Patent GB-584425-A (GB)
Title: Improvements in or connected with apparatus for averaging data such as rangefinder data
IPC: G01C11/02
Filed: 1941-08-26
Abstract: 584,425. Calculating- apparatus. BARR & STROUD, Ltd., and FRENCH, J. W. Aug. 26, 1941, No. 10898. [Class 106 (i)] An apparatus for averaging data communicated from two or more sources, particularly for use in gunnery fire control systems for averaging the data such as that derived from a group of range-finders, comprises means for deriving the average range difference value from the difference between the average range as determined by the apparatus, or the range as generated by a range clock, and the respective ranges determined by the individual range - finders, and means for adding thereto the average range and for transmitting the result to a range curve tracing pencil or other element of the control system. As shown in Fig. 1, a set of seven range-finders RF1-RF7 is provided each having a handoperated transmitter 1 which through a differential 47 and conversion gear A of known type sets the range-finder to determine the range. The transmitters are of electrical step-by-step type and each operates a motor 2 which communicates the range setting in whole or in part through a differential 4 to a store-up device 5. A range clock 8 sot by hand or automatically in accordance with the rate of change of range communicates the generated range to the differentials 4. After adjustment, the range taker presses a push-button 7 to unlock the store-up device 5 which then transmits the difference between the determined range and the generated range to a corresponding differential 6. This range difference is also communicated through a transmitter 45, motor 46 and the differential 47 to the range-finder which is thereby readjusted for a subsequent reading. The range differences are combined by the several differentials 6 and by a differential 11 and the average transmitted to the line 12 of a curve tracing point or other element of the control system. By closing clutches 48, 49, the rate setting of the range clock 8 is adjusted automatically by motion communicated through a differential 9, clutch 49 and the differentials 14, 15 and also by that received from the line 12 through the clutch 48, balance being effected when the generated range and the average range correspond. The speed of response of the range clock 8 may be varied by the means shown in Fig. 2, wherein the differentials 14, 15 act upon a screwed spindle 51 with a nut carrying one end of a lever 53, the pivot of which can be manually adjusted. In a modified arrangement, Fig. 3 (not shown), the average range determined by the apparatus is subtracted in the storing-up devices instead of the generated range as in Fig. 1 for which purpose the line 12 has connections to the differentials 4. A form of storing-up device is shown in Fig. 4 and comprises the motor 2, the differential 4, a differential 18, a motor 19, an electromagnetic clutch operating device B, a store-up 'disc 21, a reversing gear 22 and a shaft 23 which receives generated range values from the range clock. In operation, the disc 21 rotates in accordance with the range difference and causes the lever 25 of the clutch of the reversing gear 22 to move to one side or the other. No rotation is transmitted by the clutch until the range-taker depresses his button 7, whereupon the electromagnet 28 is energized to engage the cone clutch elements 29 which are rotated by the motor 19 to impart the range difference movement to the shaft 24. The disc 21 returns to its neutral position and restores clutch lever 25 to its central open position, thereby breaking the circuit and opening the clutch 29. A similar store-up device may be substituted for the elements 45, 46 and 47 of Fig. 1. The contribution of any of the range-finders can be varied in accordance with its reliability by the provision of bias mechanism indicated D in Fig. 1. A form of such gear is shown in Fig. 6 and comprises a rotatable disc 20, a roller 64 and a carrier with balls 65 associated with a rack and pinion 67, 68. The pinion can be adjusted by hand and indicated on a pointer 69. In this arrangement the bias is applied to each range-finder independently ; in a modification, Fig. 7 (not shown), the various spindles of the gears 68 are connected through differentials to a balance indicating dial which 'is arranged to show zero when the total change or bias over all the range-finders is properly adjusted. If the rate of change of range is not constant, a conversion mechanism for effecting adjustment appropriate to the particular function of range or other data is provided. In Fig. 9, a balancing differential 76 is connected to the range clock 8, to the average range transmission shaft 12 and to a differential 78 interposed between a clutch 77 and conversion gear E. When the clutch 77 is disengaged automatic rate setting has no influence and the adjustment may be made by hand. The conversion gear E is shown in Fig. 10 and comprises a variable lead screw 79, a slotted arm 80 movable thereon, a slotted arm 81 on a fixed pivot and engaging a stud of a nut on a screw shaft 83, a slidable element 86 with a stud 87 engaging the slots of the arms 80, 81 and having a rack engaging a pinion 88. The pinion 88 imparts movement to the range clocks to set automatically the rate of change of range. The apparatus is applicable to the average. of data such as parallax, heights, angles of elevation, bearing and course angles.