Cooper Tire's Toshulin SKS 12 VTL packs a 100-hp drive and a toolchanger that holds 12 CAT-50 tools, 3 live spindle attachments, and 12 turning tools. Photo courtesy of Pilsen Imports Inc.
A right-angle, live-spindle attachment on the Toshulin VTL lets Cooper Tire drill holes in the side of its tire-mold end plates. Photo courtesy of Pilsen Imports Inc.
Because it had to compete for valuable machining time with jobshops specializing in tire-mold work and modifying or replacing molds took over a month, Cooper Tire of Findlay, Ohio, decided to invest in its own mold shop. After five years in operation, the new shop needed more machining capacity, so the company added a VTL with live-spindle capability.The machine is a Toshulin SKS 12, and because of a live spindle, it speeds mold production for Cooper by eliminating the need to move parts to a separate machine for drilling and tapping operations. During typical mold-plate machining, the shop cut one side on a VTL, then flipped the part and machined the other side. Assembly holes were then drilled and tapped vertically and horizontally on another machine.
The Toshulin SKS has a 49-in. table diameter with 100-hp drive. Its toolchanger holds 12 CAT-50 tools, three live spindle attachments, and 12 turning tools. The live spindle is 25 hp and delivers a top speed of 3,000 rpm. Cooper uses two of these live-spindle adapters for drilling and the third for tapping. A right-angle, live-spindle attachment on the machine handles the holes in the side of the tire-mold end plate.
"Another benefit of the Toshulin is rigidity," says Dave Grant, a moldmaker at Cooper, "that gives us longer tool life." This rigidity comes from the machine's base, column, and rail — all of which are cast components. In addition, the Toshulin's high horsepower and speed let Cooper take large rough cuts and turn small-diameter holes.
Plus, the machine features a self-centering, 4-jaw chuck that quickly positions parts and reduces setup time, especially for high-speed turning. "The combined effect of all the SKS features is improved cycle times," says Grant. "We produce finished molds in only one week after design. And the accuracies in these engraved molds are much better in comparison to cast molds," he adds.
Pilsen Imports Inc.