US323606A - Frank - Google Patents

Description

(No Mode.)

1:". M. STEVENS.

VALVE OPERATING MEGHANISM.

No. 3Z3,'606 Patented Augi 4., 1885.

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WITNESSES: l NVENTOR:

WA@ mi) W2- M N. PETERS, Fholellhvgrzpbr, Walhington. D, C.

NITED STATES PATENT Orricn.

FRANK. M. STEVENS, OF NEV YORK, N. Y., ASSIGNOR TO TIIE STEVENS LOCOMOTIVE AND MACHINE COMPANY.

VALVE-OPERATING MECHANISM.

SPECIFICATION forming part of Letters Patent. No. 323,606, dated August 4, 1885.

(No model.)

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splined thereon. By sliding clutch E along Be it known that I, FRANK. M. STEVENS, a said `shaft the segment D is caused to shift the citizen ofthe United States, and a resident of the city, county, and State ol' New York,have invented certain new and useful Improvements in Valve-Operating liIeclianisnis,of which the following is a spcoiiication.

My invention relates to means for operating a valvemfhereby its regular reciprocating motion may be accelerated and retarded, and whereby the valve-operating eccentric may be shifted to vary the cut-off or reverse the engine. The novel fea-tures of the invention will be fully hereinafter described and defined in the claims.

In the drawings, which serve to illustrate my invention, Figure I is a sectional side elevation on line l I in Fig. 2. Fig. 2 is a plan with a part of the expansion-guide broken away. Fig. 3 is a sectional elevation on lines 3 3 in Figs. l and 2. Fig. 4 is a transverse section on line et It in Figs. l and Fig. 5 is a sectional elevation on line 5 5 in Fig. 2. Fig. 6 is a detached view of what I call the multi plying-lever and its operating-eccentric. Fig. 7 is a detached side view of the carrier-block, and Fig. 8 a detached View of the disk link or die. Fig. S illustrates a modification that will be described.

Referring now to the first eight figures, A is the shaft driven by the engine. Itmay or may not be the main shaft.

B is an eccentric mounted on this shaft,the shaft passing loosely through a slot or slotted aperture therein. The eccentric is embraced by tivo keeper-disks, C C, xed on the shaft, and it bears on its opposite faces ribs a a, which engage corresponding grooves in the inner faces of said disks C, whereby the eccentric is compelled to rotate ivithsaid disks and the shaft-,but is free to move at right angles to the axis of the shaft, so as to vary the throw or reverse the engine. On one face of the eccentric is a rack, b, (seen best in Fig. 3,) and opposite said rack is aslot in one ofthe disks C, and extending through-this slot so as to en* gage said rack I) is a toothed segment, D, which is fulcrnmed at c on a stud fixed to the shaft A. Coupled to an arm on segment D at d is a link, e, which is coupled at its other end to a clutch, E, which slides on thc shaft A, being eccentric on the shaft and vary its position and throw'. This may be ettectcd While the shaft A is revolving, and through the medium of a clutch-fork, F, which engages a groove in clutch, as shown 4in Fig.

I Will now describe the means employed for accelerating and retarding the reciprocating movement imparted to the valve by eccentrics B.

G is the eccentric-rod, the strap G of which embraces eccentric B.

II is what I call the expansion-guide, which I usually bolt to the engine-frame,(not showin) but which may be secured to any part and in any Way so long as it is immovable. In this guide is mounted to play in keepers a carrienblock, I, to which is coupled the eccentric-rod G. Thus the eccentric B imparts by its rotation areciprocatory motion to the block I. The method of connecting the rod G tothe block I will be described hereinafter.

In the block I is mounted a shaft, J, and on the outer or projecting end of this shaft is fulcriiined loosely what I call a multiplyinglever, M, in the lower end of which is mounted a sliding block, N in which turns an eccentric, O, fixed on a shaft, l?, mounted roA tatively in block I.

On the inner end of shaft ILthat is, inside ol' the expansion-guide His lined a pinion,

- to any form of valve capable of being recipro` cated as alocoinotive slide-valve. This valve I have not considered it necessary to show.

It will be seen that when the block I is reciprocated through the medium of eccentric B the lever M is carried along with it, thereby imparting a reciprocating motion to the valve; but this reciprocating motion is modified-that is, either accelerated or retardedby the vibration of said lever, which is effccted by the eccentric O, the gear-Wheels, and the fixed rack T. The character of these modifications will be governed by the distance IOO through which theV block I travels and the respective sizes of the gear-wheels. I have shown the intermediate R as much longer than the pinion Q; but the relative sizes of the gear-wheels may be varied to suit the circumstances of the case.

It will be obvious that the lever M has but one function-namely, to multiply or magnify the mot-ion imparted by the eccentric O. The use of this lever enables me -to employ a smaller eccentric than I otherwise could, and to operate when the axis of the valve stem is considerably above or below the horizontal plane in which the axis of the eccentric plays. ThiSleVer, however, performs, otherwise, only the ordinary functions of an eccentric yoke and rod to connect the eccentric to the valvestem, and thus impart to the valve the reciprocating motion due to rotation of the eccentric, as in all eccentric mechanisms for converting rotary into reciprocating motion. It is obvious, also, that if the eccentric O be given the proper throw it may be coupled to the valve-stein by the usual connection.

The shaft Jmay be fixed in the block I, and the link-disk K and gears R S may rotate on it; or it may be rotative and the gears R S be fixed on it; or the disk K and lever M may be mounted on a stud projecting` from block I outwardly, and the gears R S -be mounted on another stud projecting inwardly from block I. I employ the construction shown for convenience only.

I will now describe the mode of connecting the eccentric-rod G to the carrier-block I.

It will be obvious that when the eccentric B is rotating, the stem G is constantly shifting from aposition parallel with the line of movement ot' block I to an angular position therewith; and it will also be obvious that when the eccentric is shifted at either end of its stroke, in order to vary its thrw or reverse the engine, the same shifting of the rod G will occur. Now, if the rod was coupled directly to block I-as by a wrist or pinthere would be a slight reciprocating movement of said block I independent of the regular reciprocation of said block by the eccentric, and due to this change of angle of the eccentric -rod. This independent movement would be such as to accelerate the movement Vof said block at certain times, thus destroying its regularity. To avoid this I employ by preference a die, K, which is circular or disklike, and which fits snugly but rotatively in an eye in the end G of rod G. This die is sary compensation to preventv any reciprocation of block I other than that due to the rotation of the eccentric or the shifting of the eccentric at other points than at the ends of its stroke. This mechanism performs the same function as a'link if one end of it was coupled to shaft J and the other to rod G at a point corresponding to the center of die K. I employ the die in order to get a firm extended bearing. In lieu of this die I might employ the modification illustrated in Fig. S In this construction the end G of rod G is provided with a curved slot, K, which is engaged by the shaft J. The radius of this slot is governed by the amount oflongitudinal movement of rod (I, due to the maximum angle it makes with the line of travel of block I when the eccentric is set at its maximum throw. The effeet of this device is to permit the rod G to vibrate on its fulcrum Il without said vibration disturbing block I.

In order to keep the die K in place, I provide a washer, K, mounted concentrically on shaft J, so as to lap over the die K, and I prefer to make this washer in one with said die. They might, however, be separate. I also allow the washer on the fulcrum-pin L to extend over the edgeof the die K for the same reason. These washers form a lateral bearing for the die on the outside, and the lever K forms a lateral bearing for it on the inside.

I wish it understood that I may employ my means for modifying the reciprocating motion of the valve with any means for producing vthe reciprocating motion; but I prefer the means shown; and I do not limit myself to a train of gear-wheels such as I have shown. For example, the rack T may, in some instances, be arranged to mesh directly with the pinion Q, and the other wheels be omitted,and the rack T need not, necessarily, be mounted on or in the guide H. The disk or plate K', being merely a washer, maybe made separate from K, or even omitted, if other means are provided for keeping K in place. The ribs a a might also be on keepers C, and engage grooves in the eccentric B.

I do not claim herein every means for modifying the reciprocating motion of a valve, as other means have been proposed for accomplishing this nor do I limit myself to the pre` cise construction herein shown, as I may employ any equivalent thereof.

Having thus described my invention, I claim- Y 1. In a valve-operating mechanism, amechanism for modifying the motion of the valve comprising a carrying-block adapted to be reciprocated by the engine, an eccentric mounted rotatively on said carrying-block, a rackand-pinion device, substantially as described, whereby the reciprocating motion of the carrying-block imparts rotary motion to the eccentric mounted on the carrying-block, and a connection between the said eccentric and the valve-stem, whereby the reciprocating motion imparted to the valve by the reciprocation of ICO IIO

the carrying-block is modified by the rotation of the eccentric, substantially as set forth.

2. In a valve-operating mechanism, a mechanism for modifying the reciprocating motion of the valve comprising a carrying block adapted to be reeiprocated by the engine, an eccentric mounted rotatively on said carrying-block, a rack-and-pinion device, substantially as described, for converting reciprocating motion of the carryingbloek into rotary motion of said eccentric, and alever fulcrumed on said carrying-block and constructed to connect the said eccentric to the valve-stem, whereby the motion imparted by said eccentric is magnified or multiplied, substantially as shown and described.

3. In a valve operating mechanism, the combination of a valve-operating eccentric, its strap, its rod G, `fnlcrumed-at L on the carryingbloek, the said carrying-block arranged to reciprocate, as shown, and the mechanism, substantially as described, for coupling said rod G to the carrying-block, whereby the effeet of the vibration of the said rod on said block is neutralized, substantially asset forth.

4. The combination, with the main shaft A, ofthe keepers C C, ixed thereon and provided with grooves to receive ribs on the eccentric, the slotted eccentric B, provided with ribs a c, and arack, b, the segment-rack D, pivoted at e on the shaft and arranged to mesh with rack b through a slot in one oi' the keepers C, the clutch or sleeve E, splined on the shaft and constructed to receive a fork, F, the said fork F mounted to slide, as shown, and the link e, connected at one end to rack D at d, and at the other end to clutch E, Wherebyreciprooation of said sleeve rotates rack D, substantially as shown and described.

5. The mechanism for modifying the reciprocating motion of the valve comprising the carrying-block arranged to play in guides, the oscillating lever M, the eccentric O, and its shaft, the fixed rack T, and the gear-wheel or Wheels, whereby rotation is imparted to eccentric O O, all arranged to operate substantially as set forth.

6. The combination, with the eccentric B and its rod, of the fulcrum-stud L, the linkdisk K, the stud or shaft J, and the carry-ingblock i, said block being mounted in guides, and all arranged to operate substantially as set forth.

7. The combination of the shaft A, the valveoperating eccentric and its slotted rod, the fulerum-pin L, the link-disk K, the guide H, the carrying-block I, the stud or shaft J, the lever M, fulcrumed on J, the eccentric O and its sliding block and shaft, the fixed rack T, and the geai'\vl1ee1s Q, R, and S, all arranged to operate substantially as set forth.

In Witness whereof I have hereunto signed my name in the presence of two subscribing Witnesses.

FRANK. M. STEVENS.

Witnesses:

FRED A. CAsEY, J. E, DEWEY.

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