by Jon M. Casey

One look at the patented Spring Grizzly Fingers manufactured by DEMI Equipment of Cresbard, SD, reveals the effectiveness of this innovative aggregate screening system by what isn’t there, rather than by what is. As seen in the side-by-side comparison photos here, a conventional grizzly screen regularly fills up with marginally oversized material that requires manual removal by a plant worker, usually more than once per day. With the installation of the Spring Grizzly Fingers, no longer does an employee need to enter the crusher infeed area to remove rocks with a sledgehammer. Not only does this save production time, it is also much safer since the need for endangering a worker is no longer needed.

“The Spring Grizzly Fingers act like a tuning fork,” says Tim Holmberg, inventor and manufacturer of this technology. “I expanded the idea from a similar system that is used in the C&D Recycle/trash industry. Since this application is designed for use in the aggregates industry, this screening technique required considerable development to get it to work reliably. We have a special design and metallurgical formulation for the fingers so that they will be durable and have the correct ‘spring’ in them. Rocks don’t stick between the bars; they just bounce off and keep moving.”

Holmberg said he has found other similar products on the market, but they do not work as well as his design. He said that his years of developing and perfecting the performance of his Spring Grizzly Fingers, makes them the most productive and reliable units on the market. He said he originally invented the fingers in 2004 or 2005, but it has taken time to perfect and patent his product.

“The patent came through in 2014,” he said. “The core of DEMI Equipment’s business is the Spring Finger technology. Customers often find a thirty to forty percent increase in productivity just by replacing their OEM Grizzly with one of ours. Instead of needing to buy a larger primary crusher, we can offer them a “pennies on the dollar” alternative that proves equally effective. We have recently documented one customer whose production has increased from 1400 tons per hour to upwards of 2200 tons per hour, with our fingers. Our Spring Fingers regularly last up to a year or more, and they can be changed by hand.”

For more information on DEMI Grizzly Spring Fingers, visit www.demiequipment.com or contact Tim Holmberg at tim@demiequipment.com or Cell: 605-290-7106.