US402741A - Conduit-yoke for cable-ways - Google Patents

Description

(110 Model.)

J. B. JOHNSON.

UONDUIT YOKE FOR CABLE WAYS. No. 402,741. Patented May 7, 1889.

UNITED STATES PATENT OFFICE.

JOHN B. JOHNSON, OF ST. LOUIS, MISSOURI.

CONDU lT-YOKE FOR CABLE-WAYS.

SPECIFICATION forming part Of Letters Patent NO. 402,741, dated May 7, 1889. 1

Application filed May 26, 1888. Serial IIo. 275,142. (No model.)

To all whom it may concern.-

Be it known that I, JOHN B. JOHNSON, of the city of St. Louis, in the State of Missouri, have invented a certain new and useful Improvement in Conduit-Yokes for Cable-Ways,

of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification.

This invention relates to yokes that constitute union-girders under both track and slot rails; and the invention consists in features of novelty to strengthen and stiffen said yokes against the adverse pressure of frost, &c., hereinafter fully described, and pointed out in the claims.

three figures, but having the usual openings through the web to lighten the casting, as constructed for testing purposes to try their relative strength and stifiness as compared with the solid web of my improved yoke.

Referring to the drawings, in which similar figures of reference indicate like parts in all the views, 1 represents the inner or conduit flange; 2, the outside side flanges; 3, the bottom flange; 4, the bed-rest for the track-rails; 5, the bed-rest for the slot-rails; (3, the coupling-flanges that connect the track-rail beds to the slot-rail beds, and 7 the conduit that is incased by the inn er flange.

8 represents the connecting-web, as shown in Figs. I, II, and III, of my solid-web uniongirder yokes. The solid web constitutes an unbroken connection between the flanges that is not weakened by the usual apertures, 9, in the broken-web castings of the common yokes, as shown with said usual apertures in Figs. IV, V, and VI, in contradistinction to my solid-web yoke, which presents a continuous unbroken backing that resists the shearing strains from frost, &c., which act along the neutral portion of the girder.

10 represents projecting webs that surmount the flanges connecting the track to the slotrails, as shown in Figs. 11 and V.

11 are angle-flanges that descend obliquely from the bed-rest of the track-rails to the base of the inner flange that incases the conduit, as shown in Fig. III. WVhen the yoke is constructed in the modified form shown in said figure, said yoke being. shallow, with a semi-elevated conduit and angle-flanges connecting the track-rail bed-rest with the base of the conduit, brace-flanges l2 ascend from midway on the angle-flanges to the inner or conduit flange at a given point below the bedrest of the slot-rails, and the intervening spaces between the conduit-flange, the angle-flange, and the brace-flange are occupied by connecting-webs 13. In this modification it is also preferred to retreat the outside side flanges slightly from the extreme ends of the yoke, (see Fig. 1H,) because as the yoke is shallower than in the other forms, for reasons given, the vertical brace is not as effectual as in that of the deeper yokes shown in Figs. I and 11. Therefore the side flanges are removed slightly toward the center, and webs 14: connect said side flanges and the projecting flanges above and below. Projecting webs 15 surmount the angle and brace flanges in this modification and brace the bed-rests of the slot-rails.

The bottom outside flange of the yokes and the connecting-web are preferably bilged toward the center at 16, to re-enforce the strength of the yoke at the point of greatest stress under the compression of the frozen ground, and the flange at said point is increased in thickness to strengthen it for the same purpose.

I have shown three different forms of my yokes in Figs. I, II, and III; but I do not confine myself to those forms, as they may be varied to suit especial features incident to -the location of the cable-way and to the constructive appliances with which it is associated; but they always conform to the most important features of the invention, which are the cable-yoke, which is a union-girder under both track and slot rails, with an inner or conduit flange substantially beneath and supporting the slot-rails, and an outer flange substantially beneath and supporting the track-rails, said flanges connected by a solid IOO web or webs, the whole cast integral together to constitute a continuous brace-backing of the web to resist the shearing stress on the yoke. By this constructioni. a, a solid web connected by internal and external flanges it is found by actual test that a yoke with the same weight of metal as a similar form of yoke provided with the usual apertures has more than three times the strength and more than five times the stiffness. Thus, when tested by a Rhiele testing-machine, taking the yokes shown in Figs. I and IV, which are of equal weight, but Fig. I has a solid web and Fig. IV the usual web with apertures therein, and the outlines of said yokes identically the same, for that in Fig. I had the same flat base as that of Fig. IV, being minus the curved strengthening-bilge andlthickened base-flange there shown, so as to secure a fair test of the relative advantages of a solid versus a skeleton web, the yoke shown in Fig. IV broke at six thousand four hundred pounds pressure and the slot closed 0.7 8 inches at six thousand pounds, whereas the yoke shown in Fig. I, having a solid web of the same weight and cast from the same run of metal, having the same outline form as shown in Fig. IV, (for the bilged base-flange now shown in Figs. I, II, and III was not adopted at the time of the test,) broke at twenty thousand five hundred pounds pressure and the slot had closed only 0.14; inches at six thousand pounds. This shows 3.2 times the strength and 5.6 times the stiifness as a result of making the web solid, its other constituents being exact duplicates.

It is well known that in all cases of crossbending there are always transverse and longitudinal shearing strains, which are at a maximum at the neutral axis of the beam. Now, in conduit-yokes that are extended as union-girders to couple and support the bedrests of the track-rails, as well as the slotrails, it is the practice to lighten the casting of the necessarily-wide yokes by apertures 9 in the web that unites the inner and outer flanges, as shown in Figs. IV, V, and VI, as has been stated. Now, as the shearing strain, the resultant of the heavy pressure from the expanding frozen ground in which the yokes are embedded, &c., is exercised on my solidweb yoke, as shown in Figs. I, II, and III, there is within itself the continuous unbroken backing of its solid web to brace it and withstand the strain, while in the perforated or apertured yokes shown in Figs. IV, V, and VI, whiclnas stated,are the present usual construction in union-girder yokes, there are salient points in the broken backing of the web that cannot stand the shearing strain, and the result is, as reported in the actual test case of yokes of equal weight and equal outline form, as stated above. A further advantage of these solid-web yokes is that they are more simple in construction, are much easier to cast, and avoid the internal strains resulting from many bends and angles, and, being continuously integral throughout, a stronger yoke can be produced out of a lower grade of material; but I do not advocate the use of a lower grade of material, as, considering the enormous loss on cable-ways from the breakage of yokes and the closing of the slots under pressure that present forms of yokes are not effectually able to resist, it appears evldent that it would be advantageous to keep the grade of material fully up to the present standard, while at the same time the form of construction is very materially improved.

It will be understood that my yoke is not merely a slot-yoke, but a union-girder that couples and supports alike the track-rail bedrest, as well as those of the slot-rails, the flanges of which yoke are connected by a solid web, and so providesabundant lateral as well as vertical area in said solid web to brace against the shearing action of the frost, &c., on the yokes, and, being a union-girder, the weight of the passing trains is also a resistant against the closing of the slot. A slot- -yoke, also, even if it had a solid web, does not provide effectual lateral resistance to prevent the closing of the slot, because it has not width for lateral bracage.

It will be seen that my solid-web uniongirder yokes obviate the difficulty experienced in open-web yokes, Where each flange is subj ected to bending stress, and, not being braced, as in my solid web, they yield to the shearing strain; whereas with the solid web the shearing strains are resisted and each flange is subjected to direct stress only, that in the inner flange being simply compression, and that in the outer flange being simply tension.

As the strength of a beam is as the square of its depth and the stiffness is as the cube of its depth, therefore with the same weight of material, if the web be made solid instead of open, a great increase of strength is obtained and a still greater increase of stiffness.

I claim as my invention- 1. In a conduit-yoke for cable railways, the combination, with the inner and outer flanges, of a .solid continuous web connecting said flanges together and cast integral therewith, substantially as set forth.

2. In a conduit-yoke for cable railways, the combination, with the inner and outer flanges,

2, respectively, of the bottom downwardlycurved flange, 3, and a solid continuous web connecting said flanges and formed integral therewith, substantially as set forth.

3. In a conduit-yoke for cable railways, the combination, with the inner and outer flanges, 1 2, respectively, the bed-rests for the slot and track rails supported by said flanges, respectively, and the flange 6, connecting said bedrests, of a solid continuous web connecting all of said flanges and bed-rests and formed integral therewith, substantially as set forth.

4:. In a conduit-yoke for cable railways, the combination, with the inner flange, 1, and outer flange, 2, of the bottom flange, 3, connectthickened at its mid-length, and a solid Web 10 connecting said flanges and bed-rests'and cast integral therewith, substantially as set forth.

JOHN B. JOHNSON.

In presence of BENJN. A. KNIGHT, SAML. KNIGHT.

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