A quick-coupling device is provided for suspending a rotatable work-holding fixture from a driving device. The driving device is supported from the free end of a cantilever beam attached to the inner face of a door hinged to the framework of a thermally insulated treating cabinet. The driving device has a downwardly extending power take-off shaft terminated in an enlarged plug portion peripherally bevelled to nest in a mating connector affixed to the work-holding fixture thereby forming a friction drive for said fixture. The connector has a C-shaped slot through which the plug can be passed to support the fixture at the nesting mated surfaces. The arrangement is particularly designed for use in impact blasting of coated articles in batch operation, in which the reduced loading time is a highly important consideration.