Patent GB-238519-A (GB)
Title: Improvements in or relating to automatic control means for gas making apparatus
IPC: C10J3/24
Filed: 1925-06-05
Abstract: 238,519. Humphreys & Glasgow, Ltd., (Assignees of Kennedy, J. S.). Aug. 15, 1924, [Convention date]. Producers.-In an automatic water gas plant of the kind described in Specification 229,399, control of the sequence of operations, together with automatic shut down in safe condition upon failure of any operation at its appointed time, is effected by electromagnetic means which govern the movements of the hydraulic valves. The system operates on a normally closed electric circuit, and failure of current automatically shuts down the set; " blow " and " run " periods can be varied; the set shuts down for recharging; and handcontrol may be assumed at any time. A master shaft 1, Fig. 2, rotates every 15 seconds and carries a pawl 2 which drives a ratchet-wheel 3 having 28 teeth so that its rotation is completed in 7 minutes; a weight 27 tends to rotate the wheel backwards, and is normally prevented from so doing by a spring-pawl 4. The wheel is mounted on a shaft 6 carrying a toothed wheel 7 in gear with a wheel 8 having twice as many teeth and so drives gears 10, 11, and 12; the latter are driven step-by-step 1/50 th part of a complete rotation every 15 seconds. The wheel 8, Fig. 4, is carried by a sleeve 9 within which a sleeve 13 and shaft 14 rotate independently, and an arm 15 to function at the end of the " run " is fixed to the shaft; the angular relation of the shaft and sleeve 13 can be adjusted by an indicator 16. At the front of the shaft 6, Fig. 2, is a dial plate and pointer, and when the reading of the latter corresponds with the indicator 16 the pawl 4 is withdrawn and the wheel 3 driven forwards by the pawl 2. When this has occurred, the wheel is driven backwards by the weight 27 with a corresponding movement of the gears 7. 8, 10, 11, and 12 until a pin 31 on a cam secured to the gear 11 strikes a bell-crank lever 33 and allows the pawl 4 to re-engage the wheel; the latter is stopped in the zero position at the end of a cycle by the engagement with a fixed pin 34 of an arm 35 on the gear 12. The cycle may be controlled by hand if the shaft 6 be drawn forwards to disengage the wheel 3 and pawl 2 without disengagement of the pawl 4. The gears 10, 11, 12 respectively operate three sets of switches by means of arms loosely mounted on the shafts 37, 38, and 39. Two switch arms 42, Fig. 7<a>, one behind the other, mounted on the shaft 38 bear at their upper ends 42a against cams 40, 41, Fig. 4. mounted about the shaft 14 and shaped to allows contact to be made either on left-hand or righthand side and control the circuits for the " run," the time of operation being determined by the position of a setting-arm 13a. Switch arms 45, Fig. 7<a>, on the shaft 37 are worked in a similar manner by a compound cam connected with the gear 12 and control the circuits for the " blow " and change from " down run " to " up run." Switch arms 53 on shaft 39 are operated by the gear 11 to control circuits for the oil valve and blow sequence. The arms may be interlocked bv a bar 65 having a pin-and-slot engagement with a lever 26 which pushes the bar to the extreme left when the pawl 4 is raised to free the wheel 3 at the beginning of a cycle. The arms 42 are pivoted to the bar by pins 68, and the arms 45 and 53 have pin-and-slot connections 69 and 70 with the bar so that movement of the arms 45 and 53 is not effected until after movement of arms 42. To extend the duration of the " blow " and curtail the " run," an auxiliary 15 second shaft 71, Figs. 2 and 9, located above the master shaft carries a disc 72 with an extension 72a, the position of which may be adjusted in order to delay the lifting of a rod 75 locking the bar 65 at an extension 65a. To shut down for charging after completion of a predetermined number of cycles have been completed, a pawl 81, Figs. 2 and 11, on wheel 7 makes one revolution per cycle and drives a ratchet-wheel 82 on a shaft 83 carrying a pointer over a graduated dial. A switch-arm, loosely pivoted' on the shaft, is engaged by a pin 88 on the wheel 82 at the beginning of the last cycle so as to move the arm from right to left. This movement is effected against the pull of a spring 89 attached to one arm of a bell-crank lever 90, the other arm of which acts as a stoppawl for the wheel. Further movement of the wheel is prevented at this moment by the omission of a tooth at 82a. The stop pawl is raised by turning a shaft 94 to allow the pointer to be re-set, and the plant may be shut down at any time by turning the pointer to zero. The automatic shut-down switch is mounted on a shaft 97, Fig. 13, by cross-members which carry two parallel bars with insulated contact sleeves and disc separators. The normal running position, shown in Fig. 2, is secured by a latch 105 with an extension 106 adapted to engage a notch 107 on a trigger 108 which is released by the fall of a core 111 when a solenoid 110 is de-energized; thereupon the switch is thrown over to the shutdown position. The switch is also tripped automatically if, in the event of breakage of the cord 28 carrying the wegiht 27, the wheel 3 be driven forward beyond the zero point: and the switch may be tripped by hand at any time. A bar 112 pivoted to the latch 105 rises when the switch is shut down, disengages the pawl 2 and wheel 3, and stops the entire gear train. A drum 126, Fig. 2, mounted on the master shaft co-operates with three stationary spring contacts 127 to provide two circuit controllers, one of which closes a circuit for a predetermined number of seconds at the beginning of each 15 second interval, and the other opens a circuit for the last second of each interval. Specification 229,399 is referred to.