US349705A - Sylvania - Google Patents

Description

(No Model.) 2 Sheets-Sheet 1.

D. PRI$BIE 82; E. M. LOUKWOOD;

STEAM AND GAS ENGINE.

No. 349,705. Patented Sept. 28, 1886,

W I mi I 2 Sheets-Sheet 2.

(No Model.) V

D. FRISBIE & E M. LOGKWOOD.

STEAM AND GAS ENGINE.

No.349,705. Y Patnted Sept. 28,1886.

% 'jfp/W 94 mm augm- N, PETERS, Phola-Litbognpher, Walhlngkm, n. c.

UNITED STATES PATENT OFFICE.

DENNIS FRISBIE AND EDYVARD LOOKW'OOD, OF PHILADELPHIA, PENN- SYLVANIA, ASSIGNORS TO SAID DENNIS FRISBIE.

STEAM AND GAS ENGINE.

SPECIFICATION forming part of Letters Patent No. 349,705, dated September 28 1886.

Application filed February 15, 1881. Serial No. 191,925. (No model.)

IO ating passenger and freight elevators in build-' ings where the engine will be sometimes ,required to resist motion in lowering heavy weights, and will be described as thus applied.

Our engine in its principal features resem- I bles that set forth in the patent to D. D. Hardy,

March 10, 1885, No. 313,728. \Ve have devised important improvements. WVe arrange the reversing-Valve below the cylinders with directly-connecting passages thereto from the 2o lowest point in the gyratory valve and the lowest pointin the valve-chest. This facilitates the escape of water. \Ve apply to the gyratory valve peculiarly-arranged packing,

which avoids leakage or excessive tightness, 2 5 and is cheap and durable.

For applying the invention for hoisting we so arrange the crank-pin which operates the gyratory valve that there will be lead in working in the direction to hoist. This involves disadvantage or dragin working the other way,

to lower; but this is a small evil. portant to operate efficiently in the direction to hoist. It is not as important to work efficiently in the opposite direction. The machinery 3 5 will always almost or quite go in that direction of itself. "We have devised such a construction that when the reversingvalve is placed in the position to stop the engine, steam or air offers a resistance to any movement of the pis- 40. tons. If the engine stands still long enough for theimpri'soned steam to condense,we have still, bythe leakage of air inward past the pis tons, elastic fluid filling the cylinders, and it will offer either an air or steam resistance.

4 5 Consequently we have an elastic brake, which we call a combined steam, air, and vacuum brake, to hold the engine securely. No amount of weight descending on an elevator or any ordinary amount of other force can cause theengine to turn while this condition ti'on. It is imcomplete. 1 Fig. 2 is an elevation at right anis maintained. In brief, our reversing-valve is a piston-valve having two parts or pistons. They work across ports. The port which leads away exhaust-steam in lowering is of less width than the portion of the reversing-valve 5 5 which covers it. In the form we have adopted the ports are of equal breadth, and the width of the pistons covering them is different, the piston which controls the exhaust in lowering being widest. The construction insures a liberal supply of steam, but a contracted exhaust in lowering. WVe provide a stop which is so set that this peculiar reversing-valve can never be shifted over in the direction to lower beyond a certain extent, just sufficient to give 6 5 a proper exhaust when lowering an empty cage. \Ve provide a throttle-valve in the exhaust-passage, controlled by a governor, so

that when, notwitlrstandingthe above precautions, thespeed rises beyond the proper limit by reasonof a load on a descending elevator, or of other cause, the escape of steam from the exhaust-pipe is retarded, and the resistance from back-pressure is increased, so as to restrain the engine and hold the speed down to the proper limit.

The accompanying drawings form a part of 1 this specification, and represent what we consider the best means of carrying out the invenr Figure 1 is an elevation showing the engine gles-to that in Fig. 1. Fig. 3 is a central vertical section through the cylinders. Fig. 4c is a section on the line a: x in Fig. 3. Fig. 5 is 8 5 an elevation corresponding to Fig. 1 with certain portions removed. Fig. 6 is an elevation of a portion. Fig. 7 is a vertical section through a portion on a larger scale. Fig. Sis I a vertical section through a portion on a scale 0 somewhat larger than Fig. 7. Fig. 9 is an elevation partly in longitudinal vertical section. This shows the reversing-valve in the position to hold both the steam and exhaustpassages closed. In this condition theengine is locked. Figs. 10, 11, and 12 are vertical sections through certain portions, aiding to show the relationof the parts when adjusted for different conditions. In Fig. 10 the engine is locked by the action of the steam. In Fig. 11 the re I00 portions being designated, when necessary, by

additional marks, as A A", &c.

B is the shaft, B a brake-wheel thereon, and B a crank.

O G are the pistons of two opposite cylinders. They are connected by a rigid part, 0, having a transverse slot, 0. In this latter the crank 13 is inclosed by the aid of suitable brasses, S. The revolution of the shaft '13 moves a valve in the steam-chest A so as to successively uncover the ports a leading to the outer ends of each. of the several cylinders A, and allows the steam to exhaust from the outer ends of the cylinder opposite. It will be understood that as the pistons reciprocate under the influence of the steam applied at the proper times on the outer faces of the pistons, the crank B receives motion therefrom through the brasses S, the motion of the crank in the direction transverse to each being allowed by the sliding of the brasses S alternately from one side to the other in the slot 0. The other two pistons,G 0*, are similarly connected and take hold of the same crank by similar brasses. (Not represented.) The several pistons are single acting. The ordinary atmospheric pressure obtains on the inner faces of all the .pistons.

I set that there shall be just the best amount of lead when turning in the direction to hoist. This valve, operated by the pin B loosely engaged in arecess in its center, serves both for the steam and exhaust in operating in either direction, the direction being determined by a separate reversing-valve which performs peculiar functions. One obviouseffect of this valve is that on being fully shifted from one extreme po: sition to the other it reverses the relations of the steam and exhaust in the gyratory valve.

The ports a and a lead the steam to and from the gyratory valve D, the port a terminating at the lowest point in a circular groove, a, near the periphery of the valve-chest A ,while the port a terminates at the lowest point in a corresponding circular groove, at, near the center of thesame valve-chest. Thisarrangement of the passages I insures that the port a is always in communication with a point near the bottom of the space exterior to the valve D, and that the port a is always in communication with a point near the bottom of the space in the interior of the valve D.

The packing-ring D on the gyratory valve D has two deep annular lips, one on the outer edge embracing the exterior of D, and one on its inner edge matching against the interior of D. Each makes steam-tight contact with D by means of cut rings. The cut ring (1 is recessed in the inner lip of D, and packs the joint on the inner face of D. The cut ring (1 is recessed in D, and packs the joint between D and the outer lip of D.

We attach importance to the two rings (1 and d in the gyratoryvalve. This valve being subject to pressure, either from theinterior outward or from the exterior inward, according as the engine is to be worked in one direction or the other, is peculiarly difficult to pack with a single packing. The two out rings d (I serve as duplex packing-rings. We believe that one is mainly efficient in working in one direction and the other mainly efficient in working in the other, but the theory is not essential. The two out rings d and (I both pressing outward, the ring d carried in D and pressing outward against D, and the ring d carried in D, pressing outward against the interior of the outerlip of D, constitute avery reliable packing. A. few spiral springs, d, inserted in holes in D, asindicated in Figs. 4 and 7, serve to hold the parts in position when there is no steam-pressure.

It will be readily understood that in one position of the reversingvalve the space within the steam-chest A exterior to the gyratory valve D is filled with live steam from the boiler, and the interior of such valve is filled with weak exhaust-steam having only the pressure of the atmosphere. \Vhen the reversing-valve is fully shifted these conditions 7 are reversed, the s'trongsteani being in the interior of the gyratory valve and the weak exhaust-steam exteriorthereto. These changes of condition cause the steam to turn the e11- gine in one direction or the other by the same gyratory valve D without requiring any change in the means of connecting it.

M is the reversing-valve. It is a pistonvalve, and hollow, so that steam may traverse freely through its interior from one end to the other. Through a central hub and spiderarms it receives the desired controlling motions from the valve-stem L, operated by an eccentric (not shown) ontthe controlling-shaft E, acting in a yoke, L. It is equipped with two packing-rings, M and M", which make the piston fit steam tight within the properly-finished cylinder A. Between these packed places the valve is contracted, as represented.

oblique cross-bridges, (not shown,) which contribute to the strength of the cylinder, and also perform the'important function of keeping the packings of the piston-valve in place when they are being moved across the ports. The revolutions of the engine give a corresponding gyratory motion to the valve D, which 'ing.

successively expose the proper ports, a, to reeeive steam from the exterior space, and to allow other ports,'a, to discharge steam into the interior space, or the reverse. There is a suitable amount of lap, and the pin B which actuates this valve is so set as to give the proper lead for most effective working in hoist- The corresponding retardation in the admission and discharge of the steam inlowering is of little moment, because it does not require much power to lower. The reversing is effected by shifting the position of the pistonvalve M by operating through the stem L.

We arrange the reversing-valve M below the gyratory valve D. This facilitates the discharge of water from the several cylinders. When steam is first admitted, the parts being previously cold, there is great condensation; Under all ordinary conditions there is some condensation in the several cylinders. More or less water is also liable to come from the boiler with the steam. It is desirable that this shall notaccumulate,but shall be promptly discharged with the reciprocation of each piston. Our arrangement of the passages a a and of the reversing-valve M allows the water to descend by gravity so .soon as it has been driveninto the valve-chest A and to be cleanly emptied out. The lowest point in the circular groove a discharges through a. (See dotted line in Fig. 5.) The lowest point in the circular groove a discharges through a WVhen our reversing-valve is in the central position both steam and exhaust are closed. No matter how strongly the engine tends to be turned by reason of a load on the elevator, the motion of the engine is resisted by the pressure of the steam. We allow the steam which has been previously used or air which is drawn in by leakage to press backward against the pistons to prevent the revolution of the engine. WVhen it is shifted but a little in the direction to lower, this is accomplished by live steam. This is important when it is desired to completely arrest the movement of the engine; but there are circumstances under which it is desired to render available the action of the steam to resist the motion and lower the load slowly. lVe employ a stop, V, which prevents the rod or stem L being operated in the direction to lower beyond a certain extent. This extent should be such as will give liberal opening for the admission of steam to impel the engine in the direction to lower, but will only give a sufficient opening for the exhaust to allow the exhauststeam to escape slowly. There is danger of excessive speed in this direction. \Ve limit the degree of openingof the exhaust to an amount which willj ust allow the exhaust steam to escape at the proper rate when the elevator is moving down light. We make this stop on a cam, E, keyed or otherwise fixed on a reversing-shaft, E, which, being turned in one direction or the other by ordinary connection, shifts the reversingvalve M in one direction or the other. V is a lever-arm turning on'a fulcrum (not shown) and'having a constant gentle pressure inward toward the reversing-shaft E. When this shaft is turned in the direction to lower, it presents the deep recess 0' to receive the end of the lever V, thus serving asastop. The reversingshaft can be turned easily until the lever V has dropped into the bottom of the notch e. In this position the notch 6' serves as a stop. It engages with the lever V forcibly, and forbids the latter from being turned any farther in that direction. The ports are so adjusted that this occurs at the period when the exhaust-port is open but a little.

WVe have devised means for insuring a retardation by the steam additional to the provision above described. We admit steam enough to turn the engine, and, limited by the stop above referred to, adjust the reversingvalve to open the exhaust enough to run at proper speed when the elevator is descending light. \Vhen the elevator descends loaded, it will go too fast. We obstruct or throttle the exhaust by a throttle-valve, T, mounted in the exhaust-passage a", controlled by a governor, P, driven by the engine. long as the speed is moderate this valve T stands fully open, and so far as this valve is concerned the engine exhausts freely and exerts its full power; but when from any cause the engine commences to run too fast, the rising of the flyballs of the governor partially closes the throttle-valve T. Thisinsures a furtherpressure. resisting the motion of the engine. This back-pressurejs increased when the velocity becomes excessive, and forms a reliable means of controlling the motion under all circumstances. WVe employ another independent governor, which controls the flow of steam from the boiler to act on the pistons, urging them forward. This acts independently of the governor I, and may be adjusted to regulate in any manner desired. It is important that it shall never be allowed to forbid access to live steam entirely. There must always be steam admitted, even when lowering the heaviest loads, so that by retarding its discharge by the action of the governor P and its connections the motion of the engine may be retarded.

Modifications may be made in the details without departing from the principle or sacrificing the advantages of the invention. We can use a greater number than four cylinders. A less number will suffice. Parts of the invention may be used without the whole. An obvious mechanical equivalent for the wide piston M would be to reduce the width of the port a, and to make the two parts M M of the piston-valve equal in width.

Some of the advantages due to certain fea tures of the invention may be separately enumerated as follows: First, by reason of the fact that we operate to hoist and lower, and that our pin or crank B which impels the gyratory valve D, is set to give lead in hoisting and drag in lowering, we attain the greatest efficiency of theengine at the time when it is needed, sacrificing merely a corresponding measure of efficiency when it is not needed; second, by reason of the two packings d and d recessed one in the inner lip ot' the ring D and the other in the outer surface of the valve D, we are able, when the direction of the pressure is reversed, to provide by one packing for resisting the leakage of the steam from the interior outward, and by the other packing for resisting the leakage of the steam from the exterior inward; third, by rea son of the circular valve D and means B for gyrating it within a steam-chest, A having cylinder-port a, annular grooves a and a, and ports a a, leading from the lowest point in each to the reversing-valve M, mounted at a lower level, we are able to insure efficient action in either direction under all conditions, and also to attain the prompt discharge of all water which comes with the exhaust-steam into the steam-chest A; fourth, by reason of the fact that the bearing-surface M in the reversing-valve M'is much wider than its port a, while the bearing-surface M of said valve is only a little wider than its port (1 and that the excess of width of M retards the exhaust in lowering, we insure that steam is admitted freely, and that the exhaust alone is obstructedv in lowering, thus obtaining a liberal supply of the elastic fluid by which to retard the engine in case the load shall urge it to go too fast; fifth, by reason of the stop 6 we are able to limit the area of the passage for the escape of exhaust-steam in lowering, so as to restrain the engine by the back-pressure of the steam to the proper extent to serve well under the conditions which require the least restraint. that of lowering an empty cage; sixth, by reason of the throttle-valve '1 in the exhaust-passage, we are able to further contract the exhaust-passage, as required, to restrain the motion to greater extents in lowering a heavy load; seventh, by reason of the two governors P and 0, one, 0, contracting the live-steam passage to a variable extent, and the other, P, contracting the exhaust-passage to a variable extent, we are able to control the area of each. independently, and thus by continuing to close the exhaust-passage while the steam-passage is held partiallyopen to avoid dangerouslyhigh speeds, even in lowering the heaviest loads.

'We claini as our invention- 1. I11 an engine reversed by reversing the direction of the pressure, the packing-ring D,

having two lips, in combination with the valve D and its operating means, and with two pack ings, d and (2 arranged for joint operation as herein specified,

2. The valve-chest A having the two annu- 6o lar grooves of and a and the ports a a", in combination with the gyratory valve D and means B for driving it, and with a reversingvalve, as M, operating at a lower level, all arranged for joint operation as herein specified. 6 5

3. In a hoisting and lowering engine arranged to reverse the conditions in the'steam and exhaust passages, areversing-valve having a bearing, M, wider than its port a, ar-

ranged to give a freer passage for the live steam than for the exhaust in lowering, as herein specified.

4. The stop V, in combination with the notched wheel E, shaft E and connections with the reversing-valve M, andwith means 7 for operating it, arranged to limit the movement of the reversing-valve in the direction to lower, substantially as and for the purposes herein specified.

5. In a steam or gas engine, the two gov- 8o ernors I? and O, in combination with means for controlling independently the area of the steam and exhaust passages, as herein specified.

In testimony whereof we have hereunto set our hands at Philadelphia, this 1st day of Feb- 8 5

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