Patent GB-521871-A (GB)
Title: Improvements in or relating to computing, calculating and like apparatus
IPC: G06G3/00
Filed: 1938-11-29
Abstract: 521,871. Calculating apparatus. BROIDO, D. Nov. 29, 1938, No. 34717. [Class 106 (i)] [Also in Group XL] An apparatus for solving equations involving more than two variables comprises means for obtaining functions of the variables to be dealt with, scanning mechanism for producing electrical impulses corresponding to these functions, means for transmitting the impulses to multiplying and or additive mechanism according to the terms of the equation, and means for providing a visible indication or registration of the computed values. The invention may be used for solving any kind of equation and is described as applied to a navigational problem utilising the formula Sin A=Sin L Sin D + Cos L Cos D Cos H where A is the altitude, L is the latitude, D the declination, and H the hour-angle. The known values of the angles L, D and H are set up on drums 3, Figs. 1 and 2, and displace corresponding film strips 9<SP>1</SP>, <SP>2</SP>, 9<SP>3,4</SP>, and 95 to position slots 15 therein to represent the trigonometrical values of Sin L and Cos L, Sin D and Cos D, and Cos H respectively. The slots are exposed to a corresponding light source 16 mounted in the interior of scanning cylinders 17<SP>1, 2</SP>, 17<SP>3, 4</SP> and 17<SP>5</SP> and directed on to photo cells C<SP>1</SP>, C<SP>2</SP>, C3, C4 and C5. The scanning cylinders are furnished with slots 19 and one revolution of the cylinders effects the reading- off and transmission of the values to multiplying devices M<SP>6</SP>, M<SP>7</SP> and M<SP>8</SP>. The photo cells C<SP>1</SP> and C<SP>3</SP> through amplifying devices T<SP>1</SP> and T', operate relays R<SP>1</SP> and R' of the multiplying device M<SP>6</SP>. The relay R<SP>1</SP>, Figs. 1 and 3, coacts with clutch forks 23 to disconnect the clutches 25 and ratchet wheels 27 from gear wheels 28 that are driven by gear segments 29 on a shaft 37 operated in synchronism with the scanning cylinder 17. When the clutches are operative they drive corresponding gear wheels 30 in mesh with teeth 31 of cylindrical frames 32 carrying films 35 as shown in Fig. 4 representing multiplication tables. The digits of the multiplicand (Sin L) is thus transmitted to the films 35. The relay R' forms the operative element of the multiplier device (Sin D) which comprises sets of selector cams 41 with clutch forks 42 and gears 44 adapted to be driven by other gear segments 29, a set of rocking levers 47, and selector cams 49 one for each multiplier digit for controlling movement of the levers 47 to co-operate with stop studs 52 on a drum 51 driven by pinions 53, all operating to carry out the multiplication process as described in Specification 493,277. During this first cycle the photocells C<SP>2</SP>, C<SP>4</SP> and C<SP>5</SP> control the transmission of the values Cos L, Cos D and Cos H to the multiplication devices M<SP>7</SP> and M<SP>8</SP>. After the scanning cylinders 17 and gears 29 have completed one revolution the gears 21 and 38 are disconnected and a gear 61 is operated to drive scanning cylinders 57 one revolution for each multiplier digit. During this cycle the light from lamps 39 activate photocells C<SP>6</SP>, C<SP>7</SP>. The impulses from the cell C<SP>6</SP> corresponding to the partial products of the product (Sin L Sin D) are transmitted through a switch 65 to a relay R<SP>6</SP> of an accumulator A9. This relay controls clutch levers 72, Fig. 6, to regulate the driving movement of gear segments 66, operated in synchronism with the scanning cylinders 57, through gearing 69, 74, 75 and 76 to operate drums 79 carrying result screens 80. After each partial product entry the segments 66 are moved axially to the next higher denomination, transfer operations being effected in any known manner by gears 82. The impulses from the cell C<SP>7</SP> representing the partial products of the product (Cos L, Cos D) control the energization of a relay R' of the multiplication device 78. Each revolution of the scanning cylinder 57 of the device M' transmits a partial product by the gear segments 89 and clutches 86 to the selector cams 92 corresponding to the cams 44. After each transmission the segments 89 are moved axially until the cams 92 are set to represent the product (Cos L, Cos D). The switch 65 is thereupon turned to establish a connection with a photocell C<SP>8</SP> to transmit successively and add the partial products of the product of the factors Cos L, Cos D and Cos H to the values entered on the result screens 80. To find the angle A from the result Sin A on the screens 80 a beam of light from a lamp 103 is intercepted by a perforated mask plate 128, Figs. 6 and 9, and by a film strip 107, Fig. 8, with slots representing the sine values and the value of the angle in degrees, minutes, and seconds. At the beginning of this reading operation the lowermost slot in the mask 128 is aligned with the photocell C' and when a slot in the highest order of the film 107 the relay R‹ is energized to operate a ratchet pawl 123 and' drive the feed drum 99. The step movement of the drum 99 and of the mask is repeated for each digit of Sin A until the last digit has been registered whereupon a projection 119 on a clutch lever 113, Figs. 1 and 7, enters a notch 121 in a cam 120 to disengage the drum 99. A second notch may be provided in the cam 120 to operate a brake device to slow down the movement of the film before the last digit is registered. The angle A may be represented by slots which can be read by other photoelectric means or the film strip 107 and screens 80 may be replaced by numeral drums . Specifications 446,338, 475,943 and 481,798 also are referred to.