Device for administering a liquid product

1. A device for the administration of a liquid product, comprising a receptacle for storing the product, a piston plug axially moveable in an advancing direction toward an outlet of the receptacle by an output member, and a connecting mechanism comprising a plurality of hook elements comprised of flexurally elastic bristles spaced about a non-threaded portion of an outer circumferential surface of the output member, wherein the flexurally elastic bristles are arranged in at least one ring and protrude obliquely away from the advancing direction of the output member, said connecting mechanism for releasably connecting the piston plug to the output member by way of the flexurally elastic bristles to secure a connection between piston plug and output member against axial displacement of the output member relative to the piston plug wherein the connection between the piston plug and output member is releasable by relative twisting between the piston plug and the output member.

2. The device as claimed in claim 1 , the piston plug comprising a cavity defined by a plurality of threads, and the connecting mechanism hook elements comprising the flexurally elastic bristles moveable in a substantially radial direction during axial displacement of the output member.

3. The device as claimed in claim 2 , in which the plurality of threads defining the cavity comprise screw-like threads.

4. The device as claimed in claim 1 , in which the output member comprises an abutment for abutting a surface of the piston plug, and the hook elements are arranged in front of the abutment in the axial direction.

5. The device as claimed in claim 1 , in which the hook elements of the connecting mechanism are configured to pivot or bend counter to elastic restoring forces, such that connection between the piston plug and the output member is established by axial, linear displacement of the output member relative to the piston plug.

6. The device as claimed in claim 1 , in which the hook elements are configured to yield in the circumferential direction during the relative twisting of the output member with respect to the piston plug, such that the connection between the piston plug and output member is releasable by relative twisting between the piston plug and the output member.

7. The device as claimed in claim 1 , in which the hook elements are radially displaceable by a motor for establishing the connection between piston plug and output member.

8. The device as claimed in claim 1 , in which a 30 gauge or 31 gauge hollow needle for dispensing the product is secured on the outlet.

9. A device for administering a liquid product, comprising a receptacle for the product, a piston plug axially moveable by an output member in an advancing direction toward an outlet of the receptacle to cause product to be dispensed from the receptacle, and a connecting mechanism comprising a plurality of hook elements comprised of flexurally elastic bristles disposed on a non-threaded surface and arranged in at least one ring configuration arranged on one of the piston plug and an outer circumferential portion of the output member and a cavity defined by threaded walls disposed on the other of the piston plug and the outer circumferential portion of the output member, the connecting mechanism for releasably connecting the piston plug to the output member, wherein a connection between the piston plug and the output member is established by axial, linear displacement of the output member and the piston plug relative to one another, wherein when the piston plug and the output member are connected, said connecting mechanism prevents axial displacement of the output member and of the piston plug relative to one another, and wherein the connection is releasable by relatively twisting the piston plug and the output member.

10. The device as claimed in claim 9 , wherein one of the piston plug and output member comprises at least one relieved area associated with the cavity, and the other component of the connecting mechanism comprising the plurality of hook elements moveable in a substantially radial direction during the axial displacement, so that, by engaging the at least one of the plurality of hook elements in the at least one relieved area, the axial displacement of the output member relative to the piston plug is prevented.

11. A device for the administration of a liquid product, comprising a receptacle for storing the product, a piston plug comprising a cavity defined by screw-like threads, the piston plug axially moveable in an advancing direction toward an outlet of the receptacle by an output member to cause product to be dispensed from the receptacle, and a connecting mechanism comprising a plurality of hook elements formed of flexurally elastic bristles spaced about a non-threaded portion of an outer circumferential surface of the output member for releasably connecting the piston plug to the output member to secure a connection between piston plug and output member against axial displacement of the output member relative to the piston plug, the connection being established by engagement of one or more of the plurality of flexurally elastic bristles of the connecting mechanism with the screw-like threads of the piston plug, and the connection being releasable by relative twisting between the piston plug and the output member.

12. The device as claimed in claim 11 , in which the output member comprises an abutment for abutting a surface of the piston plug, and the hook elements are arranged in front of the abutment in the axial direction.

13. The device as claimed in claim 11 , wherein the flexurally elastic bristles protrude radially from a front end of the output member.

14. The device as claimed in claim 11 , in which a 30 gauge or 31 gauge hollow needle for dispensing the product is secured on the outlet.

15. The device as claimed in claim 1 , wherein the hook elements are clamped around an outer circumferential surface of the output member in a plurality of rings, the plurality of rings arranged in the axial direction of the output member, and the plurality of hook elements configured to engage with the screw-like threads of the piston plug.

16. The device as claimed in claim 15 , wherein hook elements provided in each respective ring are arranged at approximately the same axial height.

17. The device as claimed in claim 16 , wherein the hook elements of the different rings are flush in the axial direction.

18. The device as claimed in claim 15 , wherein the flexurally elastic bristles are formed as struts.

19. The device as claimed in claim 9 , wherein the hook elements are clamped around an outer circumferential surface of the output member in a plurality of rings, the plurality of rings arranged in the axial direction of the output member, and the plurality of hook elements configured to engage with the screw-like threads of the piston plug.

20. The device as claimed in claim 19 , wherein hook elements provided in each respective ring are arranged at approximately the same axial height.

21. The device as claimed in claim 20 , wherein the hook elements of the different rings are flush in the axial direction.

22. The device as claimed in claim 19 , wherein the flexurally elastic bristles are formed as struts.

23. The device as claimed in claim 13 , wherein the hook elements are clamped around an outer circumferential surface of the output member in a plurality of rings, the plurality of rings arranged in the axial direction of the output member, and the plurality of hook elements configured to engage with the screw-like threads of the piston plug.

24. The device as claimed in claim 23 , wherein hook elements provided in each respective ring are arranged at approximately the same axial height.

25. The device as claimed in claim 24 , wherein the hook elements of the different rings are flush in the axial direction.

26. The device as claimed in claim 23 , wherein the flexurally elastic bristles are formed as struts.