Abstract: An improved automatic loading tray comprising a frame having lateral side rails and a pair of longitudinal cross-bar arrangements spaced from each other and secured to the lateral side rails for reciprocal movement therealong, each cross-bar arrangement including two laterally spaced substantially parallel bars, an inner and outer bar, said inner bar nearer said other cross-bar arrangement than said outer bar, and means to limit maximum separation between said two spaced bars, rotatable spacer means for positioning between said spaced bars, said rotatable means being of substantially uniform non-circular or non-square cross-section looking downwardly thereon for causing the bars to abut said means to limit their maximum separation when said rotatable means is positioned between said bars in a first position and for causing said bar to loosely seat between said means to limit maximum separation when said rotatable means is in a second position, and means to rotate said rotatable spacer means.

Abstract: The circuit arrangement includes a measuring device having an output circuit connected to one input of a comparator, and including a voltage divider whose tap is connected to the other input of the comparator. A storage capacitor is connected to the tap of the voltage divider and to such other input of the comparator and provides a reference voltage bearing a fixed relation to, but always lower than, the signal voltage of the measuring device in the quiescent state of the arrangement. A bias voltage may be applied to the tap of the voltage divider. When the measuring device responds to a test object, the voltages at the comparator inputs are so switched that the reference voltage is held above the signal voltage until the measuring device returns to the quiescent state. In the quiescent state, the signal voltage exceeds the reference voltage and the comparator, changing back to the zero state, restores the initial condition of the two voltages.