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U.S. Department of Energy
Office of Scientific and Technical Information

Gamma counter shutter assembly. [for gamma counting system]

Patent ·
OSTI ID:7353181

A shutter assembly for a radioactivity measuring apparatus is described having a sample counting chamber, the assembly having a bulky solid lead cylinder with a sample access port extending therethrough for alignment with the sample chamber. The cylinder is rotated by a Geneva wheel arrangement having a drive wheel with a plurality of equi-angularly disposed pins perpendicular to the surface thereof engaging radially extending open-ended slots in a driven wheel secured to the lead cylinder for concurrent rotation therewith. The drive wheel is rotated at a constant speed with the driven wheel accelerating as a pin traverses the slot from the open end toward the driven wheel center and then decelerating as the pin traverses the reverse direction to provide precise positioning with adjacent pins engaging the open ends of adjacent slots in the stop position of the cylinder. 8 Claims, 3 Drawing Figures.

Assignee:
Beckman Instruments, Inc.
Patent Number(s):
US 3932752
OSTI ID:
7353181
Country of Publication:
United States
Language:
English