Patent GB-1268671-A (GB)
Title: Engine testing apparatus
IPC: G01R27/20
Filed: 1969-03-27
Abstract: 1,268,671. Testing ignition circuits. MARQUETTE CORP. March 27, 1969 [April 10, 1968], No.16136/69. Heading G1U. The condition of the breaker points 17, 18 in the ignition circuit of an internal combustion engine is checked while the engine is running by determining the voltage across the points during the periods when they are closed, this voltage being a function of the resistance across the points. As the engine idles there appears at the input terminals 32, 42 of measuring circuit 10 a pulsating input voltage having a high value while the points are open and a low value, which is the value to be measured, while the points are closed. Whilst the input is low zeners 45, 47 are blocked and thus a bias proportional to the inputs is applied to the base of transistor 37. Whilst the input is high, however, zeners 45, 47 conduct and so a fixed bias, independent of the input, is applied to transistor 37. Thus the mean collector-emitter voltage of transistor 37, to which meter 36 responds, is a measure of the voltage across the points while they are closed. Preferably the fixed bias applied whilst the points are open is so adjusted by means of rheostats 57, 58 that for points which are just satisfactory the bias applied to transistor 37 will be the same whether the points are open or closed, giving a predetermined reading on the meter. If the points are in an unsatisfactory condition the voltage across them whilst they are closed will rise and the meter reading will therefore fall below this value. Since the bias applied to transistor 37 when the input voltage is low may be insufficient to cause it to conduct, an additional fixed bias is applied through resistor 65. When the input voltage is high transistor 50 is switched on to remove this additional bias. Diode 55 and capacitor 56 respectively remove any negative or high frequency components in the voltage applied to transistor 50. 1,268,679. Check-weighing apparatus. GOLDEN WONDER Ltd. June 16, 1970 [July 25, 1969], No.37387/69. Heading G1W. A check-weigher for light objects comprises a weigh pan 10, to which the articles are singly supplied, mounted to pivot downwards in response to the weight of the article, and on air jet system for removal of an article from the pan in one of two directions depending upon the angle of the weigh pan is characterized in that the operation of the air jet system is controlled by means responsive to the degree of tilt of the weigh pan. The weigh pan 10 may be provided with a counterbalancing beam 14 and the means controlling the operation of the air jet system may be switch means operable by the pivotal movement of the beam assembly. Two air nozzles 24, 25 may be provided, one 24 arranged to blow an article from the weigh pan and the other 25 arranged to direct a jet of air against the underside of the pan causing the pan to return to its "empty" position and the article on it to slide off the pan in direction other than the first jet direction. Damping means 31, 32 may be provided for the weight pan, a first damping device 31 acting on the weigh pan and a second damping device 32 acting on the beam. The weigh pan 10 may have openings 16 in the base thereof adjacent the pivot axis and fixed vertical pins 17 may project upwards therethrough to provide stops for an article whenever the pan tilts downwards under the action of an article of acceptable weight.