Patent GB-863113-A (GB)
Title: Improvements in or relating to mountings for glass-cutting tools
IPC: C03B33/10
Filed: 1959-11-10
Abstract: 863,113. Glass cutting tool mountings. COMPAGNIE DE SAINT-GOBAIN. Nov. 10, 1959 [Nov. 10, 1958], No. 38141/59. Class 56. A mounting for a glass-cutting tool comprises pressure fluid operated means for applying pressure to a movable element and pressuretransmitting spring means interposed between the element and the tool. A cylinder 1 with flanges 7, 8 is secured to plates 9, 10 formed with apertures 5, 6 into which pipes are screwed for the admission of air at atmospheric or higher pressure. The cylinder piston 2 forms part of a tube 11 guided between pairs of rollers 12 and shoulders 15, 16 on the tube act as stops. Sliding freely within tube 11 is a rod 21 fixed at its upper end to a bar 22, to which a second rod 23 is secured and is a functional fit in the lining 25 of a bore 24 in plate 10 to prevent turning of rod 21. The lower end of rod 21 fits in a sleeve 26 in a locking ring 20 on the end of tube 11 and has a head 27 with an aperture by which the cutting tool is keyed thereto. A spring 3 is engaged between abutments on the ring 20 and on a washer 28 bearing on the head 27. The cylinder 1 is secured in a carriage 30 by which it is moved during the cutting operation. The particular cutting tool disclosed is provided with sensing mechanism for controlling the admission of air to the cylinder 1. An L- shaped bar 33a, 33b is secured by arm 33a to a sleeve 32 which engages over the head 27 and is keyed thereto. A second bar 36 has a bifurcated end by which it is pivoted at 37 to the arm 33b, the other end resting against a screw 34 positioned by nuts 35 on the free end of arm 33a to give the required inclination of bar 36. The cutting diamond 4a is in a mount 31 keyed. to bar 36. The sensing mechanism includes an assembly 38 pivoted at 39 to bar 36 and an assembly 40 pivoted at 41 to assembly 38, the assemblies 38, 40 carrying rollers 42, 43 to roll on a glass sheet 44. A spring 47a presses assembly 38 in the counter-clockwise direction against a stop 48 and a spring 47b between the two assemblies presses assembly 40 clockwise till a switch operating finger 46 thereon engages a microswitch 45 on assembly 38. In operating air is admitted to cylinder 1 through apertures 5, 6 at the same pressure, the air through aperture 5 pressing on the surface 18 of the piston 2 and that through aperture 6 on the smaller surface 19 so that the piston 2 descends until the rollers 42, 43 press on to the glass 44 and thereby pivot apart the finger 46 and microswitch 45 to trip a circuit to start an automatic cycle in which the electromagnetic valve controlling the admission of air through aperture 6 is closed so that the piston is locked with the diamond 4a just above the glass. The aperture 6 is then placed into communication with the atmosphere and the aperture 5 is supplied with compressed air at the cutting pressure so that the diamond 4a descends on to the glass. The carriage 30 is then moved so that the glass is scored. At the end of the glass, the roller 42 tilts over the edge so that the finger 46 is pivoted to engage the microswitch 45 to reverse the air supply to raise the piston 2 after a short period which allows the diamond to finish the cut close to the edge. The carriage 30 is then returned.