Patent GB-1306091-A (GB)
IPC: B23D36/00
Filed: 1970-02-11
Abstract: 1306091 Controlling volume GEPIPARI TECHNOLOGIAI INTEZET and KOHOES GEPIPARI MlNISZTERIUM TERVEZO IRODAI 11 Feb 1970 [12 Feb 1969] 6672/70 Heading G4H [Also in Division B3] In a device for controlling the volume of a length of rod being cut off, the length is sensed by means of friction rollers 3, and the crosssectional area of the rods is measured by means of induction coil 4. The length of the rod cut off is adjusted by means of an end stop 7, whose position is controlled by means of cam 10. Cam 10 is rotated in response to the output of a control unit in which volume is continually monitored.  Measuring the travel of the rod.-The friction wheel 3 drives a stepping motor 37, Fig. 5, by means of a mechanical transmission unit 35. The output of two of the coils of the stepping rotor 38, 38<SP>1</SP> are fed via amplitude limiter 41, shaper 42 and pulse former 43 to logic circuit 46. By detecting the relative times of arrivals of pulses from coils 38 and 38<SP>1</SP> the logic unit 46 determines the direction in which the friction roller 3 is rotating. And produces an output on either line 44 or 44<SP>1</SP> accordingly. In an alternative embodiment the same result is achieved by means of two stepping motors driven by ratchets (36) and (36<SP>1</SP>), Fig. 4 (not shown). In yet another embodiment no means for sensing the direction of friction wheel 3 is provided. The logic unit 46 which is shown in Fig. 7, receives alternately a pulse from units 43, 43<SP>1</SP> on respective lines 47, 47<SP>1</SP> and determines which of two time intervals defined by three consecutive pulses is the longest. The arrival of the first pulse causes pulse generator 52 to feed pulses into reversable counter 53. This is achieved by means of the logic elements comprising flip-flops 48, 48<SP>1</SP>, AND gates 55, 55<SP>1</SP>, 59, flip-flop 54, OR gate 62. The arrival of the second pulse reverses the direction of counting of counter 53. If the counter passes through zero, i.e. if the first time interval is the shorter, an output is produced on AND gate 60 which causes outputs to appear via various gating circuits at either 65 or 65<SP>1</SP> according as the pulse was incident at 47 or 47<SP>1</SP>. If on the other hand the third pulse arrives before counter 53 has passed through zero the logic units 51 cause a pulse incident at 47 to appear at 65<SP>1</SP> and a pulse incident at 47<SP>1</SP> to appear at 65. The length of rod fed through the material is thus represented by a series of equally weighted pulses. Measuring the area of cross-section.-The area of cross-section is sensed by means of an inductance coil 4 which forms part of a tank circuit of an oscillator. The oscillator is so designed that changes in the area of cross-section cause changes in frequency which are proportional to the changes in area and also dependent upon the cross-sectional area. The outputs from the length measuring circuits and the cross-sectional area measuring circuits are fed into an arithmetic unit. This produces a parameter which gives a measure of volume of the rod. This volume is compared with a stored value, and whenthe two values are equal the cutting operation is initiated.