Patent GB-1022194-A (GB)
Title: Machine tool with tool changer
IPC: B23Q3/157
Filed: 1963-06-11
Abstract: 1,022,194. Machine tool details. KEARNEY & TRECKER CORPORATION. June 11, 1963 [Aug. 30, 1962], No. 23183/63. Headings B3B, B3C, B3K and B3N. A machine tool comprises a power-driven spindle 169 and means 40 for interchanging a tool in the spindle with a tool in a storage device 32. The tool change arm 40 is mounted on a shaft 44 rotatable to interchange the tools by an hydraulic motor 112 through worm gearing 104 and a splined connection 98. The shaft 44 can be advanced axially to withdraw the tools from their sockets by a fluid pressure device 122 connected to a thrust block 96. As the shaft is advanced, fluid is also supplied to a piston 145 carrying a stop 49, which first abuts the rear face of the arm 40, is advanced to its further extent as the arm 40 is rotated out of contact, and finally stops the arm after it has rotated 180 degrees. The tool spindle 169 contains a rod 196 urged rearwardly by springs 202 to close a collet 194, the collet being released when a pressure-fluid device 198 is actuated. The tool storage drum 32 is rotated by a fluid-pressure motor and worm gearing. When an indexed position is reached, a dog 251 trips a lever 262 and then actuates a switch 271. The switch causes reversal of the drum's rotation until the dog 251 abuts the lever 262. Each tool, or combined tool and socket 35, is retained in its recess in the drum by a spring- pressed detent 281. The tools are positioned in the drum in the order in which they are to be used, so that only the first to be used needs to be identified. When the machine is started, the drum rotates without interruption until a switch 286 is actuated by a projection on the holder 35B. The reverse switch 271 is then energized so that the drum stops in the correct position. As the tool change arm 40 is rotated from the horizontal position Fig. 1, (not shown) to the vertical position, cams 312A, 313A depress plungers 310, Fig. 2 (not shown), to allow spring-pressed plungers 320, Fig. 9 (not shown), to move as bars 325 thereon snap over tools held respectively in the drum and the spindle. When the arm has been axially advanced and has rotated free of the cams 312A, 313A, the plungers 310 are re-engaged with the plungers 320 to prevent disengagement of the tools. As the arm 40 is retracted, the stop 49, being engaged in a recess 350A in the arm, causes the piston rod 140 to act as a guide to ensure that the tools are placed correctly in their sockets. When the tools have been interchanged, the arm is rotated back to a parked position. A signal to change tools can be given manually or by programme and first causes the spindle drive to be unclutched and a spindle brake to be actuated. Each cycle of changing a tool is controlled by a push-button and a bank of four stepping-switches. In a modification, the sockets 503, Fig. 13 (not shown), in the storage drum are pivoted to allow more tools to be accommodated. The sockets each have two rollers engaging a track, a part of which can be pivoted downwardly at the operative station to move the tool to a horizontal position. The socket engages a stop 572 to position the tool correctly. A holder may consist of an automatically-reversing tapping device including a flanged part 581, Fig. 16A (not shown), which is notched to engage a spring catch 580 to prevent rotation of the part. In a further modification, the drum is replaced by a single tool storage socket 806, Fig. 19 (not shown). Reference has been directed by the Comptroller to Specifications 916,501, 916,503 and 916,504.