Patent GB-421827-A (GB)
Title: Improvements in and connected with safety controls for winding, haulage, or lifting gears
IPC: B66B1/08
Filed: 1933-07-01
Abstract: 421,827. Winding and paying - out apparatus; fluid - pressure -actuated brakes; electric selective signalling; governors; electric switches. OLIVER, E. H., The Glebe, Dalton-le-Dale, SIMPSON, J. P., Park View, and DOBSON, R., 1, Railway Street, both in Murton, both in Co. Durham. July 1, 1933, No. 18678. [Class 78 (v)] [See also Groups XXVI, XXXIV, and XXXVIII] A safety control system for winding-apparatus comprises a generator driven in accordance with the speed of winding operating an electromagnetic control device which is linked with the manual control for the throttle, switch, &c., and brake, so that the engineman feels the electromagnetic control come into action. Visual and audible warnings of overspeed conditions are also given. The electromagnetic control comes into action at progressively slower speeds in the danger zones near the ends of the wind. Quickbraking action by the emergency brake control is normally prevented by an electromagnetic device, and this device is released by emergency and overwound control. Electromagnetic control devices are set to act at different speeds when winding with coal and with men in the cage. As shown in Fig. 1, the winding engine a drives a depth indicator d and a series-wound generator e. Brakes b are applied by the weighted piston rod h of a brake cylinder j and cataract cylinder l. The valve rod k of the brake cylinder is controlled by hand, by the slow-brake solenoid n in circuit with the generator e, and by the quick-brake solenoid o which is energized from an independent source. These controls act through mechanisms which are linked to the throttle or other power control through connections p, q. When the solenoid n is energized by overspeeding of the cage, the engine is gradually throttled and then braked, until normal speed is restored. The core of the solenoid n is provided with a dash-pot or may act as a dash-pot piston in the bobbin. The quick-brake solenoid o is normally energized by a powerful current so as to raise the weight 10 and hold an arm 14 horizontal beneath the lever 1 connected with the valverod k. When the circuit is broken the weight 10 drops and acts through a link 12 to close the throttle and through the arm 14 to apply the brakes. Lost motion in this connection prevents interference between the controls. After operation of the quick-brake mechanism, the gear is reset by a hand-lever which also closes a switch so that the solenoid o is reenergized after re-setting. The normal action of the brake cataract-cylinder l, Fig. 4, is controlled by a byepass valve 18, but a second byepass 20 is controlled by a valve 21 operated by a solenoid m in circuit with the generator e. The solenoid m comes into action before the slow-brake solenoid n, so that on overspeed the byepass valve 21 is closed before the slow-brake action commences ; but when the quick-brake solenoid o is de-energized, the speed-control of the valve 21 prevents quick action of the brake until the speed has first been reduced to normal. An arrangement in which the emergency control cannot be overridden by the engineman is shown in Fig. 7. The throttle lever q<1> is operated from the slowbrake solenoid n through a rockshaft hand link v<1> and from the quick-brake solenoid o by the release of the weight 10 which acts through a rockshaft 8, slotted link 12, and the rockshaft u. Both controls act upon the brake through the valve rod k. The engineman controls the throttle lever q<1>, and through this the brake, by a hand-lever 25 acting through connections 26, 27, 30, 31. The link 27 terminates in an L-shaped slot 28 normally engaging a pin on the lever 30, but when the solenoid o releases the weight 10, for quickbraking the link 27 is raised by movement of a lever 6, and can move idly over the pin. An arrangement in which the reversing lever is automatically set in neutral position when the quick-brake mechanism comes into action, is shown in Fig. 9. The resetting lever 15 operates through connections 34-38, 38<a> to disengage the latch 40 of the reversing lever 39 from either the forward or the reverse position, so that the lever is returned to the neutral position by the dead-centre spring 41 and counterweight 42. Steam is therefore trapped in the cylinders to brake the engine, and the reversing lever cannot be re-set until the quick-brake mechanism has been reset by moving back the lever 15. The circuit arrangements for the solenoids n, o, and the overspeed signals are shown in Fig. 10. One terminal of the slow-brake solenoid n is connected through the line 45 with the split series windings el, e<11>, which are connected in parallel with the negative brush of the generator e. The circuit of the winding e<11> contains a relay coil 43 for closing the circuits of a lamp 91 and a siren 92. The positive brush is connected to the other terminal of the solenoid through one or other of two rheostats by way of a rocking switch 48, 47 with mercury cups 52, 50 and 52<a>, 50<b>, and through the line 46. The two rheostats are of different resistance, one serving for use when winding coal and the other when winding men. Each rheostat circuit comprises a screw 58 driven from the winding drum so as to drive a depth-indicator nut 59 carrying sliding contacts 61, 62, respectively. The contact 61 is connected with the cup 52, and the contact 62 moves over a conductor 67 or over insulated contact plates 68, 69 which are connected with sectional resistances, of which only one set 70 is shown. When the tub or cage enters the danger zones at top or bottom of the wind, the slider 62 is over one of the sections 68, 69 and progressively cuts out resistance between the cups 52, 50, so that the solenoid n in series with the generator e driven from the drum is energized at progressively lower winding speeds. If overspeed occurs in the danger zone, a solenoid 66 is energized and closes a switch 72 to cut out half of the resistance 70 and ensure operation of the slow-brake solenoid n. A solenoid 74 is connected across the last two sections of the resistance 70 and closes a switch to light a red or green lamp 76 indicating that winding of coal or of men is in progress. In order to use the rheostat with the lower resistances for winding men the rocking switch 48, 47 is thrown over by a lever 53 actuated by an electromagnet which is energized by a sequence of relay actions initiated only by a predetermined sequence of operations. In the example, Fig. 11 (not shown), the banksman's ringing key must be operated thrice, signalling menwinding, in order to effect and signal the change-over. The electromagnet is energized when a rotary switch arm is moved to the last of three positions. The three successive operations of the ringing key, if they occur within the normal interval determined by timelag relays, bring the rotary switch arm step by step to the final position, in which a circuit is completed through a time-lag relay. This circuit operates a relay which moves three switches. One of these makes a circuit through a hold-on coil and the banksman's release switch, another completes the circuit of the relay for effecting the change-over and the third controls lamps to signal to the engineman or elsewhere. The engineman returns this signal to the banksman. To prevent opencircuiting of the generator e during the changeover of the rocking switch 48, 47, contacts 56 on the switch wipe over contacts of a non- inductive resistance 57. The quick-brake solenoid o, Fig. 10, is energized by an independent three-phase circuit controlled by a switch 78 which is held closed by a 220-volt coil 79 connected across the power circuit. The circuit of this coil includes a switch 83 controlled by a relay 41 in the generator circuit, and the circuit may also be broken by switches 80, 81, 82. The solenoid o is de-energized (a) through switch 83 when the speed of the winding drum and the generator is excessive, (b) through the depth indicator and switch 80 in the event of an overwind, (c) through switch 81 when the quick-brake mechanism has been released and not yet reset and (d) through a brakesman's emergency switch 82. The relay 41 being in circuit with the rheostats 70 is operated at lower speeds when the cage is in the danger zones. It may be made still more sensitive during say the last two revolutions of a wind by cutting out the resistance of the solenoid n from the generator circuit, and this may be effected, as shown in Fig. 10, by an auxiliary depth-indicator arm 84 which wipes over contacts 85, 86 at this time, and short-circuits half, and then the whole, of the solenoid winding. In a modification, Fig. 12 (not shown), some of the contact segments of the main depth indicators 68 are connected to sections of the solenoid winding for this purpose. The arrangement not only limits speed automatically down to the last revolution of the wind, but prevents winding in the wrong direction, and over-acceleration at the start of a wind.