GB889179A - Improvements in or relating to electrically driven bending apparatus - Google Patents

Abstract

889,179. Control of A.C, motors; controllers. SOC. GENERALE DE MATERIEL D'ENTREPRENEURS. Feb. 11, 1960 [July 28, 1959], No. 4797/60. Class 38 (3). [Also in Group XXII] Apparatus for bending a bar 2 round a roller 3 comprises a rotatable platform 4 carrying a bending-pin 5 in one of several holes 6 at various distances from the centre of the platform. An abutment pin 9 is fixed to the top of the machine for restraining movement of the bar. The platform is turned in a forward direction when switch 15 is closed to energize relay 12 in circuit with motor 7, the coil 14 of relay 12 being in series with interlock contacts 16 on reverse relay 33. The relay 12 has holding contacts 17 and interlock contacts 37. When the platform turns, it drives a shaft with a number of discs carrying abutments for operating switches 34, 40 and 49 the discs being driven through releasable clutches for adjusting the angular positions of the discs on the shaft in order to predetermine the angular positions of the abutments relative to the platform over a continuous range, Fig. 2 (not shown). At the end of a bending operation, switch 34 is displaced to engage contact 35 whereby relay 12 is deenergized and relay 33 is energized for reverse operation of the motor. At the end of the return motion, switch 40 is opened to deenergize relay 33 and stop the platform in its initial position. The machine may be adapted for bending bars through different angles by the provision of a further control switch 41 and auxiliary relay 43. Closure of switch 41 energizes relays 43 and 12, the latter remaining energized when switch 34 is actuated because the shunt contacts 47 are closed. The forward movement continues until switch 49 is displaced to reverse the motor, return movement then being effected until switch 40 is actuated. The switch 49 is shunted by contacts 48 when the machine is under the control of switch 15. When the bars to be bent are introduced into the machine from the left instead of from the right, the abutment 9 is re-positioned, and the platform 4 is rotated by half a turn whilst the discs carrying the switch-operating abutments are prevented from rotating. This rotation is effected by switch 52 which closes contacts 53 to energize relay 12. The original situation is re-established by operating switch 54 to energize relay 33.