US797416A - Governor. - Google Patents

Description

No. 797,416. .PATENTED AUG. 15, 1905. W. L. R. EMMETn GOVERNDR.

APPLICATION FILED MAR. 27, 1901.

Wihnesses. hwenficr WiHiamLeREmmet.

of the engine.

UNITED PATENT OFFTEE.

"WILLIAM L. R. EMWET, OF SOHENECTADY, NEW YORK, ASSlGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION Oh NEW? YORK;

tBlOWllEldhlOlqT.

Specification of Letters Patent.

Application filed March 27, 1901. Serial No- 58,0 i6.

To all] 1117210771 71?; 711/14 concern:

Be it known that I, lVILLIAM Ln ROY EM- MET, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Governors, of which the following is a specification.

When engine-driven alternator-s are operated in parallel with each other, a difficulty frequently arises due to a tendency to oscillation in the relative motions of the machines, the oscillations being naturally accompanied by periodic cross-currents between the machines. In some cases the amplitude of these oscillations is limited in extent, while in other cases the oscillations may become so violent as to throw the machines out of step. These oscillations are in their nature similar to the swing of a pendulum. Since an oscillating motion, such that of a pendulum, is not kept alive except by the supply of periodic impulses, the inquiry naturally arises as to whence come the impulses which keep alive the oscillating speed variations in the case of parallel-connected alternators. After an investigation of the matter l. have been led to the belief that these oscillations are due to the relative actions of the engine-governors, which in their efforts to compensate for the speed variations of the machines cause a periodic delivery of steam which keeps the speed of the engines continually oscillating. The oscillations of engine motion which are here referred to should not be confused with the natural variations which are caused by normal irregularity of crank effort, although these natural variations of course have a tendency to start the other trouble where the conditions are such that it may exist.

To cure the difliculty mentioned, I. have devised an arrangement whereby the efforts of the engine-governor to control the speed of the engine are prevented from becoming cf feetive until after the expiration of a period of time greater than a period of one oscillation. Speed oscillations therefore no longer have any effect upon the regulating apparatus The governor is only brought into operation when the speed of the engine is maintained for a considerable length of time either above or below the normal value.

The Various features of novelty which constitute my invention are set forth in the claims appended hereto.

For a more detailed description of my invention and of its mode of operation reference is to be had to the following description, taken in connection with the accompanying drawing.

In the drawing l have remescnted so much of the governing mechanism of a single engine as may be necessary to an understanding of my invention. For convenience of illustration 1 have shown the governor as controlling the speed of the engine by a throttle in the steam-adi'nission pipe; but it is to be understood that the invention is equally applicable to and in practice would generally be used in connection with a regulator of the type in which the point of cut-off is adjusted as, for example, in engines of the Corliss type.

Referring to the drawing it will be seen that the speed-controlling device comprises, among other elements, a ball-governor 1 of any ordinary type, this governor being driven in any suitable manner as, for example, by means of bevel-gears 2 3, operatively related to the main shaft of the engine. (Not shown.) A sleeve t, which is moved up and down upon the governor-shaft as the speed of the same varies, carries a grooved collar 5, which acts upon a bell-crank lever 6, the outer end of which is adapted to communicate motion through the governor-rod 7 to a throttle-valve 25, which controls the admission of steam to the engine. As has before been mentioned, however, this rod might equally well be employed to control the point of cut-off.

The rod '7 is broken in two and the parts are operatively connected through a dash-pot 8, the outer member 9 of which is secured to one end 10 of the rod and incloses a piston 11, fixed. to the other portion of the rod 7. The piston-rod, which is secured to the piston 11, of course makes a tight joint with the cylinder 9 of the dash-pot. Oeiiteringsprings 12, located on either side of the piston, tend to maintain the piston in a middle position with respect to the dash-pot cylinder. The interior of the dash-pot may be filled with oil, air, or some other suitable fluid for which a passage from one side of the piston to the other may be afforded either by an opening through the piston itself or by a loose fitting of the piston in the cylinder, as may be desired.

An arm 18, carried by the rod 7, has pivoted to its upper end a lever let, the outer end 15 of which is adapted to close an electric circuit through engagement with an insulated contact 16, carried on that portion of the governorrod designated as 10. A spring 17 normally urges these contacts together. A cam 18, carried by the dash-pot cylinder, is, however, adapted to engage a cooperating camsurface 19 on the lever 14. When the piston of the dash-pot moves relatively to the cylinder inclosing the same, this cam and its cooperating camsurface cause a slight movement of the lever 14 about its pivot and a consequent separation of the contacts 15 and 16. These contacts are in an electric circuit including a source of current, such as a battery 20 and an electromagnet 21, across poles of which an armature 22, fixed to the rod 10, is adapted to slide. Since the two parts 7 and 10 of the governor-rod are mounted so as to slide through fixed bearings 23 and 21, this armature 22 is at all times in close inductive relation to the poles of the magnet 21.

From the above explanation of the details of one form of apparatus embodying my invention it will be seen that the governor-rod is firmly locked from movement at all times when the piston of the dash-pot occupies a central position in the cylinder of the same. This dash-pot is adjusted so as to be slow in action, thereby preventing oscillations in speed from having any appreciable elfect in altering the relative position of the parts thereof. The governor-rod being therefore locked while these oscillations of speed take place, a jerky supply of steam to the engine is prevented, thereby allowing the oscillations to die out from want of any sustaining impulses. In case, however,'of a continued drop in speed, such as would be caused by an increased load, the governor, by acting continuously in one direction upon the daslrpot, causes a displacement of the parts thereof from their normal position and a consequent opening of the contacts 15 and 16. The armature 22 being now unlocked, the governor-rod is free to act upon the throttle 25, the supply of steam being then adjusted in the usual manner, during which operation the centering-springs of the dashpot return the parts to their normal relative positions. When this has been done, the contacts 15 16 again close and the governor-rod is again locked, this action going on from time to time, as may be required.

Although I have described and illustrated an electrical arrangement for locking the governing mechanism, it is to be understood that my invention in its broader aspects covers any suitable meansmechanical, electrical, hydraulic, or otherwise.

What 1 claim as new, and desire to secure by Letters Patent of the United States, is

1. The combination of a governor, locking means for opposing movement of said governor, and separate means whereby the tendency to govern will release said locking means after said tendency has continued a definite period.

2. The combination of a governor, electrically-controlled locking means for opposing movement of said governor, and means whereby the tendency to govern will release said locking means after said tendency has continued a definite period.

3. The combination of a governor, electrically-controlled locking means for opposing movement of said governor, and means by which the tendency to govern will release said locking means after said tendency has continued a definite period.

4:. The combination of a governor, a device movable thereby, means for locking said device, and means whereby the tendency to govern will release said locking means after said tendency has continued a definite period.

5. The combination of a governor, a device governed thereby, means for preventing the governor from exerting any governing elfect, and electrically-controlled means for allowing the governor to exert a governing eifect after a tendency to exert such effect has continued a definite time.

6. The combination of a governor, a device controlled thereby, a dash-pot mechanically connected between said governor and said device, means for locking said device, and means controlled by relative motion of the members of said dash-pot for releasing said locking means.

7. The combination of a governor, a device operatively related thereto and movable thereby, and means for momentarily delaying the response of said device to motion of said governor.

8. The combination of a governor, a device controllable thereby, and means for positively locking said device.

9. The combination of a governor, a device movable thereby, and means for locking said device until the effect of the governor has continued for a definite period and means for then unlocking said device.

10. The combination of a governor, avalvecontrolling mechanism, a delayed lost-motion connection between said governor and said mechanism, and magnetic means for locking said mechanism.

11. The combination of a governor, a valvecontrolling mechanism, a lost-motion connection between said governor and said mechanism, and means for locking said mechanism.

12. The combination of a centrifugal governor, avalve-controlling mechanism operated by said governor, and a lost-motion connection between said governor and said mechanism, said lost-motion connection consisting of a dash-pot.

13. The combination of a governor, a rod, connections between said rod and said gov ernor, and means for locking said rod.

1 1. The combination of a governor, a rod,

eonnections between said rod and said governor, and magnetic means for locking said rod.

15. The combination of a centrifugal governor, a rod movable thereby, means for looking said rod When the governor is running at normal speed, and means for unlocking the rod upon continued variation of speed from the normal.

16. The combination of a centrifugal governor, a valve or other device controlled thereby, a rod through the medium of which the control is eflected, and means for locking said rod.

17. The combination of a centrifugal governor, a rod movable thereby, means for locking the rod When the governor is running at normal speed, and means for unlocking the rod in response to change in speed of the governor.

18. The combination of a centrifugal governor, a valve controlled thereby, a dash-pot

Images