Patent GB-1276092-A (GB)
Title: A new or improved method of and apparatus for use in producing a three dimensional model of a piece of terrain
Inventor: SANDERS NORMAN THOMAS
IPC: B23Q35/08
Filed: 1968-06-18
Abstract: 1276092 Milling N T SANDERS 16 June 1969 [18 June 1968] 28961/68 Heading B3K [Also in Divisions G3 and G5] In a method of and apparatus for producing a three-dimensional model of a piece of terrain, a plan or map 12 bearing contour markings is traversed relative to a cursor 21, 22 and a model blank 13 is traversed correspondingly relative to a shaping tool 39, the operator views the plan and cursor or an image thereof 21a, 22a and adjusts the height of the tool relative to the model in dependence upon the spacing from the cursor and rate of approach thereto of the next contour line or marking which intersects the scanning path. As shown, tables 10, 11 bearing the plan and model are traversed in the scanning direction by a common lead-screw 14 driven by a common motor 15. Increments of cross traverse are applied by lead screw 16, 17 operated manually by a hand control 19. A transparent tape 23 is superimposed over the plan adjacent the cursor, and extends in the scanning direction, the tape carrying markings corresponding to altitudes. The tape is manually adjusted by a hand wheel 25 so that markings thereon corresponding to the contour marks are brought adjacent the cursor as the respective contour marks on the plan approach and move therepast, the tape 23 being connected via drums 30, 31, 32 to height adjustment means 35 controlling the height of the motor 38 and tool 39. In a second embodiment, Figs. 6, 7, the cursor element 121 is provided with a series of numbered markings arranged in the scanning direction on either side of the cursor line and a keyboard 171 is provided with keys 172 numbered correspondingly; the operator depresses a key corresponding to the number on the cursor element adjacent to the next contour line. Suitable pulse generating circuitry 173 is activated by depression of the key to apply a pulse current of fixed magnitude through line 174 to a motor 170 which adjusts the height of the shaping element, and a pulse current proportional to the distance to the next contour line as indicated by the numbers on the cursor element, through line 175 to a motor 115 which controls the line scanning movement. The signals generated in circuit 173 may be recorded by means of a tape recorder 177 and subsequently played back to apply the signals to the lines 174, 175. In this case length of tape represents distance along the scanning path and the intensity of magnetization the altitudes, the tape record thereby providing an analogue record of the terrain. In a circuit, Fig. 10, arranged for use with a manually operated keyboard as in the embodiment of Figs. 6 and 7, but adapted to provide a digital representation of the terrain a constantly operating pulse generator 200 feeds one of a number of divider circuits corresponding to the keys the particular circuit being selected by operation of the key and the output fed to a corresponding gate circuit also fed by a monostable circuit actuated by operation of the key. The output from the gate circuit is used to operate the traverse motor 215. A single corresponding circuit is arranged to operate the motor 270 controlling the height of the shaping tool. Tape recorder means may be operated in conjunction with the circuit to record the scanning steps and used subsequently to operate the traverse and height adjustment motors. In addition the tape may carry signals arranged to operate the cross traverse motor between each line scanning operation.