Fluid-release unit and manual metering device with at least one fluid-release unit

Abstract

In order to facilitate disassembly of the fluid dispensing unit (4), the latter has the covering cap (17) with which at least one sealing means (18) located in the head part (12) of the fluid dispensing unit (4) can be fixed in its use position. In order to release the covering cap (17) from the head part (12), said covering cap is rotatable relative to the head part (12). A releasable snap connection (19) is provided between the covering cap (17) and the head part (12), said snap connection being formed by at least one latching projection (20) and/or at least one latching depression (21), wherein at least one oblique surface (22) is formed on the latching projection (20) and/or on the latching depression (21), said surface being oriented in such a manner that the snap connection (19) can be released by rotation of the covering cap (17) relative to the head part (12) (FIG. 3).

Claims

1. A fluid dispensing unit (4) for a manual metering device (1), in particular for a pipette (2), the fluid dispensing unit (4) comprising: a stem (11), a head part (12), and, a receiving space (10), wherein the receiving space (10) is connected via a dispensing channel (13) formed in the stem (11) to a dispensing opening (15) formed at a free end (14) of the stem (11), wherein the head part (12) is arranged at a head end (16) of the fluid dispensing unit (4), said head end lying opposite the free end (14) of the stem (11), wherein the head part (12) has a covering cap (17) removably fastened to the head part (12) by means of a releasable snap connection (19) and with which at least one element of the fluid dispensing unit (4) is selectively covered with the covering cap (17) being fastened to the head part (12), the releasable snap connection (19) including at least one latching projection (20) and at least one latching depression (21) and, wherein at least one of the at least one latching projection (20) and the at least one latching depression (21) has at least one oblique surface (22) which is oriented in such a manner that the releasable snap connection (19) is released by rotation of the covering cap (17) relative to the head part (12).

2. The fluid dispensing unit (4) as claimed in claim 1, wherein the fluid dispensing unit (4) has a sealing means (18) which is arranged in the head part (12), the sealing means (18) being fixed with the covering cap (17) fastened to the head part (12).

3. The fluid dispensing unit (4) as claimed in claim 2, wherein the sealing means (18) is a sealing ring (27).

4. The fluid dispensing unit (4) as claimed in claim 3, wherein the sealing ring is a piston sealing ring.

5. The fluid dispensing unit (4) as claimed in claim 2, wherein, in order to pressurize the sealing means (18), a compression spring (28) is arranged between the covering cap (17) and the sealing means (18).

6. The fluid dispensing unit (4) as claimed in claim 1, wherein the at least one latching projection (20) is arranged on the covering cap (17) and the at least one latching depression (21) is arranged on the head part (12).

7. The fluid dispensing unit (4) as claimed in claim 1, wherein the at least one oblique surface (22) is arranged on the at least one latching projection (20).

8. The fluid dispensing unit (4) as claimed in claim 1, wherein the at least one oblique surface (22) is formed by a bevel on a side (23, 24) of at least one of the at least one latching projection (20) and the at least one latching depression (21), which is oriented transversely with respect to the direction of rotation of the covering cap (17).

9. The fluid dispensing unit (4) as claimed in claim 1, wherein the fluid dispensing unit (4) is a piston unit including a piston (7), and the receiving space (10) includes a cylinder portion (25).

10. The fluid dispensing unit (4) as claimed in claim 1, wherein the covering cap (17) has a passage opening (26) through which a piston (7) can be introduced into the receiving space (10).

11. The fluid dispensing unit (4) as claimed in claim 1, wherein the head part (12) has a receptacle (30) for the covering cap (17), the covering cap (17) being insertable into the receptacle (30) of the head part (12).

12. The fluid dispensing unit (4) as claimed in claim 1, wherein the fluid dispensing unit (4) further comprises at least one fastening means (31) for releasably fastening the fluid dispensing unit (4) to a main body (3) of a manual metering device (1).

13. The fluid dispensing unit (4) as claimed in claim 12, wherein the at least one fastening means (31) is a thread formed on the head part (12).

14. The fluid dispensing unit (4) as claimed in claim 1, wherein the covering cap (17) has a gripping region (32) which, with the covering cap (17) fastened to the head part (12), protrudes over the head part (12).

15. The fluid dispensing unit (4) as claimed in claim 14, wherein the gripping region (32) is one or more of a roughened surface, a knurled surface, and a surface with anti-slip coating.

16. A manual metering device (1), in particular pipette (2), with a main body (3) and with at least one fluid dispensing unit (4) as set forth in claim 1, wherein the main body (3) comprises shifting means (5) for dispensing and picking up a fluid with the at least one fluid dispensing unit (4) and actuating means (6) for actuating the shifting means (5), and wherein the main body (3) and the at least one fluid dispensing unit (4) are releasably connected to each other.

17. The manual metering device (1) as claimed in claim 16, wherein the main body (3) and the fluid dispensing unit (4) are releasably connected to each other by means of a screw connection (6).

18. The manual metering device (1) as claimed in claim 16, wherein the shifting means (5) includes at least one piston (7) which can be pushed into the receiving space (10) with the aid of the actuating means (5a).

19. The fluid dispensing unit (4) as claimed in claim 1, wherein the at least one latching depression (21) is arranged on the covering cap (17) and the at least one latching projection (20) is arranged on the head part (12).

20. The fluid dispensing unit (4) as claimed in claim 1, wherein at least one of the at least one latching projection (20) and the at least one latching depression (21) has the at least one oblique surface (22) on two opposite sides thereof oriented transversely with respect to the direction of rotation of the covering cap (17).

21. The metering device (1) as claimed in claim 16, wherein the main body (3) and the fluid dispensing unit (4) are releasably connected by a combined snap/screw connection.

22. The metering device (1) as claimed in claim 16, wherein at least one of haptic feedback and acoustic feedback is generated with proper connection between the main body (3) and the at least one fluid dispensing unit (4).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) An exemplary embodiment of the invention is described in more detail below with reference to the figures, in which, in a partially highly schematized illustration:

(2) FIG. 1 shows a perspective view of a manual metering device according to the invention designed as a pipette,

(3) FIG. 2 shows a broken-open sectional illustration of the manual metering device illustrated in FIG. 1,

(4) FIG. 3 shows a sectioned side view of the fluid dispensing unit, illustrated in FIGS. 1 and 2, of the manual metering device according to the invention,

(5) FIG. 4 shows a cross section of the head part of the fluid dispensing unit depicted in FIGS. 1 to 3,

(6) FIG. 5 shows an exploded illustration of the head part of the fluid dispensing unit illustrated in FIGS. 1 to 4, and

(7) FIG. 6 shows a perspective illustration of the head part of the fluid dispensing unit, which is depicted in the previous figures, in the mounted state.

DETAILED DESCRIPTION OF THE INVENTION

(8) FIGS. 1 to 6 show various views of a manual metering device which is denoted as a whole by 1. The manual metering device illustrated in the figures is designed as a mechanical and manually actuable pipette 2. The manual metering device 1 has a main body 3 and a fluid dispensing unit 4.

(9) The main body 3 comprises at least one shifting means 5 with which a fluid, in particular a liquid, can be dispensed and picked up with the fluid dispensing unit 4. In addition, the main body 3 has an actuating means 5a in the form of a pusher for actuating the shifting means 5.

(10) The main body 3 and the fluid dispensing unit 4 are releasably connected to each other by means of a screw connection 6.

(11) The shifting means 5 comprises a piston rod 8 which is connected to a piston 7 of the fluid dispensing unit 4 and can be seen to some extent in FIG. 2. The piston 7 and piston rod 8 are connected to each other via a connecting piece 9.

(12) The fluid dispensing unit 4 comprises a receiving space 10 for receiving an air cushion, a stem 11 and a head part 12. The receiving space 10 is connected via a dispensing channel 13 formed in the stem 11 to a dispensing opening 15 formed at a free end 14 of the stem 11. The head part 12 is arranged at a head end 16 of the fluid dispensing unit 4, said head end lying opposite the free end 14 of the stem 11. The head part 12 has a covering cap 17 which is removable from the head part 12 and with which at least one sealing means 18 which is arranged in the head part 12 can be fixed in its use position.

(13) The covering cap 17 in its use position on the head part 12 is rotatable relative to the latter and is fastened to the head part 12 by means of a releasable snap connection 19. At least one latching projection 20 and/or at least one latching depression 21 of the snap connection 19 has at least one oblique surface 22 which is oriented in such a manner that the snap connection 19 can be released by rotation of the covering cap 17.

(14) In the exemplary embodiment, illustrated in the figures, of the fluid dispensing unit 4 according to the invention, two such latching projections 20 are formed on the covering cap 17. In a manner corresponding thereto, the head part 2 has latching depressions 21.

(15) As in particular the sectional illustration of the head part 12 according to FIG. 4 clarifies, two such oblique surfaces 22 are in each case formed on each of the two latching projections 20 of the head part 12. The two oblique surfaces 22 are formed on two opposite sides 23 and 24 of each of the two latching projections 20, said sides being oriented transversely with respect to the direction of rotation of the covering cap 17.

(16) The two oblique surfaces 22 of each of the two latching projections 20 are in each case formed by a bevel on the sides 23 and 24 of the respective latching projection, which sides are oriented transversely or at right angles with respect to the direction of rotation of the covering cap 17.

(17) The fluid dispensing unit 4 is designed as a piston unit. The receiving space 10 of said piston unit 4 includes a cylinder portion 25.

(18) The covering cap 17 has an upper-side passage opening 26. Through said passage opening 26, the piston 7 and/or the piston rod 8 can be introduced into the receiving space 10, which includes a cylinder portion 25, of the fluid dispensing unit 4 for displacing an air cushion located there in the direction of the dispensing opening 15, which is connected to the cylinder portion 25 via the dispensing channel 13. The displacement of the air cushion in the direction of the dispensing opening 15 is used to discharge a volume, kept in a pipette tip, of liquid to be dispensed out of the pipette tip. In the use position, the pipette tip is plugged onto the free end 14 of the stem 11 and is then in a pressure connection with the dispensing opening 15 and with the dispensing channel 13. A shifting of the air cushion in the direction of the dispensing opening 15 can thus be used for dispensing liquid out of the pipette tip and a shifting of the air cushion into the receiving space 10 can thus be used for picking up liquid into the pipette tip.

(19) The sealing means 18 of the fluid dispensing unit 4 is a sealing ring 27 which can also be referred to as a piston sealing ring 27 since it seals a gap between a wall of the receiving space 10 and the piston 7. This takes place at least whenever the piston 7 is introduced into the receiving space 10.

(20) In order to pressurize the sealing ring 18, which is present as a sealing ring 27, between the covering cap 17 and the sealing means 18, the fluid dispensing unit 4 has a compression spring 28 and a pressure piece 29. When the covering cap 17 is in the use position, the pressure piece 29 is pressed against the sealing means 18 by the pretensioning of the compression spring 28, and therefore said sealing ring can be placed against the surfaces to be sealed from one another. In addition, the sealing means 18 can thus be reliably fixed in its use position in the head part 12 of the fluid dispensing unit 4.

(21) The head part 12 has a receptacle 30 for the covering cap 17. The covering cap 17 can therefore be inserted in the use position into the receptacle 30 of the head part 12, as can be seen clearly, for example, in FIGS. 3 and 6.

(22) As the fastening means for the releasable fastening of the fluid dispensing unit 4 to the main body 3 of the manual metering device 1, the fluid dispensing unit 4 has a thread 31 which is configured as an external thread. The external thread 31 is formed here on an outer side of the head part 12. In addition, the covering cap 17 comprises a gripping region 32 which, in the use position of the covering cap 17 on the head part 12, protrudes over the head part 12. The gripping region 32 is provided with a knurling 33, i.e. is of knurled design.

(23) The main body 3 of the manual metering device 1 has a mating thread 34 in the form of an internal thread which matches the thread 31, which is configured as an external thread, of the head part 12.

(24) In order to facilitate disassembly of the fluid dispensing unit 4, the latter has the covering cap 17 with which at least one sealing means 18 located in the head part 12 of the fluid dispensing unit 4 can be fixed in its use position. In order to release the covering cap 17 from the head part 12, said covering cap is rotatable relative to the head part 12. The releasable snap connection 19 is provided between the covering cap 17 and the head part 12, said snap connection being formed by at least one latching projection 20 and/or at least one latching depression 21, wherein at least one oblique surface 22 is formed on the latching projection 20 and/or on the latching depression 21, said surface being oriented in such a manner that the snap connection 19 can be released by rotation of the covering cap 17 relative to the head part 12.