FR2692040A1 - Dispensing appts. for liquids and pastes - uses pressurised container with first lost-motion piston controlling to outlet pipe, and second piston for controlling access to dispensing chamber - Google Patents

Abstract

The appts. comprises a cylindrical container (10) containing a piston (20) holding the contents under pressure by means of a spring (21). The top of the container is drawn into a cylindrical extension of smaller diameter than the container body. A piston (30) moves in this extension under the action of a cap (18) which can be depressed by external pressure, defining a precise volume of material to be dispensed. An output tube (19) extends from the side of the operating cap (18). USE/ADVANTAGE - Accurate and cheap dispensing of precise volume of liquid or paste.

Description

 The present invention relates to a metering device for fluid substance. This device applies more particularly to fairly thick substances, that is to say having a pasty consistency. However, it can also be used for low viscosity liquid substances.

The documents EP-A-0 378 935 and US-A-5 024 355 disclose a metering device for dispensing a fluid substance, comprising a hollow cylindrical body which defines an internal volume and which extends between a first end provided with a inlet passage and a second end with an opening,
- a first sliding piston with seal in the cylindrical body and
movable between a first stop position called the rest position, where it is
close to the second end of the body, and a second stop position
said armed position where it frees the entrance passage which thus communicates with
inside the cylindrical body,
- an actuating rod which is linked to the first piston and which extends axially
crossing the opening of the second end of the cylindrical body.

The subject of the present invention is a device having such a general structure, and characterized in that:
- the cylindrical body has an outlet passage which opens laterally to
inside the cylindrical body at a position close to the second end
of said cylindrical body,
- a second piston is mounted with lost movement on the actuating rod
between a position close to the first piston and a position distant from the first
piston, said second sliding piston with seal on the rod
actuation and in the cylindrical body the movement of the second piston
towards the second end of the body being limited by a stop which defines a
second piston rest position,
- when the first piston is in its rest position, it is in a position
intermediate between the outlet passage and the first end of the body
cylindrical,
- when the first piston is in its armed position and the second piston is
in its position remote from the first piston, the second piston is in a
intermediate position between the outlet passage and the first end of the
cylindrical body, and the first piston is at a first distance of one
position where it closes the inlet passage while the second piston is at a
second distance from a position where it frees the exit passage, the first
distance being less than or equal to the second distance.

 The term "cylindrical" is understood here in its general acceptance, that is to say not limited to a cylinder of revolution.

 This device is intended to be associated with a reservoir of said substance, in which said substance is compressed at least when the actuating rod is pressed.

 When this actuation rod is pressed, the first piston is moved to its armed position and the second piston is driven with the first piston, under the effect of the friction between the actuation rod and the second piston, and also under the effect of the vacuum created by the displacement of the first piston. At the start of the race, where the two pistons are arranged on either side of the outlet passage, this depression effect is due to the fact that the outlet passage is generally filled with said substance, and the depression is all the more more marked than the substance has a thick consistency. When said substance has a low viscosity, it may be useful to provide the outlet passage with an outlet valve, which allows the outlet of the substance but prevents the entry of air.

Advantageously, the friction between the second piston and the actuating rod may be greater than the friction between the second piston and the cylindrical body, so as to facilitate the drive of the second piston.

 When the first piston is in its armed position, it frees the entry passage of the cylindrical body, so that, under the effect of its pressure, the substance of the reservoir pushes the second piston back to its position distant from the first piston : the cylindrical body is then filled with said substance, while the second piston prevents the substance from entering the outlet passage.

When the actuating rod is released:
- if the substance contained in the tank is kept under pressure, this
pressure first requests the second piston which is pushed towards the second
end of the body by driving the first piston, until the first
piston closes the inlet passage again, then the pressure applies to the
first piston which transmits the pressure to the liquid between the two
pistons and thus pushes the second piston back into the rest position of the
second piston by releasing the outlet passage, then returns to its position
rest by expelling the dose of substance trapped between the two pistons,
- if the first piston is biased towards its rest position by a means
elastic, it closes the entry passage first, then pushes the second
piston to the rest position of the second piston, freeing the passage of
exit, then return to its rest position by expelling the dose of substance
trapped between the two pistons.

The invention also relates to a metering device for dispensing a fluid substance, comprising a hollow cylindrical body which defines an internal volume and which extends between a first end provided with an inlet passage and a second end provided with an opening,
- a first sliding piston with seal in the cylindrical body and
movable between a first stop position called the rest position, where it is
close to the second end of the body, and a second stop position
said armed position where it frees the entrance passage which thus communicates with
inside the cylindrical body,
- an actuating rod which is linked to the first piston and which extends axially
by crossing the opening of the second end of the cylindrical body, said metering device being characterized in that:
- the cylindrical body has an outlet passage which opens laterally to
inside the cylindrical body at a position close to the second end
of said cylindrical body,
- a second piston is mounted with lost movement on the actuating rod
between a position close to the first piston and a position distant from the first
piston, said second sliding piston with seal on the rod
actuation and in the cylindrical body the movement of the second piston
towards the second end of the body being limited by a stop which. defines a
second piston rest position,
- when the first piston is in its rest position, it is in a position
intermediate between the outlet passage and the first end of the body
cylindrical,
- when the first piston is in its armed position and the second piston is
in its position remote from the first piston, the second piston is in a
intermediate position between the outlet passage and the first end of the
cylindrical body,
- and when the first piston is in its armed position, the first piston is
arranged with respect to the entrance passage so that the entrance to said entrance
substance in said cylindrical body through the inlet passage urges the
first piston to its rest position.

 According to one embodiment, the invention relates to a device as described above, further comprising a pusher mounted on the actuating rod and covering the cylindrical body, and in which the second piston includes a witness which s 'extends axially towards the pusher, the pusher comprising a cutout corresponding to the indicator, so that the indicator appears in said cutout when the second piston is in the vicinity of its position remote from the first piston. The indicator indicates the complete filling of the cylindrical body.

 Advantageously, the cylindrical body comprises a hooking means which extends from its second end, the device comprising a complementary hooking means which is integral with the actuating rod, arranged so that the hooking means of the body is hooked by complementary hooking means when the first piston is in its armed position, the device further comprising a trigger means for undoing the hooking between said hooking means and said complementary hooking means. This triggering means can be the witness referred to above.

 According to an advantageous embodiment, in the case where the device comprises a pusher and a filling indicator as described above, the cylindrical body comprises an elastic rod which extends axially in the direction of the pusher, from the second end of the cylindrical body up to a hook, said elastic rod is arranged in correspondence with the cutout of the pusher, said cutout has a relief on which the hook can be snapped when the first piston is in its armed position, said indicator has a certain flexibility , said indicator has a sufficient length to project out of the pusher when the second piston is in the vicinity of its position remote from the first piston, and said indicator makes it possible to undo the snap-fastening between said hook and said relief by pressing on the indicator when it sticks out of the pusher. Thus, one can only trigger the exit of the substance when the dose of substance entering the cylindrical body is complete.

 The device may include a reservoir provided with pressurizing means, such as, for example, those disclosed in document US-A-4,750,532 (in particular FIGS. 8 to 11).

 Other advantages and characteristics will appear during the following detailed description of several embodiments of the invention, given by way of nonlimiting examples, with reference to the accompanying drawings.

In the drawings:
- Figure 1 is a vertical sectional view of a device according to a first
embodiment of the invention, in the rest position,
- Figure 2 st a perspective view of the second piston of the device of the
figure 1,
- Figure 3 is a perspective view of the upper end of the reservoir
Figure 3,
- Figures 4 to 6 are perspective views showing a detail of the pusher
device of FIG. 1,
- Figure 7 is an elevational view showing a detail of the pusher of the device
of figure 1,
FIG. 7a is a sectional view along line AA of the detail in FIG. 7,
- Figure 8 is a detailed sectional view showing an example of a valve that
we can climb to the output of the device of figure 1,
- Figure 9 is a view similar to Figure 1, when pressing the pusher
of the device,
FIG. 10 is a view similar to FIG. 1, in the armed position,
- Figure II is a view similar to Figure 1, during the expulsion of a dose
of substance, and
- Figure 12 is a sectional view of a variant of the device of Figure 1.

 In the different figures, the same references designate the same elements or similar elements. The device is described in the position shown in the drawings, the pusher upwards, but it can be used in any position, unless otherwise stated in the description.

 The device according to the invention can generally be made of molded plastic, unless otherwise specified in the description.

 Referring to Figure 1 the device may include a generally cylindrical reservoir 10. The reservoir 10 has a first cylindrical side wall 11, which extends axially between a first open end 12, and a second end 13. The second end is extended inward by a radial wall 14, which extends radially inward to a second cylindrical side wall 18, defining an inlet passage 18b towards the interior of the wall 18. The second cylindrical wall 18 extends axially upwards between a first end 18a which is part of the radial wall 14, and a second end 15. The second end 15 is extended radially inwards, over a certain distance, by a flange annulairel6. The annular flange 16 defines at its center an opening 17.

 As shown in more detail in FIG. 3, the annular flange 16 comprises an elastic rod 16a which extends axially upwards from said flange 16, to a hook 16b directed radially outwards. In addition, the flange 16 comprises a passage orifice 16c, formed in a position comprised radially between the elastic rod 16a and the second cylindrical side wall 18.

 As shown in Figure 1, the reservoir 10 further comprises a tube l9a which defines an outlet channel 19, and which extends radially outwards from the side wall 18, to a free end 19b. The outlet channel 19 opens out inside the second cylindrical side wall 18, in the vicinity of the second end 15 of said second cylindrical side wall.

 A first piston 30 slides with sealing in the second cylindrical side wall 18. The piston 30 is integral with an actuating rod 31, which extends axially upward from said first piston 30, to an upper end 31a. The rod 31 is crossed axially by a central channel 33, which has an enlarged upper part 34. The central channel 33, 34, which could be omitted without departing from the scope of the invention, is used for filling the reservoir 10, and it is closed by a metal ball 35 inserted by force into said central channel, or by other means.

 Furthermore, the device comprises a second piston 40, of annular shape, which is slidably mounted with lost movement on the actuating rod 31. The second piston 40 slides with sealing both on the actuating rod and at the inside the second cylindrical side wall 18. As shown in more detail in FIG. 2, the second piston 40 has a central ring 41 which extends axially upwards from said piston 40, up to an upper end 42. In addition, the second piston 40 comprises a control rod 41, disposed outside the ferrule 41, and which extends axially upwards from the piston 40, to an upper end 44.

As shown in FIG. 1, the control rod 43 passes through the orifice 6c of the annular flange 16.

 The device of FIG. 1 further comprises a pusher 50, which is fixed to the upper end 31a of the actuating rod 31. The pusher 50 can be fixed to the actuating rod by any known means, for example by latching as shown in Figure 1, or by force fitting. The pusher 50 has an upper bearing surface 1, formed with a central orifice 51a which communicates with the central channel 33, 34 of the actuating rod, and fixing means 51b to the actuating rod 31. The surface support 51 is extended towards the reservoir 10 by a frustoconical wall 52, itself extended downwards by a cylindrical skirt 53, which extends to a lower end 53a. The cylindrical skirt 53 has an axial slot 54, cut over a certain distance from the lower end 53a of said skirt. The slot 54 allows the passage of the outlet tube 19 when the pusher is moved axially and in addition, the slot 54 and the outlet tube 19a cooperate to guide the pusher 50, so that it does not rotate on itself.

 The pusher 50 further comprises a cutout 55 in the frustoconical wall 52 and in an outer part of its upper bearing surface 51. The cutout 55 is arranged in correspondence with the indicator rod 43 of the second piston and with the hook 16b of the reservoir . As shown in more detail in Figure 4, the cutout 55 has on one of its faces, a lug 56 of small thickness whose utility will be seen later. The lug 56 occupies only part of the width of the cutout 55.

 Finally, the device comprises a reservoir piston 20, which is slidably mounted with sealing in the first cylindrical side wall 1 1 of the reservoir. A bottom 22, pierced with a central vent orifice 23, and fixed to the open end 12 of the first cylindrical wall 11. The fixing of the bottom 22 to the end 12 can be done by any known means, for example , by screwing, snapping, gluing, or welding. In the example shown, the end 12 has an inner annular rib 12a, while the bottom 22 has an annular wall 24 provided with an outer groove 25 in which the rib 12a snaps in. A helical spring 21, metallic, is interposed between the bottom 22 and the piston of the reservoir 1, so as to urge the piston 20 towards the second end 13 of the second cylindrical side wall 11.

 The device operates as follows.

 As shown in FIG. 9, when a user presses the pusher 50, so as to move it in the direction of the arrow 80, it drives down the first piston 30, by means of the actuating rod 31. As soon as the piston 40 is below the orifice 19, the vacuum created by the displacement of the first piston 30 drives down the second piston 40. In addition, because the second piston 40 slides with a certain friction against the actuating rod, the second piston 40 is itself biased downwards. Advantageously, the second piston 40 is mounted around the actuating rod 31 with a relatively large radial tightening, so that the friction between the rod 31 and the second piston 40 is greater than the friction between the second piston 40 and the second wall lateral cylindrical 18, which facilitates the downward movement of the second piston 40.

 At the start of the piston lowering movement, the two pistons are on either side of the outlet passage. However, since the outlet channel 9 is generally filled with the substance to be dispensed, the downward movement of the first piston 30 creates a certain vacuum, which tends to move the second piston 40 downwards.

This depression is all the more marked as the substance distributed is viscous.

To increase this vacuum, in particular in the case where the substance to be dispensed is very low in viscosity, it could be useful to have an outlet valve 60 in the outlet channel 19 which allows the outlet of the product, but prevents any entry of air. . An example of such a valve is shown in Figure 8. The valve of Figure 8 comprises a support formed by a cylindrical side wall 61, fitted at the end 19b of the tube at the outlet 19a, said side wall 61 being extended radially inwards by a short radial part 62, which delimits a central orifice 68. In addition, radial arms 63 extend inwards from the radial wall 62, up to an axial rod 64, which extends towards the inside of the outlet tube 19a, up to a free end 65. In the vicinity of the free end 65 of the axial rod 64, a groove 66 is formed, in which a washer 67 of elastomeric material is mounted. The washer 67 is deformed during assembly of the valve 60 in the outlet tube 19a, so that it has a frustoconical shape of concavity turned towards the end 19b. Thus, the washer 67 has an outer periphery 67, which is applied elastically against the tube 19a. When a depression is created inside the tube 19a, this depression strengthens the seal between the washer 67 and the tube 19a. on the contrary, an overpressure is created in the tube 19a, this overpressure deforms the washer 67 towards the outlet end 19b of the tube 19a, so that the valve is open. It goes without saying that other forms of valve could be used, without departing from the scope of the invention.

 During this movement, the first piston 30 tends to compress the substance contained in the tank 10, so that the tank piston 20 is moved downward, in the direction of the arrow 81. When the first piston 30 is moved down enough to clear the central opening 1 8b delimited by the radial wall 14, the pressure of the substance contained in the reservoir 10 then applies to the second piston 40 which is moved upwards until the upper end 42 of the ferrule 41 abuts against the pusher 50. The device is then in the position shown in FIG. 10. During the ascent phase of the second piston 40, the reservoir piston 20 moves upwards, in the direction of arrow 82 in FIG. 9.

 During the movement which has just been described with regard to FIG. 9, when the first piston 30 releases the orifice 18b, the hook 16b secured to the reservoir 10 engages on the lug 56 of the cutout 55 of the pusher 50 , as shown in FIG. 5. Then, when the second piston 40 is raised to its position remote from the first piston 30, the control rod 43 enters the cutout 55 of the pusher, and projects in part outside of the pusher 50 as shown in Figure 6. As can be seen in Figures 7 and 7a, in this position, the control rod 43 can be moved to the hook 16b if a user presses radially on the control rod 43, without interfering with the lug 56 of the cutout 55. In fact, the lug 56 has a small width, and the rod 43 is arranged offset laterally relative to the lug 56.

 With reference to FIG. 10, when the first piston 30 is in its armed position, when the hook 16b is snapped onto the lug 56, and when the second piston 40 is in its position furthest from the first piston 30, the first piston 30 is at a certain distance dl below a position where it closes the inlet passage 18b, while the second piston 40 is at a distance d2 above a position where it releases the outlet passage 19. The distance dl is less than or equal to the distance d2.

 Thus, when the pusher 50 is released by pressing radially on the control rod 43 so as to undo the snap-fastening of the hook 16b on the lug 56, as indicated by the arrow 45 in FIG. 6, the pressure prevailing in the reservoir 10 pushes the second piston 40 upwards, which itself drives the pusher 50 the rod 31 and the first piston 30 by means of the ferrule 41. When the assembly is raised by the distance dl, the first piston 30 slides again with sealing in the second cylindrical side wall 18, so that the pressure is no longer exerted on the second piston 40, but on the first piston 30. Thus, the first piston 30 is in turn pushed upwards, and spacing also upwards the second piston 40 via the dose of substance between the two pistons, and by friction. When the second piston 40 has traveled the distance d2 from its initial position, the outlet passage 19 is released, and when the second piston 40 abuts against the flange 16, as shown in FIG. 11, the dose of substance between the two pistons is compressed, so that it is expelled through the outlet channel 19. During this movement, the reservoir piston 20 as well as the pusher 50 are moved upward, in the direction of the arrows 82 of the figure 11.

 Note that the distance dl could possibly be greater than d2, although this is less preferred. Indeed, in this case there is opening of the outlet passage 19 before the first piston 30 closes the inlet passage 30, but the movement of the substance of the reservoir 10 towards the inside of the cylindrical wall 18 then causes the displacement of the first piston 30 upwards, and therefore the closing of the inlet passage 18b.

 It will be noted that the product reservoir 10 could be pressurized by any other means than the piston 20 and the spring 21. For example, the reservoir 10 could have no movable wall, while the pressure prevailing in the reservoir would be obtained by a compressed gas, with or without liquefied phase. In this case, the device would be usable without modification, only in the inverted position, that is to say with the pusher 50 directed downwards. However, provided that the second cylindrical wall 18 is made as an independent piece mounted on the reservoir 10, and provided that the enlarged lower part extended downwards by a dip tube is added to the wall 18, the device according to the invention could be used with compressed gas in upright position.

 Figure 12 shows a variant of the device described so far. The component parts of the device, as well as the operation of the device, are similar to what has been described so far, and therefore will not be described again in detail. The device of Figure 12 differs from the previous device in that the piston of the reservoir 20 is not biased by a spring 21 and the open end 12 of the first cylindrical wall 1 1 has no bottom 22. On the contrary , the reservoir piston 20 has an annular wall 71 forming a base, which extends axially downward from the piston 20 to a lower end 71, adapted to rest on any bearing surface 72.

 In addition, a metal helical spring 70 is mounted between the pusher 50 and the annular flange 16 secured to the reservoir 10. In the example shown, the spring 70 is centered by an outer annular wall 15a which extends the wall 18 upwards, and by an annular wall 78 which extends over a certain distance from the pusher 50 inside the spring 70.

 When a user presses the plunger 50, because the section for supporting the liquid of the first piston 30 is smaller than the section for supporting the liquid of the reservoir piston 20, the two pistons 30 and 40 are moved down as before.

When the pusher abuts against the reservoir 10 and the first piston 30 frees the inlet passage 19b, the support of the user creates pressure in the reservoir 10, and this pressure causes the substance to penetrate inside. of the cylindrical wall 18 by raising the second piston 40, as before. The device then remains in the armed position until a user presses radially on the control rod 43, which releases the latching of the hook 16b on the lug 56, so that the spring 70 pushes the pusher upwards Thus, the first piston 30 is moved upwards and again closes the inlet passage 18b. Under the action of the spring 70, the first piston 30 then continues to rise by pushing up the second piston 40, until the second piston 40 comes to abut against the annular flange 6. The dose of substance between the two pistons is then expelled as explained above.

Claims (12)

Claims  1.- Metering device for dispensing a fluid substance, comprising a hollow cylindrical body (18) which defines an interior volume and which extends between a first end (18a) provided with an inlet passage (18b) and a second end (15) provided with an opening (17),  - a first piston (30) sliding with sealing in the cylindrical body (18)  and movable between a first abutment position called the rest position, where it  is close to the second end (15) of the body, and a second position of  so-called armed position stop where it releases the entry passage (18b) which communicates  thus with the interior of the cylindrical body (18),  - an actuating rod (31) which is linked to the first piston (30) and which extends  axially through the opening (17) of the second end (15) of the  cylindrical body (18), said metering device being characterized in that:  - the cylindrical body (18) has an outlet passage (19) which opens out  laterally inside the cylindrical body (18) at a position close to the  second end (17) of said cylindrical body,  - a second piston (40) is mounted with lost movement on the rod  actuator (31) between a position close to the first piston and a  position remote from the first piston, said second piston sliding with  sealing on the actuating rod and in the cylindrical body, the  movement of the second piston towards the second end of the body being  limited by a stop which defines a rest position of the second piston,  - when the first piston (30) is in its rest position, it is in a  intermediate position between the outlet passage (19) and the first end  (18a) of the cylindrical body,  - when the first piston (30) is in its armed position and the second piston  (40) is in its position remote from the first piston, the second piston (40)  is in an intermediate position between the outlet passage (19) and the first  end (18a) of the cylindrical body, and the first piston (30) is one  first distance (dl) from a position where it closes the entry passage while  that the second piston is at a second distance (d2) from a position where it  releases the exit passage, the first distance (dl) being less than or equal to  the second distance (d2).  2.- Metering device for dispensing a fluid substance, comprising a hollow cylindrical body (18) which defines an interior volume and which extends between a first end (18a) provided with an inlet passage (18b) and a second end (15) provided with an opening (17),  - a first piston (30) sliding with sealing in the cylindrical body (18)  and movable between a first abutment position called the rest position, where it  is close to the second end (15) of the body, and a second position of  so-called armed position stop where it releases the entry passage (18b) which communicates  thus with the interior of the cylindrical body (18),  - an actuating rod (31) which is linked to the first piston (30) and which extends  axially through the opening (17) of the second end (15) of the  cylindrical body (18), said metering device being characterized in that:  - the cylindrical body (18) has an outlet passage (19) which opens out  laterally inside the cylindrical body (18) at a position close to the  second end (17) of said cylindrical body,  - a second piston (40) is mounted with lost movement on the rod  actuator (31) between a position close to the first piston and a  position remote from the first piston, said second piston sliding with  sealing on the actuating rod and in the cylindrical body, the  movement of the second piston towards the second end of the body being  limited by a stop which defines a rest position of the second piston,  - when the first piston (30) is in its rest position, it is in a  intermediate position between the outlet passage (19) and the first end  (18a) of the cylindrical body,  - when the first piston (30) is in its armed position and the second piston  (40) is in its position remote from the first piston, the second piston (40)  is in an intermediate position between the outlet passage (19) and the first  end (18a) of the cylindrical body,  - and when the first piston is in its armed position, the first piston (30)  is arranged relative to the entry passage (18b) in such a way that the entry of  said substance in said cylindrical body (18) through the inlet passage (18b)  biases the first piston (30) to its rest position.  3.- Device according to claim I or claim 2, wherein the second piston (40) slides on the actuating rod with a first friction and in the cylindrical body (18) with a second friction, and the first friction is greater than the second friction.  4.- Device according to any one of the preceding claims, in which the outlet passage comprises an outlet valve (67) which allows the outlet of said substance, but prevents the entry of air inside the cylindrical body. (18).  5.- Device according to any one of the preceding claims, further comprising a pusher (50) mounted on the actuating rod (31) and covering the cylindrical body (18), and in which the second piston (40) comprises a witness ( 43) which extends axially towards the pusher (50), the pusher (50) comprising a cutout (55) in correspondence with the indicator (43), so that the indicator (43) appears in said cutout (55) when the second piston (40) is in the vicinity of its position remote from the first piston (30).  6.- Device according to any one of claims 1 to 4, wherein the cylindrical body (18) comprises a hooking means (16a, 16b) which extends from its second end (15), the device comprising a complementary attachment means (56) which is integral with the actuating rod (31), arranged so that the attachment means (16a, 16b) of the body attaches to the complementary attachment means (56) when the first piston (30) is in its armed position, the device further comprising a triggering means (43) for undoing the coupling between said coupling means and said complementary coupling means.  7.- Device according to claim 5, wherein the cylindrical body (18) comprises a hooking means (16a, 16b) which extends from its second end (15), the device comprising a hooking means complementary (56) which is integral with the actuating rod (31), arranged so that the hooking means (16a, 16b) of the body is hooked by the complementary hooking means (56) when the first piston ( 30) is in its armed position, and in which said indicator (43) has a certain flexibility, said indicator has a length sufficient to protrude from the pusher (50) when the second piston (40) is in the vicinity of its remote position of the first piston (30), and said indicator makes it possible to undo the attachment between said attachment means and said complementary attachment means.  8.- Device according to claim 7, wherein the cylindrical body (18) comprises an elastic rod (16a) which extends axially in the direction of the pusher (50), from the second end (15) of the cylindrical body (18) up to a hook (16b), said elastic rod and said hook constitute said attachment means, said elastic rod (16a) is arranged in correspondence with the cutout (55) of the pusher, said cutout (55) has a relief ( 56) which can snap on the hook (16a) when the first piston (30) is in its armed position, said relief (56) constituting said additional hooking means.  9.- Device according to any one of the preceding claims, wherein an elastic means (70) biases the first piston (30) towards its rest position.  10.- Device according to any one of the preceding claims, further comprising a reservoir (10) which contains said substance and which communicates with the inlet passage (18b) of the cylindrical body, said reservoir (10) comprising means (20, 21) pressurizing said substance.  11.- Device according to claim 10, wherein said reservoir is cylindrical and extends axially between a first end (12) and a second end (13), said cylindrical body (18) is disposed at the second end (13) of the reservoir, a piston (20) slides with sealing in said reservoir (10), and an elastic means (21) biases said piston (20) towards the second end (13) of the reservoir, compressing said substance.  12.- Device according to claim 9, further comprising a reservoir which contains said substance and which communicates with the inlet passage (18b) of the cylindrical body, said reservoir (10) being cylindrical and extending axially between a first end open (12) and a second end (13) where said cylindrical body (18) is arranged, a piston (20) sliding with sealing in said tank (10), said substance being between the piston (20) and the second end of the reservoir, said piston comprising a base (71) which extends axially in the opposite direction from the second end (13) of the reservoir, up to beyond the first end (12) of the reservoir, so that one can activate the device by placing the marigold (71) on a bearing surface (72) and pressing on the actuating rod (31), which temporarily compresses said substance and allows the entry of said substance into the cylindrical body (( 18).