Chuck device for tool bits

A chuck device for a tool bit, the chuck device comprising:

• a spindle with a stub formed on an end thereof, a compartment being defined in the stub;
• a tube separate from the spindle, with the tube including a first section mounted around the stub of the spindle and a second section, the tube having an outer shoulder formed on an outer periphery thereof;
• the tube including a longitudinal hole, a transverse countersink being defined in the second section and communicated with the longitudinal hole of the tube, wherein the second section of the tube includes a first inner shoulder;
• a sliding sleeve slidably mounted around the tube, with the sliding sleeve including an annular groove in an inner periphery thereof and an inner shoulder formed on the inner periphery thereof;
• a ball partially received in the transverse countersink;
• a first elastic means mounted around the tube and attached between the outer shoulder of the tube and the inner shoulder of the sliding sleeve;
• an elastic member;
• and
• a follower, the follower including a first section with a receptacle therein and a second section of a size for slideable receipt in the longitudinal hole for abutting with and moving the ball out of the longitudinal hole of the tube, the elastic member including a first end received in the compartment of the stub and a second end received in the receptacle of the follower for biasing the second section of the follower to a position so as to move the ball out of the longitudinal hole of the tube, and wherein the follower includes an outer shoulder intermediate the first and second sections of the follower and of a size larger than the longitudinal hole for bearing against the first inner shoulder of the second section of the tube when the second section of the follower is biased by the elastic member to the position for moving the ball out of the longitudinal hole of the tube;
• whereby when the chuck device is in a condition not receiving a tool bit, the ball is moved out of the longitudinal hole of the tube and partially located in the annular groove of the sliding sleeve by the abutment with the second section of the follower under the action of the elastic member with the outer shoulder of the follower abutting with the first inner shoulder of the second section of the tube, and the first elastic means is in a compressed status;
• whereby when a tool bit having an annular retaining groove is inserted into the longitudinal hole of the tube to a position where the annular retaining groove of the tool bit aligns with the transverse countersink of the tube, the elastic member is compressed and the outer shoulder of the follower is spaced from the first inner shoulder of the second section of the tube, the elastic member returns and thus causes the sliding sleeve to slide along a longitudinal direction of the tube, thereby moving the ball inward to partially engage with the annular retaining groove of the tool bit, thereby retaining the tool bit in place;
• and
• whereby when the sliding sleeve is slid along the longitudinal direction of the tube to the position where the annular groove of the sliding sleeve aligns with the transverse countersink of the tube, the elastic member returns and thus ejects the tool bit in the longitudinal hole of the tube.