Patent GB-325973-A (GB)
Title: Improvements in and relating to moving or changing advertising and display apparatus or signs
IPC: G09F11/295
Filed: 1929-01-31
Abstract: 325,973. Whitfield, J., Brander, D., and Ronald, F. A. Jan. 31, 1929. Reel and non-endless web apparatus; actuating. -An automatic advertising appliance for displaying advertising matter on a non-endless band moving between a lamp and a display opening comprises a main driving solenoid, time-lag and unlocking solenoids and reversing solenoids, the mechanism when started producing successive display of the advertisements as the web is wound on to one roller and off another roller, the winding being compensated by means of an overrunning drive and the movement of the web being automatically reversed at the ends of its travel. The display band 94 is unwound from one magazine roller 73 and wound on the other one 74 and vice versa, passing round guide rollers 75 and a driving roller 69 and behind a display opening 100. When the starting switch is closed a main solenoid M and an unlocking solenoid U are energized. The plunger of the unlocking solenoid raises a rod 40 and removes a locking bar 41 from a notched disc 43 on the driving shaft 44. The plunger 22 of the main solenoid carries a. double-sided rack 24 engaging a pair of pinions 25. The pinions 25 are mounted on sleeves and are provided with pawls engageable alternatively with glaring on the driving shaft 44, so rotating it in one or other direction, the driving shaft carrying a spur wheel 67 engaging a gear wheel 68 on the driving roller 69 and being connected through bevel gearing 72 to the magazine rollers. The gearing is such that the magazine rollers are over-run, the magazine rollers being provided with friction clutches and free-wheel clutches 79 to allow this and to compensate for the varying effective diameters of the rollers during the winding operation. The upward movement of the main solenoid plunger 22 short circuits the unlocking solenoid winding and so resets the locking device by means of a bridging contact piece 27 on the solenoid frame which engages contacts 28<a> in the circuit of the unlocking solenoid. Towards the end of the upward movement of the plunger 22, an adjustable rod 30 on the solenoid frame tilts a bent lever 31 which through linkage tilts a plate 33 and breaks the contacts 34 of a time lag solenoid T so de-energizing that solenoid. Dashpots 37 on the plate 33 provide for adjustment of the return stroke of the plate when the plunger 22 falls. Reversing mechantism : two reversing solenoids R are mounted in proximity and provided with a tiltable T-shaped armature engaging one end of a tiltable lever 49 pivotally connected to the sleeves of the pinions 25. Energization of the appropriate reversing solenoid is effected at the end of the wind by slots &c. in the display band registering with two of three metal contact rollers 86 which engage a metallic sleeve on the roller 15 and complete the circuit of the solenoid, so that pinions 25 and the drive are reversed. The time lag solenoid T, Fig. 3, has a plunger 11 pressed downwards by a spring 12 and having a downward extension 15 forming the piston of a dashpot 14 provided with an adjustable admission valve 16 and a quick release valve 17. The plunger carries a contact ring 18 adapted when raised to bridge contacts 19 and close the main circuit, so energizing the main and unlocking circuits after each interval for display. A lamp 91 is provided inside the casing for illumination. Specification 311,014 is referred to.