US1121414A - Steam-engine valve-reversing gear. - Google Patents

Description

H. R. STAFFORD. STEAM ENGINE VALVE RBVERSING GEAR.

APPLICATION FILED JULY 14, 1914. I

Patented Dec. 15, 1914.

4 SHEETS-SHEET 1.

APPLICATION FILED JULY 14, 1914.

Patented Dec. 15. 1914.

4 SHEETS-SHEET 2 @M NQ fog IN ENTOR WITNESSES I H. R. STAFFORD. STEAM ENGINE VALVE RBVBRSING GEAR.

APPLICATION FILED JULY 14 1914.

Patented Dec.

4 8HEETSSHEET 3.

H. R. STAFFORD.

STEAM ENGINE VALVE REVERSING GEAR.

APPLICATION FILED JULY14 1914.

1,121,414. Patented De0.15,1914.

4 SHEETS-SHEET 4.

III

WITNESSES UNITED STATES PATENT OFFICE.

HAL R. STAFFORD,

OF PLAINFIELD, NEW JERSEY, ASSIG-NOR TO ECONOMY DEVICES CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

STEAM-ENGINE VALVE-REVERSING GEAR.

Specification of Letters Patent.

71') all whom it may concern Be it known that I, HAL R. STAFFORD, of

Plainfield, in the county of Union and State of New Jersey, have invented a certain new and useful Improvement in Steam-Engine Valve-Reversing Gear, of which improvement the following is a specification.

' My present invention relates to power actuated valve reversing gear of the general class or type which is exemplified in Letters Patent of the United States No. 1,077 ,862, granted and issued to myself and Robert Rennie, under date of November 4, 1913, and its object is to provide simple and effective means whereby the reversing gear may be securely locked in /any adjusted position, and locking be "prevented except when the valve controlling the admission of fluid pressureto the reversing cylinder is lapped or closed.

The improvement claimed is hereinafter fully set forth.

In the accompanying drawings: Figure 1 is a side view, in elevation, of a locomotive engine, illustrating the application of my invention in connection with a Walschaert valve gear; Fig. 2, a side view, in elevation, of the reversingv cylinder and its accessories;

- Fig. 3, a plan or top view of the same; Fig.

combination lever,

3, a side view, in elevation, of the lower sliding bar of the locking mechanism; Fig. 4,. a vertical an enlarged scale, through the reversing cylinder; Fig. 5, an end view,-as seen from the left; Fig.6, a similar view, as seen from the right; Fig. 7, a vertical transverse section, on the line a a of Fig. 4; Fig. 8, a top view in elevation of the locking nut, illustrating a modification of structural detail and, Fig. 9, an end view of the same.

Referring to the drawings, my invention, which is applicable in connection with any of the various lmown types of distribution valve operating mechanism, is illustrated in Fig. 1 as applied for the control of a Walschaert valve gear of the ordinary construction, which comprises a link, 1, eccentric rod, 1, 1", and radius bar, 1, and is coupled to a distribution valve stem, 1. The radius bar is coupled to the lower arm, 2, of a reverse shaft 2, and is raised and lowered throughout its range of traverse on the link, 1, by my improved revershead, 3, of the cylinder.

longitudinal central section, on

ing mechanism, hereinafter described, which is coupled to the upper arm, 2*, of the reverse shaft.

In the practice of my invention, I provide a fluid pressure reversing cylinder, 3, which may be located in any convenient position on the locomotive, and, in this instance, is

shown as supported below the cab, on the.

right hand slde, the hand operated reverse lever, 4, being suitably mounted within the cab. The cylinder, 3, is made of considerably greater length than is required for imparting the desired degree of traverse to the Patented Dec. .15, 1914.

reverse shaft, in order to provide a large amount of clearance on each side of its piston, and is fittedwith a properly acked piston, 5, fixed on a piston rod, 5, w ich passes through a stufling box, 3, in the forward Across head, 6, which is fitted to slide between guides, 7, projecting from theforward end of the cylinder, is fixed to the forward end of the piston rod, and two parallel levers, 6", are coupled by a pin, 6, to the cross head. The lower ends of the levers, 6 are coupled by a pin, 7*, to a-block, 7 fitted to slide-vertically between guide ways, 7, fixed to the lower cross head guides, 7, and the upper ends' of the levers are coupled by a pin, 6, to the rear end of a reach rod, 8, the forward end of which is coupled to the upper arm, 2, of the reverse'shaft. The levers, 6 are thus provided with asliding fulcrum, the effect of which is to flatten the arcs traversed by the locking screw and reach rod connections.

The admission and exhaust of motive fluid to and from the'opposite ends of the reversing cylinder, 3, whereby the piston is moved in one or the other direction, as de sired, for the adjustments of the valve gear,

are, as in Letters Patent No. 1,07 7,862 aforesaid, effected and controlled by an actuating valve, 11-, which is fitted in a valve chest, 9,

secured to the lower side of the reversing air or steam, is admitted is fitted on the thread of the locking exhausted through an exhaust port, 3, and exhaust pipe, 3*. The actuating valve and floating valve seat being substantially similar, in structure and manner of operation, to the corresponding members of the appliance of Patent No. 1,077,862, and not constituting, in and of themselves, part of my present invention, will not be herein at length described. It should, however, be here noted, for the better understanding of the locking mechanism hereinafter described, that the actuating valve, 11, is manually moved, through intermediate connections, by the reverse lever, 4, and the floating valve seat, 13, is automatically moved through connections with the cross head, 6. Movement of the reverse lever, 4, is transmitted to the actuating valve 11, through a link, 12, which is coupled, at one end, to an arm on the reverse lever, and at the other, to an arm, 12*, on the outer end of a shaft, 12, which isjournaled in, and extends into,

the valve chest, 9, and carries, on its inner end, an arm, 12, which engages a slot in the valve, 11. Movement of the cross head, 6, is transmitted to the floating valve seat, 13, through a link, 16, which is coupled, at one end, to the cross head, 6, and at the other to an arm, 14, on the outer end of a shaft, 14, which is journaled in, and extends into, the valve chest, 9, and carries, on its inner end, an arm, 14, which engages a slot in the floating valve seat, 13.

The mechanism by which the reverse gear is positively locked in each of its adjusted positions, and locking prevented except when the actuating valve is lapped or closed, is of the following construction. A locking screw, 28, is located above the reversing cylinder, 3, parallel with the axial line thereof, and is coupled by a link, 28, to the levers, 6", so as to be moved longitudinally thereby, in acordance with the movement of the piston and cross head in either direction. The thread of the locking screw, which is steeply inclined, fits truly in two cylindrical bored guides, 29, 29, which are formed, in line axially one with the other, on the top of the reversing cylinder, and are separated by a space in which a revoluble locking nut, 30, screw. A bar, 31, is fitted to slide longitudinally in guides, 31, projecting laterally from the reversing cylinder, said bar having guide ways, 31*, projecting downwardly rom its lower side and fitting a block or die, 32, which carries a pin, 32, which is coupled to an arm, 33, fixed on the shaft, 12, which moves the actuating valve, 11. A bar, 34, is fitted to traverse longitudinally in the guides, 31, above the bar, 31, and is coupled,

by a link, 34*, to a pin, 34", fixed in the cross head levers, 6 The upper bar, 34, normally rests on the upper surface of the lower bar, 31, and carries two rollers, 34, which,

normally or when the two bars are in contact, rest in segmental recesses, 31", in the top of the lower bar. A shaft, 35, which is journaled transversely on the reversing cylinder above the upper bar, 34, has secured on its outer end an arm, 36, on the free end of which is journaled a roller, 37, which rests on the top of said bar. 4 A double armed locking lever, 38, .is secured on the shaft, 35, and carries, on one of its arms, a

pawl, 38, which, when the actuating valve is lapped or closed, is brought into engagement with a toothed rim, 30 on the locking nut, 30, by a spring, 39, which exerts upward pressure on the opposite arm of the latch. The pawl is disengaged from the toothed rim of the nut, when the actuating valve is moved into position to admit fluid pressure to the reversing cylinder, by the roller, 37, as hereinafter described.

Figs. 8 and 9 illustrate a structural modification in which the locking nut, 30, is held against rotation when the actuating valve is lapped, b'y friction brake action, instead of by the engagement of a pawl with a toothed rim on the nut 'as hereinbefore described. The middle portion of the periphery of the rotatable nut, 30, is, in this case, made truly cylindrical, and two friction shoes, 40, are fitted around it, said shoes being coupled together, on the side of the nut farther from the bars, 31 and 34, by a pin, 40*, fixed to the adjoining ends of the guides, 29, 29, of the locking screw. The free ends of the shoes, 40, that is to say, those adjoining the bars, 31 and 34, are coupled together by a pin, 41, on which is coiled a spring, 42, bearing against one of the shoes and against an adjusting nut on the pin and normally holding the shoes in contact with the nut with sufiicient frictional resistance to prevent its rotation. A shaft, 43, journaled in bearings in the guides, 29, of the locking screw, has acam, 44, fixed upon it between the ends of the shoes, 40, and carries an upwardly projecting arm, 45, on which is journaled a roller, 37, which traverses on the upper surface of the bar, 34. The upward movement of said bar effected by the movement of the reverse lever, as hereinbefore described, rocks the shaft, 43, in its bearings, and the cam,'44, presses the outer 'endsof the shoes, 40, apart and releases them from frictional contact with the nut, 30, thereby permitting its rotation during the movement of the reverse lever,

as in the instance first described.

It will be observed that no latch handle ,or latch is provided on, or in connection for locking the reverse lever in, adjusted position, unnecessary.

In the operation of a reverse gear e'mbodying my invention it is to be understood that normally, or when the appliance is not being operated, the actuating valve is lapped, thereby preventing the admission of motive fluid to the reversing cylinder; the reversing screw. is locked by the engagement of the pawl, 38, with the toothed'rim, 30, of the lockin nut; and the upper bar, 34, is in contact with the lower bar, 31, the rollers, 34, resting in the segmental recesses, 31, of the lower bar.

Movement of the reverse lever, 4, in either direction, to effect desired adjustment in forward or back motion. as the case may be. of the valve gear, will, through the connections before described, rock the shaft, 12, in its bearings, and thereby move the actuating valve, 11; through the extent of its lap, in the direction in which movement is desired, thereby admitting motive fluid to the reversing cylinder, and move the lower bar, 31, in the same direction. The movement of said bar will raise the rollers, 34, from the recesses, 31, and correspondingly raise the upper bar, 31, the' upward movement of which will, through the roller, 37 arm, 36, and shaft, 35, disengage the pawl, 38, of the locking lever, 38, from the toothed rim, 30 of the locking nut, 30, and thereby permit longitudinal movement of the locking screw, 28. I

The admission of motive fluid to the reversing cylinder and resultant movement of the piston cross head, reach rod, and connected valve gear, continues so long as the reverse .lever 'is progressively moved, and

upon the release of said lever by the engineman, the movement of the floating valve seat, 13, which is eflectedby its connection to the cross head, laps the ports of the actuating valve and cuts 0E the supply of mo tive fluid to the reversing cylinder, as in the construction of Letters Patent No. 1,077,862, aforesaid. The'rollers, 34, then drop into the recesses, 31, of the lower bar, 31, and release the upper bar, 34, from its bearing on the roller, 37, with the-effect also of returning the actuating valve to lapped position, and the spring, 39, forces the pawl, 38, into engagement with the toothed rim, 30 of the locking nut, 30, thereby preventing rotation of the latter and locking the'gear in adjusted position. It will be seen that such locking cannot be efl'ected except when the actuating-valve is lapped or closed.

The provision of a reversing cylinder of substantially greater length than that required for the maximum traverse of the piston, afl'ords space at each end of the cylinder for the reception of a comparatively large volume. of motive fluid, which can be pered opening, thereby admittin gradually released through a small or taof very close graduatlon ofthe speed an traverse of adjustments of the valve gear.

I claim as my invention and desire to secure by Letters Patent:

1. In a valve reversing mechanism, the

combination of a fluid pressure motor; an

actuating valve controlling the admission and exhaust of motive fluidto andiroin said motor; a screw movable longitudinally by said motor; a rotatable nut engaging said screw and normally held stationary in the various positions of valve gear adjustment; a, manually operable reverse lever for moving the actuating valve into and out of admission position, the adjusted positions of'which lever correspond with those ofthe piston of the motor; connections to said means through which the nut is released for rotation, during, and only during, the periods in which theactuating valve is in admission position; and automatically operable means for engaging the nut and its holding means, upon and during the continuance of, the cessation of motive fluid admission.

2. In a valve reversing mechanism, the

combination of a fluid pressure motor; an

tions of'valve gear adjustment; a manually operable reverse lever for moving the actuating valve into and out of admission position, and releasing the locking mechanism during, and only during, the periods of motive fluid admission, the adjusted positions of which lever correspond with those of the piston of the motor; and means, au-

tomatically operable by the motor, for engaging the locking mechanism, upon, and during the continuance of, the cessation of motive fluid admission.

3. In avalve gear reversing mechanism, the combination of a fluid pressure motor; an actuating valve controlling the admission and exhaust of motive fluid to and from said motor; means for positively locking said motor in the various positions of valve gear adjustment; a manually operable reverse lever which is free to traverse without latch engagement with a stationary member, means, connected with the motor, for preventing the forces acting through the valve gear from moving said lever; connections coupling said lever to the actuating valve, and connections through which said lever effects, by its initial movement, the release of the locking mechanism coincidently with the admission of motive fluid to the motor, and maintains such releaselduring,

tions of valve gear adjustment; a manually operable reverse lever which is free to traverse Without latch engagement with a stationary member, the adjusted positions of which lever correspond with those of the piston of the motor; connections coupling said reverse lever to the actuating valve; connections through which said reverse lever effects and maintains release of the locking mechanism during, and only during, the periods of motive fluid admission by said valve; and means for automatically engaging the locking mechanism upon the cessation of movement of the reverse lever in either direction.

5. In a valve reversing mechanism, the combination of a fluid pressure reversing cylinder; an actuating valve controlling the supply and exhaust of motive fluid to and from said cylinder; a floating valve seat interposed between the actuating valve and the ports of the reversing cylinder, and having ports continuously communicating with said latter ports and controlled by the actuating valve; a reverse lever for manually operating the actuating valve; means for imparting movement to the floating valve seat by the piston of the motor; a screw movable longitudinally by the motor; a rotatable nut engaging said screw; a locking mechanism by which said nut is held stationary in the various positions of valve gear'adjustment; connections through which the actuating valve is moved into and out of admission position by the reverse lever and the locking mechanism is released during, and only durmg, the periods of fluid pressure admission; I

cylinder; a piston fitting therein and having a cross head connected to its rod; an actuating valve controlling the.admission and exhaust' of motive fluid to and from the cylinder; a reverse lever coupled to the actuating valve; a lower bar fitted to slide in guides parallel with the axis of the revers ing cylinder and having segmental recesses in its upper face; connections through which longitudinal movement is imparted to said bar by the reverse lever; an upper bar fitted to slide parallel with the lower ianne bar and carrying rollers which normally rest in the recesses of the lower bar, and are elevated therefrom by the movement of said bar; locking mechanism for positively holding the piston and cross head in any of the positions to which they may be moved; and connections through which said locking mechanism is released, in and by the eleva tion of the rollers and the upper bar by which they are carried.

7. In a valve reversing mechanism, the combination of a fluid pressure reversing cylinder; a piston fitting therein and having a cross head connected to its rod; an actuating valve controlling the admission and exhaust of motive fluid to and from the cylinder; a reverse lever coupled to the actuating valve; a lower bar fitted to slide in guides parallel with the axis of the revers ing cylinder and having segmental recesses in its upper face; connections through wh1ch longitudinal movement is imparted to said bar by the reverse lever; an upper bar fitted to slide parallel with the lower and carrying rollers which normally rest in the recesses of the lower bar and are elevated therefrom by the movement of said bar; connections through which movement, in the direction of the movement of the lower bar, is imparted to the upper bar by the cross head; locking mechanism for positively holding the piston and cross head in any of ,the positions to which they may be moved;

and connectionsthrough which said locking mechanism is released, in and by the elevation of the rollers and the upper bar by which they are carried.

8. In a valve reversing mechanism, the combination of a fluid pressure reversing cylinder; a piston fitting therein and having a cross head connected to its rod; an actuating valve controlling the admission and exhaust of motive fluid to and from the cylinder; a reverse lever coupled to the actuating valve; a lower bar fitted to slide in guides parallel with the axis of the reversing cylinder and having segmental recesses in its upper face; connections through which longitudinal movement is imparted to said bar by the reverse lever; an upper bar fitted to slide parallel with the lower bar and carrying rollers which normally rest in the recesses of the lower bar, and are elevated therefrom by the movement of said bar; a screw connected to, and movable longitudinally by, the cross head; a revoluble nut engaging said screw; a member normally engaging said nut and preventing its rotation;

a roller traverslng on the upper bar; and connections through which said roller releases the engagement of the nut and its locking member, when elevated by said upper bar.

9. In a valve reversing mechanism, the combination of a fluid pressure reversing cylinder which is of substantially greater length than that Which accords With the maximum traverse of its piston, thereby providing receiving spaces on each side thereof from which motive fluid may be gradually exhausted; a piston fitting said cylinder and having a cross head connected to its rod; means for connecting said cross head to a distribution valve gear; means for effecting the admission and exhaust of motive fluid to and from opposite ends of-the reversing cylinder; and manually operable means for actuating said admission and exhaust means.

10. In a valve reversing mechanism, the combination of a fluid pressure reversing cylinder; a piston fitting therein and having a cross head connected to its rod; a lever coupled to said cross head; a bearing in which said lever is pivoted and which is movable transversely to the cross head; means for connecting said lever to a distribution valve gear; means for efl'ecting the admission and exhaust of motive fluid to and from opposite ends of the reversing cylinder; and manually operable means for actuating said admission and exhaust means. v

' HAL R. STAFFORD. Witnesses:

J. SNOWDEN BELL, EDWARD A; WRIGHT.

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