Patent GB-1374162-A (GB)
Title: Device for measuring the area content of flat or planar objects  and for stamping the measuring value on the said objects
IPC: G01B11/00
Filed: 1972-02-09
Abstract: 1374162 Measuring area LICENTIA PATENT VERWALTUNGS GmbH 9 Feb 1972 [17 Feb 1971] 6078/72 Heading G4H [Also in Division B6] As an article is carried on a conveyer its area i<SP>s</SP> digitally measured and printed on the article. In the embodiment of Fig. 1 the area is measured as the article 4 is carried on conveyer belts 3 by counting pulses from photo-cells receiving light through bores in wheels 5 engaging the article 4, whilst light to further photo-cells or photodiodes is obstructed by the article. The count is fed either directly or via a store to drive stepping motors 14, 15 positioning type wheels 16, 17 aligned in the direction of movement of the article beneath a gap in the conveyer belt. An inking ribbon 19, driven between reels 24, 25, is positioned between the belt and the type wheels. When the article is correctly positioned above the type wheels photodiodes 39 energize an electromagnet 25 to attract a core 36 on a pivoted punch 28 (against the bias of a spring 30) so that section 31 of the punch presses the article against the ink ribbon and type wheels, stops 32, 33 instantaneously holding the article stationary. In a second embodiment (Figs. 2, 3, not shown) the type wheels are aligned perpendicular to the direction of movement of the article with either an ink ribbon associated with each wheel, which permits different colours of ribbon to be used for different wheels, or with a single ink ribbon extending in the axial direction of the type wheels. In this embodiment the type wheels are driven from the stepping motors via gear-wheels. The printing mechanism may alternatively be positioned above the conveyer belt. One embodiment of the control circuitry for each stepping motor and type wheel is shown in Fig. 4. A counter in control circuit 120 feeds the measurement value in pure binary form to leads 121-126. Initially a control signal 138 passes via OR gate 134 to enable gates 127-132 so that the count is entered into a counter 139. AND gate 141 is enabled by a control signal on lead 144 and the non zero count in counter 139 (resulting in the enabling of OR gate 140 connected to the counter output) to pass clock pulses from generator 143 to (1) drive stepping motor 140 and hence the type wheel in one direction and (2) decrement the counter 139. At a zero count of the counter, i.e. when the associated type wheel has been correctly positioned by the stepping motor, OR gate 140 is closed to stop the supply of clock pulses. After printing OR gate 134 is again enabled so that the count is again entered into counter 139. AND gate 142 is then enabled by a signal on lead 136 so that pulses from generator 143 drive the stepping motor in the reverse direction until the count in the counter 139 is zeroized (i.e. until the type wheels are returned to their zero position). In a second embodiment of the control circuit (Fig. 5) in which each digit of the count is stored in binary coded decimal form in bi-stables 165- 158, the first pulse from a clock generator passes via gate 170 to prime gate 161 which, if enabled by the output of bi-stable 155, steps motor 169 in one direction via OR gate 165 and AND gate 166 primed by a control signal. The second and third pulses from the generator pass via gates 171 to prime gate 162 which consequently passes two pulses if bi-stable 156 is set to step the motor. The fourth-seventh pulses pass via gate 172 to AND gate 173 to prime both gates 163 and 164 so that if either bi-stable 157 or 158 is set four pulses are applied to the motor. The eightheleventh pulses pass via gate 174 and gate 173 to prime gate 164 so that if bi-stable 158 is set a further four pulses are applied to the motor. To reset each type wheel the above process is repeated except that AND gate 167 is primed so that the motor is stepped in the reverse direction.