The Trango Co. (Boulder, CO) manufactures a complete line of rock- and mountain-climbing equipment, including ropes, carabiners, harnesses and ice axes. One of the company’s more complex products is its Cinch-model belay device, which is used either for rappelling down a cliff face or for stopping another roped-in climber from being injured in the event of a fall.
In addition to being lightweight, the small device has to be utterly reliable. The result of almost any kind of failure would likely be fatal. This, in turn, requires an utterly “bomb-proof” means of assembling the two plates that make up the body of the device as well as the locking mechanism through which the climbing rope passes when it is in use.
To solve the problem, Trango lead design engineer, Seth Murray, contacted fastening and conveying equipment manufacturer Orbitform Group (Jackson, MI), which studied the device at its applications laboratory in Michigan.
Orbitform recommended that Trango employ a solid stainless-steel rivet to attach the device’s locking hardware using a conical peen. It also recommended the company use a hollow rivet form rolled out over a set of washers with an altered eyelet peen to secure the body of the assembly.
Ultimately, Trango not only accepted both recommendations, it also installed an Orbitform B500 pneumatic orbital riveting machine to execute actual assembly.
Orbital forming, or riveting, is a method of cold forming in which an angled peen is pressed against the rivet via a rapidly rotating spindle. A robust and precise process, orbital forming can be used to crown, flare, swage, peen, roll, curl, broach, seal, retain or crimp material. The resulting joint may or may not allow rotation of the mated parts, depending on the product design. Typical solid rivet sizes range from 0.02 inch to 3 inches in diameter. Orbital riveting can be used on a variety of different substrates, including metals and plastics.
The B500 has a stroke range from 0.06 inch to 2.5 inches, adjustable in 0.001-inch increments. It has a maximum downward force of 4,400 pounds.
For more on orbital forming call 800-816-9661 or visit www.orbitform.com.