WO2003042569A1

WO2003042569A1 - Spring and dispenser comprising same

Info

Publication number: WO2003042569A1
Application number: PCT/FR2002/003873
Authority: WO
Inventors: Frédéric Duquet; Firmin Garcia
Original assignee: Valois Sas
Priority date: 2001-11-14
Filing date: 2002-11-13
Publication date: 2003-05-22
Also published as: FR2832199B1; FR2832199A1

Abstract

The invention concerns a spring (4) comprising two branches (41, 42) linked by a bend (40) such that the branches form, at rest, an acute angle, said branches being elastically mobile relative to each other by relative pivoting about the bend until they are urged in contact with each other so as to extend substantially parallel. The invention is characterized in that it comprises means for varying the stiffness of the spring (43, 44) which provide different degrees of stiffness depending on whether the spring is compressed or is slackened, said variation means providing a low degree of stiffness when the branches extend substantially parallel and a higher degree of stiffness when the branches are stressed towards each other from the rest position.

Description

Spring and distributor comprising such a spring

The present invention relates to a spring and to a dispensing device using such a spring as a return spring used to return the dispenser to the rest position. However, the spring should not be limited to its sole implementation in such a distributor. Indeed, it can also be used in any other system requiring elastic return means.

There are already many types of spring, and the most commonly used is the conventional spiral spring of cylindrical shape, and more rarely conical. When such a spiral spring has to be mounted automatically in a particular device or system, this requires orienting and then gripping the spring using an appropriate machine such as a robot. This is due to the fact that a spiral spring is very difficult to stand due to its cylindrical and elongated configuration. It cannot therefore be fed directly into a device at an appropriate location from bulk storage. The present invention defines another type of spring, the orientation of which is advantageously easier, in the sense that the spring is positioned almost automatically in a position in which it can perform its spring function.

Document US-2 432 288 already discloses a spring made up of two blades bent over one another, the end of a blade coming into contact with the other blade. By pressing on this spring so as to bring the blades closer to each other, it is impossible to bring the two blades into contact with one another. This spring can therefore never be flat, that is to say having a very reduced thickness. Document US-4,932,508 also discloses a leaf spring produced in the form of a zigzag. Each leaf of the spring is formed with a window in which is cut a curved tab which can come into contact with the other leaf when the spring is compressed. The free end of the tab slides on the blade when the spring is compressed. In these springs of the prior art, it is not possible to bring them into an extremely flat configuration, because the means which give the stiffness to the spring, in this case the end of a blade or the tab, do not not allow it. The object of the present invention is to remedy this drawback of the prior art by defining a spring which can easily adopt an extremely flat configuration while having good compression stiffness.

To do this, the subject of the present invention is a spring comprising two branches connected by an elbow so that the branches form, in the rest position, an acute angle, said branches being elastically movable relative to each other by relative pivoting around the elbow until it comes into contact with one another so as to extend substantially parallel, characterized in that it comprises means for varying the stiffness of the spring which confer different stiffnesses depending on whether the spring compresses or relaxes, said variation means conferring a low stiffness when the branches extend substantially parallel and a greater stiffness when the branches are forced towards one another from the rest position. The branches of the spring are substantially identical and advantageously straight and substantially planar. In addition, the width of the branches is more than half their length. Therefore, the spring is almost automatically positioned on one of these two branches so that it can fulfill its spring function by pressing on the other branch which does not rest on the bearing surface. Advantageously, the elbow extends over the entire width of the branches.

The spring therefore has a particularly simple configuration in the form of a somewhat open hairpin which can easily be produced from a cut and folded metal blade or by plastic molding.

The stiffness variation means become fully operational only after an initial relaxation of the branches when one begins to bring them together again. It is the means of variation which act on the stiffness of the spring, and no longer on the elbow. The means of variation fill in somehow an arming function of the spring which gives full stiffness to the spring.

As soon as the variation means are fully operational, the role of the elbow is limited to an articulation between the two branches, but only represents a small contribution to the total stiffness of the spring. The elastic deformation of the spring then occurs at the branches and / or the variation means.

Advantageously, the means for varying the stiffness of the spring comprise blocking means preventing the branches from being brought back substantially parallel from the rest position.

According to one embodiment of the invention, the variation means comprise at least one lug integral with a so-called first branch and extending between the two branches towards the other so-called second branch, said lug comprising a free end and a end connected to the first branch, said second branch comprising an abutment housing intended to receive the free end of the tab, said free end being locked in abutment in the housing when the two branches are forced towards one another, thus preventing the branches from being brought against each other by pivoting around the elbow. If the free end of the tab is prevented from engaging in the housing of the second branch when the branches are brought together, it is possible to completely flatten the spring with the deformed tab elastically so as to extend substantially parallel to and between the branches. In this flattened configuration, the tab contributes to the total stiffness of the spring in association with the elbow. It is the elastic deformation of the tab at its connection with the branch which generates the stiffness. On the other hand, if the tab is left free from any external constraint, then its free end automatically engages in the housing of the second branch and remains blocked there even if the spring is compressed to the maximum. The stiffness of the spring is then much greater than that of the spring when it is flattened with the tab which extends between the parallel branches. According to a practical embodiment, the tab extends with its free end turned substantially towards the elbow, the free end of the tab being located between the abutment housing and the elbow when the branches are substantially parallel. As a variant, the lug extends with its free end turned substantially towards the free ends of the legs, the free end of the lug being located between the stop housing and the free ends of the lugs when the branches are substantially parallel. Advantageously, the first branch forms a window in which the tab is received by elastic deformation when the two branches extend substantially parallel. The subject of the invention is also a fluid product dispenser comprising:

- a reservoir containing said fluid product and provided with at least one actuating wall on which pressure is exerted to reduce the volume of the reservoir, - a dispensing orifice through which the fluid product is dispensed, characterized in that the reservoir contains a spring as defined above. Advantageously, a removable closure element closes the dispensing orifice and thus isolates the reservoir from the outside, the spring being constrained so as to occupy a minimum volume as long as the closure element closes the dispensing orifice. Thus, the spring expands to increase the volume of the reservoir as soon as the closure element is withdrawn by gas entering the reservoir through the dispensing orifice.

The use of such a spring is particularly advantageous in such a fluid dispenser, since it suffices to deposit the spring in the reservoir during the manufacture of the dispenser without having to worry about its particular orientation, since the spring automatically positions itself on one of these two branches. This saves a prior operation of orientation and entry of the spring. In addition, such a spring can be manufactured inexpensively. The invention will now be described more fully with reference to the accompanying drawings which give by way of nonlimiting example an embodiment of the spring according to the invention, as well as an implementation in a particular fluid dispenser. In the figures:

- Figure 1 is a perspective view of the spring of Figure 1, - Figure 2 is a vertical cross-sectional view through the spring of Figure 1 in the compressed state,

FIG. 3 is a view of the spring of FIGS. 1 and 3 during compression with the fully operating variation means,

FIG. 4 is a vertical cross-section view through a fluid dispenser using a spring from FIGS. 1 to 3, said dispenser being unused, and

- Figure 5 is a sectional view of the dispenser of Figure 4 ready to be used.

The spring shown in the figures and used to illustrate the present invention is in the general form of an open pin. The spring designated as a whole by the reference numeral 4 comprises two branches 41 and 42 connected together at one of their ends by an elbow 40. The two branches 41 and 42 extend relative to one another by making a acute angle, for example between 20 and 60 °. It is easily understood that such a pin can be easily elastically deformed by bringing the branches closer to one another, which is effected by a deformation / pivoting movement around the elbow 40. By choosing an appropriate material such as ^~ metal or plastic, having a good shape memory, the two branches return elastically to their original position as soon as the support force has ceased to be exerted on these branches.

Preferably, the branches of the spring are relatively wide with respect to their length: the width of the branches can for example be greater than half the length of the branches. In addition, the two branches are advantageously substantially straight and flat, so that they offer an extended and particularly stable bearing surface. Preferably, the two branches are substantially identical so that it is completely indifferent that the spring rests on one or the other of the branches. With such a configuration, the spring is automatically positioned on one of these two branches, π is in fact practically impossible for the spring to be positioned on the edge of the branches: this being made even more improbable because the free end of the branches are rounded.

According to the invention, the spring comprises means for varying the stiffness of the spring capable of preventing the branches from being brought back substantially parallel. The variation means are weakly operative or generate a low stiffness when the branches extend substantially parallel and on the contrary become fully operative or generate a greater stiffness when the branches are forced towards each other from the position rest. These variation means are here in the form of a tab 43 which extends from the branch 41 towards the other branch 42. In other words, the tab 43 extends between the two branches in the 'acute angle. The tab 43 includes one end connected to the branch 41 and a free end 431 which points towards the other branch 42. The tab 43 also extends in an inclined manner so that the free end 431 is turned towards the elbow 40. However, one can imagine a variant for the tab 43 so that its free end 431 is turned towards the free ends of the branches 41 and 42. The tab 43, like the branches 41 and 42 preferably have an elastic deformation capacity, although it can be said that they are substantially rigid. We can talk about resilience.

According to the invention, the branch 42 forms an abutment housing 44 adapted to receive the free end 431 of the tab 43. This can be seen in FIG. 3. In the rest position shown in FIG. 1, the end piece 431 of the tab 43 is not necessarily received in the abutment housing 44 of the other branch 42. The rest position can also be the position or the form of molding. As can be seen in FIG. 1, the free end 431 of the tab 43 is however positioned close to the stop housing 44 and in any case close to or in contact with the branch 42. By pressing on the branches so as to closer together, the free end 431 of the tab 43 moves by relative to the branch 42 in the direction of the stop housing 44. Continuing to press on the branches, free end 431 will be housed in the stop housing 44: however, the stop housing 44 has a configuration capable of maintaining the free end 431 blocked even if the branches are continued to be pressed so as to bring them closer to one another. Since the arms and / or the leg 43 are elastically deformable, it is possible to bring the free ends of the arms 41 and 42 closer to each other by elastic deformation of the arms and / or the leg 43, as can see it in dotted lines in Figure 3. The tab 43 prevents the branches 41 and 42 from approaching each other by pivoting around the elbow 40. Indeed, the angle that the branches make at the elbow 40 remains unchanged when the branches are pressed so as to bring them closer. Most of the stiffness of the spring is provided directly by the lug 43 which acts as a blocking or forestay between the branches. It is however possible to bring the branches one in contact with the other so as to extend substantially parallel by preventing the free end 431 from engaging in the abutment housing 44 of the branch 42. This is shown in FIG. 2. It suffices for this to slightly constrain the tab 43 so that it passes over the abutment housing 44 without engaging therein. The free end 431 can then be positioned beyond the abutment housing 44, that is to say between the latter and the elbow 40. It would be otherwise in the case where the tab 43 extends into the other direction ie towards the free ends of the branches. It is clearly seen in Figure 2 that the tab 43 is substantially parallel to the branches 41 and 42 which also are substantially or perfectly parallel. In order to allow the tab 43 to be thus housed between the branches, the latter must have a certain elasticity at its junction with the branch 41, and in addition, the branch 41 forms a window 430 inside which tab 43 can be accommodated. The spring in Figure 2 is extremely flat, its thickness corresponding approximately to the thickness of the spring at the elbow 40. The tab 43, that is to say the means of variation, are only weakly operative in this position since the free end 431 is not engaged in the abutment housing 44. However, the tab 43 because it is elastically deformed tends to urge the branches away from one another. Consequently, the tab 43 even in a weak operating position contributes, in addition to the elbow 40, to the stiffness of the spring which tends to bring the branches 41 and 42 into the rest position as shown in FIG. 1. However, the stiffness imparted by the elbow 40 and the weakly operating tab is not considerable so that a minimum force is sufficient to maintain the spring in the configuration of FIG. 2. By loosening the spring when it is in the configuration of FIG. 2, the branches 41 and 42 will pivot relative to each other around the elbow 40 helped by the release of the tab 43. When the branches are separated, the free end 431 of the tab 43 will pass over the housing stop 44 and continue on its way to the position shown in FIG. 1. The spring is then in the rest position. By pressing the branches again so as to bring them closer to one another, the free end 431 will engage and remain blocked in the abutment housing 44. The subsequent dynamic behavior has already been described below. above. It can easily be understood that the stiffness of the spring when the tab 43 is engaged in the stop housing 44 is much greater than the stiffness of the spring in the configuration of FIG. 2, that is to say with the tab 43 disengaged from the housing of stop 44. The stiffness of the spring in the configuration of FIG. 2 may just be sufficient to allow the tab 43 to come to engage in the housing 44. It is however preferable to provide a margin so that the tab 43 comes place in front of the housing as shown in Figure 1. Without external intervention to constrain the tab 43, it can never regain its position as shown in Figure 2. Indeed, the stop housing 44 acts as a impassable barrier or stop for the free end 431. It is only by constraining the tab 43 that it is possible to find the configuration of FIG. 2.

Thanks to these means of varying the stiffness of the spring, the spring has two different stiffness values, namely a low value when the branches move away from a maximum compressed state (FIG. 2), and a value larger when the branches are brought closer from the rest position in FIG. 1. This difference in stiffness value is a particularly advantageous characteristic in certain applications as will be seen below. Such a spring can for example be produced from a cut and folded metal blade. The spring can preferably be made from molded plastic.

It emerges as described above has a preferred application in a fluid dispenser as shown in Figures 4 and 5. In this non-limiting embodiment, the dispenser can be made from two sheets of flexible complex film 1 and 2 which are welded together on their periphery 11, 12 so as to define therebetween a volume which corresponds substantially to that of a reservoir of fluid product 3. An insert 5 can also be placed between the two sheets 1 and 2: this insert 5 defines a dispensing orifice 50 and a housing in which a porous fiber 6 can be housed so as to extend inside the reservoir 3. This fiber 6 is intended to be impregnated with the fluid product contained in the interior of the reservoir 3. Once this fiber is soaked in product, it suffices to pass an air flow through the fiber which creates a two-phase distribution at the level of the orifice of dis tribution 50 of the insert 5. In front of the dispensing orifice 50, the two sheets 1 and 2 welded together define a tear-away or folding tab 12 which closes the dispensing orifice 50 so as to isolate the reservoir 3 from the 'outside.

According to the invention, the reservoir 3 contains a spring 4 which is arranged between the two sheets 1 and 2. The spring 4, as can be seen in FIG. 2, acts at least on one wall 1 of the dispenser, which can be the actuating wall, so as to increase the internal volume of the reservoir 3. According to a particularly advantageous characteristic, the spring 4 is constrained in its fully compressed state as shown in FIG. 2 as long as the obturation element 12 closes the 'dispensing orifice 50 and thus isolates the reservoir 3 from the outside. In other words, the reservoir 3 was sealed during its manufacture with the spring constrained in its maximum compressed state so that the tank is then at its minimum volume. In this state shown in FIG. 1, the reservoir 1 contains practically only fluid and practically no or no gas at all. Since the reservoir 3 is perfectly isolated from the outside by the closure element 12, the spring 4 cannot relax inside the reservoir 3 due to the atmospheric pressure exerted on the walls 1 and 2 of the tank. The dispenser can then be stored before use in this state, it has a particularly reduced thickness which is defined substantially by the thickness of the spring 4 in its fully compressed state added to the cumulative thickness of the two sheets of film 1 and 2. The spring 4 then defines a minimum volume in which the fluid product is stored without undergoing practically any pressure. Thus, there is no risk of leakage by crushing of the reservoir 3. Such a dispenser can for example be inserted in a magazine since it is particularly flat and particularly resistant to pressure. As soon as the shutter element 12 is removed, the air can penetrate inside the tank 3 through the dispensing orifice 50 so that the spring 4 can relax inside the tank. so as to increase its internal volume. This is possible thanks to the stiffness of the spring imparted by the elbow and the elastically stressed tab, but located outside the stop housing. It suffices that this stiffness allows the branches to move apart despite the resistance of the sheets making up the tank. The reservoir 3 is then filled with fluid and gas, generally air. To obtain a distribution of sprayed product, it suffices to act on the wall 1 using the thumb for example against the action of the spring 4 so as to discharge air through the fiber 6 soaked in fluid product . The air passing through the soaked fiber 6 creates a two-phase spray at the level of the dispensing orifice 50. As soon as the pressure on the actuating wall 1 is released, the latter resumes its shape represented on the Figure 2 due to the elastic action of the spring 4.

The spring 4 plays a role of spacer in the storage state (FIG. 4) by determining a minimum volume for the reservoir 3, a role of initiator during the lifting of the shutter element 12 by increasing the volume of the reservoir 3, and a role of return spring during actuation by pressure on the actuating wall 1.

The use of a spring as defined above with reference to FIGS. 1 to 3 is particularly advantageous in this type of dispenser since it can be placed in the reservoir during the manufacture of the dispenser without any particular orientation, from the causes the spring to automatically position itself on one of these two arms. In addition, it is extremely flat in the fully compressed state, which makes it possible to produce particularly flat dispensers, this being advantageous for the aforementioned reasons. It should also be noted that the springs in the fully compressed state do not press very strongly on the constituent sheets of the reservoir. Indeed, due to the low value of the stiffness of the spring in this position corresponding to that of Figure 2, the branches are not strongly stressed in spacing, and therefore the branches bear less strongly against the leaves. The advantage is that the leaves are not marked or very slightly marked by the branches due to their weak support. On the other hand, as soon as the spring has been able to relax due to the penetration of air into the reservoir, the tab 43 can engage in the abutment housing 44 and the stiffness is then considerably increased. A distributor is thus obtained with a very effective return spring whereas in the fully compressed position of FIG. 2, this spring exhibited only a much less considerable force.

In FIG. 5, we can see in dotted lines the state of deformation of the spring 4 when the reservoir of the distributor is pressed. It is preferable that the tab and the branch forming the stop housing deform elastically to increase the movement of the spring.

Thanks to this particular spring with variable stiffness, it is possible to produce a dispenser from a simple packaging of fluid product without shape memory.

Claims

claims

1.- Spring (4) comprising two branches (41, 42) connected by an elbow (40) so that the branches form, in the rest position, an acute angle, said branches being elastically movable on the one hand relative to the 'other by relative pivoting around the elbow until it comes into contact with each other so as to extend substantially parallel, characterized in that it comprises means for varying the stiffness of the spring (43, 44) which confer different stiffnesses depending on whether the spring compresses or relaxes, said variation means conferring a low stiffness when the branches extend substantially parallel and a greater stiffness when the branches are forced towards each other to from the rest position.

2. A spring according to claim 1, in which the means for varying the stiffness of the spring comprise blocking means preventing the branches from being brought back substantially parallel from the rest position.

3. Spring according to claim 1 or 2, wherein the branches (41, 42) are elastically deformable.

4. Spring according to claim 2 or 3, wherein the variation means (43) are elastically deformable.

5. Spring according to any one of the preceding claims, in which the variation means comprise a tab (43) integral with a so-called first branch (41) and extending between the two branches towards the other so-called second branch. (42), said tab (43) comprising a free end (431) and one end connected to the first branch, said second branch (42) comprising an abutment housing (44) intended to receive the shaft end (431) of the tab, said end piece (431) being locked in abutment in the housing (44) when the two branches are forced towards one another, thus preventing the branches from being brought against each other by pivoting around the elbow.

6. A spring according to claim 5, in which the lug (43) extends with its end end (431) turned substantially towards the elbow (40), the free end of the lug being located between the stop housing ( 44) and the elbow (40) when the branches are substantially parallel.

7. A spring according to claim 5, in which the tab (43) extends with its free end (431) turned substantially towards the free ends of the branches, the free end (431) of the tab (43) being located between the abutment housing (44) and the free ends of the legs when the branches are substantially parallel.

8. A spring according to any one of claims 5 to 7, in which the first branch (41) forms a window (430) in which the tab (43) is received by elastic deformation when the two branches extend substantially in parallel.

9. A spring according to any one of claims 5 to 7, in which the tab (43) extends so that its free end (431) is automatically housed and remains blocked in the stop housing

(44) of the second branch (42) when the two branches are forced towards one another.

10. Spring according to any one of the preceding claims, produced by molding of plastic material.

I - Fluid product dispenser comprising: - a reservoir (3) containing said fluid product and provided with at least one actuating wall (10) on which pressure is exerted to reduce the volume of the reservoir, - a dispensing orifice (50) by which the fluid is distributed, characterized in that the reservoir (3) contains a spring (4) according to any one of the preceding claims.

12. A dispenser according to claim 11, wherein a removable closure element (12) closes the dispensing orifice (50) and thus isolates the reservoir (3) from the outside, the spring (4) being constrained to way to occupy a minimum volume as long as the closure element closes the dispensing orifice.

13. A dispenser according to claim 12, wherein the spring (4) relaxes to increase the volume of the reservoir as soon as the closure element is withdrawn by gas entering the reservoir through the dispensing orifice.

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