Patent Number: 047587261
Section: summary

The invention relates to a collimator exchanging system for moving a collimator between a measuring position and a storage position. A collimator exchanging system of this kind is described in Journal of Nuclear Medicine, Vol. 16, December 1975, pp. 1195-1196. As is mentioned therein, the system disclosed is not suitable for comparatively heavy collimators. Moreover, there is no facility for storing the collimator in a storage position. Such a facility is extremely desirable notably for heavy collimators. Using known exchanging systems, the mounting of the collimator in an active positon, for example, as a collimator for a radiation detection apparatus, such as a gamma camera, is a rather cumbersome operation and unambiguous positioning is not fully ensured. On the other hand, the storage of a collimator in a storage position is not ideal because an additional operation is required for securing the collimator. When the latter operation is omitted, which is not uncommon, the collimator could, for example, drop out of the storage position. It is an object of the invention to mitigate these drawbacks. To achieve this, a collimator exchanging system of the kind set forth in accordance with the invention is characterized in that from a position of adjustable height in a cart the collimator can be coupled only in a given orientation with respect to the measuring position, or the storage position, from a fixed position in the cart to either an active position or a fixed storage position by means of a simple operation. The exchanging system in accordance with the invention is constructed so that the collimator can be coupled only from a fixed orientation, so that the occurrence of accidents or errors during the exchange is precluded. Because uncoupling as well as coupling is realized by a simple operation and by means of a single cooperating system of means, a less stable intermediate position is avoided and the collimator cannot be coupled in an incorrect orientation. In a preferred embodiment the active device, the cart, and the storage device include a catching device which cooperates with a locking mechanism of the collimator. The active device notably includes at least two and preferably three locking pins, for example, mushroom-shaped pins, which cooperate with locking sockets in the collimator. The locking sockets may be constructed, for example, to be rotatable and be provided at the top as well as the bottom with locking holes which cooperate by a catching mechanism of the cart with locking pins of an active device or a storage device. A coupling mechanism of a further embodiment includes a ring which is secured to the collimator, and which couples and uncouples the collimator to and from the active device or the storage device by rotation, and hence to and from the cart. Notably two locking holes which are situated one over the other now cooperate so that in a fixed position of the collimator they couple the collimator to the cart in a first rotary position and couple the collimator to one of the devices in a second rotary position. For the fixed mounting of the collimator in an active position, a preferred embodiment includes a resilient clamping device which is activatable by a clamping effect between the collimator on the cart and a relevant part of the active device, and which enables coupling only in the activated condition.