| 摘要 |
The instrument to grip the caps (50) of sample containers, automatically, has a setting unit (10) to apply an active action to the clamp (25) to grip the pin of the container cap (50). The clamp (25) has a wedge clamp section (29), held together in a clamping section (30b) in the basic position. For the opening and gripping setting, a part of the clamp projects from the clamping section (30b) as it is moved. The setting unit is an electromagnet (10) which, when energized by a current flow, moves the clamp (25) with its wedge clamp section (29) out of the clamping section (30b). A return spring (45) moves the clamp (25) and the wedge clamp (29) back into the clamping section (30b). A sensor registers whether a container cap (50) has been gripped or not, using a proximity sensor, a light chamber and the like, which detects the position of a unit which moves with the clamp (25). The electromagnet (10) is a component part of the sensor. The clamping section (30b) is a component part of a nipper sleeve (30), containing the return spring (45), so that the nipper sleeve (30) can be moved to the free end of the apparatus and retracted as a unit of the clamp (25) and operating rod (18). The apparatus has a tubular housing (2), with a projecting retainer sleeve (36) at the free end, which slides into the housing (2) against the action of a retainer spring (46). A micro-switch (67) registers the position of the retainer sleeve (36), in the current circuit for the electromagnet (10). The circuit is broken when the retainer sleeve (36) is not retracted into the housing (2). The clamping section (30b) is within a stripper sleeve (35), where the section (30b) projects towards the free end of the apparatus, and the stripper sleeve (35) slides on the clamping section (30b) against a stripper spring (42). An Independent claim is included for a sample container cap removal action, where the clamp (25) is presented to the cap (50) and advanced out of the clamping section (30b) with the wedge clamp (29). The clamp (25) is released so that it grips a pin projecting from the cap (50). To insert the cap (50), the operation is reversed and the clamp (25) is retracted to release the cap pin, and return to the clamping section (30b). The start of the clamp (25) movement, on both opening and closing actions, is triggered by the micro switch (67). Unsuccessful cap gripping actions are registered by the sensor which, after a given number of attempts, generates a fault signal. The fault signal triggers the collection of a fresh cap (50) from a store by the apparatus for insertion into the sample container. If this is unsuccessful, the sensor generates a further fault signal.
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