Patent GB-1309561-A (GB)
Title: Automatic lathe
IPC: B23B7/06
Filed: 1970-05-20
Abstract: 1309561 Automatic lathes MATSUSHITA ELECTRIC INDUSTRIAL CO Ltd 20 May 1970 [26 May 1969] 24434/70 Headings B3B and B3T An automatic lathe for producing machined parts from bar-stock comprises a cam operated work feeding means 60 which includes a solenoid operated reciprocating gripper device 62, 63, a plurality of cam operated tool holders 83-85 which are displaceable radially with respect to the axis of rotation of the bar-stock, a rockable tool supporting carriage 82 carrying tools 77 and 78 and a pivotable tool mounting 127 in which are located axially displaceable tools 120, 121. The cams 92, 93, 98, 99, 100 and 123 which effect the movement of the tools are mounted on a cam-shaft 89 and are rotatable therewith by a stepping motor 87 connected to the cam-shaft by way of gears 90, 91. The work feeding means 60 is operable to traverse the bar-stock during a machining operation and is actuated by cam 72 and levers 74, 66 from a motor 67 by way of gears 69, 70, the motor drive being independent of the drive for the tool operation. The operative surfaces of the cams 92, 93, 98, 99, 100 are formed in accordance with an Archimedes curve wherein equal angular displacement of the cams effect equal linear displacements of the tools. The lathe is electrically controlled from information received and stored from punched or magnetic tape which controls the operation of the stepping motors 87 and 67. The cams for operating the tools 79 to 81 are each provided with a cam surface formed by two successive Archimedian curves which effect rapid approach and tool cutting feed respectively. Since cams of this type always have a large fall when rotated continuously and which constitutes a steep gradient, as indicated at C and A in Fig. 8, which cannot be followed, detector means 132 is provided on the cam shaft 89 and which includes limit switches positioned just before point A and at point C to emit a signal when the cam is in either of these positions to stop the stepping motor 87. A similar detector 131 is provided to indicate the position B on the cam surface corresponding to the commencement of the slow in-feed of the tools and effect subsequent control of the motor 87. In the light of the cam form referred to, the cam followers 104-106 associated with respective cams 98-100 are in the form of a member 104 (105 or 106) which is releasable by the displacement of a locking pin 110 by a switch actuated solenoid 107, 108. Therefore, interference between tools and cuttings is prevented. Similar operation of the cam follower 124 associated with the drum cam 123, is provided for the operation of the axially displaceable tools 120, 121. The rockable tool support 82 is actuated by a pair of simultaneously rotating cams 92, 93, the support being biased by a spring 97 unless restricted by a stop member 118 and whereby either of the followers 94, 95 may be brought into engagement with its respective cam both followers having a releasing mechanism as described with reference to the other cams 98-100. Means is also provided for the automatic gauging, transfer and collection of completed parts. A finished part 156 (Fig. 20), is parted off from the bar-stock 61 and retained in collet member 179 at the end of a swinging arm 182, the pivoting of the arm about shaft 183 moves the part to a gauging device having jaws 184, 185. The gauging device is electrical in operation and any deviation from the required size is indicated as a variation in voltage, the signal produced being compared with the coded requirement. The finished part is then ejected from the swinging arm and drops into a pivotable shoot 159 which, in order to separate the parts from the chips, is only located beneath the part when the machining operation is completed. The finished part is then passed to shoot 162 which is pivotable so as to pass the part 156 to either of shoots 163 or 167, both of which are themselves pivotable by solenoid means 165, 166. The finished parts may therefore be selectively separated into any one of containers 164, 174-176. The whole machine operation may be automatically controlled in accordance with a predetermined sequence determined by a coded input in the form of punched or magnetic tape.