US753159A - Valve for blowing-engines - Google Patents

Description

A. K. RARIG. VALVE FOR BLOWING BNGINES.

APPLIGATIDN FILED MAE. 2. 1903.

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PATENTED PSB.. 23,1904.

A. K. RARIG. VALVE FOB. BLWING ENGINES.

APPLIOATION FILED MAE. 2. 1903.

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Patented February 23, 1904.

ALEXANDER K. RARIG, OF COLUMBUS, OHIO.

VALVE FOR BLOWlNG-ENGINVES- SPECIFICATION forming part of Letters Patent No. 753,159,

dated. February 23, 1904.

Application led March 2, 19031 Serial No. 145,733. (No model.)

arranged to open when the air on the compression side of the valve reaches the pressure or density of the air on the receiver side of said valve and to close the instant the compressing-piston reaches the end of its compressing stroke. These actions will not fol- 10W with an ordinary arrangement of valve operatingunder the mere unbalance of pressures on opposite sides of the valve, and hence it has been proposed heretofore to employ mechanism for positively imparting the desired movements to the valve at the proper time. It has also been proposed to control movements thus imparted by the pressure in the pumping-cylinder; but arrangements of this kind have proven objectionable or not entirely satisfactory by reason of the possibility of disarrangement in the mechanism which imparts movements to the valve and consequent failure of the valve to act at the proper time. damage from this failure of positive operation; and accordingly it consists in certain features of construction whereby the air discharge valve is rendered semi-automatic in its operation in the sense that if the operating mechanism does not act at the proper time the weight of the valve is balanced or suiiiciently removed to permit it to open under slight excess of pressure on the pumping side of the valve, this being accomplished by a specially-constructed valve-piston having controlling connection with the valve working in a valve-V piston cylinder and'having its weight, together with that of the valve, balanced or relieved at the proper time through the action of pressure communicated to and exhausted from My present invention seeks to avoidY said cylinder through a passage opening into the main compression-cylinder at an intermediate point which is passed by the 'main compression-piston in its reciprocating movements. In other words, at the periods named pressure in the valve-piston cylinder becomes such that it overcomes the tendency of the valve to remain closed orso nearly overcomes it that the valve will open automatically before the development of any undesirable excess of pressure on the pumping side of the valve over thaton the receiver side. action I have herein referred to as balancing the valve.

My invention further consists incertain novel details of construction incident to the carrying out of the objects above stated.

In the accompanying drawings, Figure- '1 is a vertical section through the air-discharge valve and a portion of the compression-cylinder of a blowing-engine, the section being taken in the plane of the axis of the valve. Fig. 2 is a top plan viewV of the valve-casing, the protruding portion of the valve-stem and the overgear or positive operating mechanism for the valve being omitted.

1 represents a portion ofthe main compression-cylinder. The major'portion of this cylinder, the pumping-piston, and the air-inlet valves are omitted, as it is to be understood that these partsmay be of any approved known construction and that their specific construction has no particular bearing upon the present invention. It is also to be understood that if the blowing-engine is to be made double-acting, as is usually the case, the valve in which my present invention resides and which is now to be described will be duplicated at the bottom or opposite end-of the. pumping-cylinder with slight changes.

3 represents the valve, which is seated at 4 in the cylinder-head.. It is desired to have this valve open when the pumping -piston reaches a position which it occupies when the air has been compressed to the density of the air in the receiver 2, which position may be. indicated approximately by dotted lines at m, and to close when the piston reaches the limit of its stroke in the cylinder l in order to avoid loss of work accomplished, which vwould This IOO

occur if the valve seated after the piston had receded. These movements of the valve are normally imparted by a suitable valve-gear connected with other Working parts of the engine and timed to impart the movements at proper moments. Any suitable form of valve-gear may be employed. While it forms no part of my present invention, I have suggested in outline a valve-gear consisting of a two-armed lever a, fulcrumed at having an arm c for connection with the working part of the engine, and another arm CZ, whose pin e engages with the cam-slot f of the lever g. The lever g is mounted on a shaft zf, which also carries a shorter arm c', whose pin t is connected by a link Z with the pin m on the cross-head a, that is fixed on the valve-stem 10.

Positively-operating valve mechanism may fail to act at times with serious results. Hence I have provided the following means for rendering the valve automatic under such conditions. The valve is guided in its vertical movements by a piston 5, working in a cylinder 6, said piston having suitable packings-such, for instance, as shown at 7 and 8- and containing within it a head 9. The head y 9 is formed integrally with or otherwise xedly connected to the valve-stem 10, which extends upwardly for connecting with the valve-gear that positively operates the valve under normal conditions. The piston 5 is xedly connected with the valve 3. The valve-stem 10 on the piston 5 through the medium of its head 9 positively engages the piston 5 in the direction of unseating the valve; but the recess in the piston 5, which receives the head 9, would permit downward movement oi the valve-stem relatively to its valve; but a nest of springs 11 is introduced between the head 9 and the valve 3,which hold said valve and its stem normally in iixed relation, so that the valve will partake of the reciprocating movements imparted to the valvestem by the valve-gear. It will be seen, however, that' the valve and its stem are held in this normal relation by yielding force, so that when the valve is seated by the valve-gear operating positively upon the stem the stroke is cushioned; also, should the positively-actuating valve-gear fail to act or become disarranged, so that the valve-stem 10 is not moved at the proper time in the direction of unseating the valve or should be held stationary the Valve may rise under the influence of other forces independently of the valve-stem 10 and the head 9, the springs 11 being compressed in such a case. In other words, the yielding connection between the valve and its stem, by which it is positively actuated, will permit the valve to operate automatically in the event that the positively operating mechanism fails. Yielding thus having been provided for, the automatic action of the valve might occur when a sufciently great excess of pressure on the compression side of the valve as compared with that on the receiver side-oi` the posed by the springs 11, and the friction of the parts, and this would be very undesirable for obvious reasons. It is therefore desirable to balance the valve-that is to say, to overcome or nearly overcome the tendency of the valve to remain closed under its weight (iil the valve seats downward) and the load of springs 11 and any other influences that tend to hold it in its seated position in the event that it becomes necessary for it to act automatically, so that it will open under very slight unbalance between the pressures on its opposite sides.

For the last-named purpose a pipe 12, communicating with the blowing -cylinder at 13, leads to a port 1-1 in the cylinder 6,which port communicates, through an annular passage 16 and vertical bores 17, with the open end of the chamber 5, in which the head 9 works. So long as the pumping-piston is on the opposite side of the opening 13 from the valve 3 the pressure developed by said pumping-piston is communicated through pipe 12 to the valve-balancing piston 5; but as soon as the blowing-piston passes the opening 13, moving toward the valve 3, the pipe 12 and through it the balancing-piston 5 are in communication with the suction side of the blowing-piston whose cylinder is `taking in air at atmospheric pressure, and hence the balancing-piston 5 is relieved of the valvebalancing pressure within it, and the valve 3 is free to resume its seat under the pressure of the springs 11. This condition also continues during the stroke of the blowing-piston away from the valve 3, since after reversing its `direction the pumping-piston almost immediately passes the opening 13, so that the pipe 12 still communicates with asuction side of the pumping-piston. Again, reverting to the stroke of the pumping-piston toward the valve 3, it is to be understood that pressure transmitted through pipe 12 when the pumping-piston reaches the position shown by dotted lines will be equal to the pressure in the receiver, and the superiicial area of the parts is so determined that under this pressure in cylinder 6 the load imposed upon the valve by springs 11 and the weight of said valve, with its piston, are so balanced that ii" the valvegear does not open the valve 3 at this moment any increase in the pressure on the blowing side of the valve 3, due to further movement of the pumping-piston, will open the valve 3, moving it, with its piston, in a direction away from the seat independently of the valve-stem 10 and head 9, which are being held stationary by the improperly-timed or otherwise disarranged positively-acting valve-gear, this relative movement between the valve and its stem compressing the springs 11. It is to be un- IOO derstood Vthat the pressure communicating through the bores 17 readily enters between the head 9 and the piston 5; but as soon as the pumping-piston has passed the opening 13 in moving toward the end of the cylinder and pressure is exhausted from the piston 5 the springs 11 will immediately return the valve 3 to its seat. As the upward movement of the valve 3 takes place when the air in the compression-cylinder exceeds in density the airin the receiver, while the seating of the valve 3 takes place instantly at the end of the compression-pistons stroke when air-pressure on opposite sides of the valve has equalized and before there is any unbalance between these pressures, due to the back stroke of the piston, it follows that the movements of the valve 3 are not eii'ectively opposed by the air in the cylinder or receiver.

The conditions above described are present in the working of the valve 3 only when the valve-gear fails, since the head 9, with its stem 10,*moves with the piston 5 during the ordinary operation of the valve by the valve-gear, and pressure supplied to the piston 5 produces no effect. l It will therefore be seen that I have provided valve-controlling means semiautomatic in its character in that it will be positively operated under ordinary conditions by mechanism provided for. that purpose; but in the event of failure in the operation of the latter the valve will operate automatically under excess of pressure beneath it.

Having thus described my invention, the following is what I claim as new therein and desire to secure by Letters Patent:

l. In a blowing-engine, the combination with the valve between the compression-cylinder and the receiver and the positively-acting valve-gear therefor; of a yielding connection between the valve and its gear, a pressure-actuated valve-balancing piston connected with the valve, and means communicating pressure to the-valve-balancing piston from the compression-cylinder.

2. In a blowing-engine, the combination with the valve between the compression-cylinder and the receiver, and the valve-gear Jfor normally opening said valve; of a piston connected with said valve, and a cylinder in which said piston works, having communication with the compression-cylinder and receiving pressure therefrom to counterbalance the closing tendency of the valve when the valvegear fails to act.

3. In a blowing-engine, the combination with the valve between the compression-cylinder and the receiver, and the valve-gear normally actuating said valve; of a valve-piston connected with the valve, a valve-piston cylinder in which the valve-piston works, and a communication between said valve-piston cyli inder and a point in the compression-cylinder between the limits of motion of the pumpingpiston, whereby pressure is communicated to and exhausted from the valve-piston cylinder by the pumping-piston.

4. In a blowing-engine, the .combination with the valve between the compression-cylinder andthe receiver, and the valve-gear for normally operating said valve; of a valve-stem lthrough which said gear is connected to the valve, having yielding connection with the valve, a valve-piston surrounding said stem, a cylinder in which said valve-piston works, and a communication between the cylinder of the valve-piston and the compression-cylinder,

whereby pressure is supplied to balance the 5. In a blowing-engine, the combination of the valve between the compression-cylinder and the receiver, a balancing-piston connected with said valve, a cylinder in which said balancing-piston works, and by which the valve is guided in its movements, a valve-stem working through said piston and having yielding connection with the valve and suitable valvegear normally operating the valve through said stem.

6. In a blowing-engine, the combination of the valve located between the compression-cylinder and the receiver, a balancing-piston connected with said valve, a cylinder in which said piston works, a valve-stem moving said valve in the direction of opening, springs interposed between the valve-stem and the valve through which the stem may close the valve, a suitable valve-gear controlling the valve through said stem, and communication between the balancing-piston cylinder and the pressure-cylinder of the engine.

7. In combination with a valve for blowingengines, the balancing-piston connected with said valve, the cylinder in which said balancing-piston works, the positively-actuated valve-stem working through said piston and having a head thereon working in said piston, a passage establishing communication from the compression-cylinder to the space between Y engines, the balancing-piston connected with said valve, the cylinder in which said balancing-piston works, communicating with main compression-cylinder, the positively-actuated valve-stem for said valve, a head on said valvestem, springs interposed beneath said head, closing the valve, and a passage communicating pressure from the balancing-piston cylinder to the space between the head and piston.

9. In a blowing-engine, the combination of the valve located between the compressioncylinder and the receiver, the balancing-piston connectedwith said valve, the cylinder in which said balancing-piston works, having communication with the compression-cylinder, the valve-stem extending through and having a head working in said balancing-piston, and engaging the piston in one direction Athrough the medium of said head, pressure- IOO IIO

: nicating between the pressure-chamber in the piston and the space between said piston and head, springs located between the head and the valve, positively-acting valvegear connected with the valve-stem, and a suitable communication between the pressure-chamber of the piston1 and the compression-cylinder of the blowing-engine.

l1. In a blowing-engine, the combination of the air-discharge valve, valve-gear therefor, a cylinder arranged in line with said air-valve, a piston working in said cylinder, connected with the air-valve, a valve-stem extending through said piston and having a head working in the piston, a passage supplying pressure from the main compression-cylinder to the space between the valve-piston and the head; the superficialarea of the valve-piston exposed to pressure being such that the weight of the piston and valve is balanced when the valve-gear fails to operate, thereby permitting the valve to rise under increase of pressure beneath it. v

12. In a blowing-engine, the combination of the air-discharge valve, Valve-gear therefor, a cylinder arranged in line with said air-valve, a piston working in said cylinder, connected with the air-valve, a valve-stem extending through said piston, and having a head working in the piston, springs interposed between said head and the valve, and a passage supplying pressure from the main pumping-cylinder to the space between the valve-piston and the head; the superficial area of the valvepiston exposed to pressure being such that the weight of the piston and valve, and the pressure of said springs, are balanced when the Valve-gear fails to operate, thereby permitting the valve to 'rise under increase of pressure beneath it.

The foregoing specification signed this 19th day of February, 1903.

ALEXANDER K. RARIG.

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