US1188123A - Overcoming dead-centers. - Google Patents

Description

I. F. WILDEY.

OVERCOMING DEAD CENTERS.

APPHCATION FILED DEC. 14, I915- 6 1 9 1 0 2 e n H J d e +U n m a P 2 SHEETS-SHEET I.

INI/E/VTOR lfvvilde WITNESSES A TTOH/VEYS I F. WILDEY. OVERCOMING DEAD CENTERS.

APPLICATION FILED DEC. I4, 1915- 2 SHEETS-SHEET 2- Patented June 20, 1916.

IIHIIIIIIH l/VVE/VTOI? I. EWHdeg WITNESSES A TTOR/VEYS Tm: coygn ngu PLANOGRAPH 510., wAsHlNn'rbN. n. c.

irnn erartn IRA F. WILDEY, OF NEW YORK, N". Y.

OVERGOIVIING DEAD-CENTERS.

Specification of Letters Patent.

Patented June 20, 19116.

Application filed December 14, 1915. Serial-No. 66,875.

To all whom it may concern Be it known that I, IRA F. WILDEY, a citizen of the United States, and a resident of the city of New York, borough of the Bronx, in the county of Bronx and State of New York, have invented a new and Improved Means for Overcoming DeadCenters, of which the following is a full, clear, and exact description.

This invention relates to power machinery and has particular reference to means for overcoming deadcenters in or connected with prime movers.

Among the objects of the invention is to provide means for applying steam automatically beneath or ahead of the steam engine piston just as the engine is being stopped and the usual throttle has been closed, for the purpose of preventing the piston from making its full stroke, such cushion of steam serving to hold the piston in such position as to insure that the crank will be held substantially on the quarter.

Another object of the invention isto provide an attachment for heavy prime movers having a reciprocating piston and rotary crank shaft, with means connected to the reversing lever and made effective by the bringing of the reversing lever to midposition from either direction, to cushion the reciprocating piston and cause it to be held in a position intermediate the ends of the stroke.

With the foregoing and other objects in view, the invention consists in the arrangement and combination of parts hereinafter described and claimed, and while the inven-- tion is not restricted to the exact details of construction disclosed herein, still for the purpose of illustrating a practical embodiment thereof reference is had to the accompanying drawings, in which like reference characters designate the same parts in the several views, and in which Figure 1 is a side elevation of anupright steam engine, parts being broken away, illustrating my improvement; Fig. 2 is a rear elevation of the same; and Fig. 3 is a detail View of the automatic steam valve.

Referring now more particularly to the drawings, I show a steam cylinder 10 having a reciprocating piston 11, and at 12 is indicated the usual steam chest housing in any usual or approved manner the usual slide valve mechanism, not specifically shown and constituting no part of this invention. The cylinder 10 is mounted upon a base 13 constituting a housing for the crank 1 1 and bearings for the crank shaft 15. The piston rod 16 is connected to the cross head 17 and operates the crank shaft through the connecting rod 18 in the usual manner.

At 19 I show a reversing lever indicated in Fig. 1 as being in its mid position and adapted to be moved therefrom either forwardly or rearwardly in any usual or approved manner.

At 20 I show an eccentric secured to the crank shaft preferably just outside of one of the base bearings, and surrounding said eccentric is a strap 21 to which is secured an arm 22 having an upwardly directed bearing seat 23 adapted to cooperate with a bell crank 24: of a rock shaft 25 journaled at 26 at the rear of the base.

Above the arm 22 is secured a small steam cylinder 27 having a piston 28 and a piston rod29 extending downwardly from the piston to the arm and carrying antifriction rollers 30 between which the arm is adapted to reciprocate as a result of the rotation of the eccentric with the crank shaft. Adjacent the cylinder 27 is a steam chest 31 in which is mounted a slide valve 32 of the form indicated in Fig. 3. Steam is admitted into this chest through a pipe 33. The cylinder is provided with two steam ports 31 and 35 and with an exhaust port 36 arranged between the steam ports and in the same horizontal line. The steam port 34c leads from the steam chest to the upper end of the cylinder while the other steam port leads to the lower end of the cylinder. The slide valve 32 is of such form as to uncover the upper steam port 34 when in mid position, and while in such position it establishes co1nmunication directly between the other steam port and the exhaust port. The slide valve furthermore is so constructed that when moved either up or down from its mid position, the lower steam port will be uncovered and communication will be established between the upper steam port and the exhaust port. 1

The bell crank 37 is journaled for movement around a horizontal axis in bearings 38 above the cylinder 27. One arm of the bell crank has loose connection at 39 with a rod A0 connected to the slide valve 32. The other arm of the bell crank 37 is connected by a rod 41 to a bell crank 42 associated with the reversing lever 19. The connections are its mid position the valve will be in its mid position admitting steam into the upper end of the cylinder 27, thereby lowering the piston 28 and rod 29, bringing the arm 22 with its bearing seat 23 in position to receive the wrist pin 24 of the bell crank 24.

At 43 I show another slide valve controlling the admission and exhaust of steam to and from the main engine cylinder independently of the main steam chest 12. The inlet port is shown at 44, and live steam received therethrough is adapted to be directed through a bypass 45 to the bottom of the cylinder or through a by-pass 46 to the upperend of the cylinder, depending upon the position of the slide valve 43.

At 47 is an exhaust pipe with which a bypass 48 communicates from points adjacent either end of the slide valve. The slide valve has a rod 49 connected at its lower end to a shoe 50 adapted to be guided along a rib 51 and having communication through a rod 52 with the rearwardly projecting arm of the bell crank 24. These connections also are so arranged that they are in their mid position when the other parts-are similarly arranged, as shown in Fig. '1. This figure may be understood as indicating the position of the parts just after the engine has been stopped and with the lower end of the -main cylinder filled with steam serving as a cushion preventing the piston 11 from resting at the lower end of the cylinder. Prior to the complete stoppage of theengine, however, it may be assumed that the crank 14 will have passed far enough onward in the direction of the arrow to have caused the eccentric 20 to have lowered the valve 43 far enough to admit live steam beneath the piston 11 forming a cushion of steam having suflicient virtue to lift the piston again to bring the crank to its quarter position. should the piston creep toward either end of the main cylinder due to condensation or otherwise of thesteam, the action of the eccentric through the bell crank and rod connections with the'valve 43 will be to admit steam through the inlet 44 into that end ,of the cylinder to which the piston is creeping, thereby automatically tending to restore the piston to its mid position. 7

Having thus set forth theessential features of the mechanism, its operation may be briefly summarized as follows: Assuming that the ship or machine is operating at full speed ahead, in order to stop, the engineer will proceed as usual shutting off the steam by actuation of the main throttle (not 7 shown), and when the piston is seen to be about to stop or at any suitable time between the shutting off of the steam and the stopping of the engine, the engineer will bring Subsequently, 7

his reversing lever to mid position opening the steam port 34 to admit steam into the cylinder 27 above the piston 28, thereby causing the arm 22 to come into engagement with the wrist pin 24 of the bell crank 24. While the main piston and crank shaft are making a slight further rotation with a corresponding rotation of the eccentric 20, the wrist pin just referred to will be duly seated in the bearing socket 23. If, then, the piston 11 seeks to move toward one end of the cylinder 10, the action of the eccentric through the bell crank 24 and connections with the slide valve 43 will admit live steam from the admission port 44 through one or the other of the by- passes 45 or 46, according to the end of the cylinder to which the main piston is moving. Such live steam will cushion the piston and tend to cause it to stop midway between the ends of the cylinder. If, however, the drag of the propeller, in the case of a steamship, should be su'flicient to turn the engine over even though the steam is shut off, the action of the eccentric will still be the same as already described in causing the admission of steam into that end of the cylinder toward which the main piston is moving. It will now be seen that the action of the cushioning device or the means for admitting steam to the main cylinder independently of the main engine cut-off is made functional without special thought or attention on the part of the engineer and with no perceptible additional effort, the bell crank 42 being connected to the reversing lever and the nature of the slide valve 32 being such that the desired effect is attained irrespective of the direction of movement of the reversing lever toward its neutral position. Likewise, when the engine is to be started again, the engineer will proceed in the usual manner to manipulate the usual appliances, and upon movement of the reversing lever as may be required either ahead or astern, the slide valve 32 will be automatically moved in a corresponding direction, but irrespective of such direction the effect of such movement will be to uncover the steam port 35 admitting live steam to the lower end of the cylinder 27 and bringing the other steam port 34 into communication with the exhaust port 36, thereby lifting the piston 28 and throwing the arm 22 out of engagement with the bell crank 24. Thus the slide valve 43 will be left in its neutral position, as shown in Fig. 1, sealing both of the ports 45 and 46 during the normal running operation of the engine, and at such time the arm 22 will reciprocate idly between the rollers 30.

While I show and refer to in the foregoing specification an upright engine with the main piston and cylinder above the crank shaft, and have also made corresponding references to other parts in the description, I would have it distinctly understood that these terms have been used only as illustrative and are not to be interpreted in any sense as limiting the invention to any particular type of engine or machine or with the parts disposed in any particular relative arrangement.

I claim 1. In a reversible steam engine, the combination with a cylinder, a reciprocating piston therein, a crank shaft, connecting means between the piston and the crank shaft, and a reversing lever, of means associated with the reversing lever and. made effective automatically during the bringing of the reversing lever to neutral position to cushion the piston and serve to hold it midway between the ends of the cylinder.

2. In a reversible steam engine, the combination with a cylinder, a piston reciprocating therein, a crank shaft, connections between the piston and the crank shaft, and a reversing lever, of means independent of the usual steam control for the cylinder serving to admit live steam into that end of the cylinder toward which the piston is moving while the engine is being stopped, and means automatically making said steam admission means effective simultaneously with the actuation of the reversing lever to mid position.

8. In a steam engine having a cylinder, a piston reciprocating therein, and main steam cut-off appliances, the combination with said cylinder, a piston and a crank shaft adapted to be rotated by operation of the piston, of means to admit live steam into one end of the cylinder after the main steam supply has been cut off to stop the engine, such steam serving to cushion the piston toward that end of the cylinder to which the steam has been admitted, and connections between the crank shaft and said steam admission means to cause such admission of steam when the piston approaches the end of a full stroke.

l. In a steam engine, the combination with a cylinder, a piston reciprocating therein, a crank shaft, and connections between the piston and the crank shaft, of a slide valve adjacent the cylinder controlling the admission of live steam to either end thereof and exhaust from the other end thereof independently of the usual steam cut-off appliances, an eccentric secured to the crank shaft, and connections between the slide vtilve and the eccentric serving to cause said admission of steam into the cylinder at a time When the major axis of the eccentric approaches a position perpendicular to the axis of the piston.

5. The combination with an engine cylinder having main steam cut-off appliances, a piston reciprocating in the cylinder, a crank shaft, and connections between the piston and crank shaft, of auxiliary steam inlet and exhaust devices for the cylinder including a slide valve, and connections between the crank shaft and the slide valve to cause the slide valve to admit live steam into one end of the cylinder after the main steam supply is cut ofl, said slide valve connections being made effective automatically during the manipulation of the engine to cause it to stop.

6. In an engine, the combination with a cylinder having main steam supply and out off appliances and inlet and exhaust ports communicating with the cylinder independent of the main supply and cut-off appli ances, a piston reciprocating in the cylinder, a crank shaft, and connections between the piston and the crank shaft, of an eccentric secured to the crank shaft, the major axis of the eccentric being substantially perpendicular to the axis of the crank, an eccentric strap cooperating with the eccentric, an arm extending from the strap, a bell crank j ournaled for movement around an axis parallel to the crank shaft, a movable valve controlling the auxiliary inlet and exhaust ports of the cylinder, connections between the bell crank and the valve, and power means made effective automatically with the manipulation of the engine to stop the engine, serving to bring the eccentric strap arm into cooperation with the bell crank and thereby cause movement of the valve aforesaid.

7. In an engine, the combination with a cylinder having main steam supply and cutoff applicances, a piston reciprocating in the cylinder, a crank shaft, and connections between the piston and the crank shaft, of auxiliary steam inlet and exhaust ports for the cylinder, a movable valve cooperating with said ports to control the flow of steam therethrough independently of the main supply and cut-off appliances, a controlling member for the engine, means actuated by the crank shaft to control the position of the movable valve, and power means serving to make the last mentioned means effective automatically simultaneously with the manipulation of said controlling member.

8. The combination with an engine cylinder a piston reciprocating therein, a crank shaft, and connections between the piston and the crank shaft, of means to admit a cushioning fluid into that end of the cylinder toward which the piston is moving after the usual power means have been cut off, said fluid admission means including a controlling valve, an eccentric secured to the crank shaft, an arm adapted to be recip; rocated by the eccentric, connections between the arm and the valve, and power means to cause said arm to engage the connections automatically and simultaneously with the manipulation of the engine to stop it.

9. In a reversible steam engine, the combination with a cylinder having steam supply and cut-off appliances and having inlet and exhaust ports auxiliary thereto, a piston reciprocating in the cylinder, a crank shaft,

connections between the piston and the crank shaft, and a reversing lever, of a valve controlling the inlet and exhaust through said auxiliary ports, connections between the crank shaft and the valve tovcontrol its position with respect to the ports, a steam cylinder adjacent the crank shaft, a reciprocating piston in this cylinder, connections between the last mentioned piston and the connections aforesaid between the crank shaft and valve, and connecting means between the reversing lever and the last mentioned steam cylinder serving to cause steam to be admitted thereto to force the piston and its connections toward the shaft connections when the reversing lever is brought to its mld pos1t10n from either dnechon.

10. In a steam engine, the combination of a cylinder, a piston reciprocating therein, a

steam chest at one side of the cylinder, steam inlet ports leading to the opposite ends of the cylinder, an exhaust port, a slide valve within the steam chest, and means to control the slide valve, the structure being such that when the slide valve is in mid position steam will be admitted to one end of the cylinder and communication will be established between the other end of the cylinder and the exhaust, and when the slide valve is moved in either direction from mid position steam will be admitted to the other end of the cylinder and communication will be established between the exhaust and that end of the cylinder to which steam was first ad- (i. ll. lhrsne.

Copies of this patentimay be obtained for five cents each, by addressing the Commissioner of latex",

' Washington, D. 0."

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