Metering device

Abstract

The invention relates to a metering device (1) for the metered application of a highly viscous product onto a substrate (2), comprising a housing (3) with an inner side (7) and an outer side (6), a cartridge (10) forming a receiving space (14) for the highly viscous product to be metered, a piston (20) and a spring element (17), wherein at least one engaging element (22) is formed on the inner side (7) of the housing (3) and a row of neighboring engaging recesses (21) is formed on the piston (20), wherein both the engaging element (22) and the engaging recesses (21) are arranged outside of the receiving space (14), and wherein the engaging element (22) engages into an engaging recess (21) on the piston (20) with an actuation of the metering device (1), and wherein, after an actuation of the metering device (1), a returning movement of the housing (3) into the starting position thereof brings about a transition of the engaging element (22) from the engaging recess (21) into a neighboring engaging recess (21).

Claims

1. A metering device for the metered application of a highly viscous product onto a substrate, comprising: a housing with an inner side and an outer side, a first end which faces the substrate during actuation of the metering device and a second end opposite from the first end, wherein the housing comprises a housing opening in the area of the first end, a cartridge which is arranged at least substantially within the housing, and which forms an internal receiving space for the highly viscous product, wherein the cartridge comprises a cartridge opening in the area of the first end of the housing through which the highly viscous product can be dispensed from the metering device onto the substrate, a piston which is arranged within the housing and at least partially within the cartridge and which forms a delimitation of the receiving space opposite the cartridge opening, wherein, during the actuation of the metering device, a movement of the housing relative to the cartridge brings about a movement of the piston relative to the cartridge in the direction of the dispensing opening, whereby the highly viscous product can be dispensed through the cartridge opening and the housing opening, a spring element disposed between the inner side of the housing and the cartridge, the spring element having an extended position and a compressed position, wherein axial movement of the housing relative to the cartridge to dispense the highly viscous product moves the spring from the extended position toward the compressed position and spring element movement toward the extended position biases the housing toward a starting position, at least one engaging element formed on the inner side of the housing and a row of engaging recesses is formed on the piston, wherein both the engaging element and the engaging recesses are arranged outside of the receiving space, the engaging element engageable into one engaging recess with an actuation of the metering device, so that, movement of the housing relative to the cartridge provides movement of the piston relative to the cartridge and thus a dispensing of the highly viscous product from the metering device, and after an actuation of the metering device, the spring element biases the housing into the starting position during which the engaging element moves from the engaging recess into a neighboring engaging recess.

2. The metering device according to claim 1, wherein the engaging recesses on the piston are delimited by engaging protrusions which comprise an upper side facing the second end of the housing and a lower side facing the first end of the housing, wherein, in the case of a metering device set on a substrate, the upper side of the engaging protrusions is oriented substantially parallel to the substrate, while the lower side is oriented at an angle of 30 to 60 with respect to the substrate.

3. The metering device according to claim 1, wherein the at least one engaging element is formed as a circumferential engaging element along the entire inner circumference of the housing.

4. The metering device according to claim 1, wherein the at least one engaging element is formed as an engaging arm.

5. The metering device according to claim 1, wherein the housing has a substantially circular cross-section.

6. The metering device according to claim 1, wherein the housing is formed to be slip-resistant on the outer side thereof.

7. The metering device according to claim 1, comprising a cover cap sealingly engaged to the dispensing opening.

8. The metering device according to claim 1, wherein at least one sealing element for sealing between the piston and the cartridge is formed on the piston.

9. The metering device according to claim 1, wherein the end of the cartridge comprising the dispensing opening is formed as an application head which can be set on the substrate.

10. The metering device according to claim 1, wherein the cartridge is replaceable.

11. The metering device according to claim 1, wherein the housing comprises areas in which a filling quantity of the highly viscous product can be read.

12. A metering device for the metered dispensing of a highly viscous product onto a substrate, comprising: a cartridge having an outer wall, an inner wall defining an internal receiving space for containing the highly viscous product, a first end defining an aperture through which the highly viscous product can be dispensed onto the substrate and an open second end; a housing disposed around the cartridge, the housing having an inner side, a portion of the inner side adjacent the cartridge outer wall, an outer side, a first end adjacent the cartridge first end and a second end opposite the first end and extending beyond the cartridge second end, the inner side comprising an engaging element, the housing axially movable between a starting position wherein the housing first end is displaced away from the cartridge first end and a dispensing position wherein the housing first end is displaced toward the cartridge first end; a bias element disposed between the inner side of the housing and the outer wall of the cartridge, the bias element having an extended position biasing the housing toward the starting position and a compressed position when the housing is in the dispensing position; a piston substantially disposed within the housing, the piston having a first end disposed in the cartridge receiving space to seal highly viscous product therein, a second end proximate the housing second end, an outer wall comprising a row of engaging recesses outside of the cartridge receiving space and adjacent the housing inner side, wherein a first of the engaging recesses is interengaged with the housing engaging element so that movement of the housing toward the dispensing position moves the piston first end toward the cartridge first end.

13. The metering device of claim 12 wherein movement of the housing from the dispensing position toward the starting position moves the housing engaging element from the first engaging recess to a second engaging recess axially displaced toward the piston second end from the first engaging recess.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Below, the invention is explained in further detail in reference to an embodiment example and in reference to the drawings. In the drawings:

(2) FIG. 1 shows a view of an inventive metering device;

(3) FIG. 2 shows representation of the metering device from FIG. 1 in longitudinal cross-section;

(4) FIG. 3 shows a cross-sectional representation of a metering device during an actuation procedure;

(5) FIG. 4 shows a cross-sectional representation of a metering device after completion of an actuation procedure.

(6) In FIGS. 1 to 4, a metering device referred to as a whole with the reference numeral 1 for the metered application of structural adhesive onto a substrate 2 is represented.

(7) The metering device 1 comprises a substantially cylindrical housing 3 which comprises a first end 4 and a second end 5, and an outer side 6 and an inner side 7 facing the inner space of the housing 3. On its outer side 6, the housing 3 is provided with grooves 8 which have a slip-resistant effect. Moreover, the housing 3 comprises an opening 9 through which a scale can be seen, by means of which a filling quantity of the structural adhesive contained in the interior of the housing 3 can be read. The scale here indicates how many actuation procedures still can be performed with the metering device 1. In the example of FIG. 1, 20 actuation procedures can still be performed with the metering device 1.

(8) A cartridge 10 is arranged substantially within the housing 3. In FIG. 1, only a lower area 11 of the cartridge 10, which protrudes at the first end 4 from the housing 3, can be seen. The substantially cylindrical cartridge 10 forms a receiving space 14 for the structural adhesive to be metered. Both the housing 3 and the cartridge 10 are configured in the shape of a bell on the first end 4 and in the lower area 11, respectively. In other words, the cross-section of the cartridge 10 and of the housing 3 increases in these areas. The housing 3 is mobile relative to the cartridge 10 in the directions indicated by arrows A.

(9) In the lower area 11 of the cartridge, a dispensing opening 12 is arranged, through which the structural adhesive can be dispensed from the cartridge 10. In the representation of FIGS. 1 and 2, the dispensing opening 12 is closed by a cover cap 13.

(10) The cartridge 10 is formed in the lower area 11 thereof as an application head which, after removal of the cover cap 13, with an actuation of the metering device 1, can be set by means of a circumferential margin 15 on the substrate 2. The dispensing opening 12 is arranged recessed with respect to the circumferential margin 15, so that when the metering device 1 is set by means of the margin 15 onto a substrate 2, the dispensing opening 12 is not in direct contact with the substrate 2. This is apparent in particular in FIG. 3, in which the metering device 1 is represented during an actuation procedure.

(11) In the lower area 11, the cartridge 10 moreover comprises a circumferential projection 16 which, during an actuation procedure of the metering device 1, serves as a stop for the housing 3, as will be explained further below.

(12) Between the cartridge 10 and the housing 3, a metal coil spring 17 is arranged, the windings of which run around the cartridge 10. The coil spring 17, on its end facing the dispensing opening 12, rests on a circumferential margin 18 formed on the cartridge 10 and it is supported against said margin. On the end of the coil spring 17 facing away from the dispensing opening 12, projections 19 arranged on the inner side 7 of the housing 3 can engage, which compress the coil spring 17 when the housing 3 is moved relative to the cartridge 10, as will be explained even more precisely.

(13) On its end facing away from the dispensing opening 12, a piston 20 is introduced into the cartridge 10. The piston 20 delimits the receiving space 14 in a direction opposite the dispensing opening 12. The piston 20 comprises engaging recesses 21. Engaging arms 22 formed on the inner side 7 of the housing 3 can engage into these engaging recesses 21. The engaging recesses 21 are delimited by engaging projections 23 which comprise an upper side 24 facing the second end 5 of the housing 3, and a lower side 25 facing the first end 4 of the housing 3. In the case of a metering device 1 set on a substrate 2, the upper side 24 of the engaging projections 23 is oriented substantially parallel to the substrate 2, while the lower side 25 of the engaging projections 23 is oriented at an angle of approximately 45 relative to the substrate 2.

(14) In the area of its end 28 facing the dispensing opening 12, circumferential sealing elements 27 are formed on the piston 20 for a sealing between the piston 20 and the cartridge 10. In other words, due to the sealing elements 27, structural adhesive is prevented from coming out of the receiving space 14 defined by the cartridge 10 and delimited by the end 28 of the piston 20, in the direction of the second end 5 of the housing. In particular, due to the particular arrangement, structural adhesive is prevented from coming in contact with the engaging arms 22 and the engaging recesses 21.

(15) The metering device 1 shown in FIGS. 1 to 4 has a length a of approximately 150 mm, a housing diameter b of approximately 32 mm, and a diameter c of the cover cap 13 of approximately 45 mm. Depending on the density of the structural adhesive used, a filling quantity of approximately 30 g of structural adhesive can be received in the cartridge 10.

(16) Below, an actuation procedure of the metering device 1 is described. For the application of structural adhesive onto the substrate 2, first the cover cap 13 is removed. In this starting position the engaging arms 22 are each located in an engaging recess 21. The metering device 1 is then set by means of the margin 15 formed on the cartridge 10 onto the substrate, wherein a user grasps the metering device 1 in the area of the housing 3 provided with grooves 8. The housing 3 is then moved toward the substrate 2. Due to the engaging between engaging arms 22 and engaging recesses 21, the piston 20 is moved with the housing 3. Thus, the piston 20 is moved along within the cartridge 10 toward the dispensing opening 12 of the cartridge 10, thus pushing a defined quantity of structural adhesive out of the opening 12.

(17) The length of the distance x by which the housing 3 and along with said housing the piston 20 are moved during an actuation procedure, also referred to as stroke of the housing 3, is limited by the circumferential projection 16 formed on the cartridge 10, which the housing 3, by means of the end 4, finally hits by means of the end 4 thereof, see FIGS. 2 and 3. In FIG. 2, the metering device 1 is represented in its starting position, but with cover cap 13 still attached to it. Here, the distance x can be seen, by which the housing 3 can be moved from its starting position and limited by the circumferential protrusion 16. In FIG. 3, the metering device 1 is shown in a position in which the first end 4 of the housing 3 hits circumferential projection 16.

(18) The distance x by which the housing 3 and thus the piston 20 is moved with each actuation procedure is thus fixed by the position of the circumferential projection 16, so that, in this way, the volume of structural adhesive dispensed with each actuation procedure due to the piston advance is fixed at the same time. In the case of the embodiment example shown, for each actuation procedure, an adhesive dot 26 of approximately 1.5 g of structural adhesive is dispensed. Depending on the viscosity of the structural adhesive used, such an adhesive dot 26 can cover an area of approximately 7 to 12 cm.sup.2. In the case of a total filling quantity of approximately 30 g of structural adhesive, 20 adhesive dots 26 can be dispensed in this way with the metering device 1. Typically, such an adhesive dot 26 can have an adhesive strength of approximately 330 g.

(19) During the movement of the housing 3 toward the substrate 2, the coil spring 17 is compressed. As already mentioned, the coil spring 17, on the end thereof facing the dispensing opening 12, rests on a circumferential margin 18. Projections 19 arranged on the inner side 7 of the housing 3 engage on the end of the coil spring 17 facing away from the dispensing opening 12 and compress the coil spring 17 during a movement of the housing 3 directed at the substrate 2. The maximum compression of the coil spring 17 achievable during the course of the actuation of the metering device 1 is reached when the housing 3 hits the circumferential protrusion 16. FIG. 3 shows this state, but the compression of the coil spring 17 is only suggested here and not represented true to scale.

(20) As soon as the housing 3 has hit the circumferential projection 16, the dose of structural adhesive provided for is dispensed from the dispensing opening 12, and the metering device 1 can be removed from the substrate 2, wherein the applied adhesive dot 26 remains as intended on the substrate 2, see FIG. 4. When the metering device 1 is separated from the substrate 2, the housing 3 and the cartridge 10 move relative to one another back to their starting position due to the resetting force of the coil spring 17, so that the first end 4 of the housing 3 is again at distance x from the circumferential projection 16.

(21) During this returning movement of the housing 3 relative to the cartridge 10, the piston 20, on the other hand, remains in the position advanced by distance x within the cartridge 10, due to the friction forces generated by the sealing elements 27 between the piston 20 and the cartridge 10. The engaging arms 22 formed on the housing 3 here slide from their respective engaging recess 21 into the neighboring engaging recess 22 in direction of the second end 5 of the housing, see also FIGS. 3 and 4. Due to the above-described different orientations of lower side 25 and upper side 24 of the engaging projections 23, and due to a slightly flexible design of the engaging arms 22, this sliding can take place particularly well. The different orientations of upper side 24 and lower side 25 have the effect that, during the actuation of the metering device 1, the engaging arms 22 in each case engage firmly into an engaging recess 21 and lie on the upper side 24 of the corresponding engaging projection 23, thus ensuring the transmission of the movement of the housing 3 to the piston 20, while, after the actuation of the metering device 1 and when the housing 3 transitions into its starting position, the lower side 25 of the engaging projections 23, which is formed angled, enables a sliding of the engaging arms 22 over said lower side and a transition of the engaging arms 22 from the respective engaging recess 21 into a neighboring engaging recess 21.

(22) In this position, the metering device 1 is now ready for a new actuation, wherein, according to the above explanations, the piston 20 is advanced ever further toward the dispensing opening 12 from actuation procedure to actuation procedure, while the housing 3 and the cartridge 10 after each actuation procedure resume their starting position relative to one another.

(23) The engaging mechanism described has the effect that, with each actuation procedure, the same defined quantity of structural adhesive is always dispensed, wherein a premature curing of same within the cartridge 10 can be prevented due to the particular arrangement of the individual components of the engaging mechanism outside of the structural adhesive volume. As a result of the successive advance of the piston 20 within the cartridge 10, a simple way of dispensing the structural adhesive volume completely from the cartridge 10 is possible, without the need for additional auxiliary means for this purpose, as is the case with corresponding adhesive tubes, for example. The actuation of the metering device 1 can here always be done with one hand.