Patent ID: 6260857
Filing Date: 2001-07-17
Classification: B23B,Y10S,Y10T

Abstract:
A chuck for a tool bit, mounted to a drive shaft, comprising:a spindle including,a power end of the spindlea hub end of the spindle,a forward face disposed on the hub end,an axial bore extending into the hub end from the forward face, the bore having an inner end for receiving a shank of the tool bit,a thrust washer, fixed relative to the spindle;a sleeve disposed around and rotatably connected to the hub end, the sleeve having a spindle sidewall and an outer sidewall where a space exists between the sleeve and the thrust washer;adjustable jaws protruding through the spindle radially into the bore at an acute angle and defining an opening between the jaws, whereby the jaws threadably engage the sleeve, so that rotating the sleeve about the hub causes the adjustable jaws to translate between an open position and a closed position, the open position occurring when the jaws are retracted from the bore and the closed position occurring when the jaws are extended into the bore; andan elastic member acting to bias the jaws toward the closed position and maintaining the space between the thrust washer and the sleeve wherein overcoming the spring force of the elastic member eliminates the space between the thrust washer and the sleeve.