Coupling for rotary machine for cleaning hard surfaces

摘要

The machine has a disc-shaped tool turning on a vertical axis and with a central opening forming a detachable bayonet coupling to an inserted driving hub. Radial protrusions on the latter fit in axial grooves at the opening. At both sides of each groove are radial supporting faces at the top of the opening and protruding into it and which engage under the protrusions on the hub when this is turned. At their sides furthest from the grooves, the supporting faces have stop faces struck by the hub protrusions on rotation, and they also contain stepped recesses. Each of the latter accommodates a protrusion (13) on the hub (8), and the latter and the tool (7) slide axially in relation to each other at least for the height of the recess (25). The latter can be enclosed on one side by a stop face (22), and between the groove (20) and the recess there can be a slide face (23) for the hub protrusion. There can be a chamfer leading to the groove on each side at the top. A stop (12) can be provided on the hub, limiting the depth of insertion into the tool, while the hub protrusions are clear of the supporting faces (21) in the deepest position.