downward movement to overcome the spring force of plunger 41a it is desirable to make the number of plungers 41a per support casing 41 decided into the number of trays 2 a positive whole number each tray 2 is provided on its rear end the end opposite to the sheet entry end with a pair of rear end support tray pins 2b hereinafter called rear end pins which laterally extend from and are rigidly fixed respectively to opposite sides of the tray as exemplified in fig5 each rear end pin 2b is slidably held in a slide groove 43a provided in a pin support frame 43 the slide grooves 43a are vertically spaced by an amount equal to the spacing of the trays 2 the slide grooves 43a have a steeper backward angle of inclination than do trays 2 as shown in fig2 the pin support frame 43 is fastened to a support column 50 by screws 51 furthermore the support column 50 is secured to a base 49 as is guide shaft 24 an upper tray is raised by the screw cam 20 by means of the entry tray pin 2a and a tray entry 44 is widely formed between the upper tray 2 above screw cam 20 and lower tray 2.