Patent GB-606271-A (GB)
Title: Improvements in apparatus for indicating and recording variations in level of moltenglass
IPC: G01F23/24
Filed: 1945-07-30
Abstract: 606,271. Electric indicating systems. HOLDMAN, R. E. July 30, 1945, No. 19505. [Class 40 (i)] [Also in Group XIX] An apparatus for indicating and recording the level of molten glass in a container comprises a reversible motor which drives a block backwards and forwards as an arm moves up and down and alternately actuates a switch and contacts the surface of the liquid to complete an electric circuit in each case reversing the motor, the block moving an indicator or stylus to successive positions determined by the liquid level. A hollow shaft 4 with internal watercooling means is rotatably mounted in bearings insulated from a supporting platform 2 fixed to the side of a glass-melting vat unto which an end of the shaft 4 extends and is bent at right angles carrying at its tip an electrical contact 7 preferably of platinum. The contact 7 ascends while a nut 59 travels to the right along a screw 46, -each being driven by a motor 33 through a gear chain 34 and respectively through a shaft 21 and insulated coupling 23 and a shaft 48 and coupling 47, as long as a switch arm on the core of a solenoid 14 is held by a pivoted bell-crank lever 19 through a hook and notch 16, 15 to cause contacts'24, 25 and 29 to complete a circuit in one direction to the motor 33. However, as the contact 7 ascends, an arm 20 on the shaft 21 rotates until it strikes the bell-crank lever 19, disengages the hook 16 and allows a spring 38 to switch the contacts 24, 25 over to contacts 30 completing a circuit in the opposite direction to reverse the motor and cause the contact 7 to descend and the nut 59 to travel to the left. When the contact 7 completes a circuit through the molten glass, the solenoid 14 is excited and draws the contacts 24, 25 over to the contacts 29, thus reversing the motor and initiating a new cycle. A block 52 which is slidably mounted on two guides 50, 51 fixed parallel to the screw 46 and carries an indicator 71 cooperating with a scale 72 and a stylus 54 to record on a chart 55 driven by a synchronous motor 74, is positioned once each cycle in accordance with the liquid level by. the push or pull action on the block 52 of a yoke 60 or double cam lever 67 mounted thereon, the degree of freedom of the yoke being regulated by a spring-actuated drag 61. As the nut 59 travels from one leg of the yoke to the other, the lever 67 falls and rises, the movement being utilized only as the nut moves to the left after being reversed before the yoke reaches the block 52, the lever 67 then rides on but does not hook a peg 70 in the block 52 and draws it by its cam action into contact with the yoke. The nut continues to the left, pushes the yoke to the left and leaves the block in the position set. When reversed, the nut moves from the left to the right leg of the yoke and then pushes it to the right towards the block, failing to reach it, just touching it or pushing it to the right according to whether the liquid level has risen, remained steady or fallen during the cycle. Attached to the block is a gear rack 56 co-operating with a gear 57 on a shaft 58 which may serve as a power takeoff for any purpose.