US157821A - Improvement in car-springs - Google Patents

Description

UNITED STATES PATENT OrEroE.

WALTER P. HANSELL, OF PITTSBURG, PENNSYLVANIA.

IMPROVEMENT IN CAR-SPRINGS.

Specification forming part of Letters Patent No. 157,821, dated December l5, 1374; application lled November 24, 1874.

To all whom it may con-cera:

Be it known that I, WALTER P. HANsELL, of Pittsburg, in the county of Allegheny and State of Pennsylvania,have invented certain new and useful Improvements in Gar-Spring; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part .of this specification.

The invention herein is a carspring, made from a steel bar of greater width than thickness, coiled upon its edge in the form of two frustums of cones united at their apexes, af-

, fording broad bearings at both ends, with a center of comparatively small diameter and of greater strength, and giving the spring increased and easier action, without liability to telescope its coils.

Heretofore car-springs have been made in spiral form, of equal diameter throughout. Such springs required comparatively a very large bar through them, or some additional means to hold them in proper position; besides, the elasticity and strength are uniform throughout the coils, and not adapted to varying pressure. Springs have also been made tapering from end to end, one coil coiled around another, but these afford but one broad bearing-surface.

To overcome these objections, and, further, to lessen the friction to an approximate minimum, and give the spring broad bearings at both ends, and to give the spring different degrees of strength, are the principal objects of this invention, which consists in a metallic bar coiled so that the diameters ofthe coils decrease from the outer to the middle coils, and in which the coiled bar has a greater width than thickness.

In the accompanying drawings, Figure l represents an elevation of a spring embracing my invention; Fig. 2, a vert-ical section ofthe sa-me, showing also the double-cone mandrel upon which the spring is formed; and Fig. 3, a top view of the spring.

A rectangular bar of metal, A, of greater width than thickness, is coiled into a spring by means of a somewhat double-cone-shaped mandrel, B, having their apexes joined, so that the end coils C afford broad bearings for the spring-plates, and the inner coil D D, or coils, decrease in diameter to the middle coils E E, which are designed to be of equal diameter. used the coils E E alone will touch it, the other coils being entirely free from contact therewith, thus reducing friction. The outer coils under pressure will yield more readily than the inner ones, thus adapting the spring to varying loads. Both ends of the spring being equally yielding, and the middle portion being the least so, a uniform act-ion and great strength are secured, in which the coils of the least diameter are made the strongest.

Any form of bar may be used, but a bar of greater width than thickness will prevent telescoping of the coils under pressure, as one coil will strike against another above the center of the next coil.

In addition to these advantages the spring can be produced at a comparatively great sav- .ing of metal, in consequence of the reduction of the middle coils.

The spring can be used with or without plates at top and bottom.

A bar of about one-half inch thick, and one and a quarter inch broad, will make a good spring, but these proportions may be varied.

Any number of these springs can be grouped together.

lt will be observed that the double taper-A ing spring gives a broad flat bearing-surface at each end, with the inner edges only of the inner small coils' forming the central bearing upon the vertical holding-bar, and that these inner small coils have equal spring with the outer larger ones, while giving greater central strength to the spring.

Iam aware that a spring, tapering from its ends to the center, so that its coils decrease from the outer to the inner coils, has been proposed in what is known as the double volute spring, the coils of which, formed from a thin plate of peculiar construction, fold upon and within each other edgewise, in order that they may telescope' the one with the other, and in which the inner smaller coils present a solid and inelastic center, standing edgewise to re- Vhen a center bar or support is flat bar of steel, of greater width than thickness, and having its coils with broad flat surfaces, decreasing in diameter from each end, Y whereby the coils are prevented from telescoping, substantially in the manner described.

2. A spiral metallic car-spring, having a l large coil, C, with broad at bearing-surfaces at each end, two equal small middle coils, E E, and intermediate tapering coils D D, substantially as and for the purpose set forth.

3. Aspiral metallic car-spring, coiled from a rectangular bar of greater Width than thickness, with its greatest width presenting flat surfaces, and having its coils decrease from the outer to the inner coils, whereby only the edges of the inner small coils form the central bearing, and the broad surfaces of the end coils the seat surfaces, substantially as set V forth. l. A spiral metallic car-spring, made from a y In testimony that I claim the foregoing as my own I have affixed my signature in presence of two witnesses.

WALTER P. HANSELL. Witnesses:

WM. J. LOGAN, WILLIAM E. HAYs.

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