A hydraulic tool holder comprises a body and a piston assembly. The body defines a fluid reservoir adapted to hold a fluid. The piston assembly comprises a piston pin movably arranged within the body and including a first end in communication with the fluid reservoir, and a visual indicator. An elastic element of the piston assembly biases the piston pin toward the fluid reservoir with a predetermined elastic force. The predetermined elastic force is selected such that the visual indicator is visible from an exterior of the body when a pressure of the fluid in the fluid reservoir reaches a predetermined minimum threshold level.

A hydraulic chuck may include an expansion sleeve, a plurality of pistons, and an actuator ring. The expansion sleeve may include a bore. The plurality of pistons may be axially mounted in at least one piston chamber of the expansion sleeve. The actuator ring may be rotatably mounted relative to the expansion sleeve. The actuator ring may be configured to actuate the plurality of pistons in the at least one piston chamber to hydraulically expand the expansion sleeve to provide a varying clamping force within the bore.

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 lathe chuck for aluminum alloy hubs, including a base plate, a base, a slide plate, positioning posts, etc. The base plate is connected together with the base by screws, forming a body of the lathe chuck for hubs; a tapered mounting hole is provided under the base plate so as to fit with a machine tool; the upper and lower ends of the positioning posts are mounted on the base plate and the base by screws respectively, which can increase mounting strength of the base plate and the base; the slide plate is in sliding fit with the positioning posts by copper sleeves, and may slide upwards and downwards along the positioning posts; the large pull rod is fixed on the slide plate by screws and may drive the slide plate to move upwards and downwards.

The invention relates to a device controlling a chuck of a machine tool and an auxiliary equipment thereof, thereby facilitating a setup work. Gripping and releasing of a work are confirmed by registering a work gripping position and a work releasing position of a chuck, a kind of a used chuck, and a gripping direction of a work in an external memory device every product type of the work, transferring the work gripping position and the work releasing position in correspondence to the product type to a controller of a machine tool displaying them on a display of an operator control panel, detecting a position of an operation rod opening and closing a claw of the chuck by a stroke sensor, referring to the gripping position of the work, and detecting conformity of the detecting position and set values of the work gripping position and the work releasing position.

The invention relates to a device controlling a chuck of a machine tool and an auxiliary equipment thereof, thereby facilitating a setup work. Gripping and releasing of a work are confirmed by registering a work gripping position and a work releasing position of a chuck, a kind of a used chuck, and a gripping direction of a work in an external memory device every product type of the work, transferring the work gripping position and the work releasing position in correspondence to the product type to a controller of a machine tool displaying them on a display of an operator control panel, detecting a position of an operation rod opening and closing a claw of the chuck by a stroke sensor, referring to the gripping position of the work, and detecting conformity of the detecting position and set values of the work gripping position and the work releasing position.

A hydraulic chuck assembly includes a tool support member having an axial bore. An expansion sleeve is received within the axial bore of the tool support member. The expansion sleeve comprises an inner surface, an outer surface and a front flange extending radially outward from the outer surface. A primary pressure chamber is formed between the axial bore of the tool support member and the outer surface of the expansion sleeve. A flexibility of the expansion sleeve is increased by removing material from the expansion sleeve in a vicinity of a front braze ring and a rear braze ring, thereby decreasing a maximum stress in the front braze ring and the rear braze ring. The material is removed by undercuts that form secondary pressure chambers in fluid communication with the primary pressure chamber.

Provided is a holder device that uses a pressure medium suitable for gripping a long and thin grasped object, the device eliminating need for a small-diameter machining for a device body and allowing use of a material suitable for sleeve deformation at a portion where a pressure chamber is formed. A holder device capable of deforming in a radial direction for fastening a grasped object 7 through a function of a pressure medium, includes a device body 2, a sleeve 3 disposed at a leading end of the device body 2 for gripping the grasped object 7, a pressure chamber 8 formed circumferentially in the sleeve 3, and a support portion 9 provided continuously from the device body 2 for forming the pressure chamber 8 together with the sleeve 3.

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.

For enabling accurate and efficient cutting work on a narrow area, in a hydraulic chuck configured such that a pressurization fluid pressurized by a push member (8b) is fed through a pressurization passage (8) to a pressurization chamber (6) to reduce a diameter of an elastic deformable part (2b), the hydraulic chuck includes a body (1) having a flange accommodating part (5a) opening at a small-diameter portion at a tip end of the body and a sleeve accommodating part (5b) opening in a bottom face of the flange accommodating part (5a), and a sleeve (2) having a hole (2a) in which a gripped object is inserted, the sleeve being engageable and insertable with/to the sleeve accommodating part (5b) from a leading end side of the flange accommodating part (5a), the sleeve (2) forming the pressurization chamber (6) reserving therein an amount of the pressurization fluid between this sleeve (2) and the sleeve accommodating part (5b), the sleeve (2) having a flange (7) engageable with the flange accommodating part (5a).