GB760207A - Improvements in and relating to an electric machine having a rotating tool - Google Patents

Abstract

760,207. Drilling-machine details; tapping. SOC. DES BREVETS WAGNER. Dec. 16, 1954 [April 27, 1954], No. 36426/54. Class 83 (3). A portable electric machine for drilling, tapping, tube-beading, &c., is connected with a device 68, Fig. 5, for stopping the machine when power consumption reaches a predetermined level, and comprises an electric-motor 3 in a housing 1, Fig. 1, provided with handle 2, the motor shaft 4, Fig. 3, being connected to a tool-carrying spindle 5 through a reversing-device. Shaft 4 drives, through gears 6, 7, a shaft 8 having fixed thereon gears 9, 10, respectively meshing with gears 11, 13, the latter meshing with gear 12. Gears 11, 12 are free on spindle 5 and spaced apart by a sleeve 16, and are connectible to the spindle by a key 18. The spindle, with its forward support 30 and the key, is slidable axially between extreme positions in which the key connects gear 11 or 12 thereto. Spring 17 urges the spindle to connect gear 12 thereto, whereby the spindle is rotated in the direction of arrow #<SP>1</SP> i.e. reverse to the working direction. When a tool on spindle 5 is pressed against the work by the operator, the spindle slides to connect gear 11 thereto for forward drive. The motor is started by closing toggle-switch 54, which connects the power-supply lines 56 to the motor through lines 60 and 58, 59, through the normally-closed contact 63 of switch 53 which is situated in a housing 43 adjacent the handle. The switch-actuating-member 51 co-operates with a cam 49 on a rod 40 coupled by arm 34 to support 30, whereby when the operator presses the machine on the work, the rod slides with the spindle and thus moves member 51 which opens contact 63 and closes contact 65. The supply to one side of the motor now passes through lines 58, 66, device 68 and line 67, so that the motor is stopped when the power consumption reaches a certain level. After stopping, and when the operator releases the pressure, the motor-switch 53 will be reversed and the motor will drive the spindle in reverse through gear 12.