US2165442A - Automatic lubricant overbalance for table rolls - Google Patents

Description

E. E. BERRY July 11, 1939;

AUTOMATIC LUBRICANT OVERBALANCE FOR TABLE ROLLS Filed Sept. 21, 1936 FE U? ZAeL f. 36 918 r.

Patented July 11, 1939 PATENT OFFICE AUTOMATlC LUBRIGANT OVERBALANCE FOR TABLE ROLLS Earl E. Berry, Beloit, Wis., assignor to Beloit Iron Works, Beloit, Wis., a corporation of Wisconsin Application September 21,1936, Serial No. 101,707

12 Claims.

This invention relates to mechanism for hydraulically controlling the floating or overbalanc ing of papermachine forming wire supporting rollers in their bearing supports which extend under the wire. The mechanism of this invention automatically compensates for variations in pressure above the wire and for variations in vacuum or pressure beneath the wire and will maintain the rollers floating or overbalanced in their bearing supports at a pre-set degree by supplying more or less hydraulic pressure between the rollers and their bearing supports immediately upon changes in pressure above the wire or changes in pressure or vacuum "below the wire.

In my copending application entitled Pressure and vacuum forming paper making machine, Serial No. 71,109, filed March 2'7, 1936,

there is described and illustrated a paper making.

machine in which a forming wire is supported on loosely journalled table rolls extending transversely across the top of a drain box. Paper stock is fed from a pond to the traveling wire therein. Since the rollers support the wire, the.

pond of stock on the wire, and the fibrous Web formed on the wire, they are naturally presseddown in their bearing supports or journals. This downward pressure is'increased or decreased by the amount of vacuum or pressure maintained in the drain box compartments. However, a lubricating fluid, such as water, can be maintained at a fixed hydraulic-pressure between the bearing supports and the rollers to overbalance the'rollports. The floating of the rollers in ports causes the same to contact the top edges of the supports. These edges, therefore, act as doctors to scrape the rollers clean and prevent clogging of the bearing supports with fibers from the white Water which might be picked up by the rollers. In some instances the lubricating fluid can be maintained under a sumcient hydraulic pressure to flow out of the tops of the bearing supports. This outward ii-ow of Water further cleans and washes the rollers. I

It is obvious that the pressures above the forming Wire and the pressures or vacuum in the drain box compartments will vary during the operation of the machine, so that varying hytheir bearing supdraulic pressures will be required to fioat or overbalance the rollers in their supports at the desired degree.

, This invention now provides mechanism for automatically varying the hydraulic pressure of the lubricating fluid between the bearing supports and table rollers to compensate for variations in pressure over the forming wire and pressures or vacuum under the forming wire.

In accordance with this invention, wateror other lubricating fluid is supplied to a conduit or pipe line under pressures higher than the pressure needed for floating th table rollers in their bearing supports. A pressure reducing valve is included in this supply conduit and is set tomaintain the low side of the valve under a fixed pressure. A pipe line or conduit communicates with the low side of the valve and with each of the bearing supports for the table rolls whereby water is supplied to the table rolls under a fixed hydraulic pressure. As this pressure decreases because of loss of water from between these bearing supports and table rolls, the pressure reducing valve automatically compensates for this reduced pressure by allowing thefiow of more water into the bearing supports.

Therefore, as long as the pressures on the forming wire and the pressures or vacuum under the forming wire remain constant, the usual type of pressure reducing valve will serve to maintain a constant hydraulic pressure between the bearing supports and their table rolls for overbalancing or floating the rolls. However, when the pressure above the wire and the pressures or vacuum below the wire vary so as to increase or decrease the load on the table rolls, the usual pressure reducing valve cannot' compensate for these variations, because the pressure on the low side of the valve will not be changed."

According to this invention, therefore, Sylphon bellows operated bypressures above and below the wire, such as, for example, pressures at the bottom of a pond of stock above the wire and pressures or vacuum in the compartments of the drain box, are operatively connected tothe pressure reducing valve through a lever and link arrangement so as to increase or decrease the pressure on the low side of the valve to compensate for the increased or decreased pressure on the table rolls.

It should be understood that diaphragms, pressure bulbs, or other means capable of transforming variations in pressure into mechanical movements are operable in place of Sylphon bellows.

It is then an object of this invention to provide mechanism for controlling the floating or overbalancing of table rolls in bearing supports.

A further object of this invention is to provide an automatic mechanism to compensate for variations in pressures above the forming wire of a paper machine and variations in pressures or vacuum below the forming wire of the paper machine to maintain table rolls floating in their bearing supports.

A specific object of this invention is to hydraulically overbalance table rolls in their bearing supports irrespective of variations in load carried by the rollers without wasting hydraulic fluid.

A further object of this invention is to hydraulically overbalance each set of table rolls loosely journalled in bearing supports above a plurality of compartments in a white water receiving drain box mounted under the forming wire of a paper machine and to vary the hydraulic pressure under the table rolls with variations in the load carried by the rolls.

Other and further objects of this invention will become apparent to those skilled in the art from the following detailed description of the annexed sheet of drawings which discloses a preferred embodiment of the invention.

On the drawing:

Figure 1 is a diagrammatic side elevational view, with parts shown in vertical cross section, of the automatic lubricant overbalancefor table rollers in accordance with this invention.

As shown on the drawing:

The reference numeral H designates the forming wire of a paper machine of the Fourdrinier type adapted to travel over a drain box it while supported on a plurality of small diameter table rolls I2 which are loosely journalled in bearing supports l3 extending transversely across the top of the box 5 l on the end Walls of the box,

such as M, transverse bars l5 carried by the box,

and'partition walls 56 formed in the box. The bearing supports i3 extend transversely across the top of the box H for substantially the entire length of the rollers 52 and extend for more than 180 around the peripheries of the rollers.

The end walls M of the drain box H, the transverse bars B5 in the drain box H, and the partition Walls 56 of the drain box ll each have longitudinal wells or passageways ll extending across the tops thereof in communication with the inside bearing surfaces of the bearing supports 53 through openings E5 formed in the bottoms of the bearing supports.

The partition walls E6 of. the drain box I! define a plurality of compartments such as 59 and 2!] in the drain box. The bottom of the drain box 5 i is closed by a sloping bottom pan 25. The partition walls i6 do not extend to the bottom of the pan 2! therefrom. The ends of the partition walls it are slotted as at 22. Slides 2-3 arevertically slidable in the slots 22 of the partition walls 26 by means of lift screws (not shown) which may extend through the bottom pan 2i. The compartments l9 and 29 receive white water drained through the forming wire H3, and drainage of this white water from the compartments l9 and 28 can be regulated by positioning the slides 23.

A head box 25, of the type more fully described in my above referred to copending application, Serial No. 71,109, is mounted above the forming Wire iii and has an open bottom portion in comiunication with the forming wire. A slice plate 26 is mounted at the front end of the head. box

but terminate in spaced relation.

25, preferably at the end of the compartment [9 in the drain box i. A nozzle 2'! supplies a stream of stock 28 to the head box 25, The lower lip 29 of the nozzle 2? fits snugly over the wire H], while the upper lip 39 of the nozzle 2? is in spaced relation above the wire it. The stock 28 flowing through the nozzle Z'E is thus directed onto the forming wire it in a confined area behind the slice plate 255 and ahead of the end of the lower lip 29 of the nozzle. This stock depositing area is preferably above the compartment E9 of the drain box. Excess stock from the nozzle 2'! flows around the end of the upper lip 39 of the nozzle to form a pond 3i behind the slice plate 26. An overflow discharge outlet 32 can be provided in the head box 25 for removing an excessive amount of stock from the pond 3! if desired.

The white water from the stock on the wire Hi is drained into the compartment til under controlled conditions. For example, the compartment l9 can be evacuated or a head of, white water can be allowed to build up in the compartment for maintaining a pressure in this compartment. As the wire advances over the compartment it beyond the slice 26, it is subject to conditions prevailing in the compartment 2d of the drain box ll. This compartment 2% can be maintained under a higher or lower degree of vacuum than the compartment l9 if desired, and as a result the formation of a web W on the wire Hi can take place either before the wire advances under the slice 25 or after the wire advances under the slice. The web W has additional water extracted therefrom by suction maintained in the compartment 20 or succeeding compartments in the drain box.

It is evident that the head of stock in the pond 3! will vary somewhat during the operation of the machine, as well as the degree of vacuum or the pressure maintained in the compartment ii! of the drain box H. Since those table rolls l2 mounted above the compartment i9 and the walls defining this compartment must carry their own weight, the weight of the wire, and the pond of stock (ii above the wire, it follows that they deflect downwardly in their bearing supports l3.

In order to provide a free rotation of the rollers in their bearing supports, it is desirable to overbalance or float these rollers. by hydraulic pressure. For this purpose the passageways l1 formed in the bars 15 within the compartment l9, in the partition walls l6 defining the compartment l9 and in the end wall M of the drain box, are in communication through passageways 35 with a pipe line 36. The pipe line 36, in turn, communicates through a pressure reducing valve 3'! with a water supply line 38. Water is thus supplied from a high pressure supply line 38 through a pressure reducing valve 3? into a low pressure supply line 38 and from that into the passageways i! from which it can flow through the openings H8 in the bearing supports into contact with the rollers E2 to overbalance or float these rollers in their bearing supports.

For a given load on the roller I2, the pressure reducing valve 37 can be set to maintain a fixed pressure in the pipe line 3% sufficient to overbalance or float the rollers. However, when the load on the rollers is changed by variations in pressure above the forming wire or by variations in pressure or vacuum in the compartment 19 of the drain bo-x H, hydraulic pressure in the pipe line 36 will not be increased or decreased in order to maintain the same floating of the rolls. These variations can-be compensated for, according'ito this invention, by providing a. control device for the pressure reducing valve 31 to change the pressure in the line 36in accordance with the variations in pressure above or below the forming wire. For this'purpose, a pair of superimposed Sylphon? bellows 40 and 4| are mounted on opposite sides? of a supporting plate 42 which is suspended from a panel such as 43 by means of brackets 44. The interior of the bellows 40 communicates through a pressure tube 45 with the bottom of the pond of stock maintained above the forming wire ID as at 46. The interior of the bellows 4| communicates through a pressure tube 47 with the interior of the compartment IS in the drain box A lever 48 is pivoted to the top of the bellows 40 as at 49 and to the'panel 43 as at 5B. A link 5| connects the lever 48with a second lever 52 pivoted to the bottom of the bellows 4| as at 53 and to the panel 43 at 54. The link 5| is pivoted to the levers 48 and 52 :at55 and 56 respectively.

A tension spring 51 is securedorr the lever 48 between the pivot points 49 and 5|] thereof. The other end of the tension spring 51 is secured to an adjusting screw 58 which extends through the bellows supporting plate 42 and has a thumb nut 59 threaded therearound in abutment with the underside of the plate. In this manner the tension on the spring 51 can be set to hold the bellows 4i] and 4| through their link and lever connections in neutral position, as when the pressure reducing valve 3'! is maintaining the exact amount of hydraulicpressure in the bearing supports to float the rollers. However, assuming that the pond of stock 3| builds up above the wire it? thereby increasing the pressure on the wire. The increased head of stock in the pond will force stock through the pressure tube 45 into the bellows and expand the bellows against the spring tension.- The'expansion of the bellows raises'the pivot point 49 of the lever 48 and tilts the lever about its pivot point 5|). The pressure reducing valve 31 is joined through a rod 601 to the lever 48 between the pivot points 49 and 59, so

that when the bellows 40 expands, the rod 6}) will raise to move-an actuating arm 6| of the valve upwardly for further opening the valve and cansing an incrcasedpressure 'inthe line 35. However, since the increased head of stock in the pond 3| will normally effect an increased drainage of white water into the compartment IQ of the drain boxQthe pressure in the drain box will be increased, since the white water will not ordinarily be drained out of the compartment as fast as it enters. The increased pressure in the compartment |9is transmitted into the bellows 4| to expand the bellows thereby lowering the pivot point 53 of the lever 52 to tilt the lever about its pivot point 54 to raise the end 56 thereof. The link 5| in turn tends to force the end of the lever 48 upwardly thereby tending to offset the amount of raising of the rod 6! by the lever 48. If, on the other hand, the vacuum in the drain box increases with the increase of the head of stock on the wire, the bellows 4| will be collapsed, the

end of the lever 52 thrown downward to move the link 5| downward and further raising the rod 60 to increase the opening of the pressure reducing valve 3'5. 1

It is thus evident that the variable load carried by the rollers is determined by the pressure or vacuum within the compartment- IQ of the drain box, and the head ofstock' maintained above. the

the passageways wire I0. An increase in pressure in the compartment I9 will tend to close the pressure reducing valve 3?, while an increase in vacuum in the compartment is will tend to open the valve. At the same time, an increase in pressure on the wire H) by the pond 3| will tend to open the valve 31, while a decrease will tend to close the valve and any simultaneous opposed variations in the compartment l9 and on the wire ill will be compensated for through the lever and linkage arrangement.

Since the table rolls 12 are definitely spaced between their centers, each table roll carries a definite proportion of the load so that the pressure reducing valve can be set to maintain a sufficient hydraulic pressure beneath the rolls for a desired amount of overbalance of. these rolls. The valve, however, cannot be set to compensate for variations in pressures on top or underneath the wire as encountered during operation of the machine, and for this reason the bellows and lever arrangement are necessary to effect this compensation. Thus, from the pressure readings on pressure gauges and 66 communicating with the bottom of'the pond of stock and with the interior of the compartment H! of the drain box respectively, it can be determined how much pressure will be needed in the line 36 to maintain a sufficient hydraulic pressure for overbalancing the rolls to a desired degree. A pressure gauge 61 can be inserted'in the line 36 and the spring 51 can be set beforehand to regulate the valve 31 so that this pressure will be maintained in the line 35. Then, when the vacuum or pressure in the compartment l9 changes or when. the head of stock maintained above the wire changes, the bellows will be expanded or contracted responsive to these changes to move the lever arrangement against the spring pressure for opening or closing the valve iii.

The compartment 20 of the drain box I4 is illustrated as being maintained outside of the pond area 3| ahead of the slice 26. Since the pressure above the rollers I2 in this compartment 29 will thus be constant, it is not necessary to include the top bellows or pressure tube described above, and the hydraulic pressure regulating mechanism is thus simplified.

As shown in the right hand end of Figure l, H in the transverse bars It in the compartment 20 and in the partition wall N3 of the compartment 2B communicate through conduits 10 with a water pipe H. The water pipe H communicates through a pressure reducing valve l2 with a high pressure water supply line 13.

A Sylphon bellows I4 is mounted on a plate 15 suspended-by brackets H3 from a panel H. The interior of the bellows i4 is in communication through a pressure tube 78 with the intericr of the compartment 2a. The top of the Syl- .phon bellows is pivoted to a lever l9 at 80. The

'to a threaded rod 86 extending through a bracket 81 fastened on the panel H. A thumb nut 88 is threaded around the rod 86 and abuts the bracket 81.

The amount of vacuum in the compartment .26 of the drain box'can be ascertained by a reading of the vacuum gauge 89 in the pressure tube 18. Likewise, the amount of pressure in the low side of the pressure reducing valve 12 can be ascertained by a reading of the pressure gauge 98 in the line H supplying water to overbalance the table rolls l2 in the compartment 20. From the vacuum reading on the gauge 89, it is possible to ascertain the normal degree of vacuum maintained in the compartment 26 and to set the tension of the spring 84 so as to maintain the pressure reducing valve 12 closed against the spring pressure a desired amount for supplying just enough hydraulic pressure to the line H for overbalancing the rolls. However, when the vacuum increases in the compartment Zll, the bellows i l will be collapsed to move the lever arm 19 downward against the spring pressure and to raise the end of the lever upward thereby raising the rod upward for further opening the pressure reducing valve '52 to increase the hydraulic pressure and maintain the rolls overbalanced. It is obvious that an increase of vacuum in the compartment 20 will increase the pressure on the rolls. On the other hand, when the vacuum in the compartment 2!! falls, the bellows M will be expanded to allow the spring 86 to further close the pressure reducing valve (2 thereby decreasing the hydraulic pressure around the table rolls and maintaining the same overbalanced with less pressure.

From the above description, it should be understood that this invention provides for the floating or overbalancing of table rolls in jour nal supports and the maintenance of a desired degree of overbalance irrespective of variations in pressure conditions above and below the forming wire which the rollers support.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as my invention:

1. Automatic lubricant overbalance for paper machine table rollers which are loosely mounted in bearing supports along their lengths under the forming wire of a paper machine comprising a liquid conduit for supplying a liquid between the rollers and their bearing supports, a pressure reducing valve in said conduit, means for setting said valve to provide a constant hydraulic pressure of liquid in the bearing supports, and means esponsive to changes in load on the rollers for actuating said valve to increase or decrease the hydraulic pressure in the bearing supports when the load on the rollers is increased or decreased, thereby maintaining the rollers hydraulically overbalanced in their bearing supports to a predetermined degree.

2. Automatic lubricant overbalance for paper machine table rollers which are loosely journalled in bearing supports along their lengths below the forming wire of a paper machine comprising a liquid conduit for supplying a liquid lubricant between the rollers and their bearing supports, a pressure reducing valve in said conduit, means for setting said valve to provide a constant hydraulic pressure in the bearing supports, pressure responsive bellows communicating with the bottom of a pond of stock fed to the forming wire of the machine, and a lever arm in pivotal connection with said pressure reducing valve for transmitting expansion and collapsing movement of the bellows to the valve for opening or closing the same to increase or decrease the hydraulic pressure in the bearing supports when the pressure at the bottom of the pond of stock on the Wire increases or decreases.

3. In a paper making machine, in combination, a forming wire, a drain box mounted under said forming wire, bearing supports carried by said drain box transversely across the top thereof, table rollers loosely journalled in said bearing supports, a stock vat over said wire for maintaining a pond of stock thereon, a liquid conduit for supplying liquid between the table rollers and their bearing supports, a pressure reducing valve in said conduit, means for setting said valve to maintain a constant pressure of liquid in the bearing supports, pressure expansible and contractable devices in communication with the bottom of a pond of stock on the wire and the interior of the drain box respectively, lever arms pivotally connected to said devices and to a supporting member, a link arm connecting the ends of the levers, and means connecting an actuating member of said pressure reducing valve to one of said lever arms between its pivot points whereby variations in pressure at the bottom of the pond of stock on the wire or variations in pressure or suction in the drain box will collapse or expand the devices to move the levers for controlling the operation of the pressure reducing valve to increase or decrease the liquid pressure in the bearing supports in compensation for the increased or decreased pressure above and below the table rollers.

4. A paper making machine comprising in combination a forming wire, a drain box below said wire, bearing shells extending transversely across the top of the drain box in spaced parallel relation to each other, table rolls in said shells for supporting the forming wire, a stock vat for a pond of stock above the wire, a pair of oppositely disposed bellows adjacent the drain box secured at one end thereof on a fixed member, levers pivoted to the free ends of the bellows and to fixed points intermediate their ends, a link joining the ends of the levers, tubes joining the interiors of the bellows with the bottom of the pond of stock in the drain box respectively, a fluid pressure line for supplying lubricants to the bearing shells, a pressurereducing valve in said line having a control member thereof pivoted to one of said levers whereby movement of the levers by the bellows opens or closes the valve to increase or decrease the pressure in the supply line, and movement of the bellows is controlled by variations in pressure in the pond of stock above the wire and variations in pressure or vacuum in the drain box.

5. A device for maintaining table rollers overbalanced to a predetermined degree in their bearing supports which comprises a fluid pressure line for supplying lubricants under pressure to the bearing supports of the table rollers, a pressure reducing valve in said supply line, a bellows fixedly secured at one end, a lever pivoted to the free end of the bellows and to a fixed point intermediate the ends of the lever, a rod connecting an actuating member for the pressure reducing valve with the end of the lever, and means for actuating said bellows from variations in load on the table rolls to raise or lower the lever thereby opening or closing the pressure reducing valve to increase or decrease the pressure in the supply line.

6. In a paper making machine, in combination, a forming wire, a plurality of small diameter table rolls supporting said forming wire, bearing supports loosely journaling the table rolls throughout substantially their entire length, a conduit for conveying liquid under pressure to the bearing supports for delivery around the rolls, a valve in said conduit for controlling the pressure of said liquid in the bearing supports, and automatic control means for said valve operated by variations in loads on the rolls for progressively opening or closing the valve as the loads on the rolls increase or decrease.

7. The method of balancing table rolls in their hearing supports which comprises surrounding the under side of each table roll with an open topped bearing shell extendingmore than 180 around the roll, said shells having interior diameters larger than the external diameters of the rolls to loosely journal the rolls therein, flowing a liquid into the shells under sufiicient at: mospheric pressure to raise the rolls off of the bottoms of the shells and automatically varying the superatmospheric pressure of the liquid being supplied to the shells in accordance with variations in the load carried by the rolls to maintain a constant balanced condition of the rolls in their shells.

8. The method of balancing table rolls in their bearing supports which comprises surrounding the under side of each table roll throughout its length. with an open topped bearing shell extending more than 180 around the rolls, said shells having interior diameters larger than the external diameters of the rolls to loosely journal the rolls therein, flowing a liquid under superatmospheric pressure into the bottoms of the bearing supports against the table rolls to relieve the pressures between the rolls and the bottoms of the shells to any desired amount and automatically varying the superatmospheric pressure of the liquid being supplied to the bearing supports in accordance with variations in the load carried by the rolls to maintain said relief of pressure between the rolls and the bottoms of the shells constant 9. In a paper making machine, in combination, a forming wire, a plurality of small diameter table rolls supporting said wire, bearing supports loosely journaling the table rolls throughout substantially their entire length, means for supplying a fluid under superatmospheric pressure between the bearing supports and the table rolls, and separate means actuated by variations in load carried by the table rolls for varying the superatmospheric pressure of the fluid being supplied to the rolls.

10. In a paper making machine, in combination, a forming Wire, a plurality of small diameter table rolls supporting said forming wire, bearing shells loosely journaling the table rolls through out their entire length and extending around the rolls for more than 180 degrees of their peripheries, means for supplying a lubricating liquid under superatmospheric pressure into the bottoms of the bearing shells for acting against the table rolls to relieve the pressures between the rolls and the bottoms of the shells to any desired amount, and separate means actuated by variations in load carried by the rolls for varying the superatmospheric pressure of the liquid being supplied to the bearing shells for maintaining said relief of pressure between the-rolls and the bottoms of the shells constant.

11 In a paper making machine, in combination, a forming wire, a plurality of elongated small diameter table rolls supporting the wire, bearing shells disposed under the table rolls and p for more than 180 degrees around the peripheries between the bearing shells and the table rolls,

means for maintaining a pond of stock above the forming wire, and separate means actuated by variations in the Weight of said pond of stock on the wire for varying the superatmospheric pressure of the fluid being supplied to the bearing shells.

12. In a paper making machine, a drain box, a plurality of bearing shells carried by the drain box at the top thereof, table'rolls having an exterior diameter less than the interior diameter of the bearing shells rotatably mounted in the bearing shells in loose engagement therewith, means for supplying water under superatmospheric pressure between the table rolls and bearing shells for overbalancing the rolls in the shells, means for evacuating the drain box, and separate means actuated by variations in load carried by the table rolls for varying the superatmospheric pressure of the fluid being supplied to the rolls to maintain a constant balanced condition of the rolls in their shells.

EARL E. BERRY.

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