Blocking device for a locking stressing mechanism having a spring-actuated output drive device
A locking-stressing-mechanism with spring-actuated output drive and a counter with which an apparatus of this kind is fitted, accommodated in a two part housing the two parts of which are mounted to be rotatable relative to each other, can be blocked by means of a pre-stressed leaf spring. The leaf spring is initially accommodated in a recess in the wall of one housing part. As soon as the permitted number of actuations has been reached a push rod pushes the leaf spring out of its resting position. The leaf spring then jumps into a recess in the wall of the other housing part and the two housing parts can no longer be rotated relative to each other. The push rod may be mounted on the pointer of the counter. This blocking device can only be overcome by the application of a force which is sufficient to destroy the device. The device is suitable for blocking a high pressure atomiser or a needleless injector with which a fluid is atomised to form an aerosol or a fluid is injected into a biological tissue.
1. Blocking device for an apparatus which comprises a locking-stressing-mechanism with an operating spring and a spring transfer member in which is accommodated a piston which is mounted to be moveable in a cylinder, and these components are housed in a two part housing which comprises an upper housing part and a lower housing part, said upper housing part having an inner wall and said lower housing part having an outer wall, and the two parts are mounted to be rotatable relative to each other, and said operating spring is tensioned by means of a screw thrust gear by manually rotating said two housing parts relative to each other, and at the same time as said housing parts are rotated relative to each other a mechanical counter is actuated which comprises a threaded spindle and a slider, and said threaded spindle is mounted in said wall of the lower housing part, and said slider is moved along said spindle by an amount which depends on the number of rotations of said two housing parts relative to each other, wherein a recess is provided in said outer wall of said lower housing part and in said inner wall of said upper housing part, and the two recesses are opposite each other when said two housing parts are in a given rotary position, and a moveable blocking element is provided which is located initially only in the recess in said lower housing part and a push rod for moving said blocking element partially into the recess in said upper housing part to prevent the upper and lower housing parts from rotating relative to each other is provided which cooperates with said slider on said spindle of said counter.
2. Blocking device according to claim 1 , wherein said push rod is mounted on the slider.
3. Blocking device according to claim 1 , wherein said push rod is mounted on the blocking element.
4. Blocking device according to claim 1 , wherein said push rod is constructed as an extension of the spindle of the counter and the spindle is mounted to be axially moveable.
5. Blocking device according to claim 1 , wherein said blocking element is moveable in the axial direction.
6. Blocking device according to claim 1 , wherein said blocking element is a pre-stressed leaf spring.
7. Blocking device according to claim 1 , wherein said blocking element is a pre-stressed leaf spring with two legs.
8. Blocking device according to claim 7 , wherein said pre-stressed leaf spring is further comprised of metal.
9. Use of a blocking device according to claim 1 for blocking an atomiser for atomising a liquid which contains a pharmaceutically active substance.
10. Use of the blocking device according to claim 1 for blocking a needleless injector for injecting a liquid which contains a pharmaceutical active substance into animal or human tissue.
11. A method for blocking a needleless injector for injecting a liquid which contains a pharmaceutically active substance into animal or human tissue, said method comprised of the use of a blocking device according to claim 1 .