This invention relates generally to apparatus used for forming a work piece and more particularly to a novel die for a tube pointing machine.
It is well known in the tube fabricating arts to reduce the diameter of a tube by forcing the tube through a drawing machine. In order to facilitate initial insertion of the tube into this drawing machine, the diameter of a leading end portion thereof is first reduced. This latter practice is commonly referred to as tube pointing.
Generally speaking, machines provided for the tube pointing operation utilize a plurality of relatively movable forming dies to rather abruptly reduce the diameter of an end portion of a tube. These forming dies are often mounted with work engaging surfaces movable inwardly about a common axis relative to the tube so as to quickly yet effectively reduce the size of a leading portion of the tube by causing it to fold in upon itself.
Since this tube pointing operation is auxiliary to the diameter reduction operation, it is desirable to accomplish this pointing as quickly and simply as possible with but a minimum of handling of the tube required. Moreover, it is important that tube pointing machinery be capable of fairly rapid and frequent operation and yet remain highly reliable over a relatively long period of demanding and repetitive use.
One problem which has been encountered with prior art tube pointing machines lies in providing adequate support for the tube throughout the pointing operation, both peripherally and longitudinally. The provision of such adequate support tends to minimize the amount of handling necessary, and moreover permits conveniently location of the machine immediately adjacent the related tube diameter reduction machinery. Both of these tendencies also help to optimize the speed with which the entire tube forming process may be carried out. Moreover, such positive gripping of the tube during the pointing operation avoids any need for auxiliary handling machinery or equipment. Advantageously, therefore, with the present invention, a single worker may readily and safely insert the tube to be pointed into the novel apparatus of the invention, without the aid of any additional positioning or handling machinery.
Additionally, some prior art pointing devices have encountered problems with portions of the tube breaking off, extruding or otherwise migrating into gaps between moving dies or other related moving parts of the machinery. Needless to say, such an occurrence can damage the tube forming machine, and is therefore most undesirable.