For use with a multiple-frame system, the cables are arranged in units between supports, as shown in Fig. 6. The compensating action is similar, the tendency being to level the entire course of the load. The weight of the car and load only is compensated, and since the weight of the cable will cause a sag, the course cannot be level, but may approach this condition.
Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
This Interesting Model Cableway was Built by a Boy for Play and Experimental Purposes: The Principle by Which the Weight of the Car is Compensated in Single and Multiple Systems is Indicated in the Diagrams Above. Cars Propelled by Sail Rigging or by a Small Battery Motor may Also be Used
A model of the compensated cableway, as shown in the [page plate], or on a smaller scale, may be made by a boy of fair mechanical skill. For experimental purposes the detail may, of course, be refined to a high grade of workmanship, if desired. The size and dimensions of the parts need not be proportioned precisely as shown, but may depend more or less upon the materials available. The track cable should be made of galvanized-iron wire, the compensating cable of fishline, and the towers of 1-in. stuff, the width of the pieces making up the A-frames being increased in proportion to the height. Grooved pulley wheels, set in housings fixed to the top of the A-frames, carry the compensating cable. These may be made of wood, built up in three sections, to provide a flange on each side of the cable groove. The A-frames should be joined strongly at the top, and braced to anchors, sunk into the ground as shown. The hooks from which the track cable is suspended are made of heavy wire, bent so as not to interfere with the H-frame hanger supporting the car, and looped around the cable.
Various types of hangers may be devised to house the two pulley wheels which ride on the track cable. A simple H-frame hanger is shown in the detail sketch in the [page plate]. The grooved pulley wheels are set on bolts, and a heavy wire is bent and set through the center block as a support for the car. For experimental purposes, or even for play, when it is not desired to make a more elaborate car, a wooden block or other object of sufficient weight may be used as a load. An interesting feature of the work, especially for a boy, is to devise a realistic coach model, as suggested in the sketch. A wooden block forms the base, and the roof and platforms are made of sheet metal. The windows and doors are painted on the metal. The inventive boy may, of course, build a car with a hollow metal or wooden body, and weight it properly to provide the necessary load.
The motive power is provided by means of a cord, or traction cable, carried around two large grooved pulleys, mounted in supports fixed to the landing stages at each end of the cableway. They are made of wood, a suitable groove being cut around the edge with a saw, and smoothed with a small round file, or sandpaper wrapped over a round rod. The traction pulley is turned by means of a crank, set on the bolt which is used as an axle. The traction cable must be drawn sufficiently taut to provide the necessary pressure on the grooved pulleys, or it will slip. Rosin applied to the pulleys and the cable will tend to prevent this.
Fig. 7
The Car is Propelled by the Wind Action on a Sail Controlled Like the Main Sheet of a Sailboat in Tacking. The Trigger Device Releases the Sail, Reversing the Course of the Car