EP0738543B1 - Plastic dispensing pump for pasty materials - Google Patents

Description

The invention relates to a delivery pump made of plastic for dispensing paste-like substances from a bottle, can or tube-like paste container with a spring-elastic Bellows as a pump organ that connects between a dimensionally stable, designed as a hollow body upper housing part and a lower, coaxial, also dimensionally stable, connected to the paste container or connectable housing part is arranged, wherein the upper housing part in the lower housing part telescopically is movably guided and an upper cylindrical Wall section of the bellows sealing against one in the upper Housing part rests against the fixed ring wall, within which there is a paste channel and a lower one End section of the bellows sealing against an annular collar abuts a radial partition of the lower housing part, also in the upper, a closable Housing part having outlet opening a second hollow body is used, which with the upper Housing part one in the immediate vicinity of the Outlet opening lying in connection with the paste channel standing paste storage space in which one of the Resilient membrane wall opposite outlet opening is arranged, one to which the housing axis acute-angled axis of the outlet opening coaxial, has plug-like closing member, and in the the lower part of the housing is equipped with a suction valve is.

A dispensing pump of the generic type is known for example from DE 42 07 800 C1. In this case, the upper housing part is provided with an intermediate wall. A hollow guide body, which lies sealingly on the intermediate wall, projects into the hollow space of the hollow body of the upper housing part provided with the outlet opening and a closing end wall. This guide body, together with lateral boundary walls tightly fitting or integrally formed on the inside of the end wall, delimits a paste storage space provided with the outlet opening, which is connected via two paste guide channels to a paste passage of the intermediate wall. The guide body is provided with a resilient membrane wall opposite the outlet opening, which has a plug-like closing element for the outlet opening which is coaxial with the axis of the outlet opening in its center.
In this known embodiment, the upper housing part consists of only three individual parts. However, some of them are so complicated in terms of shape and assembly technology that simple, in particular mechanical, assembly is not possible because these individual parts have to be aligned and joined to one another during assembly at specific angular positions. In addition, this known dispenser pump is set up for the simultaneous dispensing of two paste-like substances, which leads to a further complication of the individual components in terms of shape. In addition, the hollow body used in the upper housing part, on which the membrane wall is molded in one piece, has a high dimensional stability and must therefore consist of a hard plastic, which is detrimental to the resilient functionality of the membrane wall.

Another delivery pump is from DE-Gbm 88 00 880.0 known. There is an intermediate wall of the upper, telescopic one guided in the lower housing part with one down against the partition or the suction valve directed pipe socket provided by a reinforced ring collar of the bellows sealed is. On its top is this pipe socket with provided with a strange valve seat ring surface which resiliently sits on a closing element, which is on the final end wall of the upper, two-part Supported part of the housing resiliently and by means of an axial Cross rib is axially movable in the pipe socket. Here, too, the upper part of the housing consists of two detents interconnected hollow bodies, one of which has a cylindrical guide wall with which it in the lower part of the housing axially movable between two Border positions is performed. The second hollow body of the upper part of the housing, which above the partition in a projecting cylindrical wall section used in a latching manner, has an eccentric, channel-like Outlet opening, which runs axially parallel and the communicates directly with a cavity, in which the closing element of the dispensing valve is arranged and the rest of this output valve with the Interior of the bellows is connected while the upper housing part overall relative to the lower Housing part in the course of a conveying stroke downwards emotional.

In this type of dispensing pumps, for example, too the dosing pump corresponds to EP-A-0 194 417 and as Pumporgan have a bellows are in practice automatic closing devices for the outlet opening of the movable housing part is not provided.

Paste dispensers with pumps are also known (US-PS 4,438,871 and DE-OS 30 38 917), in which plug-like Closing elements for the dispensing opening on elastic Membrane walls are arranged, which during the Working strokes of the medium to be dispensed in the opening direction be charged. It is about but not about pumps that function as bellows exhibit. Rather, the one is known Paste dispenser (US Pat. No. 4,438,871) two manually operable Delivery pistons are provided, which interact with intake valves two media from two at the same time however, separate and separate paste containers via separate channels in a surrounding the locking member and transport storage space limited by the membrane wall. In the other paste dispenser (DE-OS 30 38 917) is a rod-shaped closing element on a so-called rolling membrane attached and arranged in a conical storage space, the via an internally threaded pipe socket, on a threaded neck of a deformable cap is screwed on in connection with a paste container stands. The output pressure is with this pump due to the axial deformation of the cap wall, or caused by their downward movement in the axial direction, the container being provided with a trailing piston, of the respective return movement of the cap runs after.

The invention has for its object a dispensing pump of the generic type from as few as possible easy to manufacture and machine-mountable individual parts with a reliable locking device to create for the outlet opening of the upper housing part and at the same time a paste storage space with the smallest possible Form volume of content.

This object is achieved in that the second hollow body made of dimensionally stable plastic at a right angle to the axis of the outlet opening trending, a boundary side of the paste storage space forming end wall projecting towards the outlet opening and concentric to the axis of the outlet opening, has cylindrical approach with a vent hole, on the one the membrane wall with the plug-like Third hollow body made of elastic and having a closing element Plastic molded onto the membrane wall cylindrical wall part is placed.

Although the invention in the claims for reasons easier to understand than dispensing pump for one Paste dispenser is described, it can also be used Dispensing of liquid substances, also in connection with use an atomizing nozzle.

Such a delivery pump, which as a pump organ one out an existing molded bellows, can mechanically with relatively simple assembly devices Assemble as standard because practically all parts are coaxial can be put together.

Another important advantage of the solution according to the invention is that the paste storage space can be designed so that its receiving volume and thus the remaining amount of the medium remaining in it can be kept as small as possible, but on the other hand the membrane surface, which is necessary for a perfect opening and closing certain size required, can be optimally designed.
Another advantageous aspect can also be seen in the possibility of both the pumping function of the bellows and the closing and opening function of the closing member of the outlet opening being dry, that is to say mechanically and also practically without the medium for the dispensing of which the delivery pump is created check for free.

The subclaims 2 to 6 relate to advantageous molding technology Embodiments of the invention, both for Increase in assembly as to increase the functional safety.

Fig. 1

einen Pastenspender mit einer Abgabepumpe der erfindungsgemäßen Art im Schnitt,

Fig. 2

das obere Gehäuseteil im schnitt;

Fig. 3

einen Schnitt III-III aus Fig. 2,

Fig. 4

einen das mit der Membranwand versehene Schließorgan der Auslaßöffnung im Schnitt;

Fig. 5

den zweiten Höhlkörper als Einzelteil im Schnitt;

Fig. 6

eine Ansicht VI aus Fig. 5;

Fig. 7

eine Ansicht VII aus Fig. 5

Fig. 8

den vierten Hohlkörper im Schnitt und

Fig. 9

den oberen Endabschnitt des Faltenbalgs.

With the aid of the drawing, the invention is explained in more detail below using the example of a paste dispenser. It shows:

Fig. 1

a paste dispenser with a dispensing pump of the type according to the invention in section,

Fig. 2

the upper housing part in section;

Fig. 3

2 shows a section III-III from FIG. 2,

Fig. 4

a the closure member provided with the membrane wall of the outlet opening in section;

Fig. 5

the second cave body as a single part in section;

Fig. 6

a view VI of Fig. 5;

Fig. 7

a view VII of FIG. 5

Fig. 8

the fourth hollow body in section and

Fig. 9

the upper end portion of the bellows.

The paste dispenser shown as an exemplary embodiment in the drawing has a cylindrical cross-sectional shape. However, the embodiment according to the invention can also be implemented with an oval or other cross-sectional shape.
The paste dispenser not completely shown in section in FIG. 1 has a dispensing pump 1 as the upper part and a paste container 2 as the lower part, which is integrally formed as a cylindrical hollow body on a cylindrical lower housing part 3 and is provided in a known manner with a trailing piston 5. The interior 6 of the paste container 2 is separated from the interior 7 of the lower housing part 3 by a radial partition 8, on which an upwardly directed, round collar 10, which is concentric with the common housing axis 9, is integrally formed.

In a cylindrical outer wall 11 of the lower housing part 3, an upper housing part 4 is guided telescopically by means of a likewise cylindrical guide wall 12. This housing part 4, which is designed as an essentially cylindrical hollow body, is movable about an axial stroke H in the outer wall 11.
A coaxial bellows 13, which is connected to the lower housing part 3 or to the partition 8 thereof, serves as the pumping element. The lower cylindrical end section 14 of the bellows 3 sits sealingly in an upwardly directed annular collar 15 of the partition wall 8. The collar 10 has a central through opening 16, the edge of which is an annular valve seat surface for a plate-shaped valve closing element 17, which has at least three radial guide ribs 18 is provided, which are guided axially movably in the through opening. The valve closing element 17, which is secured against falling out by a securing ring which is arranged above and is molded onto the lower part of the bellows 13, forms the suction valve 19 of the delivery pump 1 in cooperation with the collar 10.

The upper housing part 4 of the dispensing pump 1 points above the bottom open guide wall 12 a radial something offset middle, also cylindrical wall part 20 on which in turn a radially offset Headboard 21 with an oblique, slightly concave top wall 22 connects. In a rounded wall section 29, which extends from the upper edge of the middle wall part 20 extends to the top wall 22 is an outlet opening 30 arranged, the axis 31 of the housing axis 9 under one intersects acute angle α of approximately 30 °.

In the cavity of the upper housing part 4, a second hollow body 23 is inserted, which is supported axially with its lower edge on an inner ring rib 24 of the guide wall 12, which is only slightly bulky, in order to be fixedly arranged in the housing part 4.
This second hollow body 23 has a cylindrical wall section 25 which is sealingly enclosed by the central wall part 20 of the housing part 4. An end wall part 26, which bears sealingly on the inner surface of the cover wall 22, is provided with a radially extending, wedge-shaped recess 27 into which an alignment wedge 28 integrally formed on the inside of the cover wall 22 engages in a form-fitting manner. These two elements serve as assembly aids.

Extending from the end wall part 26 to the cylindrical wall section of the second hollow body 23 is a flat end wall 35 which extends at right angles to the axis 31 of the outlet opening and which is provided with a cylindrical extension 36 projecting towards the outlet opening 30. This approach 36 in turn has an end wall 37 with a ventilation bore 38.
The end wall part 26 forms the one boundary side of a paste storage space 40, which is otherwise delimited by the wall section 29 and the cover wall 22 and to which the outlet opening 30 is assigned. This outlet opening can be closed or closed in the unactuated, relaxed normal position of the upper housing part by a closing element 41, which forms a third hollow body made of elastic plastic, which has an annular, in the direction of the axis 31, spring-elastic membrane wall 42 with a round-headed plug or nipple-like closing part 43 and has a cylindrical wall portion 44. The membrane wall 42, the cylindrical wall part 44 encloses the lateral surface of the extension 36 in the assembled state, is at a certain axial distance from the end wall 37 of the cylindrical extension 36 and is preferably weakly conical, so that the opening and closing of the outlet opening 30 through the Locking part 43 can safely perform the required axial movements.

The paste storage space 40, which is as small as possible, is also present the interior of the bellows 13 by a central Paste channel 47 in connection, which partially from one to the Housing axis 9 coaxial pipe section 48 of the second hollow body 23 and partly from one the lower end of this Pipe piece 48 sealingly receiving central sleeve 49 a fourth hollow body 50 made of dimensionally stable plastic is formed. This fourth hollow body 50 has one from an upper, substantially cylindrical wall section 51 of the bellows 13 enclosed ring wall 53 on. He is also in the bellows 13th protruding, cylindrical neck 52 of smaller diameter provided on which the annular wall 52 and one with the Sleeve 49 provided lower end wall 54 are formed. At the upper end, the annular wall 53 has a radially outward projecting collar 55.

For at least weakly jamming recording with the Ring collar 55 provided and from the upper wall section 51st of the bellows 13 enclosed ring wall 53 is the second hollow body 23 inside with a variety of axially extending centering ribs 56 are provided. Here have at least some of the centering ribs 56 radial Stop shoulders 57 for the top of the fourth Hollow body 50.

Because in the described dispensing pump 1 the assembled Individual parts, i.e. the three hollow bodies 4, 23 and 50 consist of round, rotationally symmetrical parts which be joined together by sliding them axially, can be mechanically installed without difficulty . To facilitate this process, the each meet conical edges can.

The operation of the described output pump is very simple and therefore very reliable. Assuming the bellows 13, the paste channel 47 and the paste storage space are filled with the pasty or liquid substance to be dispensed by one or more previous pumping strokes of the upper housing part 4, the next pumping stroke, which is carried out by manually pressing down the upper housing part 4 in the direction of arrow 59 , moved by the excess pressure arising in the paste storage space, the membrane wall 42 with its closing part 43 inwards and the outlet opening 30 opened. Depending on whether the full pumping stroke is carried out or not, a certain amount of the substance exits through the outlet opening 30. During the axial movements of the membrane wall 42, pressure equalization takes place in the cavity through the ventilation bore 38 with the interior of the hollow body 23, which in turn is connected to the free atmosphere by a small air gap between the guide wall 12 and the outer wall 11.
As soon as the actuated housing part 4 is released again, it returns to its starting position in FIG. 1, driven by the resilient restoring force of the bellows 13. This creates a negative pressure in the paste storage space, which results in the immediate closing of the outlet opening 30 by the closing part 43 fastened to the membrane wall 42 and leads to the suction of new substance from the paste container 2 through the suction valve 19.

Claims (7)

1. Dispensing pump made of plastic for dispensing paste-like substances from a bottle-, can- or tube-type paste container (2) with a resilient bellows (13) as pumping member, which is arranged as a connecting means between a dimensionally stable upper housing part (4) constructed as a hollow member and a lower, likewise dimensionally stable housing part (3), which is coaxial thereto and is connected or may be connected to the paste container, whereby the upper housing part (4) is disposed to move in a telescopic manner in the lower housing part (3) and an upper cylindrical wall section (51) of the bellows (13) abuts against a stationary annular wall (53) in the upper housing part to form a seal, inside said annular wall a paste duct (47) is located, and whereby a lower end section (14) of the bellows (13) abuts against an annular collar (15) of a radial separating wall (8) of the lower housing part (3) to form a seal, whereby moreover a second hollow member (23) is inserted into the upper housing part (4) having a sealable outlet (30), said second hollow member forming with the upper housing part (4) a paste holding chamber, which is located in direct proximity to the outlet (30) and connects with the paste duct (47) and in which a resilient membrane wall (42), which has a stopper-like closing member (41) coaxial to the axis (31) of the outlet (30) intersecting the housing axis (32) at an acute angle, is arranged opposite the outlet (30), and whereby the lower housing part (3) is provided with an intake valve (19), characterised in that on a face wall (35) running at right angles to the axis (31) of the outlet (30) and forming a boundary side of the paste holding chamber (40), the second hollow member (23) made of dimensionally stable plastic has a cylindrical attachment (36), which projects towards the outlet (30) and is concentric to the axis (31) of the outlet (30), with an aerating and venting hole (38), onto which attachment a third hollow member made of elastic plastic with the membrane (42) with the stopper-like closing part (43) is attached by means of a cylindrical wall part (44) moulded on the membrane wall (42).
2. Dispensing pump according to Claim 1, characterised in that the interior (46) of the bellows (13) is connected to the paste holding chamber (40) by a central paste duct (47), which is partly formed by a tubular piece (48) of the second hollow member (23) coaxial to the housing axis (9) and partly formed by a central bushing (49) of a fourth hollow member (50) made of dimensionally stable plastic receiving the lower end of the tubular piece (48) to form a seal, said fourth hollow member having the annular wall (53) enclosed by the upper wall section (51) of the bellows (13).
3. Dispensing pump according to Claim 1 or 2, characterised in that the fourth hollow member (50) has a cylindrical attachment (52) protruding axially into the bellows (13), on which attachment the annular wall (53) and a lower face wall (54) provided with the bushing (49) are moulded.
4. Dispensing pump according to Claim 2 or 3, characterised in that the second hollow member (23) is fitted on the inner end with a plurality of axially extending centring ribs (56), which receive the upper wall section (51) of the bellows (13) in a centring arrangement with an at least weak radial clamping effect.
5. Dispensing pump according to Claim 3 or 4, characterised in that at the upper end of its annular wall (53), the fourth hollow member (50) has a radially outward projecting annular collar (57).
6. Dispensing pump according to Claim 4 or 5, characterised in that at least some of the centring ribs (56) have radial abutment shoulders (57) for the upper edge of the fourth hollow member (50).
7. Dispensing pump according to Claim 1 or 2, characterised in that the second hollow member (23) is fitted with a wedge-shaped depression (27) on the face side, into which depression a locating wedge (28) moulded on the inner side of the cover wall (22) of the upper housing part (4) positively engages.

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