Patent GB-530093-A (GB)
Title: Improvements in or relating to educational devices
IPC: G06K17/00
Filed: 1939-06-16
Abstract: 530,093. Educational appliances. INTERNATIONAL BUSINESS MACHINES CORPORATION. June 16, 1939, No. 17641. Convention date, June 21, 1938. [Class 146 (ii)] [Also in Group XIX] Relates to a machine as in U.S.A. Specification 2,113,620 for the numerical establishment of the results of an examination by determining the number of correct answers to a number of questions by means of mechanical verification, in which the Examiner makes a mark on a response sheeet which contains for each question a number of answer positions, a mark in only one of which represents a correct answer, and consists in effecting a comparison with a key sheet having holes in all selected positions corresponding to correct answers, and in which a setup is effected by the key sheet and sensing means responsive to the response sheet co-operating therewith to control an indicating meter, two indicate the number of correct or incorrect answers or their difference. Response sheet.-This as shown in Fig. 5, is provided with 25 vertical columns in groups of five each group separated vertically into two 15 line fields one or more of which may be grouped together to constitute a single test. Each designating position R1 is indicated by a pair of parallel lines between which the Examiner is to draw a heavy black line R2 at the answer selected. In the example shown, the first 38 response positions constitute a " test A," positions 39-75 "test B" and 76-10C " test C." Main key sheet.-The sheet K, Fig. 7, has perforations K2 corresponding to the correct indicating position R1 of the response sheet. In addition the key sheet has a row of six perforation-receiving "field selecting positions K3 across the top and bottom. Each group of six, for each 15 consecutive response positions is divided into two sets " right " and "wrong." Secondary key sheet.-This sheet, shown in Fig. 8, is used where certain parts of the test are to be excluded from the scoring. Here perforations SK2 are made exactly duplicating the perforations K2 in the main key sheet. In addition, all the response positions SK1 relating to any question to be excluded are punched out, for instance to question 96. Perforations SK4 are made top and bottom corresponding to the K3 positions. The same sheet may be employed in a true-false type of test where there are only two vertical columns for each column of questions. Aggregate weighting-record sheet. - This is shown in Fig. 6, and has three fields WA, WB, WC and 10 pairs of marking positions W1. Any pair of columns in one of the fields may be marked to represent a percentage or numerical value by drawing a line through the marks as shown at the right or a series of short marks as shown at the left. For example the first pair of columns to the right represent "66." Key-sheet holder.-The key sheets K, SK are placed in a removable holder 22, Fig. 1, comprising three hinged sections 23, 24, 25. Plates of insulating material 27, 28, 29 are secured to the sections 23, 24 while section 25 is a cover plate with cut out portions. When both key sheets are used they are inserted in the holder as in Fig. 10 ; when only one sheet, it is placed between plates 29, 25. The holder with the sheet is inserted in a channel in a U-shaped carriage 34, 35 reciprocable on rollers 36. A handle 38 is rotated and the carriage reciprocated through cam mechanism 40, 41. The plates 28, 29 are perforated correspondingly to the possible perforations on the key sheet. The plate 27 is similarly perforated, but has no perforations in line with the field selecting positions. Response sensing unit.-A box-like frame 50, Fig. 3, slidable into grooves in the machine frame has a front wall 52 of insulating strips and a back wall 53 with a series of holes. For each of the 750 possible marking positions there is a sensing unit Fig. 17, comprising a pair of blades 54 extending from wall 52 into a cap 55 and around which is a spring 56. The cap is free to move axially in wall 53. Between the two blades and also on the outside of each is a blade 57 insulated from the blade 54. The blades 57 are electrically connected together and to one side of the circuit while blades 54 are connected through the spring 56 and connected to the other side of the circuit. When a marked response sheet is pressed against the ends of the blades, the circuit is completed at the pencil marks. Resistor units.-A frame 66, Fig. 3, has resistor units 69 one for each marking position mounted between plates 67, 68, the rods 71 from which abut against the caps 55. Key set selector unit.-A plurality of pins 76 one for each marking position are supported between walls 74, 75 of insulating material. The left hand ends Fig. 10, are supported in metallic caps 77 against which springs 78 abut. Each pin has an enlarged intermediate section having end metallic portions 79, 80 and a central insulated portion 81. The unit has at both ends sets of six field-selecting pins 82 aligned with positions K3 in the key sheet K and urged to the right Fig. 10A, by springs 83 and having enlarged sections with end metal portions 84, 85 and a central insulating portion 87. Selective setting of key-set pins.-The setting of pins 76, 82 is brought about by key sheets in the holder 22. Where both main and secondary key sheets contain perforations in the same positions, the pin 76 is not disturbed and passes through both openings. In positions where there are no perforations in the secondary sheet, the pin 76 is engaged and moved to the left. Where there is a perforation in the secondary sheet and none in the main sheet, the pin 76 is moved part of the way. Lying alongside each set of pins 76 is an insulated blade structure 92, 93 and according to the position of pin 76 electric contact is established for correct or wrong answers or eliminations. The six field identifying pins have lying adjacent thereto a blade structure 95 and take only one of two positions. Response sheet handling mechanism.- The sheet R inserted through the shoot 97, Fig. 3, and drops on to a shutter 98. The key 99 is depressed and through linkage 101, 102 rocks the shaft 103 counterclockwise and the hook 105 rocks the member 108 clockwise causing the upper extremity to close a pair of contacts 110. This completes the circuit of a motor M when the main switch is closed. The motor through worm and other gears 114, 115, 117, 118 and a clutch 120 causes the disc 122 to be driven through a half revolution when the member 108 returns and engages a dog 124 to uncouple the clutch. Latches 131 engage notches 130 to prevent rebound. The frame 141 is moved to the right to press the platen 147 against the response sheet. This is bent over at the top and the score recorded thereon. The markings on the sheet control electric circuits to determine the score. After recording, the key 99 is again depressed and the member 101 rocked to allow disc 122 to be rotated another half revolution. When the platen returns, the shutter 98 is moved away and the sheet drops into the hopper. A lamp is lit when the shutter is closed and the shoot unobstructed. When a response sheet is inserted in the machine and pressed against the sensing blades 54, 57 a circuit is completed through each pencil mark from 54 to 57 and through resistor 69. According to the position of the key set pin 76, the current from the resistor 69 flows on through blade 92 or 93 according to setting for a "wrong" or "right" answer. If the pin 76 is in an intermediate position the circuit goes on further. The apparatus is wired up and connected to switches which are adjusted according to the particular calculation desired. If there are two answers to, say test A, the main key sheet is perforated in the A-right and A-wrong positions in the field selection parts related to the field in which the two marks are made. To calibrate the meter 190, so that if both marks represent correct answers, the meter will register 2 and if wrong " 0," a response check sheet is prepared with both marks made in correct answer positions and the key sheet is also perforated in the correct answer positions and the key sheet is also perforated in the correct answer positions with the related field section positions A-right and A-wrong perforated. The response sheet is then inserted in the machine and key 99 depressed. The correct switches are set and the current through the meter and "A" potentiometers are adjusted so that the meter reads "2" A control panel is provided at one end of the machine provided with the various switches &c. A "weighted" score may also be obtained, i.e., a score in which the meter reads more than one unit for each mark closing the pencil mark circuit. Profile analysis.-A selected combination of punched holes or marks may be compared with similar sheets by preparing a sheet with a mark for each punched position of the selected combination and placing the perforated sheet in the key sheet holder and the correspondingly marked sheet in the sensing unit.