US380390A - Vehicle-spring - Google Patents

Description

(No Model.)

B. HITCHGOGK.

VEHIGLE SPRING. No. 880,390. Patented Apr. 3, 1888.

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UNITED STATES PATENT Erica ROBERT HITGHCOOK, OF SPRINGFIELD, MASSACHUSETTS.

VEHICLE-SPRING.

SPECIFICATION forming part of Letters Patent No. 380,390, dated April 3, 1888.

Application filed November 16, 1887. Serial No. 255,349.

To aZZ whom it may concern.-

Be it known that 1, ROBERT HITOHCOCK, a citizen of the United States, residing at Springfield, Ham pden county, State of Massachusetts, have invented a new and useful Vehicle-Spring, of which the following is a specification.

My improvements relate to that class of spring known as the elliptical, and have for their object increased strength and a more uniform action under strain, as well as a mechanical facility of construction, insuring a more absolute uniformity in each of a set or gang of springs; and my invention consistsin the combination and construction, as hereinafter described, and more particularly pointed out in the claim. Y

The invention is fully illustrated in the accompanying drawings, in which- Figure I is a side view of a complete spring. Fig. II is a top or plan view of the same; Fig. Illis aside View of an unbroken strap or band. Fig. IV is a plan view of aseries of my springs framed together, and FigV is atransverse section on the dotted line :0 :0 of Fig. IV.

Heretofore theso-called elliptical spring in general use as a vehicle-spring has been built up of a number of individual springs in the form of leaves or straps united at each end of the spring at points aligned with the foci of the ellipse, with a result that at opposite ends of the spring there existed dead-points or interruptions, at which there was no spring,

, necessitating heavier metal in the rest of the surface or spring space, and in this form of construction, from the fact that opposite sides of the spring form angles at these dead-points, the spring was more easily set to have opposite inner sides come in contact or bump. To obviate these disadvantages, as well as the mechanical difficulties of building up springs of so many parts to possess a uniform strength when completed, I construct a spring as follows: A single strap or band, a, (the edge of which is shown in Fig. III,) of metal, is bent upon a former having the desired elliptical form, and bent upon itself two or more times to have its sides in contact with its ends I) c, as shown in Fig. I at the same end of the (No model.)

ellipse, and to lie, respectively, upon the outside and inside of the spring thus formed. The band (6 so wouhd is secured in clamps (1 upon opposite sides upon the ends of what would be the shorter diameter of the spring. The clamps d have slots transversely therein, which, with the end and side walls thereof, conform to three sides of the built-up spring, while inner plates, bolted to the bar forming the clamp upon each-side of the spring, completely inclose a section of it and effectually prevent the displacement of the layers of the band a. Before being placed in the clamps d therequired re-enforce leaves 6 are placed upon the outside of the spring proper, to be received in the clamps themselves together with the band a. The band a, preferably of soft steel at the start, is,when wound upon itself to present the desired contour, tempered, and the leaves 6, of like soft steel, may be tempered at the same time to insure uniformity,or may be tempered by a separate process.

It will be seen that the end a, with the adjacent continuous strip a, forms adouble thickness equal in strength to the opposite end of the spring, and that the end b, while it adds nothing to the compressive resistance of the spring at the smallest part of the ellipse, is

contiii ued to balance the near upper member of the spring with the others in strength; and it will be seen that by this disposition of the ends I) 0 they are free to slide upon the surface of the band in contact with them without requiring rivet or other fastening, as in the case of the ends of the sections of the elliptical spring in common use, the strength of which is no greater than that of its weakest pointt. e., the rivet or other means for binding their leaves together. A

My improved spring, so constructed of one continuous web or band, can never set, as the curve always remains at its opposite ends, which constantly exert a resistance at the extreme opposite ends of the spring in a direo tion coincident with the weight interposed.

\Vhen two or a multiple of springs are to be used in a gang, as when applied to railwaycars, continuous bars 01 are slotted to form as many clamps to-with a continuous band or plate, f inclose and hold the individual springs relatively in position.

Now having described my invention, what 5 I claim is- A vehicle-spring consisting of a continuous I imperforate strip or band of metal bent or coiled upon itself two or more times with adjacent surfaces in contact, combined with clamps embracing the sides of the band, but :0 without rivets passing through the strip, so that there may be a limited movement'of the coils upon each other, substantially as described.

ROBERT HITOHGOOK. Witnesses:

R. F. HYDE,

LYMAN H. PERKINS.

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