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Engineers and Mechanics Encyclopedia 1839: Railways: T. F. Bergin

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For preventing or lessening the concussions to railway carriages upon stopping or starting, a contrivance, called the "buffing apparatus," has been resorted to on the Liverpool and Manchester, and other railways. This apparatus consists of a series of rods and levers, acting on springs similar to the elliptical carriage springs; the contrivance is complex and expensive, and it is found to communicate to the carriages of a train a swinging lateral motion, which causes much friction, and renders the vehicles liable to be thrown off the rails.

To obviate these disadvantages, T. F. Bergin, of Dublin, took out a patent for an invention on the 4th March, 1835, which consists of a combination of coiled springs, with rods proceeding from end to end of the carriage, designed not only to prevent the concussions at stopping or starting, but likewise any prejudicial effects taking place, in the event of two trains coming into contact; also to receive and transmit the motion of one carriage to another, free from that abruptness which is alike unpleasant to the passengers and detrimental to the vehicles.

The following Fig. 1 represents a side elevation of one of the Dublin and Kingstown Railway carriages, with Mr. Bergin's invention applied to the same.

Fig. 2 is a plan of the under part of the same, the body being removed. A-a represents a slight frame, made of two similar plates of iron, screwed to each other about three inches apart, and resting upon turned bearings in the centres of the axles. A wrought-iron tube b-b, about three inches in diameter, the entire length of the carriage, and extending about two feet beyond each end, is supported on this frame by rollers, which allows the tube to be moved thereon lengthways with facility. On this tube is placed, at either end, within the frame of the carriage, about four feet of helical springs c-c, of graduated strengths; one end of each of these sets of springs abuts against a strong collar d, fixed to the tube b, and the other end against a small box of iron attached to the frame, and furnished with one of the bearing rollers before-mentioned, also with two friction-rollers resting against the inner side of the carriage-frame end.

To each extremity of the tube b-b is attached a buffer-head f-f, by means of a rod of iron passing through the tube, and connected to the buffer-heads by screwed nuts sunken below their surfaces. At the back of each buffer-head is a cross-bar y, to which by chains and hooks, the carriages are attached together. This apparatus lies loosely on the axles, and is perfectly independent of the frame work of the carriage, which is sustained by springs in the usual manner; and there are long vertical slots made in the framing, through which the buffing-tube passes, which permits the frame to rise or fall, according to the pressure of the load thereon, without affecting the height of the buffing apparatus above the road.

The action is as follows:- The train being moved in the direction of the arrows, the locomotive power is applied to the cross-bar y, and draws forward the central tube b, thereby compressing the springs c-c between the collar d and the friction roller-box f, which rests against the end of the carriage frame, without moving the latter until the elastic force of the compressed springs becomes sufficient to overcome the resistance presented by the friction of the carriage and load.

The carriage then begins to move forward so slowly, as almost to be imperceptible to persons seated within; the second and each succeeding carriage in the train is by similar means brought from a state of rest into motion. In case of one carriage running against another, the resistance is offered by the furthest end; the effect being to drive the tube b forward, compressing the springs at the opposite end from which the concussion is given; and the carriage will be but little affected by the blow, until the elasticity communicated to the springs, by compression, overpowers the resistance of the carriage, which then begins to move, actuated by a force just sufficient to start it.

The coiled springs, which as before stated, are four feet in length, have a range of action of about two feet, beginning to be compressed by a force equal to about twenty pounds, and presenting a total resistance to entire compression of upwards of two tons. A spring of this strength, the patentee states, has been found suitable for carriages weighing, when loaded, about four tons.

It will be observed, that the entire resistance to the action of the springs is on the ends of the carriage frame; the middle of each is armed with a strong plate of iron, about fifteen inches square, through which pass the tension rods h-h, Fig. 2, to the outer angles of the opposite ends of the frame; consequently, these rods receive the entire force of the springs. The springs at either end of each carriage act totally independent of those at the other end, and of all the carriages in the train, except that to which they are attached; each has therefore to bear only its own share of the resistance of the entire train, the sum of which is made up of the separate resistances of all the springs acted upon. Mr. Bergin states, the advantages anticipated from his invention have already been fully realized, by the perfectly steady motion of the trains to which it has been applied; and he contemplates its employment to locomotive carriages on the common road.

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