US1090520A - Prime-mover-power-limiting device. - Google Patents

Description

J. E. ENGLESSON.

PRIME MOVER POWER LIMITING DEVICE.

APPLICATION FILED JUNE 27, 1912.

' 1,090,520; Patented Mar. 17, 1914.

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JOHN ELOV ENGLESSON, OF KARLSKRONA, SWEDEN, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO ALLIS-CHALMERS MANUFACTURING t'IOMPANY, A CORPORATION OF DELAWARE.

PRIME-MOVER-POWER-LIMITING DEVICE.

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Specification of Letters latent.

Patented llilar. 17, 1914..

To all whom it may concern Be it known that I, J OHN ELov ENGLES- son, a subject of the King of Sweden, residing at Karlskrona, Sweden, have invented certain new and useful Improvements in Prime-Mover-Power-Limiting Devices, of which the following is a specification.

This invention relates to devices for limiting the power furnished by a prime mover. The object of the invention is to limit the power furnished by a prime mover.

The invention is applicable generally to governors for prime movers of any kind but is specifically illustrated in the accompanying drawing as applied to a governor for controlling the gate in the pipe line of a I water wheel.

This invention is adapted for use where the head of-water is variable and where an increase in the head might so increase the power of the unit asto endanger the electrical machinery driven thereby. In sucha case the device is applied to limit the power to the maximum safe'amount Within the.

of power is sold. In such cases if a consumer is carrying a load which is-in excess of this maximum, the power furnished ,him will be limited to this maximum and the consumer will thereby automatically be forced to himself furnish the excess over said maximum of power required. In these cases it is necessary that the unit be furnishing power to this consumer alone.

One embodiment of the invention is illustrated in the accompanying drawin in which the figure diagrammatically shows the application thereof to the main valve in the pipe line furnishing water to a water wheel not shown.

Referring to the drawing, the pipe lme 31 has a main valve or gate, 29 therein pivotally mounted, having a crank arm 30 con-- nected by a connecting rod 101 to the piston 27 connected by pipes 19, 20, to the valve casing 14 in which a valve 18 reciprocates. The valve casing 14 is supplied with operating liquid through pipe 16 and has exhaust pipes 15, 17, for discharging liquid therefrom. The valve 18 has collars 6, 7, fixed to its stem 5. The cross head 8 slides on stem 5 between collars 6, 7, and is pivotally connectedto one end of floating lever 3 which. is pivotally connected intermediate its ends to the collar 2 of a speed responsive means here shown as fiyball 1. A spring 9 1s mounted on valve stem 5 between collar 6 and cross head 8. This constitutes a lostmotion connection between the valve 18 and the fiyball 1. The opposite end of floating lever 3 is pivotally connected to piston rod 102 which'is connected through a secondary compensator 103 and link 4 to the bell crank lever 24, 25, pivotally mounted on a support 104. The arm 25 of the bell crank lever is connected to the piston rod 26 by connecting rod 105. This secondary compensating device 103 is specifically described and claimed in a copending application Serial No. 706,312, filed J one 27, 1912. The

T-lever 106 of the compensating device 103 is pivotally connected at one end of the T to support 107 and at the other end of the T to mechanism within the casing of the compensating device 103 and slides at its device ,for returning the valves 18 to mid position. The secondary compensating device 103 compensates the speed changes induced by the primary compensating devicei Bell crank lever 24:, 25, carries a third arm 23 pivotally connected to a crosshead 21 adjust-ably slidable in slot 110 of link 13 by means of a screw 111 rotatable only in link 13 by means of handwheel 22 and screwing through crosshead 21. Link 13 connects at its other end to hell crank 10, 12, pivotally mounted on support 112. The outer end of arm 10 of hell crank lever 10, 12, is located directly underneath collar 26 rod 26 carrying the piston 28 of a motor lever 3 constitutes a primary compensating and serves as a stop for the downward movement of said collar and valve stem 5 to which it is connected. Hand-wheel 22 is manually adjusted to locate crosshead 21 within the slot 110 in such a position that with piston 28 in position corresponding to the desired maximum opening of main gate 29, the end of arm 10 of bell crank lever 10, 12, will be in contact with collar 6 on the valve stem 5, with the valve 18 in midposition.

With the device so adjusted and the prime mover running at normal speed, it is now supposed that an additional load is thrown upon the prime mover. The consequence is that the speed of fiyball 1 will cause collar 2 to be lowered, and as the righthand end of floating lever 3 at this time constitutes a end of motor 27 and exhaustin fulcrum, the crosshe'ad 8 will be lowered, thereby compressing spring 9 between it and the collar 6, and no motion of the valve stem 5 and valve 18 will be produced because prevented by the arm 10 of hell crank lever 10, 12. The power furnished by the prime mover will therefore remain within the limit set.

Assume that the main gate 29 is vin 'posi tion corresponding to less than the maxi-- mum load to be limited by*-the device. In such case the arm 10 of hell crank lever 10, 12, will be in such position as to be spaced from collar 6. Upon an increase in load under such circumstances, the speed of flyball 1 will be decreased, thus lowering collar 2 and crosshead 8, transmitting the )35 downward mot-ion through spring 9, the collar 6 and valve stem 5, thus-moving valve 18 downwardly, letting fluid pressure in through pipes 16, 20, to the right gang through pipes 19 and 15 from the le hand end of the motor 27. Piston 28 will therefore move to the left, thus opening main valve'29 to furnish more water to the water wheel to bring the speedup to normal under the increased load. At the same time the motion of piston 28 to the left will be communicated through the primary compensating device to, depress. the right hand end of floating lever 3 to return valve 18 to mid-position by bringing the crosshead 8 into positive contact with the collar 7 toraise same.

If the increased load is within theallowable limit, piston 28 will not have moved-- arm 10 of bell crank lever 10, 12, to the position where it contacts with collar 6, so that there will in this case be no limitation upon the power furnished to meet the increased load. But should the increased load be beyond the allowable limit, then piston 28 will move only so far to the left as to bring arm 10 into contact with collar 6, at the time the primary compensating device hascompletely returned the valve 18 to midposltion. It will thus be seen that it is impossible to move piston 28 to the left beyond a desired limiting position corresponding to the limiting position of main valve 29. The piston 28, rods 26, 105, crank lever 23, 24, 25, and link 13, constitute agencies con trolled by the valve 18 and adapted to position the stop arm 10.

In cases where the load decreases, the increased speed of fiyball 1 will raise collar 2 and the left hand end of lever 3, thus elevating crosshead 8, which motion is'communicated to collar 7 and rod 5 to valve 18, .thus placing the motor 27 in condition for operating its piston 28 to the right, thereby throttling main valve 29. This actionis again compensated through the primary compensating device to move the right hand end of floating lever 3 upwardly, thereby lowering valve 18 to central position through crosshead 8, spring 9, collar 6 and valve stem 5. i

' It will thus be seen that by this invention no objectionable force is placed upon the fiyball collar 2 and the desired limit of power is secured without necessitating a change in position of fiyball collar 2.

It should be understood that it is not desired to be limited to the exact detail of construction shown and described, for obvious modifications will occur to a person skilled in the art.

It is claimed and desired to secure by Letters Patent-,

1. In an indirect governor fora prime mover, a speed responsive means, a motor for actuating the main valve of the prime mover, a means for controlling said motor, a lost motion connection between said speed responsive means and saidmotor controlling means, and a stop positioned by said motor, and, without limiting the motion of said speed responsive-means, limiting the motion of said controlling means which said motion, if permitted, would set the motor for farther opening of, said main valve.

2. Inan indirect governor for a prime mover, a speed responsive means, a motor for actuating the main valve of said prime mover, a means for controlling said motor, means connecting said controlling means to said speed responsive means, said connecting j means being positive in one direction and on said controlling means for preventing the valve from assuming a position beyond a predetermined limiting position.

4:. In an indirect governor for a prime mover, a speed responsive means, a motor for actuating the main valve of the prime mover, a means for controlling said motor, a lost-motion connection between said speed responsive means and said controlling means, and motor afi'ected means acting directly on said controlling means for preventing the valve from assuming a position beyond a predetermined limiting position.

5. In combination with a prime mover main valve for controlling How of fluid to said prime mover, a speed responsive means, a lost-motion connection between said speed responsive means and said main valve and adapted to determine the position of said main valve, and a stop for said lost-motion connection.

6. In combination, a valve, a speed responsive means for actuating said valve, agencies controlled by said valve, and a stop for said valve positioned by said agencies, said speed responsive means remaining free to move when said valve is stopped.

7. In combination, a valve, a speed respon sive means for actuating said valve, agencies controlled by said valve, a stop for said valve normally positioned by said agencies, and manually operable means for positioning said stop, said speed responsive means remaining free to move when said valve is stopped.

In testimony whereof, the signature of the inventor is affixed hereto in the presence of two witnesses.

' J. ELOV ENGLESSON.

Witnesses:

CHAS. L. BYRON, W. H. LIEBER.

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