Patent GB-690845-A (GB)
Abstract: 690,845. Indicating-apparatus. KONINKLIJKE NEDERLANDSCHE GISTEN SPIRITUSFABRIEK N.V. March 22, 1951 [March 22, 1950], No. 6875/51. Class 106 (iv). [Also in Group XXIV] Apparatus for comparing the rate of fuel consumption with the rate of steam production in a steam-generating plant operated by combustion comprises shafts rotated at speeds proportional respectively to the instantaneous values of the rates, each shaft driving a member of a differential mechanism, whereof a third member, whose motion is derived differentially from those of the first-mentioned members, actuates a device affording a visual indication of the proportion of the rates. As shown in Fig. 1, one sun-wheel of a differential gear mechanism in the form of a .friction disc 31 fixed to a gear-wheel 17 is driven through chain-and-sprocket by a shaft 14 which is driven at a speed depending on the rate of consumption of fuel, while the other sunwheel 30 also in the form of a friction disc fixed to a gear-wheel 12 is driven through chain- and-sprocket, 11, 10, shaft 9, bevel-gears 8 and friction discs 5, 4 by a shaft 2 which is driven at a speed depending on the rate of production of steam. The disc 5 is pressed by a spring 6 against the periphery of the disc 4, the transmission ratio between the discs being set manually by adjusting the position of the disc 4 so that the sun-wheels 31, 30 rotate at equal speeds in opposite senses while a desired proportion for normal efficiency between the rate of consumption of fuel and the rate of production of steam is maintained, this proportion being indicated by a pointer 52. The planet-wheel is in the form of another friction disc 32 pressed by a spring 33 against the peripheries of the discs 31, 30 and carried by a frame 34 pivoted about the shaft 18 and carrying counter-weights 35, 36, one bearing being in the form of a screw and nut 38, 37, so that if the speeds of the wheels 12, 17 become unequal, due to a change in the proportion between the speeds of consumption and production, the planet-carrier turns about the shaft 18 and progresses axially therealong, altering the ratio between the working radii of the disc 32 in engagement with the discs 31, 30 to compensate for their difference in speed and so comes to rest. The axial or angular distance moved by the planet carrier 34 is a measure of the proportion between the speeds and may be indicated by a pointer 44 against a scale 45, the pointer being driven through bevelwheels 43, 42 by a feeler 39 engaging a hole 41 in the frame 34. Counters 3, 15 indicate the total steam produced and fuel consumed in a given time. In a modification the screw and nut compensating means are in the drive to the disc 30. In a second embodiment, Fig. 2, the fuel meter drives a shaft 201, on which is mounted a fuel counter, and which drives through gearing 204, 205, a main shaft 206 with a friction disc 207, which is pressed against a friction disc 216 by a compression spring 203. The disc 216 and an attached sleeve 217 form a nut on a screw spindle 214 integral with a main shaft 213, screw spindle and nut, when driven in the same direction, forming a screw differential. The steam meter drives a. shaft 210, having it steam counter 209 and pinion 221 which drives a pinion 222 on the shaft 213. Rotation of the shaft 213 drives the nut 217 along the spindle 214 until the friction disc 216 driven by the friction disc 207 rotates with the same speed as the spindle 214, the displacement of the disc 216 from the centre of the disc 207 being a measure of the required speed ratio and being indicated by a pointer 219 actuated by rack-andpinion 218.