US3556152A

US3556152A - Rotary valve

Info

Publication number: US3556152A
Authority: US
Inventors: Ernst Daniel Nystrand
Original assignee: International Paper Co
Current assignee: International Paper Co
Priority date: 1967-07-11
Filing date: 1968-10-24
Publication date: 1971-01-19
Anticipated expiration: 1988-01-19

Abstract

In a system for transporting limp flexible articles, a device is provided for controlling application of suction pressure to hold an article on a movable conveyor, and application of an above atmospheric pressure to accurately expel and deposit the article on a receiver. The control device includes a valve body having an interior cylindrical bore in which a vane is mounted for turning movement about the longitudinal axis of the bore. The bore is connected to a vacuum pump which applies a suction force through an opening in the valve body to hold the sheets on a mesh belt carrier. The suction force is effective until the vane turns to cover the opening and thereby effectively seals the opening to the suction force. Substantially simultaneously, a positive pressure air passageway in the vane is aligned with the opening and the positive air pressure ejects the article to the receiver. The vane extends to and in sealing engagement with the bore wall of the valve body so that the positive pressure is ineffective until the vane is aligned with the opening.

Description

United States Patent [72] Inventor Ernst Daniel Nystrand Green Bay, Wis. [211 App]. No. 798,514 [22] Filed Oct. 24, 1968 Division of Ser. No. 652,507, July 11, 1967, Patent No. 3,473,800. Patented Jan. 19, 1971 [73] Assignee International Paper Company New York, N.Y. a corporation of New York. by mesne assignments [54] ROTARY VALVE 1 Claim, 8 Drawing Figs. [52] US. Cl ..137/625.2l, 137/6253] [51] Int. Cl F16k 11/08 Field otSearch ..137/625.4l, 625.21, 625.24, 625.46, 625.47, 625.31

[56] References Cited UNITED STATES PATENTS 30,365 10/1860; Van Deren 2,620,195 12/1952 iillerstrom 3,194,267 7/1965 Lyonetal Primary Examiner- Cary Nelson Assistant Examiner-Michael O. Sturm Attorney-finderson, Luedeka, Fitch, lEven & Tabin ABSTRACT: In a system for transporting limp flexible articludes a valve body having an interior cylindrical bore in which a vane is mounted for turning movement about the longitudinal axis of the bore. The bore is connected to a vacuum pump which applies a suction force through an opening in the valve body to hold the sheets on a mesh belt carrier. The suction force is effective until the vane turns to cover the opening and thereby effectively seals the opening to the suction force. Substantially simultaneously, a positive pressure air passageway in the vane is aligned with the opening and the positive air pressure ejects the article to the receiver. The vane extends to and in sealing engagement with the bore wall of the valve body so that the positive pressure is ineffective until the vane is aligned with the opening.

a 7235 73 53 7.?3 705 7242 126 M 2: 175 I 2; s :2 for .9 p f 283 f t 770 1 5611 2- SHEET1UF3 PATENTEDJANI 9 I371 INVENTOR ERNST D. NYSTRANI) T ORNEYS mentioned and similar a'pparatu'sand systems.

seamen; U

I This is a division ofcopending application Ser. No. 652,507

filed Jul. 1 l, now Pat. Ns.3,47- 3,soo; e p

This invention relates to apparatus'for transporting limp, flexible-articlesstich as, example, creped tissue 'sheets ,-and

diapers from one location to another by employing a suction pressureto maintain the article in contact-with a continuously moving carrier and employing an above atmospheric air pressureto remoye the a 'rtiele from the carrier. T he invention re- 1 lates more particularly to. animprov'ed valve for controlling the suction and above atmospheric air pressures acting' on the articleand to'a system incorporating the valve.

An apparatusof theaforementioned type, which to herein by way of example and not by way of limitation, is

shown and described in us. Pat. application Ser, No.. 503,259 now U.S. Pat. No. 31,399,587 assigned to',tlie-assignee' of the present invention. In f such apparatus,'which is particularly adapted to receiv'e articles, such as, for example, limp sheets of creped tissue and depositthem ontoa'tissue web, a continureferred ouslymoving endless air pervious conveyof is provided having an ,upper run and a lower run. A chamber is providedabove the lower runof the conveyor and is alternately maintained below atmosphericpressure .to create a suction force at the v lower surface of the lower run capable of maintaining thetissue sheet in contact therewith, and above atmospheric pressure which positively urges thesheet from the conveyor when p it reaches a predetermined location relative to the web.

In such apparatusgfth'e below atmospheric and above atmospheric pressures withirithe chamber are controlled by a suitable valve arrangement; The present invention is principally directed to a valve arrangement useful in the afore It is the principal object'of the present invention to provide an efficient and effective valve of the typedescribed. e e Other objectsand'advantagesof the invention will become apparent withteference to thefollow'ing description and the accompanying drawings in which:

FIG. .3is a fragmentary, seetional v iewtakenalong the In accordance with the present invention, the sheets are accurately'and positively transferred at the transfer station 11 'through'the action of a control device 21 which includes a hollow valve body or housing 23 within which rotates a vane 25 ('FlGS.2-- 4). The control device provides a suction pressure 2'-a-surface of the first carrier beltll5 until the sheet is in approximate alignment with a predetermined position on the "web 12. at'which time the suction pressureis released and an above atmospheric pressureis substituted to release the sheet and expel it onto the web. The sheetis attracted to and retained by the web 12 by virtue of a'suction or vacuum box 27which is positioned beneath the belt of the carrier 13.

7 Referring now to the apparatus in greater detail, the sheets are delivered to any entry side of the carrier 11 by an endless input conveyor 29 (FIG.'1) which receives the sheets from a supply source such as, for example. a web severing and spacing mechanism. which is-not shown herein, but is shown in copending application Ser. No. '5 05,259,'referred to above.

The sheets are carried onthe upper, generally horizontal run '3! of the conveyor 29. The dischargeend of the upper run 31 is disposed immediately beneath the entry sideof the lower run-33 of the'sheet carrier beltl i, ,which is longitudinally aligned (i.e., from left to right in F1631) with the input conveyor 29. V

To facilitate transfer from the input conveyor 29 to the sheet carrier 11, and to maintain the spacingof the strips 10 along'theirpath of travel, the conveyor 29 and belt of the carrier 11 travel at the same surface speed, with the lower run 33, of the upper belt positioned in closely spaced relation to the upper run 31 of the lower belt. Thus, a sheet 10 entering the hip between the beltstravels forwardly with both belts until leaving the upper run 31 of the conveyor 29 at its horizontal supportingroller 35. v To support the belt 15 of the sheet carrier 9, a pair of horizontally spaced entry and

exit rollers

37 and 39 are jour-' 'naled forrotation-on supporting shafts 40 and 41 (FIGS. 1 and u 6) extending'transversely between front frame posts .43 and a FIG. 4 is..a fragmentary, sectional similar to that of FIG v3, but showing 1 certainof the. elements in different operational position;

FIG. 5 is an enlargedfragmentary plan view of the apparatus seen in FIGS. 2-4;

scale;

valve.

FIG. 6 is a plan view of the apparatus of FIG. 1 on a reduced As shown in the drawings for purposes of illustration, the in present invention is embodied in a sheet transfer apparatus (FIG. 1) which, very generally, includes a first article carrier 9 adapted to receive an article such as, for example, a sheetlt) and convey it to a transfer station 11 where it is transferred to ous material suchas close meshed screen, and the sheets are maintained in contact with the carrier 9 and the web 12 of the carrier 13 by suction and areejec ted from the' carrier 9 onto the web 12 byuan atmospheric pressure in a manner hereinafter described. In this instance, both the sheet 10 and the web 12 are formedof a light, flexible material such as creped tissue but the apparatus could of course be utilized with other materials. for example, an assembled diaper.

'-'rearf support frame 47 which extends longitudinally between the spaced rollers and adjacent the far side (FIGS. 1 and 6) of X the belt l5.-'The rollers are disposed between upper and lower runsof the belt 15vvith the exit roller shaft 41 connected to a drive through'a gear box 49 (FIG: 6) which; in turn, is driven bya horizontally disposed drive shaft 51 extending to a gear boxz53. An input gear 55 for the last mentioned gear box is connected to and-driven in timed relationship to a cutter (not 'shown)vfor the sheets 10 and the input carrier 29 forthe sheets Adjacent the entry roller 37 is disposed a vacuum or suction box 57(FIG. 1) which is effective-to cause a suction force at the lower surface of the lower run'33 of the sheet carrier belt 15 adjacent the entry end thereof. The suction box is sup- FIG- 7 is avfmgmemary enlarged g of an ab u ported in a suitable manner by the frame 47 and has a width ternate embodiment of the invention; and;

FIG. 8 is a diagrammatic view ofa phase adjustment for the approximately that of the belt. The forward end wall 59 of the suction box is arcuately curved and spaced adjacent to the.

entry side roller 37' to provide a suction force over. the discharge end of the input conveyor29'to assure continued uninterrupted movement of the sheet 10 from the latter to the sheet carrier. Herein, the suction box is formed with a pair of opposite sidewalls 61, a top wall 63 sloping downward from the arcuate end wall 59 to a smaller opposite enclwall 65, and a horizontal bottom plate 67. The latter is perforated with suitable intake openings and is disposed parallel to, and at the uppersurface of, the lower run of the belt to afford suction across the width and length of the box; The interior of the suc- -tion box is connected by a duct (not shown) to a suction source such as a vacuum pump to exhaust air from the box. Thus, a suction force is provided for the length of the suction box 57 to hold the sheets 10 to the lower run of the belt as the sheets travel forwardly (i.e. left to right in FIG. 1) to the entry side of the transfer station 11 at which is located the control apparatus or valve 21.

q The leading end of a sheet 10 entering the transfer station ll continues to adhere to the underside of the belt 33 due to a suction force on the belt generated through a chamber 69 which is connected to a suitable vacuum source through a hollow bore 71, (FIGS. 3 and 4) in the valve body 23 and through a conduit 73 leading to the vacuum source, which may be a vacuum pump or the intake of a blower (not shown). The chamber and valve body are suitably supported in the space between the upper and lower runs of the sheet carrier belt by horizontally spaced brackets 75 (FIG. 6) fixed at their rear ends to the frame 47. As best seen in FIGS. 2, 3 and 4, the forward ends of the brackets 75 are fastened to the upper side of the valve housing at the opposite ends of the latter. The brackets are in the form of a horizontal plate 77 stiffened by an upstanding tapered plate 79 (FIGS. 3 and 4) extending rearwardly to the frame 47.

The ends of the valve housing 23 attached to the brackets 75 are generally square in cross section (FIG. 1) and intermediate them is a longitudinally extending center portion having an upper semicylindrical outer wall 81 integrally joined to opposite longitudinal sidewalls 83 and 85 (FIGS. 3 and 4) which extend downwardly to a horizontal bottom wall 87 abutted against the top surface of an upper wall 89 of the chamber 69, the latter being secured to the bottom wall of the valve body by screws 90.

The cylindrical bore 71 in the valve body extends longitudinally along the full length of the valve body 23 and is concentric with the rounded outer top wall 81 of the housing. To close the bore 71 at the ends of the housing, end caps 93 (FIG. 2) are fastened at the opposite ends of the housing with a radially outer annular flange 95 on the end caps abutted against a vertical end wall 97 of the housing body and with an axially inwardly projecting annular boss 99 projecting into the bore and abutting against a cylindrical wall 101 defining the bore 71.

To facilitate connection of the exhaust conduits 73 to the cylindrical bore 71, tapped bosses 103 are provided in the rear vertical housing wall 85 adjacent the opposite ends of the cylinder body and the exhaust conduits 73 are threaded into the tapped bosses. The air being drawn from the valve body bore 71 enters the latter from the chamber through a plurality of openings 105 in the bottom wall 87 of the housing, the openings 105 being aligned with similar openings 107 in the top wall 89 of the chamber 69. In the present instance, the aligned openings 105 and 107 are aligned vertically and lie along a longitudinal line extending generally the full length of the valve body. As best seen in FIGS. 2-4, the openings are radially aligned with the longitudinal axis of the bore 71. When air is being exhausted from the chamber 69 and the lower run 33 of the belt 15, it travels along the path shown by the directional arrows in FIG. 4, namely, upwardly through an apertured bottom plate 109 and into a hollow interior 110 of the chamber 69, through the openings 107 in the top wall of the chamber and aligned openings 105 in the bottom housing wall 87, along the cylindrical bore 71, to the exhaust openings in the bosses 103 and through the conduits 73 to the exhaust pump (not shown).

In accordance with the present invention, during the time in which the sheet is in the transfer station 11, i.e., beneath the perforated plate 109, the valve vane 25 moves into a position to change essentially instantaneously the inward suction pres sure in the chamber 69 to an outward positive pressure of air to expel the sheet 10 to the web carrier 13 which, in the present instance, has its upper run and the web 12 about onehalf inch beneath the sheet 10 being transferred. To achieve this quick and accurately timed change of pressure, the outer end 113 of the vane seals the openings 105 from the suction of the cylindrical bore 71 and, substantially simultaneously, air is delivered under pressure through hollow passageways 115 in the vane to the openings 105 which are now aligned with the passageways 115 in the vane. Herein, the volume of the chamber 69 is made relatively small by having a narrow spacing between the perforated plate 109 and the top wall 89 so that the interior 110 of the chamber quickly changes from a suction pressure to a positive or above atmospheric pressure.

Because the edge of the vane 25 which engages the wall of the bore 71 is narrow relative to the cross-sectional area of the openings in the wall of the bore, the vane delivers air under pressure for only a small portion of its cycle of rotation. The positive pressure in the hollow passageway in the vane is sealed during the major portion of its rotational cycle by the cylindrical wall 101 of the bore against which it is in contact. In this respect, the edge of the vane includes an elongated bar 119 of rectangular cross section fastened in a longitudinal groove 121 at the radially outwardly projecting end of the vane. The seal bar 119 extends radiallyoutwardly from the vane and slides on the cylindrical wall and is preferably made of a material such as, for example, nylon. which will slide along the cylindrical wall without undue friction or wear. The seal bar extends longitudinally across the full length of the vane and is provided with a series of radial openings 122 aligned with and constituting a portion of the radial passageways 115.

In the present instance, the vane 25 is in the form of an elongated block of generally rectangular cross section, except for tapering sidewalls 124 at the end carrying the seal bar. A longitudinal bore 123 of circular cross section extends the full length of the vane between opposite end walls 125 (FIG. 2) and is disposed medially between opposite longitudinal sidewalls 126 of the vane and intersects'the radial passageways 115 so that the latter are in fluid communication with the longitudinal bore 123. The vane extends longitudinally in the valve body bore 71 between the opposite end caps 93 and is mounted for rotation about the longitudinal axis of the bore 123 by stub shafts 129 fixed to the opposite ends of the vane and journaled in bearings 131 seated in the respective end caps 93 for the valve housing. Circular bosses 133 on the stub shafts are telescoped into the opposite ends of the longitudinal bore 123 and outwardly projecting flanges 135 are abutted against and secured to the end walls 125 of the vane by screws 137. On each stub shaft adjacent the flange 135 is a reduced diameter portion 139 which is sized to fit into the bore of the inner bearing race which abuts an inner and radially directed shoulder on the shaft. To limit longitudinal movement of the shaft, a retaining collar 141 is fastened to the stub shaft adjacent the outer radial wall of the bearing 131, the latter being held against longitudinal movement in its end cap opening by a pair of Tru-Arc rings 143 abutted against opposite sides of a bearing and seated in grooves in the wall of the end cap opening 145.

To deliver air under pressure to the interior passageway in the rotating vane, each of the stub shafts is provided with a longitudinal bore 147 extending the full length of the respective shafts. The inner end of each shaft bore opens into the longitudinal bore 123 in the vane and the outer end of each shaft bore is in fluid communication with an attached air conduit 149 (FIG. 6). The latter is connected to a stub shaft by a suitable union 151 which permits the stub shaft to rotate without twisting the conduits which lead to the pressure pump (not shown). Thus, air under pressure enters the opposite conduits 149 and moves through the stub shaft bores 147 to the longitudinal passageway or bore 123 in the vane and then moves radially and outwardly through the passageways 115 to the seal bar 119. When these radial passageways'in the vane. are aligned with the openings 105 in the bottom wall 87 of the valve housing (FIG. 3) the air under greater than atmospheric pressure leaves the latter and enters into the interior of the chamber 69 to exit downwardly through the perforated plate 109 and through air pervious belt 15 to expel the strip to the lower web carrier 13.

To time the rotation of the vane 25 to the position of the strip 10 so that the strip 10 ejects at the proper time to the web carrier 13, the vane 25 is rotated by a' driving connection 153 (FIG. 6) with the drive sheet conveyor 11. The driving connection is in the form of a drive roller 155 fixed to one of the stub shafts 129 and a timing belt 157 disposed between this roller and a belt roller 159 keyed to the drive shaft 51 for the gear box 49 driving the carrier roller 39.

, s The placement of the sheets in relatively precise positions on the web 12 with a right angle change in directions is difficult to achieve as it involves a consideration of the inertia,

i.e., the continued forward motion of the sheets as the air blast is pushing the sheets down to the web 12 and also the alignment of the vane with the opening 107 at the proper instant when a sheet is disposed beneath the chamber. In accordance withanother aspect of the invention, the placement can be controlled and adjusted for misalignments while the system is in operation. To this end, the belt 3,driving the roller 155 and attached vane shaft 129 is controlled by adjustment means 160 (FIG. 8) which includes a threaded adjustment screw 161 and traveling rollers 162 for shifting the belt 157 relative to the. rollers 155and 159. MorespecificallyQthe belt 153 may be disposed about a second set of spaced rollers 163 and 164 fixed to a support plate 165. The belt is formed with an upper loop intermediate the rollers 155 and 159 to receive the upper one of the traveling rollers 162 and is formed with a lower loop intermediate the lower. rollers 163 and 164, to receive the lower one of the traveling rollers 162. These traveling rollers are secured to and journaled in a carriage 166 guided for reciprocation in said support plate for movement along a vertical path. The upper end of the adjustment screw is attached to the carriage to move the latter with turning of the screw in a nut 167 fixed to the support plate 165. By increasing or decreasing the sizeof the. upper loop between the rollers 155 and 159 with turning of the adjustment screw 161, the angular position of the vane and its roller 155 can be adjusted relative to the angular position of the roller l59 with a relatively fine. adjustment. Thus,v the position of the deposited sheets can be adjusted to compensate for changing conditions and to provide an initial alignment with case.

It will be recalled that the roller 159 is being driven by the gear box 53 and shaft 51 in direct phase with the roller 137 driving the endless belt 15 so that the shifting of phase between the

rollers

155 ,and 157 results in a change in phase between the sheet on the carrier 15 and the rotatable vane.

In accordance with one embodiment of the invention, a

more uniform and accurate transfer of the sheet is obtained by programming the arrangement of holes 169 (P16. 5) in the perforated bottom plate 109 of the chamber 69. That is, the holes are programmed to distribute the air in'such a manner that the sheet travels more evenly fromthe chamber to its predetermined location on the web 19. Herein, the holes are programmed by size with the smallest diameter holes aligned in two central longitudinal rows 171 (FIG. 5) approximately at the middle of-the plate and with parallel rows of holes of progressively large diameters in each of the adjacent outer rows 173. The largest diameter holes are aligned in' longitudinal rows 175 paralleling and adjacent to an opposite longitudinal edge of the plate. For example, the hole sizes may be one sixteenth inch in diameter for the holes in rows 171, and have an increase of one sixty-fourth inch in diameter in each of the next outward rows 173 until the outer rows 175 in which the hole diameters are thirteenth sixty-fourths of an inch.

A nonprogrammed perforated plate having holes each with an identical diameter has been successfully employed on the chamber 69 and may be used in lieu of the programmed plate simply by removing a series of bolts 177 threaded into opposite pairs of depending sidewalls 179 of the chamber 69.

' The perforated plate 109 abuts the lower edges of the sidewalls 179 and the lower edges of a pair of transversely spaced spacer plates 181 (FIG. 2) which extend vertically from the plate 109 to the top wall of the chamber housing. The interior 110 of the chamber is provided with a contoured wall 183'which slopes from the center downwardly and outwardly through a series of steps or lands to each of the longitudinal.

sidewalls 179. The hollow space in the outer side portions of uniform velocity of airflow through the Plateand belt 15.

in accordance with another aspect O the invention the seal bar 119 may be provided with a trailing sealing portion 187 (FIG. 8) on the counterclockwise side of the clockwise rotating vane 25. This trailing sealing portion briefly seals the openings as the vane rotates away, from the position of FIG. 3 so that the sheet being expelled is afforded a longer period of time to travel to the web 19 prior to the return of the vacuum pressure which tends to return the sheet to the chamber. 69. The trailing portion of the vane therefore seals the openings 105 against the return of a suction which would pull the sheet back toward the perforated plate 109, if the same has not yet adhered to the web 19 and to carrier 13.

From the foregoing, it will be seen that the present invention is directed to a simple and efficient apparatus for controlling the depositing of a,v sheet, such as a flexible and thin sheet of creped tissue, from a moving; carrier to a moving receiver. in its preferred form, a hollow pressurized vane moves into position over an outlet port in a cylinder bore to cut off a chamber from the vacuum pressure in the bore and to connect the chamber with the air above atmospheric pressure in the vane. The air above atmospheric pressure expels the sheet from the perforated plate to the receiver and, as the vane continues to rotate, the chamber is againconnected with the vacuum pressure in the bore for the: larger portion of th cycle of rotation of the vane.

While a preferred embodiment has been shown and described, it will be understood that there is no intent to limit the invention by such disclosure but, rather, it is intended to cover all modifications and alternative constructions falling within the spirit and scope of the invention as defined in the appended claims. 1

I claim: I

l. A rotary valve for providing at time intervals a differential pressure flow of fluid comprising a valve body having a cylindrical interior wall defining an elongated bore about a longitudinal axis, said valve body having an opening extending to said bore and in fluid communication therewith, endcaps on said valve body closing the ends of said elongated cylindrical bore with at least one of said end caps having a port therein, an elongated vane extending longitudinally within said bore between said end caps and mounted for turning about the longitudinal axis of said bore, means on said end caps for journaling said vane for rotation, said vane having a portion extending radially from said-axis to adjacent to said cylindrical bore wall, a passageway in said vane extending longitudinally of said vane and in fluid communication with said port in said cap, said vane passageway having a radially directed portion extending radially towards and longitudinally along said cylindrical wall, a seal bar on said radial end of said vane having a series=of apertures therein alignment with said passageway portion in said vane to permit the flow of fluid therethrough, said seal bar extending to said cylindrical wall so that said series of apertures therein are substantially covered by said cylindrical wall during a substantial turning movement of said vane, a series of apertures disposed longitudinally along said valve body and defining a second fluid flow port in said valve body and being aligned with said apertures on said seal bar during a portion of the turning movement of said vane, said seal bar having a trailing sealing portion bridging said apertures in said valve body, and means for continuously turning said vane to alternately expose said second port to fluid flow from said vane and said bore as the vane turns.

Dedication 3,556,152.-Emt Daniel Nystmnd, Green Bay, Wis. ROTARY VALVE.

Patent dated Jan. 19, 1971. Dedication filed Dec. 17, 1974, by the assignee, [ntemational Paper Company.

Hereby dedicates to the Public the entire remaining term of said patent.

[Ofiicz'al Gazette April 22, 1.975.

Claims

1. A rotary valve for providing at time intervals a differential pressure flow of fluid comprising a valve body having a cylindrical interior wall defining an elongated bore about a longitudinal axis, said valve body having an opening extending to said bore and in fluid communication therewith, end caps on said valve body closing the ends of said elongated cylindrical bore with at least one of said end caps having a port therein, an elongated vane extending longitudinally within said bore between said end caps and mounted for turning about the longitudinal axis of said bore, means on said end caps for journaling said vane for rotation, said vane having a portion extending radially from said axis to adjacent to said cylindrical bore wall, a passageway in said vane extending longitudinally of said vane and in fluid communication with said port in said cap, said vane passageway having a radially directed portion extending radially towards and longitudinally along said cylindrical wall, a seal bar on said radial end of said vane having a series of apertures therein alignment with said passageway portion in said vane to permit the flow of fluid therethrough, said seal bar extending to said cylindrical wall so that said series of apertures therein are substantially covered by said cylindrical wall during a substantial turning movement of said vane, a series of apertures disposed longitudinally along said valve body and defining a second fluid flow port in said valve body and being aligned with said apertures on said seal bar during a portion of the turning movement of said vane, said seal bar having a trailing sealing portion bridging said apertures in said valve body, and means for continuously turning said vane to alternately expose said second port to fluid flow from said vane and said bore as the vane turns.