Springs are tough to feed. They’re flexible, and they tangle easily. Centricity Corp. has developed a machine, called the Versa-Stack, that overcomes the challenges of feeding and assembling springs and other tubular parts.
Recently, the machine was put to the test. It had to stack three cylindrical parts-a ring formed from steel wire, a metal tube, and a small or large coil spring-and place the stack into a larger assembly. The OD of each part was approximately 0.15 inch; the ID was 0.1 inch.
The Versa-Stack consists of a vertically oriented servo-driven rotary indexer fitted with a custom dial plate. Mounted radially around the edge of the plate are 35 replaceable pins. Above the plate are two vibratory bowl feeders and two spring feeders fitted with Centricity’s Feedscape systems.
The Feedscape is designed to feed parts with a high diameter-to-length ratio, such as washers, retaining rings, wave washers, Belleville springs, seals and bearings. Instead of handling parts by their outer surfaces, it handles parts by their inside surfaces. The parts are threaded onto a rod and secured by a series of alternating jaws. Parts are free to travel down the rod as the jaws open and close. This maintains control of the part at all times. There is no chance for parts to flip, shingle or fall off. The Feedscape does not require a vibratory in-line track, and tooling is inexpensive and flexible.
As the dial indexes clockwise to the 11:00 position, a ring is fed from the bowl to a Feedscape, which drops it onto a pin. The dial then indexes to the next position, where the tube is dropped onto the same pin. Next, the dial indexes to the final position, where the small spring is dropped onto the pin. If the assembly requires the large spring, the first spring feeder is bypassed and the second feeder is activated.
The stacks are held in place by an integrated retaining system until they reach the 6:00 position. At that point, the stack is threaded onto another Feedscape mechanism, which passes it off to a robot at a rate of 15 per minute.
For more information, call 330-545-5624 or visit www.centricity.net.
Editor’s note: “We Fed It” is a regular series profiling parts feeders for automated assembly. Whether it’s a vibratory bowl, a tray feeder or a flexible robotic system, if you’ve solved a parts-feeding challenge, we’d like to hear about it. Send an e-mail to John Sprovieri, editor of ASSEMBLY, at email@example.com, or call 630-694-4012.