Tubes having indentations formed therein

Abstract

A hollow metal tube having a sharp-angled indentation that is made without removing any material and without deforming the external diameter while conserving the fiber orientation of the metal and maintaining a constant thickness of the tube. The process of forming the sharp-angled indentation comprises the steps of, providing a riveting machine, the riveting machine having an epicycloid mechanism and a spherical joint and comprising a riveting head fitted to a spindle, operating in conjunction with pressing devices and a fixed half-clamp, replacing the spindle of riveting machine with a sharp angled former adapted to the profile of the indentation to be made and to the former's sharp angle, inserting the tube on which indentations are to be made between the former and the fixed half-clamp, and activating the pressing devices to cause movement of the spindle in order to form the sharp-angle indentation in the tube.

What is claimed is:  
     
         1 . A hollow metal tube having a sharp-angled indentation that is made without removing any material and without deforming the external diameter while conserving the fiber orientation of the metal and maintaining a constant thickness of the tube, where the process of forming the sharp-angled indentation comprises the steps of, providing a riveting machine, the riveting machine having an epicycloid mechanism and a spherical joint and comprising a riveting head fitted to a spindle, operating in conjunction with pressing devices and a fixed half-clamp, replacing the spindle of riveting machine with a sharp angled former adapted to the profile of the indentation to be made and to the former's sharp angle, inserting the tube on which indentations are to be made between the former and the fixed half-clamp, and activating the pressing devices to cause movement of the spindle in order to form the sharp-angle indentation in the tube.  
     
     
         2 . A hollow metal tube as described in    claim 1   , characterized in that the spindle of the riveting machine is fitted with a holding-down clamp, the front part of which secures the tube in which indentations are to be made and holds it tightly against the fixed half-clamp.  
     
     
         3 . A hollow metal tube as described in    claim 1   , characterized in that the riveting machine effects riveting by a rotational movement and the rotational movement of the indentation former is prevented by means of a stabilizing device.  
     
     
         4 . A hollow metal tube as described in    claim 2   , characterized in that the riveting machine effects riveting by a rotational movement and rotational movement of the indentation former is prevented by means of a stabilizing device.  
     
     
         5 . A process for making a hollow metal tube having a sharp-angled indentation formed without removing any material and without deforming the external diameter while conserving the fiber orientation of the metal and maintaining a constant thickness of the tube, where the sharp-angled indentation is formed by a process comprising the steps of, providing a riveting machine, the riveting machine effecting riveting by a rotational movement and comprising a riveting head fitted to a spindle, operating in conjunction with pressing devices and a fixed half-clamp, replacing the spindle of the riveting machine with a sharp angled former adapted to the profile of the indentation to be made and the former's sharp angle, inserting the tube on which indentations are to be made between the former and the fixed half-clamp and activating the pressing devices causing movement of the spindle in order to allow indentations to be made in the tube and preventing rotational movement of the indentation former by means of a stabilizing device.  
     
     
         6 . A process for making a hollow metal tube having a sharp-angled indentation formed without removing any material and without deforming the external diameter while conserving the fiber orientation of the metal and maintaining a constant thickness of the tube, where the sharp-angled indentation is formed by a process comprising the steps of, providing a riveting machine, the riveting machine effecting riveting by a rotational movement and comprising a riveting head fitted to a spindle, operating in conjunction with pressing devices and a fixed half-clamp, replacing the spindle of the riveting machine with a sharp angled former adapted to the profile of the indentation to be made and the former's sharp angle, inserting the tube on which indentations are to be made between the former and the fixed half-clamp and fitting the spindle of the riveting machine with a holding-down clamp, the front part of which secures the tube in which indentations are to be made and holds it tightly against the fixed half-clamp, and activating the pressing devices causing movement of the spindle in order to allow indentations to be made in the tube and preventing rotational movement of the indentation former by means of a stabilizing device.