Image Number 2 for United States Patent #4475375.
The mandrel is a high strength mandrel for bending tubing that is easily assembled in uniform pitch or multiple pitch ring spacing or combination of each embodiments. It is a mandrel with ring segments pivoting about their own center with the ring string flexible in any direction or multiple directions simultaneously. The mandrel has a detent structure tending to hold the ring string straight during loading of the tube over the mandrel using two detent balls and one spring in each ring ball segment in a mandrel linkage design absorbing, generally, the total flex angle within the first two links thereby allowing a larger link diameter for greater mandrel strength. The individual ring ball segments rotate about the centerline of the mandrel to effectively distribute wear around the circumference of each ring segment. The mandrel components include a body, a body split link retainer, a body link, a pivot ball, two detent balls and a single detent spring within each ring ball, a connecting link to each ball unit, two link retainer elements in a split retainer in each ring ball segment, a ball segment, a lock ring segment retainer and a socket head cap screw.