EP1834704A2 - Discharge device for a flowable medium - Google Patents

Abstract

A piston (24) is operatively connected to an actuating device (30) which can be manually pressed in a pumping direction, and held by a securing element (50) in a pressed-in state. The pumping direction forms approximately a right angle with the principal direction of an extent (2). A pumping device (20) has a pumping chamber (22) closed off on one side by the piston. The piston is movable longitudinally along the pumping direction to generate a discharge pressure.

Description

The invention relates to a discharge device for a flowable medium with a pumping device comprising a pumping chamber, which is closed on one side by a longitudinally movable piston.

Generic discharge devices serve the discharge of cosmetic or pharmaceutical media. These are conveyed by actuation of the pump from a media storage and discharged through a discharge opening into an environment. The pumping process is usually triggered by a manually operable actuator, by means of which a piston is displaced in the pump. Thereby, a discharge pressure is generated, which pushes the medium in the pumping chamber through the discharge opening from the discharge device.

A disadvantage of known discharge devices is considered that the sealing of the pumping chamber with respect to the environment, in particular in the region of the actuator, is often unsatisfactory. There is an unwanted escape of medium from the discharge and an unintentional entry of contaminants in the discharge.

Task and solution

The object of the invention is to improve the known from the prior art discharge devices, in particular with regard to the sealing of the pumping chamber.

This object is achieved by a generic discharge device in which the pump chamber is hermetically sealed on the piston side with respect to an ambient atmosphere outside the discharge device by means of a gas-impermeable and at least partially flexible membrane, wherein the membrane is firmly connected in its edge region to a housing of the discharge device.

The membrane is preferably formed as a thin plastic layer. It is elastic in order to still be able to follow the stroke movement of an actuating device or of the piston when the clamping is fixed to the housing at its edge region. Compared to the known from the prior art discharge devices in which the actuator and the piston are mounted relative to the housing of the discharge by means of sliding guides, the fixed housing clamping ensures safe protection against contamination, especially from microbiological contaminants. The stationary clamping a hermetic seal is achieved in contrast to sliding and usually play with sealing surfaces. The clamping of the edge region is preferably carried out by latching or clamping means, by which the edge region is pressed against a housing-side support surface, so that the sealing effect is also given in this Einspannungsbereich. By a thickening of the membrane in the edge region, a stiffening can be achieved in addition, the sliding out of the Counteracts membrane from the locking or clamping means. As an alternative to latching and clamping means, embodiments with a glued attachment of the edge region of the membrane may also be expedient. In addition, embodiments of the invention are also included in which the membrane is integrally connected to the housing. This can be achieved by using the same material for housing and membrane with significantly reduced wall thickness in the membrane. Alternatively, the integral nature of a two-stage injection process but also with different materials can be achieved. As a material combination, for example, offers PP for the housing and TPE for the membrane. The fixed connection of the membrane with the housing need not be made in the area of the outer surface. Under housing are to be understood in the context of the invention housing-fixed components. In particular, the housing also includes the inner wall of the pumping chamber, which need not be integrally formed with an outer surface of the housing.

In a development of the invention, the membrane is connected to an operating device operatively connected to the piston. Particularly preferred is a one-piece design. The edge region of the membrane is preferably fixed to the outer wall of the housing, for example, clamped in an outwardly facing groove on the housing surface. The connection with the actuator is preferably made in one piece, so that the actuator is made of the same material as the membrane and obtains the required stability by a correspondingly thicker material thickness. Alternatively, however, the membrane may also be provided as a separate component which completely covers the actuating device in the manner of a protective cover.

In a further development of the invention, the membrane is connected to the piston. Particularly preferred is a one-piece design. In this development, the pumping chamber is closed directly from the elastic membrane, so that the change in volume of the pumping chamber is achieved in the course of actuation on the elastic deformation of this membrane. The membrane is preferably attached to the pumping chamber wall. An advantage of such a configuration is that even impurities that penetrate into other places than the actuator in the discharge, can not get into the pumping chamber. In a particularly advantageous embodiment of this development, the edge region of such a membrane simultaneously forms the bearing surface for a return spring of the actuator, so that the return spring in addition to the task to push the actuator back to the starting position, also fulfills the task to press the membrane against its support surface, so that a very good seal in the edge region of the membrane is achieved.

In a development of the invention, the membrane is provided as a separate component between the piston and the pumping chamber.

In a further development of the invention, the piston is longitudinally movable in a piston direction, which encloses a right angle with a main extension direction of the discharge device. In such discharge devices in which the pumping and actuating direction is perpendicular to a main extension direction of the discharge, the invention is very simple and inexpensive to implement. This is mainly due to the fact that the membrane is not arranged on a side facing the media storage side of the pumping chamber and thus does not complicate the supply of the medium into the pumping chamber by their location.

In a further development of the invention, an inlet channel and / or an outlet channel are arranged in the pumping chamber on the side facing away from the piston. As a result, particularly in such embodiments in which the membrane is arranged as intended or separately within the pump chamber as part of the piston, a particularly advantageous supply and discharge of the medium in the pumping chamber and out of the pumping chamber allows out. In these embodiments, in which the membrane is arranged in the pumping chamber, this solves the problem that a media supply to a lateral pumping chamber wall is difficult to realize.

Embodiments are particularly preferred in which an actuating element is provided on the piston side, which is in operative connection with the inlet channel or the outlet channel depending on the piston position, the operative connection particularly comprising opening or closing the inlet channel or the outlet channel. The purpose of such a configuration is that the piston depending on its position can prevent a supply or discharge of the medium into the pumping chamber or from the pumping chamber. This is particularly advantageous because in discharge devices according to the invention, in which the piston or a piston-fixed membrane is fixed to the side wall of the pumping chamber, a conventional control of the outflow or inflow via inlets or outlets, which are provided on a lateral pumping chamber , are not feasible.

A particularly simple embodiment of this development provides that a closing pin extends in the direction of piston movement, starting from the piston in the pumping chamber, which causes a decoupling of the pumping chamber from the media storage from a fixed stroke position by entering into the media inlet. From this stroke position further movement of the piston causes an increase in pressure in the pumping chamber, resulting in a discharge.

Alternatively or additionally, the actuating element can also be used to connect the pumping chamber again with the media reservoir from a second fixed stroke position in order to cause a sudden pressure drop in the pumping chamber. Such a configuration is expedient with regard to the so-called priming, ie the first filling of the pumping chamber with medium. In this case, the piston is fully inserted into the pumping chamber until it reaches the second stroke position. In this stroke position, the compressed air escapes from the pumping chamber in the media reservoir or in the environment, so that the return stroke creates a negative pressure, which causes the Erstbefüllung the pumping chamber.

Preferably, this is realized by an air outlet device for discharging the air in the pumping chamber in the course of commissioning, wherein the air outlet device is arranged and designed such that it is opened at a pump chamber volume reducing movement of the piston in a second stroke position, which is beyond a first Lifting position is in which causes in a normal operation, the fluid pressure of the medium in the pumping chamber, an opening of an exhaust valve of the discharge.

With such a discharge device, the piston is pressed into the air-filled pumping chamber during startup until the second stroke position is reached, in which the air outlet device is opened by the piston. The compressed air can then escape through the air outlet device, for example, to the outside or into the media container. In the course of the return stroke, the air outlet device is directly or indirectly closed again by the piston, so that the air can not get back into the pumping chamber. Instead, during the return stroke, depending on the embodiment of the pumping device, medium is transferred directly from the media container into the pumping chamber sucked or generates a negative pressure in the pumping chamber, which suddenly leads to a filling of the pumping chamber with the medium upon release of a media channel from the media container to the pumping chamber through the piston. In the subsequent operations of the pumping device in normal operation, the second stroke position is not reached or only after opening the exhaust valve of the discharge and a discharge associated therewith, so that no medium or only a small amount of the medium in the second stroke position escapes through the air outlet. The air outlet device may additionally have a filter which prevents unwanted escape of liquid medium through the air outlet device during normal operation.

Brief description of the drawings

Fig. 1

zeigt eine erste Ausführungsform einer erfindungsgemäßen Austragvorrichtung in einer geschnittenen Darstellung,

Fig. 2a und 2b

eine zweite Ausführungsform einer erfindungsgemäßen Austragvorrichtung in geschnittenen Darstellungen von zwei Zuständen der Betätigung,

Fig. 3a bis 3d

eine dritte Ausführungsform einer erfindungsgemäßen Austragvorrichtung in geschnittenen Darstellungen von vier Zuständen der Inbetriebnahme der Austragvorrichtung und

Fig. 4a bis 4d

eine vierte Ausführungsform einer erfindungsgemäßen Austragvorrichtung in geschnittenen Darstellungen von vier Zuständen der Inbetriebnahme.

Further advantages and features of the invention will become apparent from the claims and the following description of preferred embodiments of the invention, which are illustrated by the drawings. Showing:

Fig. 1

shows a first embodiment of a discharge device according to the invention in a sectional view,

Fig. 2a and 2b

A second embodiment of a discharge device according to the invention in sectional representations of two states of actuation,

Fig. 3a to 3d

a third embodiment of a discharge device according to the invention in sectional representations of four states of commissioning of the discharge and

Fig. 4a to 4d

a fourth embodiment of a discharge device according to the invention in sectional representations of four states of commissioning.

Detailed description of the embodiments

Fig. 1 shows a first embodiment of a discharge device according to the invention. This discharge device is provided for the application of a medium in an eye. It has, as essential main components, a housing 10 with an actuating device 30, a pump device 40 arranged in the housing and a discharge valve unit 60. By means of a provided on the inner wall of the housing internal thread 12 is connected by unspecified detents secured against loosening media container 80 with the discharge device.

The connection of the media container 80 to a pumping chamber 46 of the pumping device 40 is made through an inlet channel 44 which extends into the media container 80 within an opening mandrel 48. By means of this opening mandrel 48, a membrane 82 of the media container 80 is pierced.

The inlet channel 44 leads into a pumping chamber 46, which is closed on one side by a piston 50. On the side of the pumping chamber 46 applied to the piston 50, an outlet channel 56 is provided which leads to the discharge valve unit 60. The piston 50 is fixedly connected by a latching connection with a main shaft 32 of the actuator 30. At the outer end of the main shaft 32, this integrally merges into the approximately hemispherical elastic membrane 34. This membrane 34 is at its outer end in an edge region 36 with increased wall thickness, which by a one-piece on the housing 10 molded circumferential locking ridge 14 is fixed in a housing-fixed position. By a return spring 38, the actuating device 30 is always pushed outwards, whereby the piston 50 is pulled in a stroke end position at maximum volume of the pumping chamber 46. In a non-illustrated embodiment, a separate return spring is avoided in that the elastic membrane itself applies the restoring forces.

The discharge valve unit 60 has an integrally formed on the housing 10 discharge sleeve 62, within which a lock pin 64 is disposed. If - as in the illustrated state - there is no pressure in the pumping chamber 46 and in the discharge chamber 56 connected to the pumping chamber 46 through the discharge port 56, the closing pin 64 is pressed by a closing spring 66 in the discharge sleeve 62, so that a discharge opening 68 at the distal End of the discharge sleeve 62 is sealed by the lock pin 64. The closing pin 64 has, on its side facing away from the discharge opening 68, a particularly large collar-shaped pressure plate 70, which is adjoined externally by a circumferential support web 72, which rests against the pumping device 40. The pressure plate 70 itself is spaced from the pumping device 40, wherein the gap is sealed by means of the support web 72 to the outside and filled with air.

If, after start-up of the discharge device by filling the pumping chamber 46 with the medium from the medium container 80, the actuating device 30 is depressed in normal operation in a pumping direction 90, deforms the membrane 34, wherein the edge portion 36 is clamped to the housing 10. After about one third of the stroke, the connection of the inlet channel 44 to the pumping chamber 46 is interrupted by the piston 50. In the course of the further piston movement, the fluid pressure of the medium in the pumping chamber 46, in the outlet channel 56 and in the discharge valve unit 60 becomes increases until the pressure on the pressure plate 70 is sufficiently high to move the closing pin 64 against the spring force of the closing spring 66. Due to the size of the pressure plate 70, a comparatively low pressure is sufficient for this purpose. The pressure plate 70 is elastically deformed by the pressure.

As soon as the closing pin 64 has released the discharge opening 68 as a result, the medium escapes through the discharge opening 68 in a main extension direction 92 of the discharge device, wherein it does not form a spray jet due to the low pressure, but rather drops are formed at the discharge opening 68.

An advantage of the discharge device shown in Fig. 1 and described above is the structure which allows a comfortable and safer handling.

The inventive hermetic encapsulation of the pumping chamber 46 is particularly advantageous from an outside atmosphere due to the special design of the actuating device 30 with the deformable membrane 34, which effectively prevents contamination of the medium in the pumping chamber 46. This encapsulation is particularly easy to implement in the orthogonal design of the discharge because it does not come into conflict with a supply line from the media container 80 with respect to the arrangement.

The hermetic encapsulation prevents both the escape of medium into the environment, which passes on the piston 50 from the pumping chamber 46 in the direction of the actuator 30. Above all, however, it prevents the occurrence of soiling, in particular of microbacterial contaminants.

2a and 2b show a second embodiment of a discharge device according to the invention in two different states, wherein Fig. 2a shows a state prior to actuation of an actuator 130 and Fig. 2b shows a state during actuation of the actuator 130.

The construction of the discharge device of FIGS. 2 a and 2 b is similar to the construction of the embodiment of FIG. 1. Again, the discharge device has a housing 110 with the actuating device 130 and a discharge valve unit 160. In the housing 110 there is a pumping device 140 with a piston 150, wherein a pumping direction 190 of the piston, which simultaneously represents the direction of movement of the actuating device 130, is perpendicular to a main extension direction 192 of the discharge device, which corresponds to the discharge direction of the medium.

The differences from the embodiment of FIG. 1 lie in particular in the design of the piston 150 and the design of the discharge valve unit 160.

The piston 150 is formed as a flexible membrane, which is fixedly connected in a central region 152 with the actuator 130. At the outer edge region 154 of the membrane, this is fixed in the pumping device and thus seals off a pumping chamber 146 limited thereby against the actuating device 130 and in the case of penetrating contaminants. Since the piston 150 is not suitable due to the determination in the edge region, to close a medium in the wall region of the pumping chamber 146 inlet passage for medium in the course of the piston stroke, the inlet channel 144 is arranged so that it opens at the piston 150 opposite end face of the pumping chamber 146 , The piston 150 is formed in its central portion 152 so that it in the course of actuation of this inlet channel 144 closes and thereby allows the structure of the liquid pressure required for the discharge process.

The design of the discharge valve unit 160 comprises a closing pin 164, which is integrally formed on the housing 110. Around the closing pin 164, a circular groove 174 is provided on the housing surface into which an edge region 176 of an elastic discharge sleeve 162 is inserted. Depending on the fluid pressure in a pressure chamber 170 between the housing 110 and the discharge sleeve 162, the discharge valve unit 160 opens by releasing a discharge opening 168. The closed state is shown in FIG. 2a. The opened state is shown in FIG. 2b.

If, starting from the initial state of FIG. 2a, the actuating device 130 is pressed in the pumping direction 190, the piston 150 is thereby also pressed into the pumping chamber 146, wherein the edge region 154 of the piston remains immovably fixed to the housing and prevents the penetration of impurities into the pumping chamber 146 , The central region 152 of the piston 150 is pressed into the inlet channel 144 and closes it with respect to the pumping chamber 146. From a stroke position in which the inlet channel 144 is closed, the progressive stroke movement of the piston leads to an increase in the fluid pressure in the pumping chamber 146, Outlet channel and the pressure chamber 170. This increase in the liquid pressure results in the manner described above to open the Austragventileinheit 160, as shown in Fig. 2b. In a manner not shown, the discharge returns after discharge of the medium in its original position and elastically relaxed original form. The actuator 130 is pushed back by a return spring 138 in the original position, with a negative pressure in the pumping chamber 146 sets. Only when the central region 152 of the piston 150, the inlet channel 144 releases again, can again Medium are sucked out of a media container 180 by the resulting negative pressure in the pumping chamber 146.

FIGS. 3a to 3d show a third embodiment of a discharge device according to the invention.

With regard to the basic structure with an actuating direction and a pumping direction 290 orthogonal to a main direction of extent 292 of the discharge device, this embodiment corresponds to the embodiments of FIGS. 1, 2a and 2b. With respect to the hermetic sealing of a pump chamber 246 by means of a hemispherical membrane 234, which is made integral with an actuator 230, it corresponds to the embodiment of Fig. 1. The peculiarity of this embodiment is a special design of the pumping device 240 in terms of commissioning. In addition to a first piston 250 fixedly connected to the hermetic actuator 230, this third embodiment has an opposed piston 260 disposed on the opposite side of the pumping chamber 246. This is acted upon by a spring force of a counter-piston spring 264 in the direction of an upper end position and the first piston 250. The opposed piston 260 is guided by means of a counter piston guide 262 which limits its freedom of movement between the upper end position, in which an outlet channel 256 is separated to a discharge opening 268 of the pumping chamber 246, and a lower end position, in which the outlet channel 256 with the pumping chamber 246th connected is. This structure allows a particularly advantageous venting of the pumping chamber 246 in the course of commissioning. This is described below with reference to the sequence of FIGS. 3a to 3d.

Fig. 3a shows the delivery state in which the pumping chamber 246 is completely filled with air. The first piston 250 is pressed by a return spring 238 in its upper end position. The opposing piston 260 is also urged by the opposing piston spring 264 in its upper end position, so that the pumping chamber 246 is separated from the outlet channel 256.

Starting from this starting position, the first piston 250 is manually pressed downwards by means of the actuating device 230. In this case, the membrane 234 is elastically deformed while maintaining the hermetic seal of the pumping chamber 246. After the first piston 250 has been moved past an inlet channel 244, the pumping chamber 246 is sealed to the outside. In the course of further movement, the air in the pumping chamber 246 is compressed until the air pressure is sufficiently high to urge the opposed piston 260 against the spring force of the opposed piston spring 264 towards its lower limit position. Once the opposed piston 260, as shown in Fig. 3b is shown; When the first piston 250 reaches the edge of the outlet channel 256, the pumping chamber is completely empty. Pressed up by the force of the opposing piston spring 264, the opposing piston 260 is pressed flush against the first piston 250, so that the volume of the pumping chamber 246 in this state is approximately zero.

During the return stroke of the piston 250, the counter-piston 260 remains pressed flush against the piston 250 until the counter-piston 260 has reached its upper end position, which is defined by the boundary of the counter-piston guide 262. From this position, which is shown in FIG. 3c, the pumping chamber volume 246 increases again in the course of the further return stroke of the first piston 250, whereby a strong negative pressure is created in the pumping chamber 246. As soon as the first piston 250 has again arrived in the region of the inlet channel 244, medium is therefore suddenly drawn from a media container (not shown) through the inlet channel 244 into the pumping chamber 246.

This state with filled pumping chamber 246 is shown in Fig. 3d. Based on this state, the discharge can be used as intended.

FIGS. 4a to 4d show a fourth embodiment of a discharge device according to the invention. The transverse arrangement of a pump in the discharge device in this fourth embodiment corresponds to the first three embodiments.

The peculiarity of this fourth embodiment lies in a specially designed pumping device 340. A pumping chamber 346 is delimited on one end by a piston 350. The side wall of the pumping chamber is formed by a bellows 347. This bellows 347 is fixed in the housing on the side facing away from the piston, so that the pumping chamber 346 closed by it remains free of contaminants which penetrate into the housing in the region of the piston 350. At the end opposite the piston 350, a media inlet channel 344 and a media outlet channel 356 open into the pumping chamber 346, wherein an inlet valve 330 with a valve slide 332 is provided at the inlet channel 344. The valve spool 332 is provided as a hollow cylinder closed on one side, on the open lower side of which a circumferential latching edge 334 extends inwards, which prevents the valve spool 332 from slipping off a cylindrical extension piece 345 of the inlet channel 344. Corresponding to the valve spool 332, an actuating pin 351 is formed on the piston 350, which extends in a pumping direction 390 and is disposed over an outer edge of the closed side of the valve spool 332.

The pumping device 340 shown allows a good venting of the pumping chamber 346 in the course of the commissioning of the discharge.

The commissioning is explained below with reference to FIGS. 4a to 4d.

Fig. 4a shows an initial position of the discharge device. In this delivery state, the pumping chamber 346 has its maximum volume and is filled with air. Starting from this state, the piston 350, which simultaneously constitutes an actuating device, is pressed down in the pumping direction 390. This results in an increase of the air pressure in the pumping chamber, with the result that the valve slide 332 on the extension 345 of the inlet channel 344 slides down and thus closes the inlet channel 344, as shown in Fig. 4b. In the course of the further stroke movement of the piston 350, the air in the pumping chamber 346 is further compressed until the actuating pin 351 reaches the valve slide 332. By the eccentric force exerted by the actuating pin 351 on the valve spool, this is - as shown in Fig. 4c - tilted so that the inlet channel 344 is opened and the pressurized air from the pumping chamber 346 can escape. As shown in FIG. 4d, during the return stroke, the medium then flows from an unrepresented media container through the inlet channel 344 into the pumping chamber after the valve slide 332 has been withdrawn from the inlet channel due to the negative pressure in the pumping chamber 346 during the return stroke. The medium which has entered the pumping chamber can then escape through the discharge opening 368 of the discharge valve unit 360 during the subsequent actuation of the piston 350, whereby the valve slide 330 ensures that the inlet channel 344 is closed to build up pressure in the pumping chamber 346 even in this normal operation. If in such a lifting movement in normal operation in the lower end position of the inlet channel 344 is opened by the actuating pin 351, the remaining medium escapes from the pumping chamber 346 back into the media container.

Claims (9)

A flowable medium dispenser comprising a pumping device (40; 140; 340) comprising a pumping chamber (46; 146; 246; 346) closed on one side by a longitudinally movable piston (50; 150; 250; 350),
characterized in that
the pump chamber (46; 146; 246; 346) is hermetically sealed from the piston side with respect to an ambient atmosphere outside the discharge device by means of a gas-impermeable and at least partially flexible membrane (34; 50; 234; 347), the membrane (34; ) in its edge region (36; 154) is fixedly connected to a housing (10; 110) of the discharge device. Discharge device according to claim 1,
characterized in that
the diaphragm (34; 234; 347) is connected to an actuator (30; 230; 350) operatively connected to the piston (50; 250; 350). Discharge device according to claim 2,
characterized in that
the membrane (34; 234; 347) is formed in one piece with the actuating device (30; 230; 350). Discharge device according to one of the preceding claims,
characterized in that
the membrane (150; 347) is connected to the piston (150; 350). Discharge device according to claim 4,
characterized in that
the membrane (150; 347) is integrally formed with the piston (150; 350). Discharge device according to claim 1,
characterized in that
the membrane is provided as a separate component between the piston and the pumping chamber. Discharge device according to one of the preceding claims,
characterized in that
the piston (50; 150; 250; 350) being longitudinally movable in a piston direction (90; 190; 290; 390) which forms a right angle with a main extension direction (92; 192; 292) of the discharge device. Discharge device according to one of the preceding claims,
characterized in that
an inlet channel (344; 144) and / or an outlet channel (344) are arranged in the pumping chamber (146; 346) on the side facing away from the piston (150; 350). Discharge device according to claim 8,
characterized in that
an actuating element (152; 351) is provided, which is in operative connection with the inlet channel (344; 144) or the outlet channel (344) depending on the piston position, the operative connection in particular opening or closing the inlet channel (344; 144). or the outlet channel (344).

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