Abstract: A bus bar connection which electrically interconnects switchboard sections by at least one electrical connection element, the bus bar connection including bellows which can be mounted between the switchboard sections, can be filled with insulting gas, and surround the electrical coupling element of the bus bar connection in a gas-tight manner.

Abstract: The grinding and polishing machine has a tool-carrying spindle (1) driven th a combined rotating and rocking action. It has a driving shaft (4) which is reciprocated axially and passes through a disc (8) which slopes at an acute angle. Above this disc is a second disc attached to the shaft, with a roller (5) attached to its periphery which rotates against the sloping disc. The tool spindle also passes through another sloping disc and through a plate (12) with a peripheral roller (16) which travels against this second sloping disc.The tool spindle carries an arm (13) with a dog projecting from it to fit into a hole in the plate to rotate the same. This plate also has a dog (14) which fits into a hole (15) in the disc attached to the driving shaft so that it transmits rotary movement for driving the tool spindle.