US1962477A - Vacuum control mechanism - Google Patents

Description

June 12, 1934. v A. E. BROUGHTON 1,962,477

VACUUM CONTROL MECHANISM Filed Aug. 28, 1933 s sheets-shea 1 `405 QM@ 4@ Z9 @a E? Y n nii-em @Fw 1-1 el #MII -A-A'I June 12, 1934. A. E. BROUGHTON 1,962,477

VACUUM CONTROL MECHNI SM Filed Aug. 28, 1955 3 Sheets-Sheet 2 June 12, 1934. l* A. E. BROUGHTON 1,962,477

VACUUM CONTROL MECHANISM V Filed Aug. 28, 1933 5 Sheets-Sheet 3 Patented June 12, 1934 UNIT-ED STATES ixaiu'iflr'rI OFFICE 1,962,477 VACUUM CONTROL MEcnAmsM Arthur E. Brought-ou, wiuoouuiu Rapids, wu. Appiiouiiou August 2s, 1933, serial No. 687,139 V14 claims. '(01. :iz-44) This invention relates to vacuum control mechanisms which, although particularly adapted for use in connection with paper making machines, are also adapted for use elsewhere wherever it is desired to maintain a substantially constant vacuum pressure.

It is the general object of the invention to provide novel and improved mechanism for automatically maintaining the pressure in a vacuum head substantially constant.

` It is another object to provide mechanism for maintaining the pressure in a vacuum head at a desired constant.

More specifically it is an object of the invention toY provide novel meansfor automatically controlling the pressure in the suction heads o f a paper making machine, such as the flat boxes, couch rolls, felt suction boxes, and the suction pressvrolls over which the' paper web runs.

The objects and advantages of the present invention will more fully Vappear from the following description, madein connection with the accompanying drawings, wherein like reference characters refer to the same or similar parts throughoutthe various views, and, in which,

Fig. 1 is a view diagrammatically illustrating an application of the invention applied to the at boxes of a paper making machine;

Fig. 2 is a view taken chiefly in vertical transverse section through the major part of one control mechanism shown in Fig. 1, the view being in enlarged scale; i

Fig. 3 is a vertical section taken on the line 3-3 of Fig. 1, as indicated by the arrows;

Fig. 4 is a horizontal section taken on .the line 4-4 of'Fig. 2, as indicated by-the arrows; and

F.' g. 5 shows a modified application of the "in,

vention to the flat boxes ofv a paper making machine.

Referring to the drawings, and particularly to Figs. 1, 2, 3 and 4 thereof, there are more or less diagramm'atically illustrated certain parts of a paper making machine of standard construction. The first floor of a paper mill is designated by lthe numeral 5, while the basement iioor is designated by the numeral 6. The Fourdrinier wire upon which the mat of paper is formed at the wet end of the paper machine is designated by the numeral 'I and this wire runs over flat' boxes 8, rollers 9 and couch roll 10. The dandy roll l1 located between the second and third flat boxes.8is illustrated, as

-vacuum in the rst two flat boxes.

is the roller 12 under which the web of paper .A passes as the sheet is carried ofi the wire 'l at the couch roll 10 and moves on to the felt 13 from whence it advances to the presses (not illustrated). One of the rollers over which the felt 13 travels is shown and designated by the numeral 14. Each of the ilat boxes 8 over which the wire 7 travels is connected by a flexible connection 15 to a four-way fitting 16 which I substitute for the usual tee found on a paper making machine of usual construction. The water drawn from the paper web A, as it is carried over the flat boxes 8 bythe wire 7, is separated from the air drawn from the various hat boxes in the various four-way fittings 16 and the water from each flat box runs downwardly from the tting 16 connected thereto into a seal box 17 through a water leg or pipe 18 connectedat its upperend to the lower connection of the particular tting 16. The water legs 18 running downwardly from the fittings 16 connected to the rst two flat boxes 8 are preferably vertical pipes, in order that as the Water passes down through these pipes considerable suction willbe created to assist in maintaining or to maintain Without assistance the necessary The seal box 17 is provided with a wier 19 which empties into a tank 20 located usually on the basement iioor 6. Air legs or pipes 21 are connected to the upper connections of the four-way fittings 16 and these air legs run upwardly therefrom to carry off the air separated from the water in the four-way ttings 16.

A'conduit 22 runs from the couch roll 10 to the intake side of a couch pump 23 and this couch pump is provided with an outlet 24 which drains into the tank 20 in accordance with the usual practice. A manifold 25 located well above the dat boxes 8 is connected by a pipe 26 to the conduit 22 running to the couch pump 23. In accordance with the invention, the air legs 21 are connected at their upper ends tol valves 2'7 which are in turn connected to themanifold 25. Each valve 27 may include a body 27a closed at its lower end by a plug 27h forming a lower guide for a vertically reciprocating valve stem 27o. The valvev27 used is preferably a double seated valve, and includes a U-shaped web 27d in vertical cross section which forms a chamber 27e joining the intake port of the valve. An upper valve seat 27j is provided in the top of the web 27d forcooper'ation with an upwardly engaging valvemernber 27g, while the Abottom of the web 27d is `provided with a lower valve seatY 27h of a diameter slightly greater than the diameter of the valve member 27g and with which a valve member 271 is adapted to cooperatively engage by upward movement. Of course, the two valve members 27g and 27i are secured to the valve stem 27c. The upper end of the valve body 27a is closed by a casting 28 through The piston 30 is provided with a central aper ture 30h of somewhat larger size than asleeve 31 which projects therethrough into the 'cylinder 29. This sleeve below the piston 30 is provided with an external flange 31a which cooperates with a downwardly extending ridge 30o on the piston 30 adjacent the aperture 30h as do' a valve member and valve seat. To guide the flange 31a and prevent lateral movement of the sleeve 31 relative to the piston 30, the piston 30 is provided with a number of downwardly projecting lugs 30d between which the flange 31a is received. The sleeve 31 near its lower end is provided with an internally reduced end screw threaded portion 31h which is screwed onto the stud 32 Ysecured as by a cross pin 33 to the upper end of the valve stem 27e. It is desirable to prevent rotation of the stud 32 and valve stem 27o and for this purpose a pair of small pins 34 are secured in the lower end of the stud 32 and these pins project downwardly therefrom andare received within pin receiving openings 28a formed in an upwardly projecting boss on the casting 28. It will be understood that the pins 34 can freely slide upwardly and down- Wardly in the pin receiving openings 28a. The lower end of the sleeve 31 is preferably provided with an external flange 31e having a knurled outer surface for 'hand operation. The casting 28 adjacent the sleeve 3b is preferably cupped as shown so as to permit of easy access to the sleeve 3l for turning the same.

A relatively heavy coiled compression spring 35 is located within the cylinder 29 and bears at one end against the closed endof the cylinder and it bears at its other end against the upper side of the piston 30, the piston being preferably provided with a grooved rib 30e to receive the lower end of the spring. The sleeve 31 projects for some little distance beyond the piston 30 into the cylinder 29 and a collar 36 is mounted on the sleeve near its upper end and retained in position on the sleeve as by means of a cross pin 37. A coiled compression spring 38 considerably lighter than the spring 35 surrounds the upper portion of the sleeve 31 and bears at one end against the collar 36 and at its other end against the piston 30. The collar 36 is preferably provided with a grooved rib 36a to receive the upper end of the spring 38, while the piston 30 is preferably 'provided with a grooved rib 30f to receive the lower end of the same spring. l

Each cylinder 29 has conn/ected thereto between its clo'sed end and the4 piston 30, a pressure equalizing pipe 39 which runs downwardly from the cylinder and is connected -to the fourway fitting 16 for the flat box 8 in connection with which the cylinder 29 is used. A pressure gauge 20 is preferably connected to the closed end of each cylinder 29.

In a paper making machine, it lis highly desirable that the vacuum pressure -in cach ilat box 8 be maintained as nearly constant as possible when paper is being made but at the same time it is highly desirable that it be possible to change the vacuum pressure in the flat box when desired to maintain the flat box under a different substantially constant vacuum pressure. With the present control mechanism, it is possible to automatically maintain the vacuum pressure substantially constant in each flat box and it is also possible to readily adjust the mechanism to permit the flat box to be automatically maintained under a different substantially constant vacuum pressure.

Assuming that the paper making machine with my mechanism applied thereto, as shown in Figs. 1 to 4 inclusive, is in'full operation, the couch pump 23 will, of course, tend to withdraw the `air from the manifold 25 and pipe 26 into the conduit 22 and from this conduit into the pump to discharge with the air and water from the couch roll 10 through the outlet 24. The position of the valve members 27g and,.27i of each valve 27, relative to the seats 27f and 27h of4 that valve, will, of course, determine whether or not air will be drawn by the couch pump from the particular air leg 21 connected to that valve 27. Let us consider the action of a single control mechanism in connection with a ,single fiat box 8 and let us assume further that when the paper web A is running over the flat box, the proper vacuum is provided in the flat box when the valve 27 is partly opened up. When operating in this manner, the parts of the control mechanism will assume approximately the position shown in Fig. 2 with possibly the valve closed to a slightly greater extent than as illustrated. As the pressure equalizing pipe 39 is connected to the four-way fitting 16 )communicating directly with the flat box 8 through the flexible connection 15, and as this pressure equalizing pipe communicates at its upper end with the cylinder 29, there will be the same air pressure, as registered by the gauge 40, in the cylinder 29 as in the flat b'ox. As this pressure is considerably below atmospheric pressure, there is partial vacuum created in the cylinder 29 which tends to raise the piston 30. Raising movement of the piston is balanced by the spring 35, which, of course, exerts its pressure to remove the piston downwardly. The spring 38 which bears against the piston 30 exerts its pressure against the collar 36 to move'the sleeve upwardly to thereby maintain the flange 31a in seating relation with the ridge 30h, so that no atmospheric air can' pass into the' cylinder 29 through the aperture 30h which is of course closed when the angela bears against the ridge 30h.

Now let us assume that for some reason the vacuum in the flat box 8 is increased beyond the requisite degree, i.e. the pressure in the flat boxis reduced. When this occurs, of course, the pressure in the cylinder 29 will be correspondingly reduced and the piston' 30 will rise against-the tension of the spring 35. As this occurs, the spring 38 will force the sleeve 31 upwardly with the piston until such time as the pressure in the flatbox has been increased to its formerv level or until suoliA time as the two Vvalve members 27g and-2.7i -closes'aga'instl'the seats `27j and 27h.v respectively.` As thev'alve members more closely approach their seats, of

l course, less air will be drawn from the airleg 21 than formerly into the manifold 25 by the. couch pump 23 until when the Vvalve Vmembers are seated no ,further air will be drawn from the airV leg 21 into the manifoldlf the, vacuum in the flat box still remains higher., when the valve 27 is closed, than therequisite vacuum,

for which the control mechanism is set, of

' course, piston 30 will continue to'rise in the cylinder 29 but the sleeveuiil4 cannot Vfollowup tive seats will limit the possible upward movethe movement oi' l the piston, as engagement i of the valve members 27g and 271' with their respecment of the sleeve. The piston acc'ordingly,

will draw away from the flange 31a`of .the

' sleeve to expose the aperture 30h and; allow air mospheric air rushing into the cylinder 29 will permit the spring to again move the piston 30 downwardly until the ridge 30e seats with the flange 31a of the sleeve 31, whereupon no further air can be admitted through the aperture 30D into the cylinder and the correct,

vacuum in the flat box will be restored either through opening of the valve 27 or by the vacuum created by reason of the passage of water through the water leg 18 connected to the ilat box.

If for any reason the vacuum in the flat box should fall beyond the level for which the control mechanism is set, i.e. the pressure in the flat box should increase, then the pressure within the cylinder 29 will similarly increase and the spring 35 will force the piston 30 downwardly to push the sleeve 31 and valve stem 27e downwardly to open valve 27 farther, so that the couch pump 23 may draw greater quantities of` air from the air leg 21. The control mechanism, therefore, automatically controls and maintains the vacuum pressure in the flat box` substantially constant irrespective of outside factors that may tend to change `the vacuum in the flat box.

The pressure level at which the vacuum is maintained in the flat box, isA dependent entirely upon adjustment of the sleeve 31 respective to the stud 32. By unscrewing the sleeve 31 somewhat from the stud 32, the air pressure in the flat box may be maintained lower than formerly. By screwing the sleeve 31 farther up onto the stud 32, the air pressure in the flat box may be maintained higher than formerly. As the stud 32 is guided in its movement by the pins 34 working in the pin openings 28a, so that the stud cannot turn, it will be iseen that the control mechanism can be very easily adjusted as occasion Idemands by merely turning one part, the sleeve 31. The casting 28 is so constructed that easy access may be had to the head of this sleeve to permit the same being readily turned by hand. It will, of course, be appreciated that mechanism can be provided (not illustrated), to enable the sleeve to be adjusted from a point remote from the control mechanism proper.

The movement of the flange 31a away from during this movement. Preferably the double seated valve 27 isffusedfi'n place of a single 1 l seated valve toreduce resistance to the opening course be appreciated that any suitable type of valve may be substituted for that shown.

In the application of the' invention to the various viTatWboxes as shown in Figs. 1 to 4 of the drawings, it will bla/observed 'that there isl anA individualv controlmechanism `for each flat box. lIt is accordingly possible to. maintain each flat box underva desired vacuum' pressure which may be the same or different than the vacuum pressure` maintained on the otherboxes.

This is, oftenhighly desirable depending v on what type ofslieet is being run.

boxes or for all `the flat boxes in the paper making machine as shown in Fig. 5. When a single control mechanism is used for a plurality of flat boxes 8, theflat boxes may be connected to the usual type of tee -41 from which water legs 42 run downwardly and Jfrom which air legs 43 run upwardly. 'I'he air legs 43` may be all connected at their. upper ends to a manifold 44, connected to a valve 45 exactly similar to the valve 27previously described. A control mechani'sm 46 exactly similar` to the control mechanism of the previously described mechanism is used for operating the valve 45 and for admitting atmospheric air lat proper times to the cylinder of the control mechanism vand a pressure equalizingv pipe 47 corresponding to the pressure equalizing pipe 39 runs from' the cylinder of the control mechanism into the end of' the manifold 44 remote from the valve 45. Of course a pipe 48 runs from the valve 45 and connects into the receiving conduit of the couch pump (not illustrated). The one control mechanism 46 acts to maintain all of the at boxes automatically under substantially the same constant pressure, in the same manner that the control mechanism previously described automatically maintains a single flat box under. substantially a constant pressure.

Although the control mechanism of the present invention is illustrated as applied to the flat boxes of a paper making machine, to control the vacuum pressure therein, it will be understood that the control mechanism can as well be used for controlling the vacuum pressure in couch rolls, felt suction boxes and suction press rolls of paper making machines. It will further be understood that the invention is not limited to its use with paper making machines inasmuch as the control mechanism may be used for automatically maintaining a substantially constant vacuum pressure in any box, vacuum head, line etc. subject to vacuum pressure.

The control mechanism of the invention is simple of construction and it can be easily installed. The control mechanism has been successfully demonstrated in actual practice on lpaper making machines. v

In some paper making machines, both the water and air from the at boxes or couch rolls, or felt suction boxes or press rolls are carried together through a common conduit rather than divided into water streams and air streams in water and air legs. The control mechanism of the invention can be effectively applied to these conduits which carry away both the air and the water from the different parts of the machine.

- It will, of course, be understood that `various fbi; 4

-changes may be made in the form, details, ar-

rangement and proportions of the various parts Without departing from the scope of the present invention, which, generally stated, consistsvin the matter shown and described and set forth in the appended claims,

What is claimed isz- 1. In a paper making machine, the combination of a suction head over which the pulp web travels, a conduit receiving from said head, means for withdrawing the fluid from said conduit, a valve in said conduit controlling the ow of fluid therethrough and automatic means closing oil said valve and supplying atmospheric air to said head to break the vacuum therein as the vacuum increases beyond a certain point and opening said valve as the vacuum in said head decreases beyond a certain point.

2. In a paper making machine, the combination of a suction head over which the pulp web travels, a conduit receiving from said head, means for withdrawing the uid from said conduit, a valve in said conduit controlling the flow of fluid therethrough, automatic means closing off said valve and supplying atmospheric air to said head to break the vacuum therein as the vacuum increases beyond a certain point and opening said valve as the vacuum in said head decreases beyond a certain point, and means for regulating said automatic means to vary the substantially constant vacuum pressure under which said head will be maintained.

3. In a paper making machine, the combination of a suction head over which the pulp web travels, a .conduit receiving from said head, means for withdrawing the fluid from said conduit, a valve in said conduit controlling the flow of uid therethrough, automatic means closing off said valve and supplying atmospheric air to said head to break the vacuum therein as the vacuum increases beyond a certain point and opening said valve as the vacuum in said head decreases beyond a certain point, and a single adjustable member for regulating said automatic means to vary the substantially constant vacuum pressure under which said head will be maintained.

4. In a paper making machine, the combination of a suction head over .which the pulp web travels, a separator chamber communicating with said head, a `water leg running downwardly from said chamber, an air leg running upwardly therefrom, a suction pump, a conduit connecting said air leg to said suction pump, a valve in said conduit controlling the flow of air therethrough, and automatic means fclosing off said valve and supplying atmospheric air to said head to break the vacuum therein as the vacuum increases beyond a certain point and opening said valve as the vacuum in said head decreases beyond acertain point.

5. In a paper making machine, the combination of a suction head over which the pulp web travels, a conduit receiving from said head, means for withdrawing the fluid from said conduit, a valve in said conduit controlling the flow of uid therethrough, an air chamber communieating with said suction head, a movable member controlled by the pressure of air within said air chamber, an operative connection between said member and said valve for closing said valve as the pressure of said air chamber falls below a certain point and for opening said valve as the air pressure in said chamber rises above a certain point and means controlled by the movement of said member after it has closed said valve for admitting air under atmospheric pressure to said head to break the vacuum therein.

6. In a paper making machine, the comblnation of asuction head over which the pulp web travels, a conduit receiving from said head, meansy for withdrawing the fluid from said conduit, a, valve in said conduit controlling the ow of fluid therethrough, a cylinder open at one end and closed at its other end and communieating with said suction head, a piston working within said cylinder, resilient means urging said piston toward the open end of said cylinder and means operatively associated with said piston and said valve and opening said valve as said piston moves towards the open end of said cylinder, closing said valve as said piston moves towards the closed end of said cylinder and supplying air to said piston to break the vacuum in said head after said piston has moved towards the closed endof said cylinder beyond a position where said valve is completely closed.

7. In a paper making machine, the combination of a suction head over which the pulp web travels, a conduit receiving from said head, means for withdrawing the fluid from said conduit, a valve in said conduit controlling the flow of uid therethrough, a cylinder open at one end and closed at its other end and communicating with said suction head, a piston working within said cylinder, resilient means urging said piston toward the open end of said cylinder, said piston having an aperture therein, a member resiliently urged against said piston toward the closed end of said'cylinder to normally close said aperture and moving for a limited distance with said piston as said piston moves and a connection between said member and said valve for closing and opening said valve as said member moves respectively to and from the closed end of said cylinder, said member being limited in its movement toward the closed end of said cylinder by the closing of said valve, said'pi'ston being capable of movement away from said member after said valve has closed to expose said aperture and admit air to said cylinder to break the vacuum in said head.

8. In a paper making machine, the combination of a suction head over which the pulp web travels, a conduit receiving fromy said head, means for withdrawing the fluid from said conduit, a valve in said conduit controlling the flow of iiuid therethrough, said vvalve including a valve stem for operating the same, a cylinder open at one end and closed at its other end and communicating with said suction head, a piston working within said cylinder, resilient means urging said piston toward the open end of said cylinder, said piston having an aperture therein, a member'resiliently urged against said piston toward the closeduend of said cylinder to normallyclose said aperture and move for a limited distance with said piston as said piston moves toward the closed end of said cylinder, and a longitudinally adjustable connection between said member and said valve stem, said conection causing said valve stem to move to close the valve as said piston moves towards the closed end of said cylinder and causing said valve stem to move to open the valve as said piston moves towards the open end of said cylinder, the movement of said member toward the closed end of said cylinder being'limited by said valve as said valve is closed and said piston being capable of movement away from said member after said Vvalve has beenclosed to expose said aperture and admit air lto said cylinder to break the .vacuumin said head. v Vi). Mechanism for automatically controlling and maintaining a substantially constant vacuum pressurein a vacuum head, comprising a conduit adapted to communicate at one end 'with the head and at its other end with a suction pump, a valve in said conduit controlling the passage of fluid therethrough, a cylinder open at one end and'closedat its other endandmountedadjacent said valve, a piston working within said cylinder', resilient means urging said piston toward the open end o! said cylinder, a conduit adapted to communicate at one end with the head and communicating at its other end with, said cylinder between the closed endthereof and. said piston, and means operatively associated with saidvpiston andfsaid valve and open-V` l v ing said valve as said piston moves toward thev open end or said cylinder, closing said valve as said piston moves toward the closed end vof said A, cylinder and supplying air to-said piston to brefakthe vacuum in said head after said` piston has vmoved toward the closed end of said cylinder Y 4 yonda position where said valve is completelyh 10,'1/Ieclianism for automatically controlling' adgmaintaining'a substantially constant vacuum'pressurefin a vacuum head, comprising a conduitjadapted to communicate at one end withthe head and at its other end with a suction line, 'l a valve Vin said conduit controlling the passage for air therethrough, said valve having a stem, a5 ya; cylinder closed at one end and open at its other end and mountedadjacent said valve, a piston working within said cylinder and having an aperture' therein, a pressurev equalization conduit connected to said cylinder between the 40 closed'` end thereof and the said piston and adapted` to be connected at its other end to the vacuum head, a rod connected to said valve stem, said rod at its end remote from said valve forming 'a closure member for said aperture,

resilient means urging said piston toward the open end of said cylinder, resilient means urging .said closure member into engagement with said piston to close saidV aperture ,in a direction toward the closed end Vof said piston, said valve closing-as said closure' member moves toward, the .closed end of said cylinder and opening as said closure member moves in ran opposite direction. 11. The structure defined in claim 10, said --rod being longitudinally adjustable and including two parts movable to and from each other.

12. The structure defined in claim 10, said rod comprising a stud connected to said stem, and a sleeve having screw threaded engagement with said stud, said sleeve having the closure member formed thereon.

13. Mechanism for automatically controlling and maintaining a substantially constant vac- Yuumv pressure in a'vacuum head, comprising a conduit adapted to communicate at one end with the head and atits other end with a suction line, a valve'in said conduit controlling the 95 passage of air therethrough, said valve having a stem, a cylinderjclosed at one end and open at itsl other end and mounted adjacent said valve, a piston working within said cylinder and having a central aperture therein, a rod connectedrto-V said stem and projecting through the central-aperture in. said piston into said cylinder.. said rod having a flange outwardly disposed from said piston relative to said cylinder and forming -a'valve member with which the portionsrof said piston adjacent said aperture may engage to -close Vsaid aperture, a compression spring interposed between the closed end of said vcylinder and said piston and a compression spring interposed between the inner end of said rod and said piston, said valve in said conduit 'closing as saidrod moves toward the closed end of the cylinder and opening as it moves in the opposite direction.

14. The structure deilned in claim 13, said rodl comprising a stud connected to said stem, means guiding said stud for reciprocating movement to and' from said valve without turning and a sleeve having screw threaded engagement with saidv stud, Said sleeve carrying said ilange.

ARTHUR E. BROUGHTON.

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