US854389A - Method of casting trolley-wheels. - Google Patents

Description

No. 854,389. BATEN'TED MAY 21, 1907.

1-". B. TORREY.

METHOD OF CASTING TROLLBY WHEELS.

APPLIOATION FILED MAR. 9, 1906.

IINITED STATES PATNT OFFICE.

METHOD OF CASTING TROLLEY-=\NHEELS..

Specification of Letters Patent.

Patented May 21, 1907.

Application filed G 9, 1906. Serial No. 305,106-

To aZZ whom it may concern.-

Be it known that I, FRANCIS BOWEN TOR- REY, a citizen of the United States, residing at Portland, Cumberland county, Maine, have invented certain new and useful Improvements in Trolley-I/Vheels, of which the following is a specification.

My invention hereinafter described relates to trolley wheels, and is designed to increase the durability of the wheel, with these advantages.

My said invention consists in the special construction of the wheel and in the mode of casting the same.

The general form of the wheel is not dif- 'ferent from that of such wheels now in use.

In the particular structure however, my

wheel consists of a ring of metal having hard-' ness preferably due to its composition, said ring being embedded in the metal of the body of the wheel at the bottom of the peripheral groove of such trolley wheels.

The special method of casting my improved wheel with its hard embedded ring reinforcing is explained hereinafter, in connection with the description of the special construction. The metal of this ring which forms the wearing surface, exposed to the pressure and friction of the wire, is of a more expensive material and it is desirable to reduce the amount of this material as much as possible. Further, its outer periphery must be grooved and its inner may be of corresponding shape. The metal should be thicker on the central peripheral line, and decrease in thickness to the edge. Its best form therefore is in cross section at any point, that of a crescent as shown for ex ample in Fig. 4 and it is a continuous ring. With the ring in such shape and of such material the problem to be solved was that of casting it, embedded in the cheaper and softer metal of the wheel. It should be cast with its bearing surface against metal, in order that such surface may be smooth, since the required hardness precludes turning it down smooth. Further it is necessary that it be supported accurately in the mold, and desirable that the mold should form a continuation of the surface of the groove of the ring to complete the entire groove surface. I have solved this problem by means and in the manner hereinafter described and I refer for illustration to the accompanying drawings, in which Figure 1 shows a diametrical section of the reinforcing ring, with like section of its former ring. Fig. 2 shows a perspective view of the reinforcing ring. Fig. 3 shows a like section of the reinforcing ring with its supporting former, the parts being in place for insertion in the mold and Fig. 4 shows a like section of the completed wheel. Fig. 5 shows a like section of the full pattern.

In casting the ring I use a metal ring former A, made in two parts, and, on its inner periphery shaped and fitted to form the smooth groove of the external periphery of the wearing ring 2. This ring is cast on the ring former, in a suitable mold, and when completed has a smooth external groove formed by casting against the smooth metal; and an interior rounded surface giving with the groove, the approximate form of a crescent. It is not necessary that the edges of the ring 2 be made to extend to the edges of the wheel groove, since the main part of the wear falls upon the bottom and the supporting former B (Fig. 3) may serve as a part of the wall of the mold, to form the outer marginal surfaces 2" of the wheel groove.

The supporting former B is a metal ring made in two parts removably connected. The central part of the inner periphery of this ring is made exactly to lit upon the grooved surface of the ring 2, the edges of which, so fitted, extend upon the sloping sides of the former, to line, for example, indicated at 4. The curved margin between the peripheral lines 4 and 5, afford forming or mold surfaces, for these outer annular zones of the wheel groove, which, when the wheel is cast, will be continuous with the groove surface of the ring 2. I provide also a pat tern O for the wheel shown in central cross section in Fig. 5. This in external form is the same in shape and dimension (except that it has no axial hole) as the finished wheel with the supporting former added. This pattern O is used to form the mold in the sand. It is then withdrawn, the axial core, inserted and the supporting former with the wearing ring put in place in the mold, and upon these the metal is poured and the casting formed. The supporting ring 2 thus serves to hold the ring accurately in place and also completes the mold where the ring does not extend to the edges of the wheel.

The wheel cast herein is shown as an illus tration in Fig. 4. Any approved form of bearing may be used in this, but I prefer that ing a Wearing ring of relatively hard material upon a suitable former; forming, by means of a suitable pattern, a mold cavity; Withdrawing the pattern; placing the Wearing ring together with its supporting former in the mold cavity; and then casting the Wheel, substantially as described.

In testimony whereof I affix my signature in presence of tWo Witnesses.

FRANCIS BOWEN TORREY. Witnesses:

EDWARD N. SARToN, HENRY E. COOPER.

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