Patent GB-933014-A (GB)
Title: Improvements in or relating to apparatus for the examination of fibres for stapling processes
IPC: G01B11/02
Filed: 1960-09-06
Abstract: 933,014. Testing fibres. UNIVERSITY OF TENNESSEE RESEARCH CORPORATION. Sept. 6, 1960 [Sept. 10, 1959], No. 30669/60. Class 120 (3). [Also in Group XL (b)] An instrument for deriving information concerning the lengths of fibres from a sample of substantially parallel fibres comprises means for holding the fibres along a grip line, means for sensing the number of fibres intersecting a parallel scan line, means for moving the holding means and the sensing means relative to each other, and control means responsive to both the number of fibres sensed at a scan line and the distance between the grip line and the scan line and operating to control said relative movement. The apparatus is designed to give an indication of the amount of protrusion of a predetermined percentage of the total number of fibres which protrude or extend a fixed small distance beyond the gripping line of a bundle of fibres. In relation to the graph, Fig. 2, the abscissa " a " indicates the number of fibres extending a distance " b " from the scanning line, and for a portion " c " of these fibres the protrusion is represented by the ordinate " d." The fibre sample 4 is mounted by a movable holder 6 between a photo-electric cell 14 and a light source 8 with a slit 12 in a diaphragm 10 defining the scanning line. In the operation of the system tapping points, 36, 54 on potentiometers 38, 48 are manually adjusted according to desired values of b and c, and switches 39, 58, 64, 66 and 70 are closed. Unbalance of signals fed from the tapping 32 on a potentiometer 34 and the tapping 36 on the potentiometer 38 to a converter-amplifier 40 operates a motor 24 to move the tapping 32 to a position to effect balance and also to move the holder 6 to a position corresponding to the distance b which is displayed on an indicator 26. The tapping 18 on potentiometer 16 is normally such that no signal is applied to a converter 20. The movement of the holder 6 produces a signal from the photo cell 14 and via motor 28 moves the tapping 18 on the potentiometer 16 to restore the zero input to the circuit 20. The motor 28 also moves a tapping point 42 on potentiometer 44 so that its position is representative of the number of fibres intersecting the scan line. Also, the potentials from the potentiometers 44, 46 are fed via an amplifierconverter 56 and unbalance causes a motor 52 to move a tapping point 50 to a position of balance corresponding to the position of tapping point 42. The switches 58, 64, 66, 70 are now opened and switches 60, 62, 68 are closed. The inputs to the amplifier 56 from the tapping points 42, 54 are now different and motor 28 rotates and moves tapping point 42 to effect balance. The operation of the motor 28 also shifts the tapping point 18 on the potentiometer 16 to produce from converter 20 a signal which rotates motor 24 to move the holder 6 until the signal applied from the tapping point is restored to zero. The rotation of the motor 24 also actuates the register device 26 to indicate the protrusion d of the fibres forming a predetermined percentage of the total number of fibres having a small protrusion b relative to the gripping line. A detailed circuit arrangement operated by switches corresponding to different values of " b," and further switches allocated to percentages corresponding to different valves of " c " is described in connection with Fig. 3 (not shown). U.S.A. Specifications 2,299,983 and 2,648,251 are referred to.