Fig. 1, in page 428, shows a plan of switches for a single crossing. The switches may be formed various ways, but the patentee recommends the following; viz. rivetting the bars, whether two or more, to a flat plate c half an inch thick, 10 or 12 inches wide, and 15 feet long; the bars having a section to correspond with the rails, are rivetted to this plate c; one rail being bent to correspond with the curve or cross line, and the other straight to correspond with the main line (if straight), or should both be curved then both bars are curved to correspond with their respective lines: upon the back or underside the centres f and stud plates g g are rivetted.
The best shape is to make them round, with a flat face or flange, and the studs welded into them. The bed planks a are formed of oak planks 3 inches thick, and at regular distances the stud plates I I are let into the oak bed planks, rising about l-8th of an inch above the surface, so that the iron plates ride upon the iron surfaces of the stud plates, with less friction than if they were level with the timber. Towards each extremity of the stud plates studs are raised, which confine the switches within their limits of motion, and form supports against which they rest, and thus acquire a certaiu degree of solidity, whilst the trains pass over them. The oak planks are then let into the longitudinal timbers of the railway, if formed upon that plan, or bolted to timber of sufficient solidity and united in the usual way with the rails, if the system of stone blocks and iron chairs be employed. A plate k forms the centre plate for the centre studs to work in; a hole is bored in it to suit the pin, and it is then bolted to the bed planks, and thus the switches are secured at the end.
Two radius bars h h, connect the switches in the usual manner, the longer rod passes to the lever l, by which the movement of the switch is effected; the lever L shown in the plan, acts in the manner of a treadle, and the upright bar o, as a string or holding bar: thus, a man depresses the end of the lever l, by pressing his foot upon the flat part x, and laying hold by the cross head p, of the upright bar o, he exerts a force as if he were lifting a weight, by which means his weight and muscular force are brought into action at the same time, and he is able to lift the counterbalance weight m of nearly three hundred weight with great ease: thus a very heavy counterbalance weight may be employed to keep the switch open. The upright bar o is flexible, and formed like a spring, with a notch or stud which shuts under the lower side of the lever l when the switch is open, or right for the line, and prevents the possibility of the train opening it as it passes over it; the counterbalance weight is enclosed in the usual way, in the ground box n. d d d d, are the rails of the line, and the cross line at the head of the switch, and e e the rails at the foot of the switch.
The oak bed planks are made long enough so that about 18 inches or two feet of the rails at each end lie upon it; thus making the whole steady and secure. A hand lever may be employed instead of the treadle, or any other suitable means to work the switch; also if the crossing be a compound one, or any number of turn-outs take place from one line, then each plate has rivetted to it as many bars as there are separate lines, and each bar must be bent or otherwise as before explained.
The safety-guard rail o. shown in the figures, is contrived with the view of preventing an engine or train running off the rails, by the switches being placed wrong. As has been before observed, the balance weight keeps the switch right for the line, but whilst right for the line it is wrong for the cross line; in this case, if an engine were to pass along the switch of the cross, the wheel would impinge against the guard rail q, push the switch over, and make it right for that line, and when it is passed over, the switch will shut again by the reaction of the counterbalance, and keep it right for the main line as before stated.
Fig. 2, in page 430, shows a modification of these switches: the main features of this arrangement are the same as those of the former one, the bars being bent to the curves of the respective lines to which they belong, and the same clearance spaces left; the principal difference between the two is that in the latter case the switch has a movement transversely to the line, and not moving from a centre as before: the bars are bolted to a cross frame of timber a, held together by bolts passing through the frame, and the transverse movement of the frame is produced by the levers l l l, fixed upon the lying shaft f; to these levers are attached the connecting links h h h, connected with joints fixed in the transverse frame; then by moving the long hand lever l l, either of the bars of the switches is brought in contact with the main or cross lines at will: stopping pieces n n n are placed to confine the movement of the switch as in the case of Fig. 1. m is a cast-iron standard for the lever to work against, and holes are made in the segment for a pin to be inserted, to confine the lever in the usual way. d d d' d' are the bars of the switches, d d d' d' the bars of the line and cross line, and e e the bars of the line at the foot of switch..
Fig. 3, in page 431, represents an adaptation of these switches to points or crossings. The switches are made in the same way as those previously described, except that they are shorter, the length whatever it may be being determined by the distance for clearance between the rails which may be fixed upon by the engineer, and for which 3 inches will be generally found to be sufficient. The point of contact for the foot of the switch, may be at the point where the inner edges intersect each other, or at any place between that point where the outer edges of the rails intersect each other; then measure from this point until the rails open 3 inches (or the space required for clearance) which gives the place for the head or centre end of the switch: stud or joggle pieces are placed as before described, to confine the switches within their limits of motion. The switches may be either double or single and accordingly one is shown as single, and the other as double in the figure, but in all cases the head or centre of the switch should be placed as shown in this figure, because whichever way the switch is laid, it is held in its place by the fixed stud pieces 11, so that a train passing over the switches, has a tendency by its action to push the rails out to keep the switches the more steady.
h h is the connecting link worked by the bell crank m, which crank may be connected with a lever, cam,crank,or eccentric by means of the link N: the rod slides through the guides f f f f which answer the purpose of the guide boxes and glands: these guide pieces as well as the guide boxes are fixed in any usual, secure, and suitable manner. By the movement of the bell crank, the connecting link h is moved towards the right hand, and the rods e e are made to occupy the position indicated by the dotted lines: the switches are then thrown into gear with the other or cross lines.
Fig. 4, in page 432, represents in plan these switches arranged to form the points of a double crossing, where m m shows the main lines, and y y one pair of cross lines, and h h another pair of cross lines. The intersections of the cross lines is shown by the dotted lines; thus the bars d d alternately make the connexion with y y and h h: the switches are formed in the same way as those before described, and joggle or stud pieces I I I I r, are provided to limit the motion of the switches as before described. b shows the circular case in which the upright shaft of the hand crank or lever works. Upon the lower end of the upright shaft a three-pronged crank is formed, and to one of these cranks or prongs the connecting link h is united by a pin joint; each of these prongs catches into the latch e, as it passes over it, so that when the centre prong is held in the latch as shown in the figure, the main line M m is complete as drawn, but when the handle is moved to the one side or the other, and the switch made to complete either of the cross lines y or h, then the prong c y or c h is held in the latch, and retains the switch in its position.
The latch e is depressed by a man placing his foot upon the spring s, which when released raises the latch again: the rods h h connect the switches together, and the switches are based upon timber as before described, or are placed in a cast-iron bed-plate, or finished in any other usual and suitable manner. The centre studs f f work in cast-iron bed-plates.