Patent GB-567504-A (GB)
Title: Improvements in and relating to a device applied to a tool-holder spindle of machine-tool and intended for the rapid fixation and extraction of the tool
IPC: B23B31/26
Filed: 1943-06-02
Abstract: 567,504. Sockets. SOC. GENEVOISE D'INSTRUMENTS DE PHYSIQUE. June 2, 1943, No. 8868. Convention date, July 15, 1942. [Class 83 (iii)] In means for securing a tool 10 in the socket 11 of a machine spindle 1, a central rod 13 has a head 12 insertable in a recess 15 in the tool and rotatable to engage behind projections 91 of the recess so that axial motion may be given to the rod to draw the tool into the socket. The rod 13 also serves to eject the tool after release, and the drive is effected positively through a rectangular portion 11 of the tool engaging a similar recess in the socket. The head 12 on the rod is elongated to pass between the projections 91 and a neck 12b thereon has a trapezoidal section so as to limit its rotation between the projections. A screw-thread on the rod 13 engages a nut 16 on a sleeve attached to a casing 30 containing two loose barrels 29, 291 attached to the outer ends of two volute springs 24 of opposite hand whose inner ends are attached to sleeves 30<1> keyed on the squared end of a rod 28, the other squared end of this rod being splined within the rod 13. Dogs 40, 401 on the barrels 29 are normally maintained by the springs in contact with opposite sides of a pin 26 projecting from the casing 30 and also in contact with opposite sides of a stop 25<1> on a ring 25 splined to the rod 28, the parts being yieldingly held in this position by a spring detent 31 on the casing engaging a recess 31<1> on the spindle. To mount a tool in the spindle, the tool is inserted in the socket 1<1>, the head 12 being in line with the space between the projections 9<1> so that it passes into the recess 15. A clutch 20 is then pressed manually against its spring to engage clutch teeth on the casing 30 and rotated, the drive being transmitted from the pin 26 on the casing through the dog 40 and spring 24 to the rods 28, 13, thus causing the head 12 on the latter to pass behind the projections 9<1>. When rotation of the rod 13 is stopped by the neck 12b engaging the projections, further rotation of the casing rotates the nut 16 on the rod 13 and draws the bead 12 against the projections to force the tool axially into the socket. The detent 31 rides out of its recess in the spindle during this operation, and the friction of the parts maintains them in the locked position so that the casing 30 and rods &c. rotate with the spindle 1. To release the tool, the casing 30 is rotated in the opposite direction, first unscrewing the nut 16 from the rod 13, then bringing the dog 40 against the stop 25 to rotate the head 12 into line with the space between the projections 91, in which position further rotation of the rod 13 is prevented, and finally causing the casing to rotate the nut 16 in the reverse direction, through the pin 25 and dog 40<1>, to eject the tool positively from the socket. The casing 30 may be rotated from the tool end of the spindle 1 by a manually-operated clutch shaft parallel to the spindle, or the casing may be rotated by an electric motor operating through a clutch controlled by a hand lever near the tool end of the spindle, a switch being placed in the circuit to the motor so that it cannot be operated whilst the spindle is being rotated.