CARRIERS, MECHANICAL. 



97 



sion of cash alone to and from the cashier's 

 desk. Each carrier consists of two hollow 

 hemispheres fastened together by any of the 

 simple mechanical devices, and provided with 

 interior springs which hold the coin and bills 

 near the center of gravity after the two hemis- 

 pheres are joined together. The balls are of 

 as many different sizes as there are stations to 

 be served, varying perhaps of an inch in their 

 succcesive diameters. The railway consists in 

 its simplest form of two slightly divergent 

 rails (see Fig. 7) laid at a sufficient angle of in- 

 clination from the cashier's desk C, past the 

 salesmen's stations S S' S". Now, suppose the 

 three balls to be started on the incline from 

 the cashier's desk, number 3 will fall between 

 the rails at S, number 2 will follow suit at S', 

 and number 1 will go on to the end of the line. 

 Under the rails at each station is a net or 

 pocket into which the balls drop convenient 

 to the salesman's hand. For the return of the 

 balls to the cashier a set of parallel rails is 

 provided, inclined in the contrary direction, 

 and various devices are resorted to for hoisting 

 the balls to the rails where they are out of 

 reach. Several systems provide baskets of 

 different kinds, which are hoisted by pulley in- 

 to position, and release the balls through vari- 

 ous mechanical devices. One system adopts a 

 flexible tube, large enough to receive the balls. 

 The loaded ball is dropped into the open end 

 of this tube which is hoisted, until the ball 

 rolls out upon the rails, and goes its way. 

 (See dotted lines in lower section of Fig. 7.) 



Another plan provides a system of tubes 

 communicating with a main tube leading to 

 the cashier's desk, which must usually be on 



BALL-CARRIER SYSTEM. 



the floor below the salesroom. The small 

 tubes rise through the counter, and the sales- 

 man merely drops in the balls destined for the 

 cashier. They are returned to the salesmen 

 through a separate tube, or upon rails to which 

 they are necessarily hoisted mechanically. 

 VOL. xxvii. 7 A 



This is distinct from the pneumatic systems 

 described farther on. 



The best ball- carrier systems, as used at 

 present, are either modifications of the diver- 

 gent track, or use a parallel track with auto- 

 matically-opening switches or traps, for the 

 operation of which many most ingenious de- 



GRAVITY PARCEL-CARRIER. 



vices are employed. The fundamental idea of 

 most of these is the impact of a moving ball 

 against a trigger so placed that only a ball of a 

 certain size can touch it. The trigger releases 

 a catch, which allows a trap to fall open, or 

 disengages a switch, like those of an ordinary 

 railway, which turns the ball off upon a little 

 side platform or cage that can be lowered to 

 the counter if not within reach, or hoisted to 

 the return track when desired. Fig. 8 shows 

 a ball-carrier system in operation. The arrows 

 indicate the direction of the balls going and 

 returning. C is the cashier, and S the station 

 with the automatic appliances for stopping the 

 balls and lowering them to the counter. 



Parcel-carriers have the advantage of doing 

 double duty, since they serve as cash-carriers 

 as well. A simple and effective one is shown 

 in operation in Fig. 9. The hoisting-appara- 

 tus at the station S (similar to that shown 

 in Fig. 4) raises the car to the wire, the 

 wheels automatically adjusting themselves. 

 Then the same apparatus hoists the wire itself 

 till the grade is sufficiently changed. This sys- 

 tem requires a separate wire for each sales- 

 man's station. 



More elaborate systems use but a single fixed 

 rail instead of a wire. Switches are provided 

 at each station, and a simple hoisting-apparatus 

 enables the salesman to lower the carrier or 

 hoist it to either of the rails overhead. The 

 switching devices used for carriers having 

 wheels are similar to those described under 

 ball- carriers, but are somewhat more direct 

 and certain in operation. In Fig. 10, for in- 

 stance, A is a frame set over the track, and B 

 an attachment to a carrier. Each of these 

 frames is pierced with holes, which register 

 upon radii of the same circle. C is a pin, 

 which can be set in any hole on the carrier, 



