US691384A - Valve-gear for engines. - Google Patents

Description

Patented Jan. 2|, I902.

0. JACKSON. VALVE GEAR FOB ENGINES..

(Application'filed Jan. 26, 1901.)

2 Sheets-Sheet I.

(No Model.)

co. PHOYO-LIYH narrow a. c.

No. 691,384; Patentfl Jan. 21, I902.

.0. JACKSON. VALVE GEAR FOB ENGINES.

( Application filed Jan. 26 1901.

2 Sheets-Sheet 2.

(No Model.) I

TM: mums PETERS c0. FNOTD-LITHO, WASHINGTON. n. a

UNITED STATES PATENT OFFICE.

OSWALD JACKSON, OF OARBOLLTON, ILLINOIS.

VALVE-GEAR FOR ENGINES.

SPECIFICATION forming part of Letters Patent No. 691,384, dated January 21, 1902.

Application filed January 26, 1901. Serial No. 44,795. (No model.)

To all whom it may concern.-

Be it known that I, OSWALD JACKSON, residing in Oarrollton, in the county of Greene and State of Illinois, have invented a new and useful Improvement in Valve-Gear for Engines, of which the following is a description, referehce being had to the accompanying drawings, which are a part of this specification.

My invention has relation to improvements in valve-gear for engines, being adaptable to any common slide-valve of a stationary, traction, or locomotive engine.

The primary object of the invention is to provide an improved construction whereby an actuating agent may be automatically cut off from the cylinder as the load on the engine may vary.

A further object is to provide for admitting and cutting off the steam instantly.

A further object is to provide an improved construction whereby the engineer is enabled to cut off the steam at any part of the stroke and thereby permit said steam to work expansively for the remainderof the stroke without changing any part of the gear and in marine engines enabling the engineer to run onehalf, three-fourths, or anyspeed he desires.

With the above objects and other incidental objects in view the invention consists of the devices and parts or their equivalents as hereinafter set forth.

In the accompanying drawings, Figure 1 is a plan View of the engine. Fig. 2 is a section on the line 2 2 of Fig. 1. Fig. 3 is a section through the valve-casing. Fig. 4: is a detail of one of the governor-weights and allied parts. Fig. 5 is a cross-section through the saddle-plate, and Fig. 6 is a view of a modified form of valve-operating mechanism.

Referring to the drawings, the letter a indicates a valve-casing of an ordinary engine mechanism into which steam is admitted either from the top or side, as desired. This valve-casing is provided in its bottom with the usual channels band 0, respectively,which lead to the cylinder below, (not shown,) and with an exhaust channel 61. Within the valve-casing is the usual valve 6, which is adapted to connect either of the channels leading to the cylinder with the exhaust-channel. Extending from the valve and through one end of the valve-casing is a valve-rodf. Pass ing through the outer end of this valve-rod is a pivot-bolt g, said bolt carrying an antifriction-roller h, which works in a slot 1', formed in a plate j for the purpose of keeping the valve-rod in a central position. also passes loosely through a rod'k. Extending through the outer end of the rod is is a bolt Z, said bolt passing through an elongated slot m, formed in a saddle-plate 12, said slot being preferably curved. The lower end of the bolt Z passes through an elongated slot 0, formed in a lever 17, said lever being pivoted at one end, as indicated by the letter q. The lower end of the bolt Z, which projects below the leverp, has a nut r screwed thereon to prevent the withdrawal of the bolt from the slot. The free end of the lever 19 is in the form of a fork, asindicated by the letters, and the ends of the arms of the fork carry antifrictionrollers t t.

The letter it indicates the ordinary crankshaft of an engine mechanism, said shaft having mounted on one end thereof the usual crank-disk n, which is connected to the piston-rod (not shown) of a cylinder by means of the usual pitman. (Also not shown.) As is well understood in this class of mechanism, the reciprocation of the piston in the cylinder causes the rotation of the crank-shaft.

Surroundinga medial portion of the crankshaft is a cam w. This cam is pivoted on the shaft, preferably-by means of threaded studs a; m. The inner ends of these studs are conical and engage conical recesses at diametrically opposite points of the shaft, (see Fig. 2,) while their outer ends are secured to diametrically opposite points of the inner circumference of the cam. By thus mounting the cam upon the shaft said cam may be readily turned upon the pivots w to a more or less oblique plane. Nuts y y engage the threads of the screw-studs and when turned are adapted to adjust the studs, so as to compensate for any wear at the conical ends of said studs.

The cam w is of peculiar shape, (best illustrated in Figs. 1 and 2) that is to say, it consists of the two portions 2' 2, which are on a plane concentric to the axis of the crankshaft, but considerably removed from each other in the direction of the length of the The bolt g ICC shaft, and the connecting portions 1 1, which are on diagonal planes across the axis of the crankshaft. The arms of the fork s are adapted to straddle the portions .2 and 1 1 of the cam, and the antifriction-rollers t t of said arms bear against opposite sides of said portions of the cam. Around the innercircumference of the cam is a flange 2, which projects at right angles to the portionsz z and 1 1.

From opposite points of the crank-shaft extend short posts 3 3, to which are pivotally connected governor-arms 4 1, the inner ends of said arms being formed or provided with weights 5 5, the inner sides of said weights preferably conforming to the contour of the shaft. Pivotally connected to the weights and extending therefrom in directions opposite to the directions in which the arms 4 extend are links 6 6. The other ends of these links are pivotally connected to diametrically opposite points of the inner side of the flange 2 of the cam. Projecting from each weight are lugs 7 7, and to the ends of these lugs are connected coiled springs 8 S. The ends of these springs which project beyond the lugsare threaded to receive nuts 9 9. The opposite ends of the springs are connected to collars 1O 10, which are mounted on the pivotstuds 00. It is obvious that by turning the nuts the tension of the springs may bereadily regulated.

Pivoted to diametrically opposite points of the crank-shaft are cushion-pots in the form of small cylinders 11 11. These pots areintended to be filled with some suitable resisting agent, preferably a liquid, such as glyc erin or oil of any kind. A piston 12 is adapted to reciprocate in each cylinder, and each piston is provided with a small aperture 13. To each piston is also connected a piston-rod 14, said rod extending outwardly through one end of the cylinder and being pivotallyconnected at its outer end to an arm 15, projecting from the inner flange.

Mounted slidingly on the crank-shaft is a flanged collar 16. The sliding movement is preferably obtained by providing the collar with a key 17, which engages an elongated groove 18 in the crank-shaft.

The numeral 19 indicates a medially-pivoted lever. One end of this lever is forked, and the arms of the fork engage diametrically opposite points of the groove of the collar, the extremities of the arms of the fork being preferably provided with antifrictionrollers 20. The collar 16 has extending from one side thereof a projection 21, which is in the form of a wedge and is adapted when the collar 16 is moved in one direction to slide under the lug extending from the flange 2, and to which lug one of the links 6 is connected.

In explanation of the operation of the invention it is to be stated that when the shaft to is revolved the cam w is of course revolved therewith. As this cam revolves when one of the inclined portions 1 thereof is brought into contact with the arms of the fork s, the lever 11 is turned on its pivot, and as this lever is connected to the rod is and said rod in turn to the valve-rod f the pivot-bolt is forced to travel in the slot m. This will actuate the valve-rod f and cause said rod to move the valve e in a direction to open either of the channels I) or c, in accordance with the direction of the movement of the valve-rod. Now when the cam has rotated sufliciently far to bring either of the surfaces 5 ,2 into contact with the arms of the fork 8 no movement whatever is imparted to the lever 19, and this occurs at the time either one or the other of the channels b or c is open, the said channel receiving the full head of steam during the time the portion 2 is in engagement with the arms of the fork 3. When the portion .2 of the cam is rotated out of engagement with the fork-arms and said fork-arms thereby brought into engagement with the other inclined portion 1 of the cam, this inclined portion will turn the lever 13 in an opposite direction to gradually open the other channel, and when the cam is revolved sufficiently far to bring the other portion 2 into engagement with the arms of the fork 3 said other channel is opened fully and is kept open until said portion ,2 rides out of engagement with the fork-arms, and so on throughout the rotation of a cam. Heretofore in all valvegears operated by eccentrics and yokes the admission of steam into the cylinder is gradual and the cut-off of steam also gradual, with the result that the channel or port is only open to its full extent for the smallest possible length of time, and of course the piston-head is only obtaining the full pressure of steam from the boiler during the short period of time this channel or port is fully open. It will be seen, however, that by my construction the full head of steam is permitted to enter the cylinder for a considerable period of time, and thereby the full pressure of the steam is utilized for a much longer period of time than has heretofore been the case. If

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during the operation the speed of the engine becomes too great, the governor-weights will fly outwardly, and this movement of the weights by reason of the connection of the links 6 with the cam will cause said cam to be automatically tilted to a less oblique position against the contrary force exerted by the springs 8, and when thus tilted the throw of the lever 29 will be lessened, and consequently the channels I) and 0 will not be fully opened, and which of course will have the effect of reducing the speed of the engine. When the speed falls to a certain point, the weights will again fly inwardly, and consequently the cam will be tilted back toward its more oblique position. As previously stated, by adjusting the nuts 9 the tension of the springs 8 may be regulated so as to offer greater or less resistance to the governorweights flying outwardly. When the cam is tilted in the manner explained, the pistonrods 14: are necessarily moved in and out, and this has the effect of reciprocating the pistons in the cushion-pots 11. As these pistons move the oil is forced through the small aperture 13 in each piston from-one side of the piston to the other in the alternate reciprocation of the piston, which of course insuresa steady movement. Whenever the engineer desires to cut ofi the steam at any part of the stroke in order that the steam may work expansively for the remainder of the stroke without changing any part of the valvegear, the lever 19 is grasped and turned in a direction to cause the flanged collar 16 to move toward the cam; As said collar thus moves the wedge 21 thereof acts upon the cam, and thus raises the cam to a less oblique position. This raising of the cam to a less oblique position by manipulation of the engineer will be found of particular advantage in marine engines, as the engineer is enabled to go one-half, three-fourths, or any speed-he wishes. Of course when the lever 19 is turned in the opposite direction to that first explained thesprings 8 will turn the cam back to a more oblique position.

While the mechanism for turning the cam to a less oblique position by manipulation of the engineer which is shown in the accompanying drawings and just described is the preferred arrangement for that purpose, yet

I do not wish to be understood as limiting myself specifically thereto, as any other equivalent mechanism for accomplishing that purpose may be provided without departing from the spirit and scope of my invention. I also wish it understood that my improvement may be employed in connect-ion with mechanism operated by an actuating agent other than steam-as, for instance, gas, air, and the like. I furthermore do not wish to be understood as restricting myself to the particular form of connection between the lever 19 and the valve e, as various forms of connection may be employed withoutdeparting from the spirit and scope of my invention, and in Fig. 6 I have illustrated a form of connection which is applicable to reversible engines. In the connection illustrated in the other figures of the drawings such form of connection is only applicable to non-reversible engines. In the modified form for reversible engines illustrated in said Fig. 6 the lever p instead of being pivoted at its end, as shown in the other figures of the drawings, is pivoted at a medial point on a plate 22. The end of the lever opposite to the forked end thereof is pivoted at the point 23 to a link 24. The center of the slot m of the saddle-plate n is in line with the valve-rod f, and said plate instead of being fixed, as in the other figures of the drawings, is pivoted at the point 25. Pivoted to one end of the saddle-plate is a link 26, and to the end of this link is pivoted a lever 27, which carries a dog working over the toothed edge of a segment 28. By manipulating the lever 27 it is obvious that the engineer can change the course of the bolt Z, which bolt passes through the elongated slot m, and consequently the course of the valve 6 is thereby changed. It will be understood, of course,that the bolt Z, which passes through the slot m and connecting-rod It), also passes through the link 24.

What I claim as my invention is l. In a valve-gear, the combination of a valve-casing, a valve therein for regulating the channels or ports leading to and from the cylinder, a valve-rod extending from the valve, a connecting-rod pivoted to the valverod, a plate provided with an elongated slot, a crank-shaft, a lever actuated by the crankshaft, said lever being pivoted at one end, and a bolt extending through the slot of the plate and connected to a medial point of the lever and tothe end of the connecting-rod.

2. In a valvegear, the combination of a valve-casing, a valve therein for regulating the channels or ports leading to and from the cylinder, a valve-rod extending from the valve, a connecting-rod pivoted to the valverod, a plate provided with a curved, elongated slot, a crank-shaft, a lever actuated by the crank-shaft, said lever being pivoted at one end and provided at a medial point with'an elongated slot, and a bolt connected to the end of the connecting-rod and passing through the curved slot of the plate and through the slot of the lever and held against withdrawal from said slot of the lever.

3. In a valve-gear, the combination of a valve-casing, having a valve therein for regulating the channels or ports leading to and from the cylinder,a crank-shaft,a cam mounted at an obliquity upon the crank-shaft," a pivoted lever provided at one end with a fork, the arms of said fork engaging opposite faces of the cam, whereby the lever is caused to be turned on its pivot as the cam is revolved, a connection between the lever and the valve, and governor mechanism adapted to act on the cam in order to throw said cam to a more or less oblique position dependent upon the speed of the engine, and thereby regulate the throw of the valve.

4:. In a valve-gear, the combination of a valve-casing having a valve therein for regulating the channels or ports leading to and from the cylinder,a crank-shaft, a cam mounted at an obliquity upon the crank-shaft, a pivoted lever provided at one end with a fork, thearms of said fork carrying antifrictionrollers which engage the opposite faces of the cam, whereby the lever is caused to be turned on its pivot as the cam is revolved, a connection between the lever and the valve,and governor mechanism adapted to act on the cam in order to throw said cam to a more or less oblique position dependent upon the speed of the engine, and thereby regulate the throw of the valve.

5. In a valve-gear, the combination of a valve-casing having a valve therein for regulating the channels or ports leading to and ICC from the cylinder, a crank-shaft,a cam mounted upon the crank-shaft in such manner as to be turned to a more or less oblique position, mechanism between the cam and the valve-rod and adapted to be actuated by the cam as said cam is revolved to thereby cause the actuation of the valve, and governor mechanism adapted to act on the cam and automatically throw said cam to a more oraless oblique position dependent upon the speed of theengine, and thereby automatically regulate the throw of the valve.

6. In a valve-gear, the combination of a valve-casing having a valve therein for regulating the channels or ports leading to and from the cylinder, a crank-shaft,a cam mounted upon said shaft in such a manner as to be turned to a more or less oblique position, said cam provided with two portions which are concentric with the axis of the crankshaft but a distance removed from each other in the direction of the length of the shaft, and with two connecting portions disposed in planes oblique to the axis of the shaft, mechanism between the cam and the valve and adapted to be acted upon by said portions of the cam as the Y cam is revolved to thereby cause an actuation of the valve, and governor mechanism adapted to act on the cam in order to throw said cam to a more or less oblique position dependent upon the speed of the engine, and thereby regulate the throw of the valve. i

7. In a valve-gear, the combination of a valve-casing having a valve therein for regulating the channels or ports leading to and from the cylinder, a cran k-shaft,a cam mounted upon the crank-shaft in such a manner as to be turned to a more or less oblique position, said cam provided with two portions which are concentric to the axis of the crankshaft but a distance removed from each other in the direction of the length of the said shaft, and with two connecting portions disposed in planes oblique to the axis of the shaft, a lever provided with a forked end, the arms of said fork adapted to be acted upon by the said portions of the cam as the cam is revolved, connections between said lever and the valve, and governor mechanism adapted to act on the cam in order to throw said cam to a more or less oblique position dependent upon the speed of the engine, and thereby regulate the throw of.the valve.

8. In a valve-gear, the combination of a valve-casing having avalve therein for regulating the channels or ports leading to and from the cylinder, a cran k-shaft, a cam mounted thereon in such a manner as to be turned to a more or less oblique position, a governorarm pivotally connected to the crank-shaft, a governor-weight at the end of said arm, a link pivotally connected at one end to the weight and at its opposite end to the cam, and mechanism between the cam and the valve and adapted to be actuated by the cam as said cam is revolved to thereby cause the actuation of thevalve.

9. In a valve-gear, the combination of a valve-casin g having a valve therein for regulating the channels or ports leading to and from the cylinder, a crank-shaft, a cam mounted thereon insuch a manner as to be turned to a more or less oblique position, governorarms pivotally connected to the crank-shaft, governor-weights at the ends of the governorarms, links, each pivotally connected at one end to a governor-weight and at its opposite end to the cam, and mechanism between the cam and the valve, and adapted to be actuated by the cam as said cam is revolved to thereby cause the actuation of the valve.

10. In a valve-gear, the combination of a valve-casing having a valve therein for regulating the channels or ports leading to and from the cylinder, a crankshaft, a cam mounted thereon in such a manner as to be turned to a more orless oblique position, a governor arm pivotally connected to the crank-shaft, a spring-tensioned governor-weight at the end of the governor-arm, a link pivotally connected at one end to the governor-weight but at its opposite end to the cam, and mechanism between the cam and the valve and adapted to be actuated by the cam as said cam is re volved, and thereby cause the actuation of the valve.

11. In a valve-gear, the combination of a valve-casing having a valve therein for regulating the channels or ports leading to and from the cylinder, a crank-shaft, a cam mounted thereon in such a manner as to be turned to a more or less oblique position, a governorarm pivotally connected to the crank-shaft, a spring-tensioned governor-weight at the end of the governor-arm, means for adjusting the spring tension, a link pivotally connected at one end to the governor-weight and at its opposite end to the cam, and mechanism between the cam and the valve, and adapted to be actuated by the cam as said cam revolves to thereby cause the actuation of the valve.

12. In a valve-gear, the combination of a valve-casing having a valve therein for regulating the channels or'ports leading to and from the cylinder, acrank-shaft, a cam mountedthereon in such a manner as to be turned to a more or less oblique position as the speed of the rotation of the shaft changes, mechanism betweenthe cam and the valve and adapted to be actuated by the cam as the cam revolves, to thereby cause the actuation of the valve, a cushion-pot pivoted to the crankshaft and adapted to contain a resisting agent,

a piston in the pot and provided with an aperture, a piston-rod extending from thepot, and a connection between said rod and the cam.

13. In a valve-gear, the combination of a valve-casing having a valve therein for regulating the channels or ports leading to and from the cylinder, a crank shaft, a cam III;

mounted thereon in such a manner as to be turned to a more or less oblique position as the speed of rotation of the shaft changes, mechanism between the cam and the valve and adapted to be actuated by the cam as said cam revolves and thereby cause the actuation of the valve, cushion-pots pivoted to the shaft and adapted to contain a resisting agent, pistons in the pots, each provided with an aperture, piston-rods extending from the pots, and a connection betweeneach pistonrod and the cam.

14. In a valve-gear, the combination of a valve-casin'ghaving a valve therein for regulating the channels or ports leading to and from the cylinder, a crank-shaft, a cam mounted thereon in such a manner as to be turned to a more or less oblique position, mechanism between the cam and the valve and adapted to be operated by the cam as said cam is revolved, and thereby cause the actuation of the valve, and mechanism under the manual 1 control of the operator, and constructed when operated to cause the cam to be turned to a more or less oblique position. v

15. In a valve-gear, the combination of a valve-casing having a valve therein for regu-' lating the channels or ports leading to and from the cylinder, a crank-shaft, a cam mounted thereon in such a manner as to be turned to a more or less oblique position, mechanism between the cam and the valve and adapted to be operated by the cam as said cam is revolved, and thereby cause the actuation of the valve, a slidable collar on the shaft, said collar provided with a projection adapted to act on the cam, and means for causing a sliding movement of the collar to thereby cause the projection thereof to throw the cam to a .more or less oblique position.

' 16. In a valve-gear, the combination of a -valve-casing, a valve therein for regulating Witnessesf D. O. FOLEY, W. L. CLOSE.

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