Clamping device for rotary index device for machine tool

A clamping device (2) for a rotary index device for a machine tool, the rotary index device (1) including a rotary shaft (5), a clamp disc (11), and clamping means (6), the rotary shaft (5) being rotatably provided in a housing (3) and to whose one end portion a member that is rotationally driven (4) is mounted, the clamp disc (11) being mounted to the rotary shaft (5) so as to be incapable of rotating relative to the rotary shaft (5), the clamping means (6) pressing the clamp disc (11) against a clamp surface (12), integrated to the housing (3), and clamping the clamp disc (11) in cooperation with the clamp surface (12),

• in which the clamping means (6) is normally urged towards the clamp disc (11) by urging means (10) to maintain an index position of the member that is rotationally driven (4), and in which, when an indexing operation is performed, unclamping means (13) stops the urging means (10) from urging the clamping means (6) to cause the member that is rotationally driven (4) to be capable of rotating,
• wherein the clamping means (6) includes:
• a fixing portion (7) fixed to the housing (3);
• a resiliently deformable supporting portion (8) joined to the fixing portion (7) at one end thereof, a pressing portion (9) having a face that opposes the clamp disc (11) being provided at the other end thereof;
• and
• the urging means (10) that normally urges the supporting portion (8) towards the clamp disc (11) to realize a state in which the clamp disc (11) is pressed by the pressing portion (9), the urging means (10) extending in a circumferential direction along a circumference having an axial line of the rotary shaft (5) as center, and
• wherein the clamping means (6) is a spring member (14) in which the fixing portion (7) and the supporting portion (8) are integrally formed with each other, and in which the supporting portion (8) functions as the urging means (10).