| 摘要 |
The particular machine described has a series of main collets mounted in an indexable drum, each main collet having an associated reciprocable feed tube carrying at its rear end a one-way feed collet employing wedging elements in the form of spring-loaded balls carried in inclined bores of the feed collet body, the feed tubes and feed collets being indexed with the main collets and with a reel-type bar holder. When the collets are arranged to feed non-round bar stock each feed collet is keyed to its associated main collet to enable non-rotating bar stock to be introduced into a rotating feed collet from the bar holder, to be rotated by the feed collet, and then fed through the main collet without stopping the main collet. An axially movable and retractable stop is provided at the feeding station to ensure that an adequate length of bar stock is gripped by a main collet during subsequent machining. Each feed collet is formed in two parts which are capable of axial movement apart against spring-biassing to accommodate the axial movement of the stop at the feed station. At the station preceding the feed station an attempt is made to move the feed collet there towards its associated main collet which is in its closed condition. If a bar is present then movement of the feed collet will not be permitted, but if movement is allowed due to the absence of a bar this is indicated to the machine operator so that the operator can load a new bar into that feed collet. All of the machine mechanisms associated with feeding bar stock are drived from the principal prime mover of the machine. It is unnecessary to provide an automatic mechanism for feeding the bar-loader. |
