Machine tool with automatic tool changing apparatus

Claim 2

A machine tool comprising: a base; a spindle head mounted on said base; a spindle rotatably mounted in said spindle head, said spindle having a coaxial bore and a projection at one end thereof; drawing means provided in said spindle for clamping a tool in the spindle; power means for rotating said spindle; a tool magazine for removably storing diverse tools, each of said diverse tools having a projection at the periphery thereof; tool transfer means for transferring the tool between said spindle and said tool magazine; first control means for controlling a stopping range of said projections on said spindle in order to avoid interference between said projection on said spindle and a succeeding tool when said succeeding tool is transferred to said spindle by said tool transfer means; second control means for operating said power means to rotate said spindle through at least one revolution, while the tool for use in a succeeding machining operation is held by said tool transfer means in said bore of the spindle, so as to abut the projection of the spindle on the projection of said succeeding tool; and third control means for causing said drawing means to clamp said succeeding tool in the spindle after completing the rotation of said spindle by said first control means.

Claim 3

A machine tool comprising: a base; a spinDle head mounted on said base; a spindle rotatably mounted in said spindle head, said spindle having a coaxial bore and a projection at one end thereof; drawing means provided in said spindle for clamping a tool in the spindle; first power means for rotating said spindle; a tool magazine for removably storing diverse tools, each of said diverse tools having a projection at the periphery thereof; tool transfer means for transferring the tool between said spindle and said tool magazine, said tool transfer means having at least one pair of fingers for gripping the tool therebetween; second power means for operating said pair of fingers; first control means for controlling said second power means to decrease the gripping force of the fingers when the tool for use in a succeeding machining operation is inserted into said bore of said spindle; second control means for operating said first power means to rotate said spindle through at least one revolution in accordance with the decrease of the gripping force of the fingers so as to abut the projection of the spindle on the projection of the next succeeding tool; and third control means for causing said drawing means to clamp the next succeeding tool in the spindle after the completion of rotation of said spindle by said second control means.

Claim 4

A machine tool comprising: a base; a spinDle head mounted on said base; a spindle rotatably mounted in said spindle head, said spindle having a coaxial bore and a projection at one end thereof; drawing means provided in said spindle for clamping a tool in the spindle; first power means for rotating said spindle; a tool magazine for removably storing diverse tools, each of said diverse tools having a projection at the periphery thereof; tool transfer means for transferring the tool between said spindle and said tool magazine, said tool transfer means having at least one pair of fingers for gripping the tool therebetween; second power means for operating said pair of fingers; first control means for controlling said second power means to decrease the gripping force of the fingers when the tool for use in a succeeding machining operation is inserted into said bore of said spindle; second control means for operating said first power means to rotate said spindle through at least one revolution in accordance with the decrease of the gripping force of the fingers so as to abut the projection of the spindle on the projection of the next succeeding tool; and third control means for causing said drawing means to clamp the next succeeding tool in the spindle after the completion of rotation of said spindle by said second control means.

Claim 5

A machine tool comprising: a base; a spindle head mounted on said base; a spindle rotatably mounted in said spindle head, said spindle having a coaxial bore and a projection at one end thereof; drawing means provided in said spindle for clamping a tool in said spindle; first power means for rotating said spindle; indicating means for indicating the position of the projection of the spindle; a tool magazine for removably storing diverse tools, each of said diverse tools having a projection at the periphery thereof; intermediate tool transfer means for transferring the tool between said tool magazine and an intermediate station; inspecting means for inspecting the position of the projection of the tool at said intermediate station; tool transfer means for transferring the tool between said intermediate station and said spindle; first control means for causing said first power means to rotate the spindle in response to said inspecting means for inserting the tool into the bore of said spindle through said tool transfer means without interference between the projection of the spindle and the projection of the tool; second control means for operating said first power means for rotating the spindle through at least one revolution, while the tool for use in a next succeeding machining operation is held by said tool transfer means in said bore of the spindle, so as to abut the projection of the spindle on the projection of the next succeeding tool; nd third control means for causing said drawing means to clamp the next succeeding tool in the spindle after completion of the rotation of said spindle by said second control means.

Claim 6

A machine tool comprising: a base; a spindle head mounted on said base; a spindle rotatably mounted in said spindle head, said spindle having a coaxial bore and a projection at one end thereof; drawing means provided in said spindle for clamping a tool in said spindle; first power means for rotating said spindle; indicating means for indicating the position of the projection of the spindle; a tool magazine for removably storing diverse tools, each of said diverse tools having a projection at the periphery thereof; intermediate tool transfer means for transferring the tool between said tool magazine and an intermediate station; inspecting means for inspecting the position of the projection of the tool at said intermediate station; tool transfer means for transferring the tool between said intermediate station and said spindle; first control means for causing said first power means to rotate the spindle in response to said inspecting means for inserting the tool into the bore of said spindle through said tool transfer means without interference between the projection of the spindle and the projection of the tool; second control means for operating said first power means for rotating the spindle through at least one revolution, while the tool for use in a next succeeding machining operation is held by said tool transfer means in said bore of the spindle, so as to abut the projection of the spindle on the projection of the next succeeding tool; nd third control means for causing said drawing means to clamp the next succeeding tool in the spindle after completion of the rotation of said spindle by said second control means.

Claim 7

A machine tool as set forth in claim 3, wherein said indicating means comprises: first detecting means mounted on said spindle head for indicating that the projection of the spindle is in a first stop range; a first dog mounted on said spindle for actuating said first detecting means; second detecting means mounted on said spindle head for indicating that the projection of the spindle is in a second stop range; and a second dog mounted on said spindle for actuating said second detecting means.

Claim 8

A machine tool as set forth in claim 3, wherein said inspecting means comprises: a bracket disposed at said intermediate station; a lever pivotally mounted on said bracket; an arc-shaped member secured to one end of said lever such that the same is aligned with the periphery of the tool at said intermediate station; and detecting means for indicating the engagement of the projection of the tool with said arc-shaped member beiNg mounted on said bracket in opposed relation with the other end of said lever.

Claim 9

A machine tool as set forth in claim 3, wherein said intermediate tool transfer means comprises: a support mounted on said spindle head; a shaft rotatably mounted on said support; second power means mounted on said support for rotating the shaft; a piston secured to the end of said shaft; a cylinder slidably and non-rotatably receiving said piston; an arm fixedly mounted on said cylinder; and holding means provided on the end portion of said arm for holding the tool.

Claim 10

A machine tool as set forth in claim 3, wherein said tool transfer means comprises: a shaft mounted on said spindle head; second power means for moving said shaft in an axial direction; third power means for rotating said shaft; a change arm secured to said shaft at the middle portion thereof; opposing cylinders provided on both ends of said change arm; respective pistons slidably received in said opposing cylinders, each of said pistons being provided with racks at the opposite sides thereof; a pair of fingers pivotally mounted on each end of said change arm, said fingers being provided with respective gears engaged with said opposite racks.

Claim 11

A machine tool as set forth in claim 7, further comprising: a reducing valve connected to the outer chambers of said cylinders through a changeover valve, said reducing valve and said changeover valve being respectively connected to a pressure source.

Claim 12

A machine tool comprising: a base; a spindle head mounted on said base; a spindle rotatably mounted in said spindle head and provided with an engaging means; a power means for rotating said spindle; a tool magazine for removably storing diverse tools, each of said diverse tools having an engaging means; drawing means provided in said spindle for clamping a tool therewithin; tool transfer means for transferring a tool between said spindle and said tool magazine; inspecting means for inspecting an angular position of said engaging means on said tool; detecting means for controlling a stopping range of said engaging means on said spindle in response to said inspecting means in order to avoid interference between said engaging means on said spindle and said engaging means on said tool being transferred; and control means for abutting both said engaging means on said spindle and said engaging means on said tool with each other by relative rotation between said spindle and said tool while said tool is supported within said spindle by said tool transfer means after a tool change operation is performed thereby.

Claim 13

A machine tool comprising: a base; a spindle head mounted on said base; a spindle rotatably mounted in said spindle head and provided with an engaging means; a power means for rotating said spindle; a tool magazine for removably storing diverse tools, each of said diverse tools having an engaging means; drawing means provided in said spindle for clamping a tool therewithin; tool transfer means for transferring a tool between said spindle and said tool magazine; inspecting means for inspecting an angular position of said engaging means on said tool; detecting means for controlling a stopping range of said engaging means on said spindle in response to said inspecting means in order to avoid interference between said engaging means on said spindle and said engaging means on said tool being transferred; and control means for abutting both said engaging means on said spindle and said engaging means on said tool with each other by relative rotation between said spindle and said tool while said tool is supported within said spindle by said tool transfer means after a tool change operation is performed thereby.