Kiosk Installation: 'The Early Years'
Lifting and Turning the Kiosk:
The larger number of trailers of the latest type that have been obtained, permitted the elimination of the wire ropes which frayed and stretched somewhat after continual use. The pair of rotatable interconnected radius arms are now secured to a segment of a gear wheel which is moved through approximately 120 degrees by means of a worm wheel. To reduce the manual effort required to turn this worm gearing the driving shaft is chain-geared to the operating handle located at the front nearside of the trailer.
The effort exerted by the operator of the earlier type of trailer when raising or lowering the kiosk varied appreciably according to the outreach of the centre of gravity of the kiosk from the pivoting point of the radius arms. In order to reduce the maximum effort required a system of assistor gears has been included in the later type.
The assistor gear consists primarily of a strong spring mounted in the centre of the chassis. This spring is compressed by a lever when the bolster is farthest from the central vertical position and is moving downwards. The stored energy in the spring is utilised to assist the operator when the bolster is moving upwards with the kiosk. Similarly, when the radius arms are in the position for loading the kiosk, the spring is compressed by means of a second lever via a steel rope attached to the bolster. The energy stored in the spring then assists the operator in the initial lifting of the kiosk during loading and unloading. The extent of the assistance afforded to the operator by the gear is such to reduce the manual effort by approximately 50% at those stages when the maximum effort is exerted.