EP0368062A1 - Paste dispenser - Google Patents

Abstract

The paste dispenser is provided with a metering pump for dispensing metered amounts of paste-like substances such as toothpaste or the like, from bottle- or can-like paste containers (5), which has a bellows (3) made of rubber-like elastic plastic, which connects between two telescopically resiliently guided housing parts (1, 2) made of dimensionally stable plastic. One housing part (1) is provided with a tube-like dispensing mouthpiece (17) forming a paste strand, which is connected to an annular channel (16) which is formed by two concentrically with one another and coaxially formed on this housing part (1) with the bellows axis (13) Pipe socket (14, 15) is formed. The inner pipe socket (14) is enclosed in the manner of a valve seat by a radially elastic annular wall section (22) of the bellows (3), which adjoins a wall section (21) of the bellows (3) sealingly abutting the inner surface of the outer pipe socket (15). In order to add colored strips with the sharpest possible contour to the paste strand, the inner tube stub (14) is provided with one or more strip channels (31, 32, 33, 34) for use as a storage container for a colored strip paste in the area of the dispensing mouthpiece (17) open into the dispensing mouthpiece (17).

Description

The invention relates to a paste dispenser with a metering pump for dispensing metered amounts of low-viscosity, in particular pasty substances, such as toothpaste, ointments or the like. Made of bottle- or can-like paste containers with a bellows made of rubber-like elastic plastic, which is connected between two housing parts made of dimensionally stable plastic which telescopically interlock in the axial direction and which can be moved against one another between two stroke limits and can be reset by axial return spring forces, one housing part being provided with a tube-like dispensing mouthpiece which forms a paste strand and is connected to an annular channel which is connected by two to one another concentric and coaxial to the bellows axis on this housing part, only on their inner end faces each open pipe socket is formed and wherein the inner pipe socket valve-like is surrounded by a radially elastic, sleeve-like ring wall portion of the bellows, which adjoins a sealing portion on the inner surface of the outer pipe socket of the bellows, and also the second housing part with a paste container is provided.

In most known paste dispensers, either a displacement piston in connection with a trailing piston or a pushing piston is provided for pressing the paste out of the paste container through the dispensing mouthpiece, the displacement piston or the pushing piston being operated by a button-type or lever-type actuating member within the Container is gradually shifted in the axial direction in the discharge direction. By using a displacement piston in connection with a follower piston or a push piston which is actuated by means of a push rod via a directional lock, pump valves can be dispensed with in such paste dispensers. As a result, such paste dispensers can be produced relatively simply and inexpensively (DE-OS 35 07 355, DE-OS 33 04 926, US Pat. No. 4,120,431, US Pat. No. 3,255,935, GB 2 172 664 A).

With such paste dispensers, it is relatively easy to add an additional stripe paste of a different color to the strip of paste flowing through the dispensing mouthpiece. It is only necessary in the area where the output channel is in the Container opens out to provide an annular wall projecting into the container, around which the strip paste is arranged, and to provide this annular wall with radial bores through which the strip paste is introduced in the form of thin strips into the discharge channel and thus into the actual paste strand.

In the case of a paste dispenser of the generic type, in which a bellows is arranged between the container of the medium to be dispensed and the dispensing mouthpiece as a pump organ, the strip paste in the form described cannot be added to the paste strand because the dispensing mouthpiece or its output channel in which the paste strand is located is formed, does not reach into the paste container.

The invention has for its object to provide a paste dispenser of the generic type in a simple way as possible to add a colored stripe paste to the paste strand leaving the dispensing mouthpiece or through the bellows and through the ring channel into the dispensing mouthpiece in the form of several strips , so that the resulting color stripes in the paste strand have the sharpest possible contour.

This object is achieved according to the invention in that the inner pipe socket for its use as a storage container for a colored strip paste in the area of the dispensing mouthpiece is provided with one or more strip channels which directly into the Dispense mouthpiece.

Since the strip channels in the form of radial bores or openings can be made directly in the inner pipe socket during injection molding, these strip channels do not cause any additional manufacturing costs, apart from the slightly higher tool costs.
Since it is usual with the generic paste dispensers anyway, the dispensing mouthpiece is to be arranged radially or obliquely to the housing axis and radially at the end of the one housing part that is turned away from the paste container (see, for example, DE-OS 35 09 178 and European patent application No. 88 10 93 67.8), there is also the possibility of keeping the channel of the dispensing mouthpiece relatively short and thereby ensuring a very sharp contouring of the color strips, to which the configurations according to claims 2 and 3 also contribute.

Due to the configuration according to claim 4, the capacity of the pipe socket for the required strip paste can be increased to the required level without difficulty.

In particular, if the dispensing mouthpiece is arranged at right angles to the axis of the pipe socket, the configuration according to claim 5 ensures that the strip channels do not open into the ring channel surrounding the inner pipe socket, but directly into the dispensing channel of the dispensing mouthpiece. This configuration is also sharp for generation Contoured strips in the paste strand are important.

In paste dispensers of the type according to the invention, it is readily possible to connect the interior of the bellows directly to the paste container if a paste piston is provided in the paste container, which is prevented from moving in the direction by means of a directional lock, for example in the form of a spring lock washer to move the bottom of the container. Therefore, there is also the possibility of filling the inner pipe socket with strip paste after the two housing parts and the bellows have been joined, by means of a tube or a hose which, through the connection between the bellows and the container, from the bottom side of the container is passed through into the interior of the inner pipe socket. However, this must be done before the paste container is filled with the paste and the trailing piston is subsequently inserted into the container from the bottom side.
Furthermore, there is also the possibility of providing a trailing piston without a directional lock in the paste container if a suction valve is fitted between the bellows and the paste container. In order to enable the inner pipe socket to be filled with strip paste after the two housing parts and the bellows have been joined, the configuration of the invention according to claim 6 is provided.

In contrast, filling the inner pipe socket with strip paste can also be done before joining the two Housing parts and the bellows are performed. In such a case, the configuration of the intake valve according to claim 6 can be dispensed with, which means that the intake valve can be provided with any closing element. It is then advantageous, however, to provide the configuration according to claim 7, so that it is ensured that the filled strip paste does not leak out of the inner pipe socket during transport and when the two housing parts and the bellows are assembled. The piston used here can consist of a simple circular disk provided with a guide edge.

• Fig. 1 einen Pastenspender im Schnitt;
• Fig. 2 eine Teilansicht II aus Fig. 1;
• Fig. 3 einen Teilschnitt III-III aus Fig. 1.

The invention is explained in more detail below with reference to the accompanying drawing. It shows:

• Figure 1 shows a paste dispenser in section.
• FIG. 2 shows a partial view II from FIG. 1;
• 3 shows a partial section III-III from FIG. 1.

The paste dispenser shown in the drawing consists of two each one-piece housing parts 1 and 2 made of dimensionally stable plastic and a bellows 3, which is arranged connecting between the two housing parts 1 and 2 in a manner described in more detail below. In contrast to the two housing parts 1 and 2, the bellows 3 consists of a rubber-like elastic, soft plastic, so that it is axially compressible and able to apply the restoring forces necessary for a suction process, through which the housing part 1 after a rich direction of the arrow 4 output stroke is returned to its initial position shown in Fig. 1.

The housing part 2 consists of a one-piece, cylindrical paste container 5, in which there is a follower piston 6 which is inserted into the paste container from the open bottom side thereof. Above a radially extending end wall 7, the housing part 2 is provided with a cylindrical guide sleeve 8, which has an inwardly projecting annular rib 9 at its upper end. In this guide sleeve 8, a cylindrical guide section 10 of the housing part 1 is axially movably guided, the length b 1 of which is approximately one third less than the axial length b 2 of the guide sleeve 8. The housing part 1 is thus telescopic in the guide sleeve 8 by the stroke length h movable. The outer diameter of the guide section 10 of the housing part 1 is so matched to the inner diameter of the guide sleeve 8 that an almost play-free guidance is ensured between these two parts and that the annular rib 9 at the upper end of the guide sleeve 8 on the one hand and the end wall 7 at the lower end of the guide sleeve 8 on the other hand form the stroke limits for the housing part 1 or the guide section 10. The likewise cylindrical head part 11 of the housing part 1 which adjoins the guide section 10 upwards has an outer diameter which corresponds to the inner diameter of the annular rib 9 and is provided with a closed end wall 12. On this end wall 12 there are concentric to the common housing axis 13 at a radial distance from one another Pipe socket 14 and an outer pipe socket 15 are formed, which together form an annular channel 16. This ring channel 16 is directly connected to a dispensing mouthpiece 17, the axis 18 of which extends obliquely radially to the housing axis 13 and intersects it. While the outer pipe socket 15 still ends within the head part 11 with its end face open at the bottom, the outer pipe socket 14 has an extension 19 which is tapered in the outer diameter and also in the wall thickness and which projects up to about half with radial play into the bellows 3. Through this extension 19, the pipe socket 14 has the required holding capacity for the colored strip paste, which is added to the paste strand of the paste removed from the paste container 5 in strip form and which differs at least in color from the paste located in the paste container 5.

The bellows 3 is provided at its upper end section with a flange-like support ring 20 which bears in a supportive manner on the lower end face of the outer pipe socket 15. This support ring 20 is adjoined by a cylindrical section 21, which bears sealingly on the inside of the outer pipe socket 15 and on which a conical ring wall section 22 is formed, which bears in a valve-seat-like manner on the outer lateral surface of the inner pipe socket 14. The wall thickness of this conical ring wall section 22 is selected depending on the elasticity of the material from which the bellows 3 is made so that when the pumping stroke of the housing part 1 takes place in the direction of arrow 4, part of the bellows 3 located paste between the ring wall section 22 and the outer surface of the pipe socket 14 into the ring channel 16 and from there into the dispensing mouthpiece 17. The annular wall section 22 of the bellows 3 thus forms, in cooperation with the pipe socket 14, the discharge-side pump valve which opens under pressure during the discharge stroke and closes during the subsequent suction stroke.
The lower end of the bellows 3 facing the end wall 7 of the housing part 2 is sealingly placed with a cylindrical end section 23 on a cylindrical annular connector 24 of the end wall 7 which is concentric with the housing axis 13. This ring socket 24 has a slightly larger inner diameter than the inner pipe socket 14, and it is provided with an offset from the end wall 7 ring wall 25, which has a cylindrical passage opening 26 with a valve seat ring 27 in the form of an upwardly directed annular rib, which has the passage opening 26 concentrically surrounds.
A circular valve flap 29 is integrally formed on the cylindrical end section 23 of the bellows 3 in the plane of the valve seat ring 27 and is integrally connected to an end wall ring 30 of the bellows 3 via a cut-out, semicircular ring web 28. This valve flap 29 rests on the valve seat ring 27 when the housing part 1 executes a pressure or output stroke in the direction of the arrow 4. It stands out from the valve seat ring 27 when the housing part 1 executes the opposite suction stroke and thereby returns to its rest position shown in FIG. 1.

Through the cut-free ring web 28, the valve flap 29 also has the option of moving into the position A indicated by dash-dotted lines if, for filling the pipe socket 14 with colored strip paste from the still empty paste container 5, a hose or a tube through the passage opening 26 into the Pipe socket 14 is pushed. Instead of the pivotable valve flap 29, an organ that can be inserted into the passage opening 26 after filling the pipe socket 14 with colored strip paste could be provided.

So that the strip paste filled into the interior of the pipe socket 14 in the form of sharply contoured, thin, visible strips can be added to the paste strand formed in the dispensing mouthpiece 17, the pipe socket 14 is in the area of the dispensing mouthpiece 17 with four strip channels 31, each offset by 90 ° to one another. 32, 33 and 34 provided, which are arranged along or in extension of the inner contour 35 of the dispensing mouthpiece 17 so that they have the same direction as the axis 18. While the upper strip channel 31 consists only of a bore penetrating the wall of the pipe socket 14, the strip channels 32, 33 and 34 are each extended by radial projections 36, 37 and 38 so far towards the dispensing mouthpiece 17 that they bridge the width of the ring channel 16 in flow into this. In this way it is ensured that the strands of strands flowing through the stripe channels 31 to 34 into the dispensing mouthpiece 17 are embedded in the main paste strand in a sharply contoured manner and are clearly visible as straight stripes on the circumference thereof. These Projections 36, 37 and 38 have the effect that the paste flowing in from the annular channel 16 into the dispensing mouthpiece cannot blur the shape and contour of the thin strips of strip paste.

While in the above-described paste dispenser there is the possibility of filling the cavity of the pipe socket 14 with strip paste by means of the pivotable valve flap 29 after the two housing parts 1 and 2 have been joined together in the form shown together with the bellows 3 by means of a hose or tube , which is passed through the open, still empty container 5 and the passage opening 26 into the pipe socket 14, there is also the possibility of filling the pipe socket 14 even before assembly with the bellows 3 and / or the housing part 2 with strip paste. In this case, a piston 39 is provided in the form of a circular circular disk provided with a guide edge 40, which is inserted into the pipe socket 14 after the strip paste has been filled in and gradually moves deeper into the guide socket 14 with each delivery stroke.

Since the outlet opening 26 is closed by the valve flap 29 during the output stroke of the housing part 1, the trailing piston 6 in the container 5 does not require a locking device which prevents it from migrating downward to the open container end. If, however, a trailing piston 6 is provided with such a locking device, a suction valve or a valve closing flap or another closing element in the region of the valve can be used Passage opening 26 can be dispensed with.

The inner pipe socket 14 fulfills a total of three functions:
- It serves as a container for the strip paste;
- It serves as a valve seat ring for the conical, radially elastic ring wall section 22 of the bellows 3 and
- As long as it is still filled to a certain extent with strip paste, it serves as a displacement body within the bellows 3.

Since the pressure prevailing in bellows 3 during an output stroke also always affects the strip paste located in the open pipe socket 14 in the same relation, it is also ensured that the same amount of strip paste of the same amount of the other paste is always added until the last output stroke . An advantage that results from the constant cross-sectional and pressure conditions.

The arrangement according to the invention can also be implemented in a paste dispenser in which the dispensing mouthpiece is not directed radially but axially and e.g. is arranged in a coaxial extension to the pipe socket 14 on the housing part 1. In this case, the strip channels ran axially parallel to the housing axis 13.

Claims (8)

1.Paste dispenser with a metering pump for dispensing dosed quantities of low-viscosity, in particular pasty substances such as toothpaste, ointments or the like, from bottle- or can-like paste containers with a bellows made of rubber-like elastic plastic, which is connected between two housing parts made of dimensionally stable plastic, which interlock telescopically in the axial direction and which are mutually movable between two stroke limits and resettable by axial return spring forces, the one housing part being provided with a paste-like, tubular dispensing mouthpiece which is connected to an annular channel which is concentric with one another and two to the bellows axis coaxially formed on this housing part, is formed only on its inner end faces each open pipe socket and the inner pipe socket valve-like from one radially elastic, sleeve-like annular wall section of the bellows is enclosed, which adjoins a wall section of the bellows sealingly abutting the inner surface of the outer pipe socket, and furthermore the second housing part is provided with a paste container, characterized in that
that the inner tube stub (14) for its use as a storage container for a colored strip paste in the region of the dispensing mouthpiece (17) is provided with one or more strip channels (31, 32, 33, 34) which open directly into the dispensing mouthpiece (17). 2. Paste dispenser according to claim 1, characterized in that the strip channels (31, 32, 33, 34) have the same direction as the axis (18) of the dispensing mouthpiece (17). 3. Paste dispenser according to claim 1 or 2, characterized in that the strip channels (31, 32, 33, 34) along the inner contour (35) of the dispensing mouthpiece (17) are arranged. 4. paste dispenser according to one of claims 1 to 3, characterized in that the inner pipe socket (14) is longer than the outer pipe socket (15) and with a tapered in the outer diameter extension portion (19) with radial play approximately protrudes concentrically into the bellows (3) over half its length. 5. paste dispenser according to one of claims 1 to 4, characterized in that the strip channels (32, 33, 34) by radial projections (36, 37, 38) of the pipe socket (14) are extended to the initial region of the dispensing piece (17). 6. paste dispenser according to one of claims 1 to 5 in which a suction valve is arranged between the bellows (3) and the paste container (5), characterized in that the suction valve for filling the inner pipe socket (14) from its valve seat (27) locking member (29) which can be pivoted away completely or can be used subsequently. 7. Paste dispenser according to one of claims 1 to 5, characterized in that the inner pipe socket (14) has an axially movable piston (39) which closes the inside of the pipe socket (14) filled with strip paste on the end face. 8. paste dispenser according to claim 7, characterized in that the piston (39) of the inner pipe socket (14) consists of a circular disk provided with a guide edge (40).

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