Eureka Magazine, January 2004
Plastic sleeve grips tools at lower cost
Problem: Precision machining at acceptable cost depends on swift tool changes in tool holders that can nonetheless be relied on to grip firmly and cencentrically. To meet these needs hydraulic chucks use oil pressure to force in the sides of clamping sleeve to grip tools. Hydraulic pressure is applied by turning a grub screw, which pushes in a piston. The only problems are that these devices are relatively expensive and are quite difficult to repair.
Solution: Schunk has developed and patented a tool holder that replaces the hydraulic oil round the bush with an elastomeric plastic.