part of the outer periphery of the ring corresponding to the counterfoil 15. Preferably, the counterfoπ 15 and the protrusion 14' extend over more than half of the periphery, as shown in FIG. 6, so that the ring 12 is perfectly maintained on the base crown 1. In fact, the ring 12 is materially secured to the crown 1 only by the bridge of material 13 which thus constitutes a point of articulation around which the ring can pivot on the crown. The engagement of housing 14 / protuberance 14 ′ therefore ensures solid fixing of the ring on the crown. We will see below that said engagement housing / outgrowth is essential, because of the valve molding technique. Of course, one can imagine other means of holding the ring on the crown while these are secured by a bridge of material. The snap-fitting effected by this housing / growth commitment is only one simple and effective means among others.

As we have just seen, the ring 12 is fixedly mounted on the crown 1. Elastic tabs 21 extend from the inner periphery of the ring inward to join the needle member 2. The tabs 21 also extend helically to allow vertical movement of the needle member. In the rest position, the needle member rests with an external peripheral surface against the surface 111 defined on the crown 1. The contact between these two surfaces is sealed, even in the rest position because the needle member is slightly prestressed on its valve seat 111.

This state of prestressing of the valve comes from the molding technique. This valve, as shown in Figure 5, can not be molded as is. According to the invention, the valve is molded flat as shown in Figure 2. The crown 1 of a pan, and the ring 12, the elastic tabs 21 and the needle member 2, on the other hand, are molded side by side, head to tail, only the material bridge 13 connecting them. At the outlet of the mold, the valve is presented as in FIG. 2. A subsequent folding operation is necessary to bring the valve into its final state of use. The two lines A-A represent the axis of symmetry of the valve, which once folded, overlap. The prestress is generated after the ring is snapped onto the crown. This can simply be obtained by providing a surplus of peripheral material either at the surface 1 1 1 or at the needle member 2. The contact between the needle member and the surface 1 1 1 is made then before the ring is completely snapped onto the crown. The prestressing is thus automatically obtained during the folding / snap-fastening of the valve ring.

Another important advantage of this valve is that it is completely autonomous, in the sense that it incorporates all the necessary functions of an intake valve. Indeed, the crown 1 defines the valve seat 1 11. This characteristic is advantageous, because the pump body can thus be produced with greater tolerances, since the valve seat is incorporated in the valve.

The valve according to this second embodiment is also easily moldable. Indeed, the necessary molding assembly only comprises two different mold halves, a first mold half having an imprint corresponding to the negative of the lower part of the base crown and of the upper part of the needle member and of the ring, and a second mold half having an imprint corresponding to the negative of the upper part of the base crown and the lower part of the needle member and the ring, the base crown and the ring to which is fixed the needle member being molded head to tail side by side with the material bridge defining a communication channel between them. Thus, with an extremely simple molding assembly, it is possible to produce an autonomous valve with a prestressed needle member.

Claims

claims

1.- Pump for the distribution of fluid products, comprising a pump chamber (5) in communication with a fluid reservoir through an inlet channel (41), said pump chamber (5) being provided with an intake valve adapted to isolate the pump chamber (5) from said reservoir during the distribution of the fluid product, characterized in that said intake valve is formed in one piece integrating at least the following members:

a base ring (1) fixedly mounted in the pump chamber (5) circumferentially to said intake channel (41),

- a valve seat (111), - a needle member (2) resiliently movable between a rest position in which said needle member (2) is in sealed contact with the valve seat (1 1 1) and a position d admission in which a passage is established between the reservoir and the pump chamber (5), and

- elastic means (21) connecting the base crown (1) to the needle member (2) and urging the latter by elastic prestressing in the rest position against the valve seat (11 1).

2.- Pump according to claim 1, wherein the valve seat is formed by a contact surface (111) defined by the base ring (1).

3.- Pump according to any one of the preceding claims, in which the base ring (1) is fixedly held in the pump chamber (5) by a return spring (6) which is supported thereon.

4.- Pump according to any one of the preceding claims, in which the base crown (1) is formed with a ring (12) on which said elastic means (21) are fixed, said ring being connected to the remainder of the crown (1) only by a material bridge (13) so that the ring (12) and its needle member (2) elastically connected are aπiculées relative to the rest of the base crown (1).

5.- Pump according to any one of the preceding claims, wherein the elastic means are elastic tabs (21) extending substantially helically between the base crown (1) and the needle member (2).

6.- molding assembly for molding an inlet valve according to any one of the preceding claims, characterized in that it comprises two different mold halves, a first mold half having an imprint coπespondant to the negative of the lower part of the base crown and of the upper part of the needle member and of the ring, and a second mold half having an imprint corresponding to the negative of the upper part of the base crown and of the lower part of the needle and ring member, the base crown and the ring to which the needle member is fixed being molded head to tail side by side with the material bridge defining a communication channel between them.