Abstract:
In a discharge device including two mutually shiftable units (2, 3) permanent magnets (14, 24, 33, 34) are provided for controlling a piston unit (20) and valves (13, 23, 45), the magnetic force of these magnets being provided more particularly to cause a reset movement into the starting position. These magnets may be immersed in the medium or surrounded on all sides by the medium flow, thus enabling mechanical springs to be eliminated and assuring highly reliable functioning.

Description:
TECHNICAL FIELD OF THE INVENTION 
     The invention relates to a discharge device for media such as gaseous, liquid, creamy, gel-like, powdery and/or solid media or the like which for discharging are preferably exposed to an overpressure in a pressure or pump chamber and are discharged at this pressure from the medium orifice of the discharge device, thereby totally exiting from the discharge device. In this arrangement the flowable medium may be discharged as an undispersed line of medium or as a spray or atomized spray suitable for technical, cosmetic and/or medical applications. 
     To open for discharging the medium or to create a pressure, the discharge device comprises two device units which can be moved relative to each other in a single hand of a user, which also simultaneously carries the discharge device. This causes the shape or length of the discharge device to change, more particularly, it becomes smaller. The device units or their base bodies may be configured integrally with each other or formed as separate items and then joined together. If the discharge delivery component is provided as a pump, such as a plunger pump, then the first discharge unit contains the pump housing including a pump cylinder and, where necessary, a fastener member for securing the discharge device to a medium reservoir. The second discharge unit contains a piston unit with an actuating head in which the medium orifice may be provided. An inlet valve which opens and closes in response to the actuating stroke is expediently provided at the first discharge unit for filling the pressure space, whilst an outlet valve for opening and closing may be provided at the second discharge unit. 
     Advantageously, the discharge device comprises a component for influencing the medium, for example, for separating particles; for defining closed spaces, such as medium spaces or flow paths; for exerting a retaining or latching force; or for exerting a controlling, setting, resetting, activating, closing, driving force and/or counterforce acting against the pressure of the medium, for changing the cross-section of the cited spaces or passages and/or for positionally locating the complete discharge device with respect to a counterhold. Such an influencing component may act bondingly, springingly, attenuatingly in the fashion of a latching or snap-action connection or serve similar to a spring also for preventing movement or play. 
     OBJECTS OF THE INVENTION 
     The invention provides a discharge device for media in which the drawbacks of known discharge devices are avoided and which includes, more particularly, at least one force member for exerting a useful force, said force member being configured very simply. 
     SUMMARY OF THE INVENTION 
     In accordance with the invention, the discharge device includes at least one component having ferromagnetic properties. This component may be magnetized or non-magnetized and defines, in a first case, a magnetic field having two or more opposing magnetic poles from which a magnetic field emanates. This magnetic field may exert its effects on the aforementioned component. The ferromagnetic component is more particularly arranged by being totally enclosed within the discharge device. It may contain iron or a suitable alloy or consist of a compacted polarized bulk material, the particles of which are consolidated into a rigidly dimensioned or flexible body of a plastic binding material, where necessary. This component may be freely movable as a result of the magnetic field or of the forces of gravity and as a component of an assembly in which it is loosely or firmly connected, e.g. by adhesion, embedding or the like. 
     The magnetic force is more particularly suited as a closing force for a valve, as a resetting force for a valve or for the device units, or as a force countering the pressure of the medium or the like. In this arrangement the ferromagnetic component may be totally surrounded by the flow of the medium or comprise at least one peripheral or similar surface area which seals off contact with the medium and which is a dry surface area. Furthermore, the magnetic force may have an axial and/or rotating effect, e.g. in the case of a setting or counting means for discharge strokes in which the two device units are incrementally and continuously rotated one against the other. The magnetic force may also, however, be used as the force that causes an increase in pressure, e.g. for moving a piston or plunger in the pump cylinder. Furthermore, the magnetic force may be employed to facilitate the assembly of the discharge device, for instance, to locate the two device units with respect to each other. 
     The ferromagnetic component is resistant to changes in temperature and aging and may be sterilized by simple methods. Preferably, for manufacturing the ferromagnetic component is made of a material permitting processing by injection molding and is magnetized and polarized in the production tool under the influence of a magnetic force of a solenoid. This material may contain 2% at the least, 10%-20% plastics material at the most, whilst the remainder is a magnetic powder having a grain size in the μm range. Such plastomagnets may contain, as the ferromagnetic component, an alloy, for instance, neodymium-iron-boron, the polarization of which is oriented prior to the component becoming cold or solidifying. After this production the component may be again demagnetized or neutralized by an opposing magnetic force to prevent disadvantageous effects of magnetization, for example, an undesirable attraction to other ferromagnetic component bodies prior to assembly. Directly prior to and/or after assembly the ferromagnetic component is then remagnetized or activated and thus translated into its functioning or working condition. These and further features are also evident from the description and the drawings, each of the individual features being achieved by themselves or severally in the form of subcombinations in one embodiment of the invention and in other fields and may represent advantageous aspects as well as being patentable in their own right, for which protection is sought herein. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Example embodiments of the invention are explained in more detail in the following and illustrated in the drawings in which: 
     FIG. 1 is an elevational view of a discharge device in accordance with the invention, 
     FIG. 2 is an axial section detail view of the device shown in FIG. 1, 
     FIG. 3 is an axial section view of a valve mechanism in the device of FIG. 1, 
     FIG. 4 is a detail sectional view of a magnet drive for medium discharge, 
     FIG. 5 is a detail sectional view showing a variation of the drive means in accordance with FIG. 4, 
     FIG. 6 is a transverse sectional view showing an embodiment for rotational positional location, 
     FIG. 7 is an axial section view of a second embodiment of a valve mechanism in accordance with the present invention, 
     FIG. 8 is an axial section view of a variation of the second embodiment of the valve mechanism of FIG. 7, 
     FIG. 9 is an axial section view of a third embodiment of the valve mechanism of the present invention, 
     FIG. 10 is a detail sectional view of a second embodiment of an inlet valve seen in FIGS. 7 and 9, 
     FIG. 11 shows the inlet valve in accordance with FIG. 10 in its activated closed condition, 
     FIG. 12 is an axial section view of another embodiment of a medium valve closure, 
     FIG. 13 is a detail section view of a further embodiment of a medium closure, 
     FIG. 14 is an axial section view of a further embodiment of a plunger closure, and 
     FIG. 15 is a detail section view of a further embodiment of a positioning means. 
    
    
     DETAILED DESCRIPTION 
     The discharge device 1 comprises two mutually movable units 2,3 for manually increasing pressure on the medium, each unit having a respective base body 4, 5 which is to be linearly pushed against the other for generating the pressure. Referring to FIGS. 7 to 9, for example, the base body 4 of the unit 2 forms a tubular housing 6 having an inner end 7 and an outer end 8. The unit 2, 4 is inserted through the neck and into a reservoir vessel over the majority of its length, so that the end 7 is located in the reservoir and the end 8 is outside of the reservoir whilst the housing 6 is directly surrounded by the flow of the stored medium. Accordingly, in perpendicular orientation of the discharge device 1, with the medium orifice located at the top or with the main flow of the medium oriented upwards within the discharge device 1, &#34;inside&#34; is synonymous with &#34;down&#34; and &#34;outside&#34; is synonymous with &#34;up&#34;. 
     In the region of the end 7, a closable inlet 9 may be located through which, on the return stroke of the device 1, medium flows from the reservoir into the housing 6 by suction. The end 7 may be defined by the closing surfaces areas of the inlet closure, the associated bottom surface area of the pressure space or the free end of a port 11 of the base body 4, 6. An inlet or riser tube 12 may have one end adjoining the port 11, which is configured substantially narrower than the housing 6. The other end of the tube 12 has a suction effect in the bottom region of the reservoir and is configured as a component either separate from the port 11 or integral with the port 11. Substantially all arrangements and components of the discharge device are located along a single longitudinal axis 10, along which the components 1 to 6 are extended and are centered. 
     In this case the inlet closure is formed by a valve 13 which opens and closes in response to pressure of the medium or to the settings of the units 2, 3 with respect to each other. The valve element 14, which is movable within the housing 6, comprises a conical closing surface area oriented inwards for the other valve element 15. Element 15 is configured integrally with the housing 6 as an axially annular transition of the housing shell 18 into the port 11 and thus defines the inlet 9. The outermost shell 18 of the housing 6 encloses a pressure space or pump space 16 which is bounded at the inner end by the valve 13 and at the outer end by a piston 19 of a piston unit 20 or by the closing surfaces areas of a further valve 23. The inner circumference of the shell 18 forms a runway 17 for slidable movement of the plunger or piston 19 with a seal being provided by one or several piston lips along the runway 17. 
     The piston unit 20 comprises a piston neck 21 configured integrally with the dish-shaped piston 19 and constricted with respect to a longitudinal passage 22, and substantially constricted with respect to the inner circumference of the piston 19, which passes through said piston neck. The outlet valve 23 comprises, like the valve 13, two valve elements 24, 25 which move with respect to each other into an open position and a closed position. The cooperating closing surface areas of said valve elements 24, 25 are located within the piston 19 or the piston neck 21 and come up against each other in the closed position, or in accordance with FIG. 14, are a component of a plunger valve. In this case, instead of the piston neck 21 a passage shank 26 integrally containing the valve element 25 may be provided, the valve element 24 being shiftable on said passage shank 26 between two positions limited by a stop or the like. In the closed position the valve element 25 closes a transverse passage 27 in the valve element 25. The transverse passage 27 is connected to, and communicates with, a longitudinal passage 28. The outer end of the housing 6, 18 may be closed off by a separate cover 29 through which the piston unit 20, 21 passes. This closure may also be configured integrally with the shell 18. 
     In accordance with FIGS. 1 and 2, the two units 2, 4 and 3,5 are continuously urged back to their starting position in the return stroke direction by two components 31, 32 having ferromagnetic properties which under magnetic force repel each other. The two components 31, 32 are arranged to face each other, or to face away from each other, respectively, with the same magnetic poles. The components 31, 32 may be arranged annularly about the axis 10 at the outer side of the base body 4, 6 or 5 and have the same inner width and/or outer width. They produce a spring force which progressively increases when approaching each other, namely on the working stroke, and in the actuated end position may either come up against each other or be located away from each other by a gap or space. In this case they are provided in the region of the end 8, or of a fastener member, which serves to locate the position of the unit 2,4 on the reservoir neck and may be formed by the base body 4 or by the cover 29. 
     In accordance with FIG. 3, the valve 23 is arranged with its closing surface areas within the piston neck 21 and offset outwardly with respect to the piston 19. The valve element 24 is slidingly guided on the inner circumference 22 of the passage shank 21 and provides longitudinal passages which may be formed by grooves in the outer circumference of the valve element 24. The valve element 25 is located on the inner side of the valve element 24 and is inserted in the integral piston component 19, 21 or configured integrally therewith as well as accommodating a central longitudinal passage passing therethrough, the outer width of the outer end forming its valve seat. On the outer side of the valve element 24 facing away from the valve element 25 a component 30 is located having ferromagnetic properties, which repels the valve element 24 in the direction of the closed position. The component 30 is secured and firmly seated on the neck 21 by circumferential pressure and the passage 28 passes full-length through the component 30. 
     If an overpressure is produced by shifting the piston 19 in the space 16, this will act through the longitudinal passage in the valve element 25 on the conical front surface area of the valve element 24, which was moved by the magnetic force to the closed position. When the pressure force exceeds the magnetic force, the valve element 24 is lifted in the direction of the component 30 outwardly from the valve seat and the medium flows in the following sequence from the valve element: along the conical front surface area of the valve element 24, through the longitudinal passages thereof, into the flared space between the elements 24, 30, into the passage 28 and from there, without interruption by valves, up to the medium orifice, from which it is totally released from the discharge device 1. The passage 28 is substantially narrower than the space between the elements 24, 30. The valve element 24 is, like the sleeve-shaped component 30, produced throughout exclusively from a ferromagnetic material. Between the two elements 24, 30 no shielding or the like whatsoever is provided which could possibly weaken the effect of the magnetic force. In the open position too, the element 24 is spaced away from the element 30 by magnetic force. 
     The configuration as shown in FIG. 1 is more particularly suited for so-called disposable discharge devices, in which the piston 19 executes no suction or return stroke, but instead merely requires movement in one direction, with the entirety of the medium to be discharged being stored in the space 16. Along the runway 17 spaced portions or components 31 having ferromagnetic properties of the same or differing field strengths may be provided, between which, portions roughly the same in length are provided with no ferromagnetic properties. All portions may be formed directly by the integral shell 18 and may extend up to the running surface area 17. In the starting position as shown in FIG. 4, the piston 19a is located in position by a portion 31. When the piston 19a is then moved slightly outward in the stroke direction by manual actuation, the piston 19a is repelled by this portion and attracted by the next portion. As a result of this activation, the medium is expelled from the space 16 in the direction of the medium orifice. In this arrangement the piston 19a may pass by several portions 31 in one movement or be relocated in a further starting position by the subsequent portion 31 in each case, from which it is then released for the next step in the stroke in a way as already described. One such arrangement is evident from FIG. 5. 
     As evident from FIG. 6, two units or components 31a, 32a are mutually rotatable and are located in one or more positions of angular rotation with respect to each other, the two components 31a, 32a having ferromagnetic properties. In these positions, the two components 31a, 32a may be in contact with each other and pretensioned by the magnetic force when facing each other with opposite poles. The magnetic components 31a, 32a have the shape of annular segments and each of the magnetic components 31a, 32a is firmly seated on one of the base bodies 4, 5 or the like. The two bodies 4, 5 may be manually and mutually rotated against the magnetic retaining force of the components 31a, 32a and then e.g. moved axially in counter directions implement the discharge stroke, as a result of further movement being positively prevented by abutment of components 31a, 32a. 
     In accordance with FIG. 7 the valve 23b is located with its closing surface areas outside of the piston neck 21b in the pressure space which is flared with respect to the latter and which integrally adjoins the inner end. The valve element 24b is plate-shaped constant in thickness throughout so that one or more closing surfaces areas may be flat throughout. Whilst in accordance with FIG. 3 the valve element 25 does not consist of a ferromagnetic material, but of another plastics material, the valve element 24b has in accordance with FIG. 7 ferromagnetic properties and its poles are oriented so that it urges the valve element 24b to the closed position. The element 25b which is inserted in the pressure space is firmly seated by being pressed into place and may protrude beyond the inner end of the piston 19b into the shell 18b adjacent the space 16b. The longitudinal passage in element 25b is constructed with respect to the space 16b without being guided sealingly on the runway 17b. Between the non-grooved outer circumference of the valve element 24b and the inner circumference of the pressure space an annularly transverse passage is free for the medium. In the opening position the valve element 24b may abut against counter-stops of the piston component 20b so that the conduit path into the passage 22b remains free. As soon as the pressure in the space 16b drops, the valve element 24b instantly recloses the valve 23b due to the magnetic force. The valve element 24b has no passages passing through it. 
     The inlet valve 13b in accordance with FIG. 7 is configured similar to the valve described on the basis of FIG. 3. The flat ring-shaped component 33b having ferromagnetic properties is inserted and firmly seated by being pressed into place and is axially defined by abutment with the inner circumference of the shell 18b. This component 33b urges the valve element inwards to the closed position due to it being offset outwardly with respect to the element 14b and the elements 14b, 33b having the same polarity facing each other. On the return stroke of the piston unit 20b the space 16b is enlarged, causing a vacuum to be generated in the space 16b and urging the element 14b in the direction of the open position or the component 33b until it lifts from the valve element 15b. As a result of this, medium flows from the reservoir through the end 7b and the inlet 9b along the outer circumference of the element 14b into the space between the elements 14b, 33b through the central annular opening of the element 33b so that the space 16b is completely filled with medium. At the end of the return stroke the valve 13b automatically recloses due to the magnetic force. On the next subsequent working stroke, the medium is displaced in the way that has already been described with respect to the opening of the valve 23b. 
     In accordance with FIG. 3, for resetting the units 2, 3 in the starting position, a mechanical spring 50, for example a coil or pressure spring, may be provided which is supported by its inner end with respect to the housing 6, for example at component 33b in FIG. 7, and by its outer end with respect to the base body 5, for example at valve element 25 or within the piston component 19, 21 pretensioned. Instead of spring force, the reset movement in FIG. 7 may also be urged by magnetic force. For this purpose, two magnets facing each other by the same magnetic poles or components of ferromagnetic material may be provided which may be formed directly by the elements 25b, 33b. In the actuated position the elements 25b, 33b may abut against each other or remain spaced away from each other. 
     In accordance with FIG. 8, the element 25c is arranged complete within the widest shell of the piston 19c. 
     Like the FIGS. 3, 7, FIG. 9 shows differential pressure valves 13d, 23d of which the inlet valve 13d is configured similar to those in accordance with FIG. 7. In this case the valve element 24d executes its opening movement inwardly and opposite to that shown in FIG. 3. The component 34d having ferromagnetic properties or the effective pole thereof is located axially with respect to the valve element 24d that it freely protrudes into the space 16d. The two elements 24d, 34d form an inherently closed piston/cylinder unit including a variable volume dry or pressure space 48d which is always closed and free of medium, this space 48d being defined by the two pole sides of the two magnetic components 24d, 34d. The valve element 24d comprises a flared piston collar which is shiftably guided in a dish-shaped depression in the outer face side of the component 24d and is sealed off from the gas pressure in the dry space. By being pressing into place or the like, the component 34d engages and is firmly seated in the inner circumference of the piston cuff 19d with which it defines longitudinal passages which continually connect the space 16d to the annular space in the piston cuff 19d. 
     When the pressure of the medium increases in this annular space, as in the space 16d, then this pressure acts on the associated front surface area of the piston of the valve element 24d so that the latter is shifted inwardly against the cited gas pressure or against the repelling magnetic force with respect to the components 19d, 34d, causing valve 23d to be opened. The valve element 25d is configured integrally with the piston component 19d, 21d and its closing surface area is formed by the annular definition of the inner end of the passage 22d. In the course of the working or discharge stroke, the inner end of the component 34d plunges into the component 33d or into a sleeve-shaped portion having ferromagnetic properties and adjoining the latter, which portion may be configured separately from the component 33d or integrally therewith. This portion of component 33d has a greater inner width, closely adapted to the outer circumference of the component 34d. As a result of this, the resetting force described on the basis of FIG. 7 for the units 2, 3 is substantially increased. 
     The manual actuation in accordance with the invention may also be provided, as shown in FIGS. 10 and 11, so that two components 14e, 33e having ferromagnetic properties are positively located and may abut in a starting position as a result of magnetic force. If one of these components 14e, 33e is moved a short distance from its starting position by a mechanical follower or the like, then the magnetic latch of the starting position is released and this component is translated totally into its second end position in which it likewise may be limited by abutment. The movable component may be a valve element 14e of an arbitrary valve which in an end position, or the starting position, may abut directly against the other component 33e and in the other end position may abut against the valve element 15e which is stationary with respect to said component 33e to thereby close the corresponding valve 13e. The follower may be located within the housing 6e and act for example on the front surface area of the component 14e facing away from the stop 15e. In this case, the component 33e exhibiting ferromagnetic properties is configured as a thin-walled sleeve which may be inserted and firmly seated in the inner circumference of the shell 18e and expediently comprises, protruding beyond its inner circumference, a ring collar against which the component 14e abuts in the starting position. In the starting position, the component 14e is located completely within the component 33e and protrudes in the other end position beyond the corresponding end of this component 33e by part of its length. 
     In accordance with FIG. 12, the closure 23f is spaced away from the piston unit directly at the medium orifice 40f which is formed by the outer end of a nozzle passage passing through a wall, such as a face wall. The inner end of this nozzle passage is closed off by the closure element 24f and the wall forms the valve element 25f. Similar to the arrangement of FIG. 8, the component 34f is configured to be dish-shaped so that the valve element 24f is able to engage the latter by means of a piston portion and form a dry space, the components 34f, 24f being translated into the open position by the pressure of the medium. The piston collar of the valve element 24f is always located completely within the dish-shaped opening and its closing direction is the same as the direction of flow in the nozzle passage. 
     In accordance with FIG. 1, the discharge head 38 is formed with a port 39 located on the axis 10, the head 38 being continuously tapered in the direction of its free end, in the end surface area of said port 39, a discharge nozzle 40 is located, said port 39 being suitable for introduction into a body cavity such as a nasal cavity. The port 39, which may also connect to the base body 5, may also have a constant width throughout, as shown in FIG. 12, and in this case receives in its free end the valve arrangement 24f, 34f. In accordance with FIG. 13, the discharge head 38g is formed by a cap from which the medium orifice 40g emerges transversely to axis 10 oriented at the outer circumference. The medium orifice 40g is in this case formed by a sleeve-shaped component 25g, not represented in more detail, which receives in its interior the components 24g, 35g oriented transversely to the axis 10 and, for example, may be configured the same as the port described on the basis of FIG. 12. The closing direction of the valve element 24g is located in this case, similar to the situation as shown in FIG. 3, contrary to the direction of flow through the valve 23g. In this case, for receiving the rod-shaped valve element 24g the valve element 25g comprises a dish-shaped opening so that the closing surfaces areas are located with the valve element 25g spaced away from the two ends thereof. Both valve elements 24g, 25g are formed by components having ferromagnetic properties and are urged by their magnetic force in the direction of the closed position. 
     The head 38g may comprise an outermost shell 39g which in every position protrudes inwardly beyond the end 8 of the unit 2, 4 or clasps the outer circumference. The outer end surface area of the front wall adjoining the shell 39g forms the handle 41g of the head 38g, the latter forming the base body 5. In the case of FIGS. 1 and 2, the handle 41 is offset inwardly with respect to the outermost end of the head 38 or of the port 39 and protrudes on both sides beyond the port 39. 
     In each case the head 38 comprises, in its interior, a noncontacting protruding, sleeve-shaped shank 19b, 19c, 19d, 42g as a connecting member with which the outer end of the pressure space of the piston unit 20b, 20c, 20d, for example, of the piston neck 21b, 21c, 21d, or of the shank 26h, in accordance with FIG. 14 is to be connected and firmly seated. In accordance with FIG. 13, a longitudinal passage passes through the shank 42g, a transverse passage branching off from the longitudinal passage within the front wall of the head 38g, whereby this transverse passage may extend linearly up to the closing surfaces areas of the valve 23g and be coaxially located with respect to the medium orifice. 
     In accordance with FIG. 14, the valve 23h is configured as a plunger valve, the valve element 24h of which may form at the same time at least part of the piston 19h. The valve element 25h is formed by the inner end of the passage shank through which only the passage 28h passes for part of its length. A transverse passage 27h passes through the shell of the latter at the inner end of the passage 28h. The outer end or the opening of the passage 27h, which is located in the outer circumference of the valve element 25h, is sealingly covered in the closed position by the inner circumference of the component 18h. When component 19h, 24h is shifted outwardly relative to component 18h, then this opening is free and the passage 28h is communicatingly connected to the space 16h. In the closed position, the component 19h, 25h abuts by its inner front surface area against a stop 37h, which may be formed by a flared collar at the inner end of the shank. The component 19h, 24h is urged into this position magnetically by the component 34h, the latter being arranged and firmly seated on the component 25h, 26h, 37h. By being pressed into place, the flat ring-shaped component 34h is arranged and firmly seated on the outer circumference of the shank 26h, which has a constant width throughout up to the stop 37h. The component 34h may abut against the cover 29h through its side facing away from the component 19h, 24h in the starting position of the units 2, 3. If the pressure in the space 16h increases due to shifting of the piston unit 20h, then this pressure acts on the inner piston front surface area and contrary to the resetting force between the components 24h, 34h until, when this force is overcome, the component 19h, 24h is shifted against the component 34h and the valve 23h is opened. As soon as this pressure drops correspondingly the valve 23h recloses due to the magnetic force. 
     In accordance with FIG. 15, a sensing and counting means may be provided which includes two positioning members incrementally mutually switchable and, where appropriate, an indicator which renders a symbol visible corresponding to the respective mutual space. For example, a positioning device may incrementally mutually advance the positioning members by a further switching increment for each working or return stroke so that the number of discharge strokes implemented is sensed. One positioning member each is provided on each of the base bodies 4, 5 either firmly seated or integrally connected to the latter or movable with respect thereto for implementing the switching movement. The switching movement is expediently a rotary movement about the axis 10. In FIG. 15 an actuated end position of the sensing means 44 is illustrated in which the actuating cam 36 of the one switching or positioning member is located laterally adjacent to the actuating cam 35 of the other positioning member. When the cam 36 on the return stroke is moved and turned outwardly or upwards, it produces on the next working stroke the gap between two adjacent switching cams 35. The cams 35, 36 are components having ferromagnetic properties so that e.g. in the actuated end position of the stroke of the discharge device, the component 36 sticks to a component 35, to thereby locate the other in position without a spring-type latching mechanism being necessary for this purpose. From this position, the sensing means 44 or the units 2, 3 can then be retranslated into their other end position by a correspondingly large manual force being applied. The components 35, 36 may also ensure in every starting position, however, that by magnetic force a rotary clearance between the positioning members is avoided. Furthermore, in each starting position the magnetic force can urge the cam 36 with the associated positioning member into the next starting position and thus affect incremental switching advancement, even when no mutual mechanical drive connection exists between the positioning members so that a mechanical incremental sensing means is not needed. 
     In accordance with the FIGS. 7 to 9, the discharge device 1 may also comprise a valve 45d in the vicinity of the end 8d and outside of, as well as separate from, the pressure space 16d, this valve serving more particularly to vent the reservoir vessel so that no vacuum materializes therein due to the increasing drainage thereof. The vent valve comprises a valve element 46d, movable with the piston unit 20d, and a valve element 47d, which is firmly seated with respect to the base body 4d, whereby said valve element 47d may be formed by the end of a collar of the cover 8d, protruding from the end 8d into the shell 18d and guiding the shank 21d or 26d with radial clearance so that the guide gap permits the passage of the surrounding air. The valve element 46d may be formed by the piston component 19d, 21d or the conically stepped transition between the piston shell 19d and the neck 21d, the outer circumference of the latter forming the closing surface area of the valve 45d, this closing surface area like the other closing surface area being located on the side of the piston 19d in a dry space facing away from the space 16d. An opening passes transversely through the shell 18d in the region of this dry space, this opening communicatingly connecting the reservoir interior to the dry space at all times. In the starting position, the valve 45d is closed and, on the start of the working stroke, it opens due to the valve element 46d lifting off from the valve element 47d. As a result of this, the reservoir space is then communicatingly connected to the outer atmosphere via the aforementioned guide gap. In accordance with FIG. 14, the valve element 46d may be formed by the component 34d or provided at outer side or the like facing away from space 16d. 
     In the embodiment in accordance with FIG. 15, the handles 41 for activating the piston 19 or the actuating members engaging the piston 19 are moved transversely to the axis 10, e.g. through openings in the shell 18. 
     It will be appreciated that all features of every embodiment described may be provided analogously in the case of a single discharge device, this being the reason why all passages of the description apply accordingly to all embodiments. Each of the components having ferromagnetic properties is configured expediently as a permanent magnet, the corresponding component comprising an homogenous grain structure throughout or is configured integrally. All properties and effects may be provided precisely as described or merely roughly or substantially as described or even greatly departing therefrom, depending on the demands the discharge device is required to satisfy. The valves 13, 23, 45, as well as the piston units 20, and all ferromagnetic components too, may be interchanged analogously as required. Furthermore, each of the features described may also be omitted.