A brake mechanism has a brake disk, multiple clutches, and multiple brake assemblies. The brake disk is coaxially connected to a rotatable work table. The multiple clutches are capable of clamping the brake disk. The multiple brake assemblies correspond in position to the multiple clutches. Each one of the multiple brake assemblies has a housing, an abutting shaft inserted in the housing, and multiple elastic units received in the housing and abutting against the abutting shaft. The multiple abutting shafts of the multiple brake assemblies abut against the brake disk for stopping the work table from rotating. A hydraulic system applies hydraulic pressure inside the multiple housings of the multiple brake assemblies and forces the multiple abutting shafts to depart from the corresponding clutch, making the work table rotate again.

A rotary table includes a clamping mechanism including a piston driven by operating fluid in a direction of either of clamping and unclamping a brake disc, and a biasing means fixed by a case and the piston to always bias the piston in a direction of either of clamping and unclamping the brake disc by a recovery force of elastic deformation.

Provided is a clamp device of an indexing apparatus that indexes a main shaft, which is rotatably supported in an accommodation hole of a frame via a bearing, to a set angular position by rotating the main shaft by using a driving device. The clamp device includes a working channel that connects an air supply device, which supplies compressed air, to a pressure chamber in the clamp device. The clamp device operates to retain an angular position of the main shaft when compressed air is supplied from the air supply device. The clamp device includes a pressure transmitting portion that is interposed in the working channel and in which a piston is slidably disposed. A portion of the working channel on the pressure chamber side of the piston in the pressure transmitting portion is filled with an incompressible fluid.

A rotation table mounted on a machining table of a machine tool includes a clamping mechanism which is driven by air so as to clamp a rotation shaft, and an air purging pressure is applied into a casing so as to prevent a cutting fluid or foreign matter from intruding into the casing of the rotation table. Then, air discharged from the clamping mechanism does not pass through the casing, to which the air purging pressure is applied, and is discharged to the outside of the rotation table through a flow passage.

A clamping mechanism of rotation table device includes a shaft fixing a workpiece to an end portion thereof, a brake disk fixed to the shaft, and a clamping mechanism clamping or unclamping the brake disk by driving a piston. The clamping mechanism includes a plate spring fixed to a rear plate fixed to a casing and a piston and urging the piston in a clamping direction at all times by an elastic deformation restoring force and the plate spring is fixed to the rear plate or the piston through an annular plate.

A tooling pivot is configured to pivot and to hold a tool in a plurality of operating positions. The tooling pivot includes a bracket, a tooling plate, a motor, a brake, and a controller. The tooling plate is connected to the bracket, connectable to the tool, and rotatable. The motor is connected to the bracket and to the tooling plate and is configured to rotate the tooling plate to an operating position. The brake is connected to the bracket and is configured to hold the tooling plate in the operating position. The controller is connected to the motor and to the brake and is configured to control the motion and position of the tooling plate and to control the holding of the tooling plate. The brake is configured to release the tooling plate when the motor rotates the tooling plate to the operating position.

A numerical controller for use in a machining system including a rotary table device that has a table, a drive mechanism for rotating and positioning the table around an axis, and a clamp mechanism for restricting rotation of the table, the numerical controller being adapted to control the rotary table device according to a machining program containing a plurality of instruction statements and including an unclamp adding unit that adds an unclamp operation for releasing restriction of the table immediately before execution of a table rotation instruction statement that is contained in the machining program to designate an operation of the drive mechanism and a clamp adding unit that adds a clamp operation for restricting the table immediately after execution of the table rotation instruction statement.