| 摘要 |
1455870 Drive for bag or envelope making machine WINKLER & DUNNEBIER MASCHINENFABRIK UND EISENGIESSEREI KG 27 Nov 1973 [27 Nov 1972] 54865/73 Heading B5D [Also in Divisions B8 and F2] In a machine for making envelopes or bags from blanks, the drives of echeloning conveyer belts 11, blank drawing-out conveyer belts 31 and conveyer chains 41, 42 of a gum drying line 4 are interconnected by gearing in predetermined ratios, a gear box 70 is provided between a constant speed main driving shaft 72 and the interconnected drives, and a control arrangement is further provided for controlling the selection of the appropriate gear ratio in the gear box 70. Transport conveyer belts (51, 61) Fig. 2 (not shown) which are located downstream of the drying line 4, also have their drives interconnected with those of the abovementioned belts and chains 11, 31, 41 and 42. The gear box 70 is of the draw-key speed change type whose gear change spindle 73 is actuated by a control motor such as an electric motor 75 or a hydraulic or pneumatic piston and cylinder unit. The control motor is operated in response to signals from a comparator circuit which compares voltages generated across potentiometers and representing the actual speed of the output shaft 71 of the gear box 70 and a desired speed for said out-put shaft 71. The gear change spindle 173 can be locked in its desired position by a solenoid operated latch arrangement 76-79. The machine also includes echeloning discs 6 which have a higher blank conveying speed than the conveyer belts 11 with which they cooperate to echelon the blanks, and a closure flap gumming arrangement 21-24. |
