Abstract: In an apparatus for automatically feeding bar stock material into a numerically-controlled automatic lathe, a bar is rotatably clamped and borne by the clamp jaws of several bearing clamps disposed in a row at intervals along the bar and orientated at respectively different angles about the bar, each clamp jaw comprising three pulleys in triangular formation and an endless belt supported on these pulleys, one of which is driven, the bar being clamped between a span of the belt between two pulleys of one jaw and that of the other jaw of each bearing clamp. The bar is thus held at clamping positions that vary helically about the bar as it is fed by a feed pipe into the lathe.

Abstract: In a machine tool having a horizontal, hollow main spindle having therein a main chuck for gripping a bar stock and confronting at a front thereof a machining zone, into which the forward end of the bar stock is intermittently fed through the main chuck from the rear for every cycle of machining by a selected tool mounted on a tool support structure on feed slides and brought into the machining zone to carry out machining of the bar stock, a bar end support engages and supports the forward end of the bar stock at the start of each intermittent feeding thereof and stably guides the same fully into position for machining, unrelatedly to the rotation of the main spindle, whereby the cyclic bar feeding and machining operation can be continuously carried out without stopping the main spindle. Means are provided whereby bar stocks of circular cross-sectional shape and any shape other than a circle can be thus machined.