Fluid substance dispenser with easily disengageable snap-locking elements

Abstract: A fluid substance dispenser comprising a dispensing head (2) or pusher to be fitted onto the stem of a pump, and a cap to be fixed onto the mouth of a container containing the substance to be dispensed, on the outer surface of the head and on the inner surface of the cap there being provided respective spiral ribs (8,9) extending in the same direction, these ribs (8,9) interfering with each other and passing snapwise over each other when the head is pressed onto the cap, they cooperating with each other to cause the head to withdraw from the cap when the head is rotated about the cap.

Description: This invention relates to a pressurized fluid substance dispenser with elements for snap-locking it when in its lowered position. Fluid substances (liquids or creams) are commonly dispensed under pressure by pumps mounted on the mouth of containers containing the substance to be dispensed. The pressurized fluid is discharged to the outside by passing through cavities provided in a dispensing head or pusher press-fitted onto the free end of the pump stem. The delivery pump and head occupy when at rest a relatively large space in their length direction, but this is in many cases a serious drawback, hence various systems have been designed and used for locking the head on the respective pump during storage, packaging and transport, and for preventing delivery of the substance if the head is accidentally pressed towards the respective pump. This is achieved by fixing onto the mouth of each container (on which a pump is mounted) a cap provided with elements which cooperate with corresponding elements provided on the delivery head, to retain this head when lowered onto the cap. As this head lowering operation is carried out in industrial plants operating at high speed, the delivery head has to be able to be engaged and retained automatically by the respective cap whatever the angular position of the head relative to the cap. The most simple engagement system is the snap type such as that described in US-A-4,368,830 and in EP-A-0065214 and EP-A-0686432, which show a rib projecting inwards from the upper free edge (that facing the outside of the pump) of the cap to snap-engage a corresponding rib or tooth projecting outwards from the lower free edge of the respective delivery head. The head is disengaged from the respective cap (to return the head to its raised position, in which it is operable) by different methods in the three aforesaid patents, but always with certain difficulties which it would be desirable to overcome. In the case of US-A-4,368,830, to disengage the head 18 from the cap 13 the tab 24 projecting from the head 10 must be pressed laterally with a finger to bent this tab inwards and release the profiled tooth 27 projecting from this tab, from the annular rib 21 projecting from the cap 13. It is immediately apparent that releasing the head 18 from the cap 13 is not easy to achieve, and moreover the structure of the head 18 makes it very costly because the tab 24 is connected to the lateral wall 25 of the head at its lower end, which can be achieved only by using very complicated and costly moulds of low productivity. In the case of EP-A-0065214, the dispenser is locked in its lowered position by an endless annular rib 18 projecting outwards from the lower end of the head engaging with and being retained by a plurality of annular rib segments 19 projecting inwards from respective flexible appendices 17 on the cap. A serious drawback of this system is that to release the head from the cap, the head must be pulled in the sense of withdrawing it from the cap. Initially there is a strong resistance to this withdrawal (because the ribs 19 retain the rib 18), then the rib 18 suddenly (rather than gradually) overcomes the rib 19, such that the head (which is being pulled to release it from the cap) may be pulled completely away from the end of the stem of the pump on which it is mounted. EP-A-0686432 describes a dispenser in which when in its lowered position the head 1 is locked to the cap 2 by the engagement between a tooth 17 projecting from the head and an annular rib 7 projecting from the cap. The tooth 17 projects from a flexible tab 13 which is formed by making two distinct longitudinal cuts to separate the tab from the remaining portion of the cylindrical skirt 11 forming part of the head 1. Forming the two longitudinal cuts 12 at the same time as the tooth 17 projecting laterally from the tab 13 requires the use of moulds of complex structure with relatively bulky components able to operate only at relatively low speed, with the result that the head cost is rather high. The main object of the present invention is to provide a fluid substance dispenser comprising elements which enable it to be snap-locked when in its lowered position whatever the angular position of the head relative to the cap, while enabling the head to be freely rotated about the cap to which it is locked when in its lowered position, and in particular which can be produced by moulds of relatively simple structure to minimize their cost, but which is very easy to move from the lowered position in which the head is locked to the cap, to the operational position in which the head is free and released from the cap. This and still further objects are attained by a fluid substance dispenser comprising a cap and a delivery head, the cap being provided with means for its fixing onto the mouth of a container containing a substance to be delivered by a pump mounted on this mouth, the head having a seat for housing the free end of the stem of said pump, said seat communicating with a substance discharge hole, from the cap there projecting a substantially cylindrical skirt into which a substantially cylindrical skirt forming part of said head can be inserted to be movable longitudinally therein, from the inner surface of the cap skirt there projecting at least one profiled rib engagable by a corresponding profiled rib projecting outwards from the head skirt to retain the head in a lowered position in which the head skirt is inserted into the space bounded by the cap skirt, characterised in that the ribs projecting from the cap skirt and from the head skirt consist of spiral ribs of at least one start which wind in the same direction on both the cap and the head and extend for a limited portion of the length of the respective skirts, the cap skirt being dimensioned and shaped such as to define below the ribs projecting from it, ie towards that end on which the means for its fixing onto the container are provided, a free space in which the rib projecting from the head skirt can be housed and can freely rotate, said ribs being shaped such as to be overcome snapwise when the head is pressed from its free operational position to its lowered position locked to the cap, the ribs projecting from the head skirt being able to engage the ribs of the cap skirt to enable the head to be unscrewed on the cap until said ribs are disengaged from each other to free the head from the cap. The structure and characteristics of the dispenser of the invention will be more apparent from the description of a preferred embodiment thereof given hereinafter by way of nonlimiting example with reference to the accompanying drawing, on which: Figure 1 is a partly sectional view of the dispenser shown in its free operational position; and Figure 2 shows the same dispenser in its locked position. The dispenser is formed from two component parts, namely a cap 1 and a delivery head 2. The cap is provided with means (for example an annular rib 3) which enable it to be fixed on the mouth or neck 4 of a container carrying a pump of any known type, the stem 5 of which extends into and beyond the space bounded by a cylindrical skirt 6 forming part of the cap 1. From the delivery head 2 there projects a cylindrical skirt 7 which, when the dispenser has been mounted (as shown in the figures) on the neck 4 of the container containing the substance to be dispensed, is coaxial with the stem 5 of the pump mounted on the container mouth. The skirt 7 is shaped and dimensioned such as to enable it to penetrate into and rotate within the space bounded by the skirt 6. A multi-start spiral rib 8, clearly visible in Figure 1, projects from the inner surface of the skirt 6 in proximity to its free edge. A spiral rib 9 extending in the same direction as the rib 8 also projects from the outer surface of the skirt 7 in proximity to its free edge. The ribs 8 and 9 are shaped and dimensioned such that when the head 2 is pressed towards the cap 1 (to pass from its free operational position of Figure 1 to its lowered locked position of Figure 2) the ribs 9 pass beyond the ribs 8 snapwise on interfering with them. When the head skirt 7 is positioned within the space bounded by the skirt 6 (Figure 2), with the ribs 9 lying below (with respect to the figures) the ribs 8, the ribs 9 are urged against the ribs 8 by the spring forming part of the pump on the stem 5 of which the head 2 is mounted, but the head is retained securely in the lowered position because the ribs 8 have only their upper surface inclined downwards, this to enable them to be easily passed over by the ribs 9 in passing from the position of Figure 1 to the position of Figure 2. It is essential that below the ribs 8, the skirt 6 defines a free space within which the ribs 9 of the skirt 7 of the head 2 can be positioned and freely housed, as shown in Figure 2. When in this position the head 2 is securely retained in the lowered position, in which the head can be freely rotated in one direction about the cap (essential for packaging, if the head is of elongate or irregular shape) because the ribs 8 and 9 have the same development, whereas if the head is rotated in the opposite direction to the preceding the ribs 0 engage the ribs 8 to hence cause the head to "unscrew" on the cap. This unscrewing is very easy to achieve, to return the head 2 to its operational position of Figure 1. The head 2 and cap 1 are of very simple structure, so that they can be produced using simple moulds of relatively low cost which can operate at high speed, so that the cost of the dispenser produced with these moulds is low.

Claims: A fluid substance dispenser comprising a cap (1) and a delivery head (2), the cap being provided with means for its fixing onto the mouth of a container containing a substance to be delivered by a pump mounted on this mouth (4) the head (2) having a seat for housing the free end of the stem (5) of said pump, said seat communicating with a substance discharge hole, from the cap (1) there projecting a substantially cylindrical skirt (7) into which a substantially cylindrical skirt (6) forming part of said head (2) can be inserted to be movable longitudinally therein, from the inner surface of the cap skirt (6) there projecting at least one profiled rib (8) engagable by a corresponding profiled rib (9) projecting outwards from the head skirt (7) to retain the head (2) in a lowered position in which the head skirt (7) is inserted into the space bounded by the cap skirt (6), characterised in that the ribs projecting from the cap skirt (6) and from the head skirt (7) consist of spiral ribs (8, 9) of at least one start which wind in the same direction on both the cap and the head and extend for a limited portion of the length of the respective skirts, the cap skirt (6) being dimensioned and shaped such as to define below the ribs (8) projecting from it, ie towards that end on which the means for its fixing onto the container are provided, a free space in which the rib (9) projecting from the head skirt (7) can be housed and can freely rotate, said ribs (8, 9) being shaped such as to be overcome snapwise when the head (2) is pressed from its free operational position to its lowered position locked to the cap, the ribs (9) projecting from the head skirt (7) being able to engage the ribs (8) of the cap skirt (6) to enable the head (2) to be unscrewed on the cap until said ribs (8, 9) are disengaged from each other to free the head (2) from the cap. A dispenser as claimed in claim 1, characterised in that said spiral ribs (8, 9) are of more than one start. A dispenser as claimed in claims 1 and 2, characterised in that the upper surface of those spiral ribs (8) projecting from the cap is inclined downwards.

Inventors: RAGNO ANTONINO, RAGNO, ANTONINO
Applicants: LUMSON SPA, LUMSON S.P.A.
Application year: 2000
Main classification: B05B11
IPC codes: B05B11, B65D47