Patent GB-107996-A (GB)
Title: Automatic Machine for Cutting and Polishing Precious, Semi-precious or Synthetic Stones or Imitations thereof.
Inventor: BARKER REGINALD WALTER
IPC: B24B9/16
Filed: 1916-05-16
Abstract: 107,996. Barker, R. W., (Heller & Sons, L.). May 16, 1916. Gems, treating.-An automatic gem cutting and polishing machine comprises a lapidary wheel 3 and one or more gem-holders 13 which are pressed yieldingly towards the wheel and are periodically turned and tilted to present successive facets to the wheel and to alter the inclination of the facets. The wheel is lifted preparatory to cutting and polishing a facet and is lowered during the adjustment of the holders to relieve the pressure on the gems, and the antomatic - controlling mechanism is timed so that, after each adjustment, the gems are pressed against the wheel for the time required to cut and polish a facet on each gem. The wheel is secured to a shaft 33 driven by a pulley 34 and mounted on a lever 60 controlled through a rod 59 by a cam 53 which causes the wheel to be raised and lowered in each cycle of operations. To cause an orbital movement to be imparted to the. wheel, the shaft 33 is journaled eccentrically in a bush 35 which is normally at rest but can be rotated simultaneously with the rotation of the shaft. For this purpose, a clutch-sleeve 37 splined on the bush can be shifted by a lever 38 into gear either with a pulley 36 or a bevel-wheel 40 driven by a hand-wheel 44, the pulley imparting a quick movement and the hand-wheel a slow movement. The holders 13 consist of sleeves adapted to receive sticks 8 to which the gems 11 are cemented. The gems are preferably roughcut before being dealt with by the machine. The holders 13 are mounted on carriers 5, there being preferably sixteen carriers each with three holders. Two or more lapidary wheels may be provided and the support for the carriers may be rotatable to permit the carriers to be brought over the wheels successively so that the operations can be divided into stages performed on different wheels. As shown, carriers are mounted on a support 4 which is rotatably mounted in the pedestal 1 and can be turned by bevel-gearing 111, 112 operated by a hand-wheel 113. Each carrier is mounted on trunnions 31 in a hub 4<1> and a detachable bracket 32, respectively formed on and secured to the support 4, and the holders are supported independently by parallel links 17 mounted freely on shafts 18, Fig. 4. The holders are pressed against the wheel bv means of levers 30 mounted on a lever 29 which is mounted on a lever 28 on the carrier. The lever 28 engages a bell-crank 26 operated by a rod 25 which passes through one of the trunnions and is connected through a bell-crank 82 and a link 81 to a spider 80 common to all the carriers. The spider is engaged by a cam-lever 77 operated by a spring-plunger 75 on a bell-crank 74 operated by a lever 71 through a roller 83 which can be shifted to alter the leverage. The spring- plunger imparts to the holders a yielding pressure which is relieved automatically when the polish. ing of a facet is finished. The levers 30 and the links 17 enable each gem to adjust itself to irregularities in the wheel without altering the angle of the facet. For tilting the holders to adjust the inclination of the facets, the carriers are tilted in either direction by means of a ring 97 provided with forks 15 engaging arm 16 on the carriers, the ring being turned by means of a cam 93 engaging a lever 94 which is connected bv a link 95 to the ring. For turning the gems to present new facets, the holders are provided with ratchet-wheels 14 engaging a rack 21 connected by a lever 22 to a rod 24 passing through one of the trunnions and arranged in the path of a cone 100 on a plunger 99. The automatic controlling-device consists of a travelling belt 103, Fig. 1<b>, provided with sets of pins 108 adapted to close contacts 109 in the circuits of electro-magnets. The driving-mechanism comprises the cam 53 and disks 69, 88 loose on geared shafts 51, and provided with pawls 54, 64, 89 adapted to engage ratchet-wheels on the shafts. The pawl 54 is normally engaged by the armature 56 of an electro-magnet 58 and, on energizing the circuit of this electro-magnet, the latch can engage the ratchet-wheel and the cam 53 makes a half revolution and the latch is then caught and released from the ratchet-wheel by the armature 55 of an electro-magnet 57. On energizing this electro-magnet, the latch again engages the ratchet-wheel and the cam 53 makes a second half revolution. The disk 69 is coupled by a link 70 to the lever 71 and the latch 64 is controlled by the armatures 65, 66 of electro-magnets 67, 68 in the same manner as the latch 54. The disk 88 is provided with a pawl 92 driving a ratchet-wheel 87 secured to stepped cams 85, 93 which operate respectively a lever 84, coupled to the roller 83, and the lever 94 which is coupled to the ring 97. The latch 89 is controlled by the armature 90 of an electro-magnet 91 and causes the disk to make a full revolution on each release. The plunger 99 is operated by the armature 101 of an electromagnet 102.