Method and apparatus for making step wall tubing
US4788841A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 18, 1987 |
| Grant date | Dec 6, 1988 |
| Priority date | — |
| Expiry date | Nov 18, 2007 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21C37/16
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Apparatus and method for providing the wall of an elongated metal tube with a plurality of precisely located thick and thin wall portions lengthwise on the tube. The apparatus includes a drawing die having a relatively wide mouth, and a drawing bulb located in the tube to be drawn and for entering the die when the tube is pulled through the die. The bulb has a constant cross section and a relatively square nose. An actuator is provided for inserting the nose of the bulb into the mouth of the die to provide each thin wall portion and for withdrawing the nose from the die to provide each thick wall portion while drawing the tube. An electrical controller controls the actuator, and a distance measuring device outputs signals to the controller that are representative of precise increments of tube travel. The controller, in response to the signals, is effective to precisely control the occurrences of bulb insertion and withdrawal. The speed and accuracy of the apparatus make the step wall tube products cost competitive with traditional straight wall products while saving weight and raw material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.