US1251563A - Valve mechanism. - Google Patents

Description

1. F. onoNINELL.l VALVE MEGHANISM.

APPLlCATlQN FILED OCT.' I6. 1916.

Patented Jan. 1, 1918.

2 sains-SHEET 1 J. F. ODONNELL.

VALVE MEGHANISM.

APPLICATION FILED 001116. 1916.

1,251,563. Patented 1311.1, 1918'.l

2 SHEETS-SHEET 2.

Rg. l?

WITNESS:

UNITED STATES PATENT. oEEIcE.

JOHN F. ODONNELL, 0F MIDLAND, PENNSYLVANIA.

vALvE MECHANISH.

Specication of Letters Patent.

Patented` J an. 1, 1918.

Application illed October 16, 1918. Serial No. 126,048.

To all whom z't may concern: Be it known that I, JOHN F. ODONNELL, a citizen of the United States, residin at Midland, in the county of Beaver and tate of Pennsylvania, have invented certain new and useful Improvements in Valve Mechan ism, of which the following is a specification.

This invention relates to valve mechanism and more particularly to that class of valves used in controlling ingot turning machinery in blooming mills, or other heavy maichinery wherein amain valve of considerable size is controlled by a comparatively small pilot valve. Main valves for the operation of such machines usually have a neutral or central position. When the valve is in neutral position the machine under its control is stationary. When the valve is shifted in one direction the machine continues to move inthat direction until it reaches the limit of its travel or until the valve is returned to neutral, at which time, under the latter circumstance, the machine will come to a stop before it has reached the limit of its travel. Reversal of the position ofthe valve will cause the machine to reverse.

When a pilot valve is used to control the main valve, it is the custom to provide a pilot valve having a neutral or central position, and so connected to the main valve that when the ilot valve is in central or neutral position tie main valve will be caused to moveto central position. When the pilot valve is moved in one direction, its movevalve valve, may be converted intoa pilot valve,

giving to the pilot valve all the well known advantages of the Aiken type main valve; and such other objects as may hereinafter` appear. One embodiment of the invention is shown in the accompanying drawings, wherein- Figure 1 is a longitudinal section through a pilot valve and Fig. 2 is a longitudinal section on a reduced scale showing vthe centeling motor and the spindles ofthe main va v Referring'to the drawings and more particularly to Fig. 2, the main valve'and centering motors will be described. This part of the apparatus is of the usual type and the spindles of the Aiken main valve are dia- -grammatically shown. The motor may,

however, be used to operate any form of l oscillating or reciprocating valve. 1 is a cylinder casing supported upon'the frame 2; 3 and 4 are the motor pistons for operatF ing the main valve; 5 and 6 arey cylinders in which the motor pistons 3 and 4 reciprocate, respectively; 7 and 8 are centering pistons mounted in line with vthe motor pistons 3 and 4, respectively, and are for the purpose of normally mov-ing the motor pistons to central position; 9 and 10 are cylinders in which the centering pistons 7 and 8 reciprocate, respectively; 11 is a supply pipe :for

constantly supplying fluid pressure to the pistons 7 and 8 through the branch tubes 12 and 13, respectively. Constant pressure on the underface of the pistons, and 8 causes them to be normally held in raised position as indicated in Fig. 2. The up-A per ends of the istons 7 and 8 enga e the lower ends of t 'e motor pistons an support them in centered positlon.

The main valve may be of any type and .for'thepurpose of illustration, a pair of main valve spindles or pistons 14 and 15 are shown, allned vwith the motor pistons 3 and 4 respectively. The upper ends of the main valve pistons are pivotally connected to a rocking lever 16 which osclllates upon a pivot shaft 17. Instead of the two spindle type of valve shown, an oscillating valve may be secured to the pin 17 and operated with the motor just described. f

The loperation ofthe 'motor and main valve is as follows: A constant source of pressure is applied to the passage 11 which enters the cylinders 9' and 104 through the branch pipes 12 and 13. This pressure cony stantly exerted upon the lower ends of the pistons 7 and 8 normally holds them in raised position. The cylinders 5 and 6 are supplied with uid pressure through ports 5 and 6 connectedto pipes 18 and 19 leading to the pilot valve, to ybe hereinafter described. When pressure is .supplied to the cylinder 5 the fluid inhl the cylinder passes the enlarged portion of the Piston 3 through a slot 20 cut from one face of the enlarged Portion to the other, thereby caus ing pressure tobe exerted upon the under side of the piston 3, which action causes the iston 3 to be moved upward, moving with 1t the main, valve spindle 14. This action also raises the left 'end of the rocking lever 16 thereby lowering the right end of the rocking lever which pushes down the valve spindle' 15 and with it the motor piston 4. The pressure usually supplied to the cylinder 5 is about 600 pounds per square inch and as the area of the piston 3 is greater than the area of the lower end of the piston 8, the pressure exerted upon the-piston 8 will be overcome by the| superior pressure exerted downward on the motor piston 4.

If pressure in the passage 19 1s supplied to the cylinder'G, the motor pistonV 4 will be raised, causing the valve spindle 15 to be raised with it andthe valve spindle 14 to be lowered, thus reversingthe action of the main valve.

In general practice the mainvalve is supplied with a supply passage and exhaust passage and two passages leading to each end of an operating cylinder. The valve ports are so arranged that when/the main valve spindles are in their central or neutral.l positlon the passages leading to the cylinder are closed oli' from communication 'with'V both the-supply and exhaust passages of the mainvalve, thereby causing the piston m the operating cylinder to remain stationary while the valveis in neutral or central position, regardless of the position of the piston in the operating cylinder.

' The main valve and the motor for operati Y inig it 'ust described are. controlled by a p ot va ve'illustrated in Fig. 1., This valve consists of'a main casing 21. provided with a palr of , cylinders 22 and 23 in which are mounted for reciprocation' a pair of valve respectively. The cas.

spindles 24 and 25 ing is provided with a fluidsu ply passage 26 communicating with the cy inder 23 ad jacent its center at 27.- The casing is also aprovided with an exhaust passage 28 communicating with the cylinder 22 adjacent its center at 29.A The pipe 18 leading from the cylinder 5 in the motor is connected to the pilot valve casing 21 and a passage 30 leads therefrom to the cylinder 23 above the supply chamber 27 and passes down through the casing 21 and communicates with the cylinder 22 below the exhaust chamber 29 at 31. The pipe 19 leading from the cylinder 6 of the motor is connected to the casing 21 and a passage 32 leads therefrom to the cylinder 22 above the exhaust chamber 29 and continues downward through the casing and communicates with the cylinder 23 below the supply chamber 27 at 33.

The pilot valve spindles 24 and 25 are Vpivotally connected at their -lower ends by a rocking lever 34 which oscillates about the pivot shaft 35 and are pivotally con nected at their upper ends by a rocking lever 36 adapted to oscillate about the pivot shaft 37. .AnH operating handle 38 is secured to the rocking lever 36 and movement of the handle"`to the rightor left Will cause the spindles 24 and 25 to reciprocate within their respective cylinders.

The spindle 25 4comprises a` solid shaft upon which is mounted a central sleeve 39 and a pair of v'alve sleeves 40 and 41. Packing leathers 42 and 43 are placed between the valve sleeves and the central sleeve 39. A packing leather 44 is placed between the upper end of the valve sleeve 40 and a collar ,45 carriedl at the upper end of the spindle between the valve sleeve 41 and a collar 47. The sleeves, collars and packing washers are all firmly clamped together by means of the nut 48 `/which is screwed to the lower end of the spindle shaft. A

f Thefsleeves 40 and 41 are each provided lwith an enlarged central section 49 which provides an annular recess 5() through which fluid may circulate around the spindle shaft. The'sleeve 40 is provided .with a port 51 leading from the passage 30 to the annular recess 50. The spindle shaft of the valve spindle 25 is provided with a longitudinal groove 52 which extends from the annular recess 50 in the sleeve 40 to the annular recess 50 in the sleeve 41, and communication between this groove andthe passage 32 in the valve casing is established by means ers 57, 58,59 and 60 securely clam between the, sleeves, the' packing 5 being clamped between the sleeve 54 and a collar' 61 for the purpose of vpreventing leakage of fluid from the upper end of the cylinder" This aov

lao'I 22, and the packing 60 bein clamped between the sleeve 56 and the co lar 62 for the purpose of preventing leaka e of fluid from the lower end of the cylinder 22. The sleeves, collars' and washers are securely clamped together by means of the nut 63 which is screwed upon the lower end of the spindle shaft. 'The sleeves 54 and 55 are each provided with an enlarged central portion which provides an annular recess 64 in each sleeve. The spindle shaft is provided with a longitudinal groove 65 establishing communication between the annular recesses 64. The port 66 in the valve sleeve 54 establishes communication between the passage 32 in the valve casing and the recess 64 1n the valve sleeve 55, and communication is established between the exhaust chamber 29 and the recess 64 in the valve sleeve 55 by a port 67 extending through the valve sleeve 55.

The primary function of the grooves 65 in the spindle 24 is to establish a constantly open exhaust passage from the cylinder 6 of the motor thr'ugh the pipe 19, passage 32, port 66, groove 65, port 67 to exhaust port 28. The ports 66 and 67 are comparatively small wlth respect to the capacity of the passage 32, pipe 19 and port 6 in the motor cylinder 6. Therefore, when pressure is exerted in the passage 32 by the admis` sion of iuid pressure therein the leakage of uid through the port 66 to the exhaust will not materially affect the ultimate pressure in the cylinder 6 of the motor.

The primary function of the groove'52 in the valve spindle 25 is to establish a constantly open exhaust passage from the passage' 30 through the port 51, groove 52, port 53, chamber 33, passage 32, port -66 in the valve sleeve 54 on the valve spindle 24, groove 65, port 67, to exhaust passage 28. The area of the ports 51 and 53 is comparatively smaller than the area of the passage 30, pipe 1 8, and port 5 which communicates with the motor cylinder 5. This constantly open communication with the exhaust, therefore, does not materially diminish the ressure in the motor cylinder 5 when lluld pressure is supplied to the passage 30. The purpose of maintaining these constantly open exhaust passages w1ll appear later. I

This pilot valve has a neutral or central position and two operative positions. The spindles are shown in their neutral or central position in Fig. 1. The supply passage26 is constantly in communication with a source of fluid pressure and it will be seen that when the spindles are in the position illustrated, fluid cannot enter either the passage 30 or chamber 33 andfthat'the only means of exhaustv from chambers 30 and 32 is through the exhaust passages just described, leading through the valve spindles. When the operating lever 38 is moved to the right the valve spindle 25 will be lowered permitting iuid pressure to low past the lower end of the valve sleeve 40 into the passage 30 through the pipe 18 to the motor cylinder 5. This action will cause the piston 3 to be raised. At this time the valve spindle 24 will be raised permitting pressure 1n the motor cylinder 6 to have quick escape ast. the upper end of the valve sleeve 55 into Vthe exhaust chamber 29 and thence to the exhaust passage 28. The main valve will be operated to permit movement ofv the piston in the motor cylinder (not shown) to continue as long as the pilot valve handle is out of neutral position. When itis dethe upper end of the valve sleeve 41 into the chamber 33 through passage 32 in theA valve casing through pipe 19 to the motor cylinder 6. This will cause the motor` pist0n 4 to rise, thereby shifting the main valve in the reverse direction causing the reversal of the piston in the motor cylinder (not shown). At this time fluid pressure in the cylinder 5 Will rapidly exhaust through pipe 18, passage 30 past the'lower end of the valve sleeve 55 into exhaust chamber 29 and thence to exhaust passage 28. When it isdesired .to stop the movement of the piston in the operating cylinder the pilot valve must be moved to central or neutral position.l After this has been done4 fluid pressure must be exhausted from the motor cylinder 6 in order that the centering piston 7 may move the motor piston 3 to central position. Thepressure in the cylinder 6 is exhausted at this time throughthe pipe 19, passage 32, port 66, groove 65, port 67, and exhaust passage 28. l

It will be observed that when the pilot valve is in neutral position that no water will waste through thev exhaust passages after the pressure has been relieved. from the cylinders A5 and 6 and thatl only a small quantity of water wastes through such passages when the valve is moved out of neutral or central position. l

Heretofore themain valve had `been con- I, trolled by pilot valves having packing wash- .ers usually expanded againstthe interior cutting .and wearing the packing 1 herein illustrated and used as a pilot valve washers are at no time sawed over perforated admitting has-'been successfully used for years 'as a mam valve 1n steel mill work. This valve isa successJ as a. main valve because the cylinder walls. Without the use of the constantly open exhaust passages illustrated as being applied to the valve spindles, this type of valve could not be successfully operated as a pilot valve. Therefore, the provision of suitable exhausting means has made it possible to convert a highly eilicient main valve into an equally eicient' pilot 'valve for controlling the main valve. It is obvious that a number of changes may be made in the details of the construction without departing from the spirit of the invention, and the mventionis, therefore, not limited to the specific means herein illustrated and ,described for providing a constant exhaust from the motor cylinders.

What I claim is:

1. A valve mechanism comprising in combination, a main valve, means for normally centering the main valve, iiuid operated motor pistons mounted in suitable cylinders for moving the main .valve out of central position in either direction, constantly open exhaust ports in communication with the cylinders for relieving the pressure on the motor pistons, uidsupply ports in communication with the cylinders having greater capacity-than the exhaust portsfor admitting pressure to the motor pistons, and a pilot valve for controlling the supply ports adapted to close them when the pilot valve is in central position.

2. A valve mechanism comprising in combination, a main valve, means for-normally centering `the main valve, fluid operated motor plstons mounted in suitable cylinders for movin the main valve out of central pos1t1on in either direction, fluid supply ports 1n communication with the' cylmdersV for 0 pressure to the motor pistons,V a ilot va ve having a supply passage' an pair of coperating pistons for controlling the Huid pressure to the motor piston c linders, adapted to close the supply ports om communication with the supply and exhaust chambers when the valve pistons are in central or "neutral position, Vand a air of haust passages extending throug the valve pistons establishing constant communication between the supply ports and the` exhaust chamber, .the said exhaust passages having less'capacity than the supply ports.

an exhaust passage controlled by a 3. The combination` with a normally centered main valve and an operating motor l motor chamber,.a pressure supply inlet in Y Y communicationv with the valve mechanism, an exhaust passage 1n communlcation with the valve mechanism, the said supply inlet and exhaust 'passage and pressure passages being located so that when the valve mechanism is in neutral or central position com- `munication between the pressure passages and the supply inlet and exhaust passage is closed and when the valve mechanism 1s in operative position in either direction past neutral position, communication between one pressure assage and supply inlet will be establishedp and communication between the other pressure passage andthe exhaust passage is also established, whereby pressure is supplied to one motor chamber and exhausted from the other, and an auxiliary exhaust passage through the valve mechanism having less capacity than the pressure passages adapted to constantly establish communication between the pressure passages and the exhaust passage whereby the ressure in the motor chambers may be reeased when the valve mechanism is in neutral position.

4. In combination a normally centered main valve and an operating motor therefor, a pilot valve for controlling the operating motor of a normally centered main valve, a casing, a pair of valve .cylinders in the casing, a 'supply control valve in one'cylinder, an exhaust control valve in the other cylinder, a pair of pressure passages each lcommunicatingl with the supply control cylinder, the exhaust control cylinder and separate operating chambers in the main valve motor, a pressure supply inlet in communication with the supply control cylinder, an exhaust passage in communication with the exhaust control c linder, a supply control piston valve in e supply control cylinder adapted when in neutral, or central positionto cut of communication between the supply inlet and the pressure passages and inoperative position 1n either direction past center position, to establish communication between either one -of the pressure passages, an exhaust control between either one of the pressurepasagA and the exhaust passage, a' connection tween the valve pistons whereby movement of the supply control piston to open one pressure passage tothe supply inlet causes the exhaust supply piston to open the oppo- 5 site pressure passage to the exhaust passage, and exhaust passages in the pistons of less capacity than the pressure passages, adapted to constantly establish lcommunication between the ressure passages and the exhaust passage w ereby the pressure in the motor 1 chambers may be released when the valve pistons are moved to neutral position.

JOHN F. ODONNELL.

Images