GB715093A - Improvements in sanding, grinding, cleaning, scraping, polishing machines and the like - Google Patents

Abstract

715,093. Reciprocating motors. I.T.E.M. SOC. R.L. March 18, 1952 [March 27, 1951], No. 7002/52. Class 35 [Also in Group XXIII] A machine for treating substantially plane surfaces, e.g. floors, comprises a shallow, upwardly dished housing containing an electro-magnetic motor comprising an electro-magnet and an armature reciprical rectilinearly with respect to one another and a work plate guidedly mounted with regard to the housing and reciprocable in its own plane, the plate substantially closing the underside of the housing and being connected to the motor for reciprocation, thereby in synchronism with an alternating, pulsating or non-continuous undirectional current applied to the motor. The electromagnet motor comprises an iron core 1, preferably laminated, with pole pieces 23 and exciting coils 4, 5; the pole pieces have teeth 2<SP>1</SP>, 3<SP>1</SP> corresponding to teeth 6<SP>1</SP> on the ferro-magnetic armature 6. The core 1 is mounted, preferably resiliently, within a flat housing 16; a supplementary mass may be secured to the core to increase its mass with respect to the armature. The ends of the armature 6 are secured to U-shaped members 11, 12 which straddle the end limbs of the core; springs 13, 14 are interposed between the outer limbs of the members 11, 12 and adjusting screws 17, 18 mounted in the housing 16. The ends of the limbs of members 11, 12 are secured to a plate 15 which substantially closes the lower open end of the housing 16. Ball bearings 7, 8 are fitted between the members 11, 12 and the end limbs of th core; ball bearings 9, 10 are fitted between the plate 15 and the side limbs of the core. The ball bearings may be replaced by flat springs which supplement or replace the springs 13, 14. A stirrup 19 pivoted about an axis 19<SP>1</SP> to the opposite longitudinal sides of the housing 16 carries a handle; the stirrup may be resiliently connected to the housing 16 and/or the handle may be furnished with sponge-rubber or like vibration-absorbing hand grips to prevent transmission of vibrations from the housing to the hand of the user. One or more low-voltage electric lamps 21 are arranged in the front end of the housing 16 to illuminate the floor in front of the machine; the lamps are energized by a coil wound about a limb of the core 1. The plate 15 is so formed as to enable tools such as sanding, grinding, cleaning, scraping or polishing pads to be attached thereto; the lower surface of the plate 15 may be contoured to act as such a tool itself.