GB572156A - Improved machine for grinding and polishing the edges of mirrors and other glass plates - Google Patents

Abstract

572,156. Grinding &c. edges of plate glass. THOMPSON, W. R. Oct. 13, 1943, No. 16817. [Class 60] A machine for grinding and polishing the edges of mirrors or other glass plates comprises a base 1, Fig. 2, on which is mounted a spindle 3 carrying an abrasive wheel or a series of wheels 4 of different grades, the base also carrying a frame 7 pivoted on a horizontal axis 8 so as to be movable to and from the grinding-spindle 3. The frame carries aligned bearings 9, 10, Fig. 1, parallel to the axis 8 and in the bearings are mounted two parts of a spindle 11, the part in bearing 10 being adjustable by a screw 12 so that the glass may be clamped between face plates or pads 14, 15 carried by the respective parts of the spindle. The frame 7 is tilted towards the spindle 3 by an arm 17 upon which is adjustable a weight 16. The frame 7 is made adjustable by mounting it upon cross-slides 18, 22 movable by screws 20, 24 and to enable bevelled edges to be treated, the slide 22 carries a turntable 25 which carries the frame 7 and is held in adjusted angular position by screws and slots. The spindle 11 is driven by an electric motor 35 through reduction gearing 36 and chain-andsprocket gearing. In order to avoid rounding of corners on the glass, a stop 28 is provided adjustably mounted on a guide 29 on the slide 22, and secured to the spindle 11 is a mask consisting of a disc 31 provided with radial arms 33 screwed into the disc and having screwed adjustable extensions 33a with points 33b adapted, as the spindle 11 rotates, to engage the stop 28 ; the number of arms employed and their setting correspond with the corners on the glass, and the radial adjustment of the arms is such that contact with the stop prevents contact of the corners with the abrading-wheel. During grinding &c., the slide 22 is reciprocated across the abrading- wheel by hand or power to distribute wear.