US1141146A - Automatic control of cut-off valves. - Google Patents

Description

Patented June 1, 1915.

3 SHEETS-SHEET lw. F. ROACH. AUTOMATIC CONTROL OF CUT-OFF VALVES.

APPLICATION FILED NOV- 6, 1912.

un' unnl: Br-rrnern nunm "m W. F. ROACH.

AUTOMATIC CONTROL OF CUT-OFF VALVES.

APPLICATION FILED NOV-6.1912.

Patented June 1, 1915.

3 SHEETS-SHEET 2.

attorney THE NORRIS PETERS 60., PHOT0-L|THO., WASHINGmN. D, c.

W. F. ROACH.

AUTOMATIC CONTROL OF CUT-OFF VALVES.

APPLICATION FILED NOV. 6. m2.

attorneg THE NORRIS PETERS 60.. PHoIc-LITHQ, WASHINGmN. D4 C.

WILLIAM F. ROACI-I, OF FBOSTBURG, MARYLAND.

AUTOMATIC CONTROL OF CUT-OFF VALVES.

Specification of Letters Patent.

Patented June 1, 1915,.

Application filed November 6, 1912. Serial No. 729,843.

To all whom it may concern:

Be it known that I, WILLIAM F. RoAoH, a citizen of the United States, residing at Frostburg, in the county of Allegany and State of Maryland, have invented certain new and useful Improvements in Automatic Control of Cut-OE Valves, of which the following is a specification.

This invention relates to improvements in automatic control of cut-off valves and while more particularly intended for use in connection with engines driving compressors or blowers, yet it may be used for other purposes.

The object of my invention is to provide means for automatically adjusting cut-ofi' valves of engines, such as the well-lmown Meyer type, rendering them exceedingly sensitive and causing them to respond to changes in the demand for power in a system before the usual centrifugal governor has acted, thereby effecting a great saving in the consumption of power and rendering this type of valve equal to the more complicated valves and therefore superior by reason of its simplicity and durability.

In the drawings, Figure 1, is a side elevation of an engine with my invention applied thereto; Figs. 2 and 3 are, respectively, a longitudinal section and an end view of the same; Figs. 4, 5 and 6 are, respectively, a side elevation, a top plan view and a longitudinal section of the clutch operating mechanism by which the adjustment of the cut-oif valve is effected; Fig. 7 is a crosssection on the line 7-7 of Fig. 4; and Figs. 8, 9 and 10, are detail views of the clutchtransmitting mechanism.

The operatingparts of the engine, shown for purposes of illustration, are well-known and need not bedescribed. The slide valve 5, and the cutofi having the parts 7 and 8 connected by rods 9 and 10 to the separate cam-actuated mechanism of the engine shaft are of the well-known Meyer valve type. The blocks 7 and 8 of the cut-off are secured to the rod 10 by oppositely directed screwthreads,'so that rotary movement of the rod in one direction causes the blocks to approach each other thereby eflecting a later cut-off of the motive fluid, while the reverse movement causes them to separate, thereby effecting an earlier cut-off. A coupling 12 may be inserted, permitting the portion 10,

of the rod to rotate without turning the part 10.

For the purpose of imparting a rotary movement to the cut-off valve rod 10 while 1t is being reciprocated during the operation 'of the engine, the free end is extended and passes through the bore of a miter-gear 14, through which it freely slides longitudinally but is caused to rotate axially therewith by having the parts squared or splined. Motion is transmitted intermittently to the gear 14 in mesh with gear 14, through the rod 15 and shaft 18, in the manner hereinafter described.

I have shown the shaft 18 connected to the engine shaft 19, by means of a series of miter-gears, but it is evident that the shaft 18 may be driven by means. of belting, sprocket and chain, or in any other convenient manner, which will cause the shaft to be constantly driven. I prefer to connect the shaft 18, and rod 15, by means of clutch operating mechanism shown in Figs. 4, 5 and 6.

The rod 15 carries the gear 20 which meshes with gears 22 and 23, loosely mounted upon the shaft 18. The end 18 of the shaft is bored or a tubular stem may be secured thereto. A clutch-operating rod 24, longitudinally slidable in bore of the hollow end 18*, carries a piston 25, operating in the steam cylinder 27. A split housing 28, bolted together about the inner tubular end 18 of the shaft is provided with lugs or boses 29 which pass through elongated slots 30 in said tubular shaft and project within an annular recess 31 in the end of the clutch rod 24. Links 34, carried by the bolts 35, of the housing 28, are pivotally connected to pivoted clutch- dogs 36, 37, fulcrumed on the collars 36 37 and which are adapted to be brought into engagement with the frictional clutch faces 40, 41, of the gears 22 and 23. It will be apparent that when the rod 24 is forced to the right by the piston 25, the housing 28 will be moved toward the right, the lugs 29 sliding in the slots 30, thereby causing the clutch-dogs 36 to engage the frictional clutch faces 40. Inasmuch as the housing 28, together with the attached clutch-dogs are constantly rotated by the shaft 18, motion will now be transmitted to the gear 22, which in turn causes the rotation of gear 20 and rod 15. When the piston moves to the left, sliding the shaft 24 and housing 28 in the same direction, the clutch-clogs 36 are disengaged from the gear 22 and the opposite dogs 41, conect the .gear 28 to the shaft 18, thus causing the gear -ton'25, is controlled by steam from steamchest 4A which is connected through the inlet pipe 45 with theboiler or live steam main. The ports leading to either end of the cylinder 27 are controlled by the oscillating valve 47. This valve is proportioned so that when in mid-position, the ports 48, e8 are slightly open so that steam may pass simultaneously to both ends of the piston and thus maintain it in a central position, thereby holding the housing 28 and clutchdogs 36, 37, also in mid-position, disengaged from the gears so that the gear 20 and rod 15 remain stationary. If the valve 17 is I shifted to the right, as indicated in Fig. 6,

the port 48 will be connected with the exhaust 50, while the port 48 will be open, thus unbalancing the pressure upon the piston 25 and forcing it to the right. Likewise when the valve 47 is shifted to the left the port 48 will be connected with exhaust and the piston will be moved to the left. I preferably locate the steam chest 44: directly beneath the cylinder 27 with all of its steam passages extending downwardly so that all condensation may pass-off quickly which facilitates the sensitive action of this device. To effect a quick and positive movement of the piston. and clutch members to the midposition when the pressure upon the ends of v the piston is equalized, I provide a pair of equalizing springs 52, which operate through rods 53 upon levers 5 1 that are pivotally connected to the shaft at 55 and to the ends of the cylinder at 56. This mechanism also prevents an accidental engagement of the clutch mechanism and insures a steady positive operation of theconnected parts.

' The position of the clutch-controlling re- I lay is preferably under the control of the usual centrifugal governor and also of the fluid-pressure of the system or other form of energy, such as electric power, which represents the work or energy being developed by the engine. For purposes of illustration I have shown the auxiliary controlling means underthe influence of fluid pressure. The centrifugal governor may be of the ball governor type or the fly-wheel or shaft type in Which the weights are pivoted to the flywheelsand as they fly outwardly shift an eccentric on the shaft which in turn operates a lever connected with the cut-off of the steam valve. The ball-governor is better adapted to low speed engines while the shaft-governor is'preferable for high speed engines. I have illustrated the ordinary form of ball governor 60 which operates by means of a toggle frame (31 to depress a rod 62. I utilize the movement of this rod by connecting it to a bell-crank 61, connected with the shaft 17 of the valve 47. The rod 62 passes through a cylinder 65, and is surrounded by a sleeve 66, which carries a piston 67 and a guide-plunger 68, normally held in its uppermost position by a spring 70. The upper end of the cylinder is connected with the compressed-air tank or with the air mains of the system by means of a pipe 72. hen the pressure in the tank or the mains increases beyond the normal pres sure, the increased pressure in the cylinder 65, causes the piston 67 and plunger 68 to descend and the latter engaging the collar 73 on the rod 62, carries it down and thereby causes the -bell-crank 64 to shift the clutch-controlling valve 47. It is evident, therefore, that the pressure-controlled governor 67, may respond instantly to a change of pressure in the system independently of the centrifugal governor and even though there has been no change in the engine speed. Likewise the centrifugal governor can operate the rod 62 and shift the valve 47 independently or in conjunction with the pressure-controlled governor.

In operation, suppose for example, the engine operating under full load caused the compressor to charge the tank or mains to a pressure of 100 lbs. and its normal speed is 160 R. P. M. A sudden decrease in the consumption of power causes an increase of fluid pressure in the mains of the system and although the engine may continue to run at the same speed, the increased pressure in the cylinder 65, instantly depresses the piston 67 and causes the valve 47 to shift thereby throwing the clutch mechanism to cause the rotation of the gear 20, rod 15, and gear 14, in a direction to cause the cut-off blocks 7, 8 to separate, thereby producing an earlier cutoff and corresponding reduc tion of steam. This action, it will be noted, has taken place independently of the centrifugal governor and whilethe engine was running at the same speed If, on the other hand, while the engine is running below normal speed, for instance at 150 It. I. M., there is an increased consumption of power, lowering the fluid pressure in the system, the reduced pressure on the piston 67, causes the spring to lift the plunger 68 above the collar 73,'and permitting the spring 78, to lift the rod 62, and shift the valve 47 in the opposite direction, thereby throwing the clutch mechanism to cause a movement of the parts and force the cut-off blocks 7, 8 toward each other. This causes a later cut-ofl and an increased consumption of steam to meet the lncreased demand for power. Thls action will continue as long as the consumption of power increases until the engine reaches its full speed of 160 R. P. M. Then if the consumption increases, the centrifugal governor will act in opposition to the pressure governor and force the rod 62, down against the spring 78, thereby shifting the valve 4:! in the opposite direction and causing the clutch mechanism to rotate the rod 10 to separate the cut-off blocks and cause an earlier cut-ofi of steam. In this example, the pressure-governor first caused the cutofi valve to increase the consumption of steam to meet the increased demand for power and then when the engine speed began to exceed the full rated speed, the centrifugal governor operates in the opposite manner to cause an early cut-ofi' and decrease the power. Again, if after the pressure-governor has shifted the parts to increase the consumption of steam and before the engine has reached full speed, the normal fluid pressure is produced, then the piston 67, of the pressure-governor will rise in the cylinder to such a position that the valve L7 will be brought to the intermediate position so that the pressure is equalized at opposite sides of the piston 25, and the springs 52 will thereupon cause the clutches to recede from the gears 22 or 23 thus permitting the rod 15 to remain stationary and maintain ing the cut-oii blocks in their proper adjustment until a change of fluid pressure in the system occurs.

The important advantages effected by my invention in the automatic control of cut-cli in valves of the Meyer type will be appreciated by steam engineers. I am not only able to effect a great economy in steam consumption but also to provide an exceedingly sensitive control which responds instantly to a change of condition in the system.

I have described in detail the construction and arrangement of mechanism illustrated in the accompanying drawings for the purpose of disclosing an embodiment of my invention, but it will be obvious to engineers that various changes can be made without departing from the spirit of my invention.

bus the engine may be employed to drive an electric generator and the variations of electric energy in the system may eflect a controlling movement of the governor rod Copies of this patent may be obtained for five cents each, by addressing the through the instrumentality of a solenoid, such a change being obviously Within the scope of this invention.

I claim 1. Governor mechanism for steam-engines of the type having slide valves provided with adjustable cut-off blocks, supplying power to an energy-storing system, comprising oppositely rotatable mechanism for causing said blocks to approach or recede, actuating means for said mechanism, and a relay device under the combined control of a speed governor and the energy of the system to control said actuating means.

2. Governor mechanism for steam engines of the type having slide valves provided with adjustable cut-0E blocks, comprising actuating mechanism for causing said blocks to approach or recede, a relay device for connecting said actuating mechanism to move the blocks in either direction to thereby change the point of cut-off, and pressurecontrolled means and speed-controlled means acting independently to efliect the operation of said relay device.

3. Governor mechanism for steam engines of the type having slide valves provided with adjustable cut-off blocks, comprising oppositely rotatable mechanism for causing said blocks to approach or recede, actuating means for said mechanism, coupling mechanism for connecting said actuating means to said rotatable mechanism to cause rotation in either direction, and a relay device under the combined control of fluid-pressure and a speed governor to control said coupling mechanism.

4:. Governor mechanism for steam engines of the type having slide valves provided with adjustable cut-off blocks, comprising oppositely rotatable mechanism for causing said blocks to approach or recede, actuating means for said mechanism, coupling mechanism for connecting said actuating means to said rotatable mechanism, to cause rotation in either direction, and a fluid-operated relay device under the combined control of fluid-pressure and a speed governor to control said coupling mechanism.

In testimony whereof I afiix my signature in presence of two witnesses.

WILLIAM F. ROACH.

Witnesses:

PAUL G. Hrronnvs, ADAM E. Hrronms.

Commissioner of Patents,

Washington, .D. C. 4

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