US352014A - Elliptic spring - Google Patents

Description

(No Model.)

E. SPAULDING.

I ELL'IPTIG SPRING. N0. 352,014. 4 Patented Nov. 2, 1886. I

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" I. 'iNVENTOR ey gg y BY fyfaya ATTORNEY UNITED STATES PAT NT OFFICE.

NORMAN E. SPAULDING, OF BROOKLYN, NEW YORK.

ELLIPTIC SPRING.

SPECIFICATION forming part of Letters Patent No. 352,014, dated November 2, J 886.

Application filed April 24, 18812. Renewed May 19, 1884. Serial No. 132,085. (No model.)

Springs, of which the following is a specifica tion. 1

This invention relates to the elliptic springs the plates of which are made in concavo-convex form in cross-section; and it consists in making the coils at theend of the springs, for

forming the edges for the connecting-bolts, of the same concavo-convex form of the plates as the rest, instead of the flat extensions, as heretofore, wherebythe advantage of the superior strength imparted to the springs by reason of the said concavo-convex form is available in the eye part aswell as in the rest.

Springs made of plates of the form described, and said plates arranged in the spring so that the tension is sustained on the middle web of the plates and the compression on the edges of said plates, are found'in practice to possess about twice the power to sustain the load that springs made of the ordinary flat plates have; but as such springshave up tor-this time been made with the main plate flattened just where the coil for the eye begins, so that in that part they are no stronger than the fiat plate-springs are, the great advantage of concavo convex form of the rest of the spring has notbeen as available as is desirable, although the defect might be remedied by thickening the plates where the shape changes from the curved to the flat form. That is not practicable, because in the manufacture of the plates it is desirable to roll them out in long strips and cut them into the short pieces of different lengths required for springs; hence it is desirable to continue the said curved form of the plates throughout the coil for the eye for the bolt that connects the two halves of the spring, ..and thus invest the said parts with about the same strength as the rest of the plate in which the eye is formed, as hereinafter more fully described, reference being made to the accompanying drawings, in which I Figure 1 is a side elevation of a portion of an elliptic spring of the kind above described, and section of the connectingbolt, and a washer employed in carrying out the invention, the

I eye being in this case formed by a half-coil in each plate, the ends of the plates meetingand butting together, and the plates being secured by the collars of the Washers shown in Fig. 4,

the section'of Fig. 1 being taken on line a: w of said Fig.4. Fig. 2 is a similar view of a spring of the kind described, the eye being formed by coiling the ends of the plates completely around the bolt, or nearly so, one of 6c The said plates being outside of the other. section of the washer and connecting-bolt is taken on line y y of Fig. 3. Fig. 3 is a section on line 2 z of Fig. 2. Fig. 4 is a section on line a a of Fig. 1, and Fig. 5 is a detail of the washers of Fig. 4.

A represents the plates of the spring, which, as before stated, are made in concavo-convex form in cross section, and arranged in the spring, with the convex sides B of said plates facing towardthe longitudinal axis of the ellipse. The said form of the plates is more clearly shown in the cross-section of them in Figs. 3 and 4. The said concavo-convex forms are produced by means ofthe dies of a drophammer or other press, in which the plates are struck while in a heated state. The dies heretofore employed for this purpose have been so formed that the concavo-convex form termi nates at O, leaving the rest of the plate flat, to

make the plain cylindrical eye for a plain bolt,D. It is this fiat part thatl'ails when the spring is loaded to the capacity of the rest of the spring, and therefore I continue the same curved form of the plate around the boltD,

thus extending the curved form of the plate to where the plate finds rest and support, that largely relieves it of supporting the load by its own unaided strength, which support is in this case afforded by the conical hubs F, which I makeon or may apply separately with the washers G H, used on the bolt D at the edges of the springs, the said conical hubs being to fill the flaring portions of the eyes for the bolt and to afford the required support to the plates.

When the plates extend only half around ICO the bolt, as in Figs. 1 and 4, I make the washers G H with a flange, I, to overlap the edges of the plates and more securely hold them, the flanges being notched, as shown in Fig. 5, where the plates branch away from the eyes. These flanged washers are also applicable to springs having the eyes made of flat coiled plates, the washers being made without the hubs. This form of the eye is preferred when it may be thought necessary to construct the spring so that it can be taken apart; but when it is not required to do so the arrangement of Figs. 2 and 3 will be the best.

The invention applies as well to semi-elliptic springs having a bolt, D, in an eye of the end for any purpose.

lVhat I claim, and desire to secure by Letters Patent, is

1. An elliptic spring the plates of which are of concavo-eonvex form in cross section, and arranged with the convex sides of the plates facing the longitudinal axis of the ellipse, the parts of the plates of which the coils for the eyes for the connecting-bolts are formed being the same in form as the body of the plates, said form being extended uniformly throughout the plates, and the eyes for 2 5 the connecting bolts, substantially as described.

2. The combination of washers having conical hubs F with elliptic springs the eyes of which are formed of plates of coneavo-convcx 0 form in cross section, substantially as described.

3. The combination of washers G H, having flanges I, with the eyebolts and the bolt-eyes of elliptic springs, said flanges overlapping 5 the edges of the coils of the plates forming the eyes, substantially as described.

NORMAN E. SPAULDING.

Witnesses:

WV. J. MORGAN, S. H. MORGAN.

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