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reduced ends, leaving the body of the rod straight. Why a cylinder should be counter bored at its ends, and the rod not counter turned at its ends, is more than I can understand. This is a thing I believe I was the first to do, and if it has been appropriated by others, I am not conscious of it.

The substitute for a stuffing box shown is also new. It consists of nothing but a long round hole, which prevents the escape of steam, not by being a tight fit to the rod, but by its length. The hole is from five to six one-thousandths of an inch larger than the rod, and is made through a bushing of Babbitt metal, some six or seven diameters in length. A spherical hub, cast on the bush, fits in a brass socket, and that, in turn, rests against a flat seat, so the bush is free to move in every direction; it is held in place by steam pressure, and a split washer at its outer end, and is held up from the rod by a slight spring, just rigid enough to take the weight; so the device is simply a round rod passing back and forth through a round hole without contact. That it is steam-tight and frictionless is evident; how long it will remain so, remains to be shown. If but one year, the cost in packing alone will be less than hemp, to say nothing of the saving in friction, piston rods, and the Sunday work of the engineer.

The method of securing the cylinder and steam chest covers is unlike the common one in this, that the studs are one size larger at the inner end than at the outer. The holes are drilled in the cylinder to a positive depth, and the hole chambered out at the bottom to the full size of the thread, and squared out so as to form a flat bottom. This permits the making of a perfect thread, and renders it possible to make the studs in advance.

The cross head, shown in Fig. 5, is about one-third longer than the stroke of the engine, and runs on slides about one-fourth longer than itself. The cross head being cast in one piece, and both lower slides in one piece also, the two, when once made absolutely flat, are likely to remain so, and with the generous wearing surface run free from friction.

very

One special feature is, making the cross-head pin turn in the cross head itself, rather than in the connecting rod, giving two long bearings in the place of one short one, and bearings that can be oiled while the engine is in motion.

A cross section of the pin is shown, greatly enlarged, in Fig. 4. It is peculiar in this, that it has its top and bottom sides cut away for about one-sixth of its circumference, so as to leave bearings on its sides only.

The hole is also cut out on its top and bottom sides, but to a greater extent on top than on the bottom. Not simply cut away in

a haphazard manner, but with a sharp clean cut to theoretically defined points. In this I believe we are alone in the practice. In the forming of the crank shaft by using the bosses of the flywheels for the throws, as will be seen in Fig. 5, this peculiarity may be noticed. Small concave grooves are turned in the crank pin, just inside the wheels, and in the shafts, just outside-such grooves as would be cut in it if one wished to break the shaft in two at that point, except that the grooves are round bottomed. These grooves are for three purposes: 1st. To prevent the oil from following out the shoulder and being thrown off as by a centrifugal pump. 2d. To leave the wearing surface of the journal exactly as long and no longer than the wearing surface in the box. 3d. To make that point the weakest point in the shaft. All spring, or nearly all spring, that takes place must take place in these reduced places, and so the journal will remain practically straight throughout its entire length.

If these same shafts were turned down one-sixth of their diameter with quarter circle fillets, they would, in my opinion, be very much stronger, but also very much more elastic and would easily spring within their own length, which, as before stated, would destroy both the alignment and wearing surface.

This form of crank-pin shaft admits of giving free end play, a feature of far greater importance than would at first appear.

A true cylinder cannot be run in a box for any great length of time or wear to any extent and remain a true cylinder, unless it has sufficient end play to prevent grooving, and unless the wearing surface of the cylinder is of the same length as the surface within which it runs. Unless a journal is made a true cylinder and so remains, the minimum of friction has not been reached.

A true cylinder with perfect alignment is only second to lubrication, and some of our methods of lubrication are shown in this same figure.

The crank box, in addition to a tallow cup which is upon itself, can be oiled while the engine is in motion by ejecting oil into the eccentric chamber from which it is thrown by centrifugal force to the crank. So too the oil for the eccentric strap is introduced into the inside of the eccentric and thrown out through oil holes in its face. In addition to oil holes for oiling the main bearings in the usual manner, there are loose rings hung upon the shafts with their lower sides dipping in the waste oil reservoirs. These rings, trundling upon the shaft, carry the oil up and keep the journal flooded.

In order to show to what extent the friction of the governor has been reduced, it becomes necessary to show the governor itself. See Fig. 6. The single governor ball is so pivoted, weighted, and

linked to the single shifting eccentric as to balance it, and its attachments, against gravitation. The very strong spring, linked also to the eccentric completes the governor mechanism. When the centrifugal force of the governor ball becomes sufficiently great, it compresses the spring, shifts the eccentric, and reduces the throw of the valve.

The pivot upon which the eccentric turns is a common journal, subject to slight pressure and little movement, while the pivots in the ends of the links, which are subject to great strain and slight movement, are made as shown in Fig. 7. A hole, somewhat larger than the pin upon which it turns, has a tempered steel plate dovetailed into it, so that its face is at right angles to the line of pressure. Upon this plate the pin rolls, thus substituting rolling for sliding friction-a pivot that requires no oil.

Motion is communicated to the valve by the eccentric through the eccentric rod and rocker arm in such a manner as to produce results not before obtained. This can be best explained by Fig. 8.

What is done in using a shifting eccentric is simply to change the throw, and what is sought in all designs is to be able to change the throw when the crank is on either dead center without giving perceptible motion to the valve. By placing the rocker arm in the position shown in this sketch, no motion is imparted to the valve, except what is due to the versed sign of the arcs. The eccentric rod and the distance between the center of the eccentric and its pivot being the radii. By this arrangement the lead of the valve (if the engine has lead) will remain practically constant, the cut-off be alike at each end of the cylinder, and the valve have the greatest opening at the end, where it is required. It may not appear what this has to do with friction-nothing-except that with this simple governor and valve motion one valve is made to serve as admission, cut-off, and exhaust, and one valve is assumed to consume less power than two or four. The valve used cannot properly be called a balanced slide valve, nor a piston valve, and yet it has the merits of both with the defects of neither.

The valve face on the side of the .cylinder, see Fig. 9, is of the same character as that used for the common slide valve. A cover plate of great strength, being cast in the form of a dome, has upon its face, recesses to correspond in size and position with the ports in the cylinder. This cover plate is held away from the valve face by two strips of metal, see Fig. 10, so that these four parts-the valve face, cover plate, and two strips-surround a rectangular opening.

A rectangular casting, moved back and forth within this opening, works precisely like a piston valve. Both steam tight and frictionless, if properly fitted, and better than the piston valve in four

respects.

The valve wearing down by its own weight, does not cause a leak over the top; water in the cylinder can find its way back into the steam chest; change of temperature does not affect the fit, and wear may be compensated for by reducing the packing strips.

This valve in its main feature is old, but is new in so far as using loose strips is concerned, and in another very important point. In use this valve showed one marked peculiarity, and one that has been noticed years without any one accounting for it. The four faces of the valve seat and the two outer faces of the cover plate remained perfect, the two inner face of the cover plate at once took on a different appearance, and after some months' use appeared cut away, and would sooner or later leak steam. Investigation revealed the cause. The exhaust steam leaving the cylinder dashed directly against these faces on its way to the exhaust port. A simple remedy has been found in casting the two projecting ledges in the valve itself.

One other point used in the construction of this valve is practiced which adds to its durability. All the edges of the valve and ports are left just as they come from the sand, special care being taken not to disturb the scale of the iron. While I believe no worse use of time and money was ever made than dressing out the ports of steam engines, the necessity for such work is less in this than in most others, as the throw of the valve is greater. About this valve and others working on the "mechanical-fit " principle, there is a feature not commonly thought of, and one that may be pretty generally denied. I make the statement, however, and feel free to maintain it, it is this: that the valve will work with a less consumption of power if worked a certain long distance than if a certain short

one.

The elements in this combination that contribute toward the reduction of friction are a free-running piston and cross head, frictionless piston and valve rods, perfect running journals and crank bearings, a governor that consumes no power, and a frictionless valve.

Against this it may be claimed that we have nothing but a shifting eccentric, a single valve, and, consequently, an imperfect distribution of steam.

While this is true, it is not true to the extent likely to be imagined. Because with this valve motion the worst defects of the shifting eccentric are avoided, and with the free running and extra large double port valve we are able to use it in an unusual manner.

It is usual to give a valve lead that is to admit steam to the cylinder before the crank has arrived to within 5° or 10° of its dead cen

linked to the single shifting eccentric as to balance it, and its attachments, against gravitation. The very strong spring, linked also to the eccentric completes the governor mechanism. When the centrifugal force of the governor ball becomes sufficiently great, it compresses the spring, shifts the eccentric, and reduces the throw of the valve.

The pivot upon which the eccentric turns is a common journal, subject to slight pressure and little movement, while the pivots in the ends of the links, which are subject to great strain and slight movement, are made as shown in Fig. 7. A hole, somewhat larger than the pin upon which it turns, has a tempered steel plate dovetailed into it, so that its face is at right angles to the line of pressure. Upon this plate the pin rolls, thus substituting rolling for sliding friction-a pivot that requires no oil.

Motion is communicated to the valve by the eccentric through the eccentric rod and rocker arm in such a manner as to produce results not before obtained. This can be best explained by Fig. 8.

What is done in using a shifting eccentric is simply to change the throw, and what is sought in all designs is to be able to change the throw when the crank is on either dead center without giving perceptible motion to the valve. By placing the rocker arm in the position shown in this sketch, no motion is imparted to the valve, except what is due to the versed sign of the arcs. The eccentric rod and the distance between the center of the eccentric and its pivot being the radii. By this arrangement the lead of the valve (if the engine has lead) will remain practically constant, the cut-off be alike at each end of the cylinder, and the valve have the greatest opening at the end, where it is required. It may not appear what this has to do with friction-nothing-except that with this simple governor and valve motion one valve is made to serve as admission, cut-off, and exhaust, and one valve is assumed to consume less power than two or four. The valve used cannot properly be called a balanced slide valve, nor a piston valve, and yet it has the merits of both with the defects of neither.

The valve face on the side of the .cylinder, see Fig. 9, is of the same character as that used for the common slide valve. A cover plate of great strength, being cast in the form of a dome, has upon its face, recesses to correspond in size and position with the ports in the cylinder. This cover plate is held away from the valve face by two strips of metal, see Fig. 10, so that these four parts-the valve face, cover plate, and two strips-surround a rectangular opening.

A rectangular casting, moved back and forth within this opening, works precisely like a piston valve. Both steam tight and frictionless, if properly fitted, and better than the piston valve in four

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