| 摘要 |
Supported in the front part (2) of the device is an exchangeable injection ampoule (4). Arranged in the rear part (1) is a gear mechanism (3) of which the drive element is a sleeve (10) comprising a control head (11), and of which the driven element is a threaded rod (12) which can move longitudinally and is locked against rotation. The threaded rod (12) is fixed in the guide thread (22) of a gear element (20), which can move axially from a rest position to a final position by means of pressure on the control head (11) against the force of a spring (26). In the rest position of the gear element (20), the threaded rod (12) which is spaced from the piston (5) of the injection ampoule (4), is threaded in the guide thread (22) of the element (20) by rotation of the control head (11) over a distance corresponding to the piston travel required for the quantity of liquid to be injected without the threaded rod (12) striking the piston (5). Next, the needle (7) is inserted and the gear element (20) is pushed foward from the rest position to the final position by pressing on the control head (11). During the travel (h) the threaded rod (12) strikes the piston (5) and pushes it forward over the preselected distance. The device makes it possible to preselect any desired quantity of liquid by rotating the control head (11) and injecting it simply by inserting the needle and by applying one single pressure to the head (11). |
