A twisting sleeve or collar which is cylindrical and has an elongated guide or channel fluidly connecting the outer annular wall with the inner annular wall of the sleeve is disclosed. A connector having at least one open end and an elongated slot with a floor and a pin guide through the floor is further disclosed. The pin guide is open to the inside of the connector. Between the sleeve and the slot is a pin, having a pin head visible through the elongated guide, and two opposing spring arms of a size and shape to fit in said slot, and a pin body which movably fits inside pin guide.

A shrink fit tool holder assembly has a holder, a tool, and two fastening units. The holder has an axis, an inserting portion, and a fastening hole defined through the inserting portion. The inserting portion has two assembling holes communicating with the fastening hole. Each one of the two assembling holes has an extending axis inclined relative to the axis of the holder. The two extending axes of the two assembling holes are a pair of skew lines. The tool has a shank section inserted in the fastening hole of the holder. The shank section has two engaging grooves. The two fastening units are respectively inserted into the two assembling holes and respectively engage with the two engaging grooves to prevent the tool from sliding or rotating relative to the holder.

A twisting sleeve or collar which is cylindrical and has an elongated guide or channel fluidly connecting the outer annular wall with the inner annular wall of the sleeve is disclosed. A connector having at least one open end and an elongated slot with a floor and a pin guide through the floor is further disclosed. The pin guide is open to the inside of the connector. Between the sleeve and the slot is a pin, having a pin head visible through the elongated guide, and two opposing spring arms of a size and shape to fit in said slot, and a pin body which movably fits inside pin guide.

A twisting sleeve or collar which is cylindrical and has an elongated guide or channel fluidly connecting the outer annular wall with the inner annular wall of the sleeve is disclosed. A connector having at least one open end and an elongated slot with a floor and a pin guide through the floor is further disclosed. The pin guide is open to the inside of the connector. Between the sleeve and the slot is a pin, having a pin head visible through the elongated guide, and two opposing spring arms of a size and shape to fit in said slot, and a pin body which movably fits inside pin guide.

Hydraulic expansion chuck with a basic body, with an expansion bush which is received in the basic body and defines a reception space for a tool to be clamped, and with a pressure chamber which is delimited between the expansion bush and the basic body. A securing pin extends through the basic body and the expansion bush into the reception space. Also broadly contemplated herein is a method for producing a hydraulic expansion chuck via: providing a basic body with a blind hole, into which an internal thread is cut. An expansion bush is then soldered into the basic body. Finally, an orifice is made at the bottom of the blind hole and extends through the material of the expansion bush into a tool reception space which is delimited in the expansion bush.

Hydraulic expansion chuck with a basic body, with an expansion bush which is received in the basic body and defines a reception space for a tool to be clamped, and with a pressure chamber which is delimited between the expansion bush and the basic body. A securing pin which extends through the basic body and the expansion bush into the reception space. Also broadly contemplated herein is a method for producing a hydraulic expansion chuck via: providing a basic body with a blind hole, into which an internal thread is cut. An expansion bush is then soldered into the basic body. Finally, an orifice is made at the bottom of the blind hole and extends through the material of the expansion bush into a tool reception space which is delimited in the expansion bush.

A hydraulic expansion chuck includes a basic body, an expansion bush which is received in the basic body and defines a reception space for a tool to be clamped, and a pressure chamber which is delimited between the expansion bush and the basic body. A securing pin is provided, which extends through the basic body and the expansion bush into the reception space. A method for producing a hydraulic expansion chuck is disclosed. First, a basic body is provided with a blind hole, into which an internal thread is cut. Then, an expansion bush is soldered into the basic body. Finally, an orifice is made at the bottom of the blind hole and extends through the material of the expansion bush into a tool reception space which is delimited in the expansion bush.

A bit holder has a shank at a proximal end thereof and a blind bit-accepting hole at a distal end thereof, shaped to receive a correspondingly-shaped tool bit. The bit holder has at least one locking mechanism which includes an angled path defined in the bit holder, opening into a side of the bit-accepting hole, extending away from the bit-accepting hole in a proximal direction at an acute angle A from a central axis. A locking element is slideable in the path. A sleeve around the shank is biased towards the bit-accepting hole by a spring, such that a distal end of the locking element extends slightly into the bit-accepting hole. Moving the sleeve towards the proximal end of the bit holder retracts the locking element from the bit-accepting hole, thereby releasing the bit. A spring-loaded plunger in the blind hole may be used to eject the bit automatically when the locking mechanism is released by the sleeve.

What is provided is a hydraulic expansion chuck (1) with a central clamping opening extending along a longitudinal central axis (5) for receiving and clamping a tool shank and a pressure chamber, which surrounds the clamping opening and to which pressurized fluid can be applied, and which is delimited from the clamping opening by means of a radially elastically deformable dividing wall (34). A plurality of expansion joints (38), which are distributed around the clamping opening and which extend along the longitudinal central axis (5) and which are open towards the clamping opening and closed towards the pressure chamber, are formed in the dividing wall (34).