Patent GB-885624-A (GB)
Title: Process of and machine for cutting plates
IPC: B23D47/08
Filed: 1960-07-27
Abstract: 885,624. Severing by grinding. FOUQUET, E. July 27, 1960 [July 27, 1959], No. 26148/60. Class 60. A plate is cut by a thin grinding wheel which performs simultaneously a rapid rotational movement about its own axis, a translational movement along the line of cut, and an oscillating movement about an axis parallel to the rotational axis of the grinding wheel. The grinding wheel is continuously shaped and is continuously, lubricated in the region of attack upon the plate. After each run, that is at the end of each translational movement of the grinding wheel, the latter and the shaping and lubricating devices are jointly shifted one step towards the plate, and the shaping and lubricating devices undergo a movement towards the grinding wheel in order to make allowance for the wear of the grinding wheel. A machine comprises a casing A supported, by shoes, on longitudinal rails 1, 2 and reciprocated thereon by a pinion 9 driven by a reversible electric motor 7 and meshing with a rack 10 secured to the rail 1. A grinding wheel 11 is secured on a spindle 12 rotated, in a boss 15, through a belt 60 by a motor 21. The boss 15 is mounted in bores in arms 18, 19 journalled, by ball bearings 22, 23, concentrically with the shaft 20 of the motor 21. The boss 15, has toothed segments 24, 25 meshing with curved racks 26, 27 and rollers 30, 31 running on curved tracks 28, 29, the axis of the racks and tracks coinciding with that of the motor shaft 20. A part 32 integral with the boss 15 is connected by an adjustable rod 33 to a crankpin 34 radially adjustable, by screw 36, on a flywheel 39 driven, through belts 43, by the motor 21. The motor 21 is positioned inside a casing A<SP>1</SP>, on one side-piece of which is mounted a bracket A<SP>111</SP> pivoted in bearings 54-57 by a shaft 58. Mounted on the opposite side-piece of the casing A<SP>1</SP> is a bracket A<SP>11</SP> supported on a nut 46 on a screw 51. A head 62 carrying diamonds 63 is integral with a shaft 64 passing through an externally screw-threaded rod 65 housed in a boss 66 on the arm 18. The rod 65 is restrained against rotation and engages in the screw-threaded bore of a worm-wheel 67 meshing with a worm 69 on a shaft 70. The lower end of shaft 64 has a longitudinally slotted section 73 on which is slidably mounted a pulley 74 round which passes a cable 75 anchored at one end to the casing A<SP>1</SP> secured at the other end to a spring 77 anchored to the casing A<SP>1</SP>. The shaft 70 is connected by a chain 72 with a shaft 82 on which are keyed a ratchet wheel 83 and a worm 84, the latter meshing with worm-wheel 85 keyed to the lower end of the screw 51. Loose on the shaft 82 is a lever 86 on which is pivoted a pawl 88 engaging the ratchet wheel 83, one end of the lever 86 having connected thereto a handle 95 and also being connected by a rod 90 to a lever 92 pivoted on the casing A level with the other end of the lever 86 and with the free end of the lever 92, towards the limits of travel of the casing A, are adjustable stops 97, 98, The lever 86 carries a needle 99 alternately actuating electrical contactors 100, 101 and the lever 92 carries a needle 102 alternately actuating electrical contactors 103, 104. The arm 18 has lateral projections 105, 106. terminating in tubular guides 107, 108 through which pass pipes 111, 112 also passing through apertures in further lateral projections 109, 110 of the arm 18. The pipes 111, 112 are connected by a hose 115 to a pump in a supply tank and carry nozzles 116, 117 lying in the plane of the grinding wheel 11. The pipes 111, 112 are acted on by springs 127, 128. A swivelling anchorage 125 mounted loosely at the end of the slotted section 73 of the shaft 64 has secured thereto cables 124, 126 passing round pulleys 122, 123 mounted on the arm 18 and secured at their other ends to the unions for the pipes 111, 112. The nozzles are formed of two thin plates separated by spacers. Cutting waste falls into a pit 137 between the longitudinal rails 1, 2; through the whole length of the pit extends an Archimedean screw 138 terminating at a collecting shaft 139 and driven through a chain 141 from a shaft carrying a control wheel 143; this is carried by a control station 144 surmounted by a main switchboard 145. A work-supporting table comprises an apron 146, longer than the longest plate T to be cut, supported with an overhang by pillars 147 bearing on the ground or bed 149 and also by horizontal joists 152 supported by pillars 153. Pillars 156 support apron sections 155 with their edges aligned and spaced from the facing edge of the apron 146 to form a gap in which the grinding wheel operates. To facilitate handling of the plate T, the apron 146 and joists 152 may have suitably distributed ball or other supports. To secure the plate T on the apron 146 and apron sections 155, permanent or electro-magnets 159, 160 are provided, either along the whole length of the table or at spaced locations. Additionally, one or more electromagnets 164 may be mounted on a beam 163 secured to arms 162 keyed on a shaft 161 passing through the pillars 156 and rotated by a handwheel 165. Operation. The plate T having being correctly positioned on the table and clamped thereon, and the casing A being in its right-hand position, the motors 7, 21 are started. The casing A travels to the left, the grinding wheel 11 is rotated, and the frame 18, 15, 19 is oscillated. Due to the oscillation, the cable 75 effects alternating rotary movement of the trueing device 62, 63. When the casing A reaches its left-hand position, the lever 86 encounters the stop 97 and is moved to operate the pawl 88, ratchet wheel 83, worm 84 and worm-wheel 85 so turning the screw 51 to raise the nut 46 and swing the casing A<SP>1</SP> upwardly about the shaft 58. Simultaneously the needle 99 breaks switch 100 and makes switch 101 reversing the direction of rotation of the motor 7 to reverse the motion of the casing A. Also the movement of the lever 86 operates the chain 72, the worm 69 and the worm-wheel 67 so moving the rod 65 axially to adjust the trueing device 62, 63 to compensate for wear of the grinding wheel 11. The nozzles 116, 117 are simultaneously adjusted through the cables 124, 126. When the casing A reaches its right-hand position, the lever 92 encounters the stop 98 and is moved, the needle 102 effecting reversal of the motor 7 and the lever 86 being moved, through the connecting rod 90 to effect the adjustments previously described. Reversal of the motion of the casing A can be effected by actuating the handle 95.