US2833184A

US2833184A - Movable table and suction box structure for fourdrinier machine

Info

Publication number: US2833184A
Application number: US580596A
Authority: US
Inventors: Jr Joseph Baxter
Original assignee: Black Clawson Co
Current assignee: Black Clawson Co
Priority date: 1951-12-29
Filing date: 1956-04-25
Publication date: 1958-05-06
Anticipated expiration: 1975-05-06

Description

J. BAXTER, JR MOVABLE TABLE AND SUCTION BOX STRUCTURE May 6, 1958 FOR FOURDRINIER MACHINE Original Filed Dec. 29. 1951 5 Sheets-Sheet 1 I l I Illlilll lllllll ATTORNEYS May 6, 1958 J. BAXTER, JR 2,833,134

MOVABLE TABLE AND SUCTION BOX STRUCTURE FOR FOURDRINIER MACHINE Original Filed Dec. 29. 1951 5 Sheets-Sheet 2 INVENTOR.

JOSEPH BAXTER JR.

ATTORNEYS y 6, 1958 Y J. BAXTER, JR 2,833,184

MOVABLE TABLE AND SUCTION BOX STRUCTURE FOR FOURDRINIER MACHINE Original Filed Dec. 29, 1951 Sheets-Sheet 3 132, PRESSURE I SWITCH mmawma.

167 E" JosEPH JR.

May 6, 1958 J. BAXTER, JR 2,833,134

MOVABLE TABLE AND SUCTION BOX STRUCTURE FOR FOURDRINIER MACHINE 5 Sheets-Sheet 4 Original Filed Dec. 29, 1951 INVE NTOR JOSEPH BAXTER JR.

BY W,MZ,M+73

ATTORNEKS May 6, 1958 J. BAXTER, JR

MOVABLE TABLE AND SUCTION BOX STRUCTURE FOR FOURDRINIER MACHINE Original Filed D90. 29. 1951 T 5 Sheets-Sheet 5 i JUL 4 INVENTOR JOSEPH BAXTER Ja.

ATTORNE YS United States Patent MOVABLE TABLE AND SUCTION -BOX STRUC- TURE FOR FOURDRINIER MACHINE Joseph Baxter, Jr., Franklin, Ohio, assignor to The Black- Chaiwson Company, Hamilton, Ohio, a corporation of Original application December 29, 1951, Serial No. 264,088, now Patent No. 2,760,411, datedAugust 28, 1956. Divided and this application April 25, 1956, Serial No. 580,596

6 Claims. (Cl. 92-44) 'lhis'invention relates to a Fourdrinier paper machine. This application is a division of my application Serial No. 264,088, filed December 29, 1951, now Patent No. 2,760,411.

It is generally a primary object of the invention to provide a Fourdrinier paper machine which is of lightweight and rigid construction eliminating a major proportion of the weight and many of the component parts of conventional Fourdrinier machines of present day manufacture without sacrificing size or capacity, which may therefore be advantageously fabricated of more desirable materials for improved overall construction and maintenance at economical cost, and which in addition may readily be constructed with all portions of the wire section mounted in cantilever fashion for tilting as a unit to facilitate wire changing.

More specifically it is an object of the invention to provide a Fourdrinier paper machine incorporating a control arrangement for the water draining from the newly formed paper web such that the water is directed outwardly to one or both sides of the machine from between the top and bottom runs of the wire without the necessity of saveall trays and the like, and thus to eliminate a large proportion of the weight of conventional Fourdrinier machines represented by such trays and their supporting structure with resulting economy of manufacture and maintenance as well as generally improved operation.

In one embodiment of the invention, the major portion of the wire section which supports the table rolls comprises a plurality of spaced truss members extending transversely of the direction of wire travel and connected by simple reinforcing members to form a main frame of rigid bridge-like construction which may at the same time be comparatively light in weight for economical manufacture as well as convenient operation. The truss members of the frame cooperate to support a covering roof of sheet metal formed at its sides to overhang thefront and back of the machine in such manner as to deliver the white water draining from the top run of the wire and paper web thereon away from the bottom run of the wire. The truss frame also forms a convenient support for the table rolls and cooperating deflector members for stripping the table rolls of Water and thus causing all water draining from the wire as it crosses the table rolls to fall to the roof, and this entire structure is readily supported at one side by a horizontal pivotal mounting on the base of the machine and forms a rigid unit which may be tilted about its pivotal mounting for support in cantilever fashion across its entire width for convenient wire changing.

It is accordingly an object of the invention to provide a wire section of a Fourdrinier paper machine of cantilever type truss roof construction wherein multiple truss members extending transversely of the wire in spaced relation longitudinally of the machine cooperate to form a lightweight but highly rigid and strong main frame for 2,833,184 Patented May ,6, 1958 chine having a wire section including a truss roof as outlined above wherein a lightweight roof member of sheet material is mounted on topof the trusses and below the table rolls and is inclined downwardly towards one or both sides of the machine to receive water draining from the table rollsand to direct this water laterally of the machine for ready discharge to the pit without passing' through the return flight of the wire below the machine;

The invention has special relation to the control of tension in the Fourdrinier wire, from the standpoint both of facilitating wire changing and also of maintaining controlled tension in the wire during operation, and one of the objects of the invention is to provide a Fourdrinier paper machine having an adjustable tensioning device for the wire which incorporates a continuously operable control for measuring the tension in the wire and a drive automatically responsive to the measuring control in such manner as to correct during operation of the machine for variations in tension from a desired maintained substantially constant tension.

An additional object is to provide an automatic tension controlling device for the wire of a Fourdrinier paper machine which is constructed and arranged for ready shifting between an operating position wherein it establishes and maintains desired tension in the wire and a release position such that not only is it free of the wire but also in its movement to the release position, it provides suflicient slack in the wire for ready removal and changing thereof without requiring the release or removal of other parts of the machine. A i

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims. In the drawings Fig. 1 is a side elevational view illustrating the wire section of a Fourdrinier paper machine constructed in accordance with the present invention;

Fig. 2 is a fragmentary section on the line 2- 2. of

Fig. 3 is an enlarged fragmentary view in side elevation showing the mounting arrangement for the breastroll and with the roll in its raised or operative position;

Fig. 4 is a view similar to Fig. 3 showing thebreast roll in its release position;

Fig. 5 is a section on the line 5-5 of Fig.1 showing the general construction of the main supporting frame work of the machine; A

Fig. 6 is a view similar to Fig. 5 showing the Wire section tilted for wire changing;

Fig. 7 is a fragmentary section-on the line 7-7 of? Fig. 5;

Figs. 8 and 9 are enlarged fragmentary views showing the controlling and locking mechanism for tilting the wire] section, Fig. 8 showing the parts released as in Fig. 5; and Fig. 9 showing the parts in their machine tilted as shown in Fig. 6;

Fig. 10 is an enlarged fragmentary section showing the mounting arrangement for one of the shake rails which support the table rolls, the view being in section approximately on the line 10-10 of Fig. 1;

Fig. 11 is a section on the line 11-11 of Fig. 1 show- .1

ing the arrangement of stretch rolls for tensioning the forming wire; s

Fig. 12 is a fragmentary and-somewhat diagrammatic perspective showing a drive for 1 view in the nature of a the stretch rolls;

positions with the aeaaisa Fig. 13 is a fragmentaryelevational view on a larger scale showing the position of the stretch rolls during operation of the machine;

Fig. 14 is a view similar to Fig. 13 showing the position of thestretchrolls during wire changing;

Fig. 15 is a further enlarged fragmentary elevational view showing a detail of the stretch roll mechanism;

Fig. 16 is a section on the line 16-16 of Fig. 1 illustrating one of the suction boxes and its supporting structure;

Fig. 17 is a fragmentary section on the line 17-17 of Fig. .l6illustrating internal details of the suction box;

Fig. .18 is a section on the line 18-18 of Fig. 16 illustrating the pivotal mounting of one of the suction boxes;

Fig. 19 is a fragmentary section on the line 1919 of Fig. 1 showing the suction couch roll and its supporting structure;

Fig. 20 is a fragmentary view looking from right to left in Fig. 19 to show the tilting mechanism for the.

couch roll;

' Fig.21 -is a perspective view of the wire section of a Fourdrinier machine embodying a modified construction in accordance with the present invention;

Fig. 22 is a transverse vertical section through the paperrnachine of Fig. 21.

Fig. 23 is a fragmentary view looking from right to left in :Fig.25 and partly broken away showing a portion of the wire tensioning mechanism of the machine of Fig. 21;and

Figs. 24 and 25 are diagrammatic views in side elevation illustrating the operation of the wire tensioning mechanism of Fig. 23.

Referring to the drawings, which illustrate preferred embodiments of .the invention, Fig. 1 shows the general arrangement of the wire section of a Fourdrinier paper machine including the continuous forming wire 30, the breastroll 31, table rolls 32 provided with water deflectors 33, suctionboxes 34and the suction couch roll 35. The stock inlet or slice is indicated fragmentarily at 36, and similarly the usual forming board and its saveall tray are indicated at 37 and 38 respectively. The main frame structure supporting. the breast roll and table rolls includes a plurality of truss members 40, which extend transversely of the direction of wire travel in spaced relation longitudinally of the machine, and each truss member 40 has a supporting post 42 at the'back of the machine. The suctionboxes are supported separately from the truss frame but are connected therewithas de scribed hereinafter.

The truss members 40 are shown as formed of main cross members 44, top members 45 and a plurality of diagonally and vertically arranged sections 46. These parts may be welded together in any suitable'truss design, with the

parts

44 and 46 being formed of tubular sections of stainless steel or other suitable material pr0- viding adequate strength and rigidity together with light ness in weight, and with the parts 45 formed of similar material in strap form for more convenient fabrication. Longitudinal bracing is :lprovided by means of

additional sections

47 and 48 welded between adjacent trusses as shown in Fig. 7,the number of such longitudinal reinforcements depending in large measure upon the width of ithe machine, and these longitudinal braces may also connect the suctionboxes together and to the 'truss'frame. Additional reinforcing members 50 may be welded as shown between approximately the midpoint of each truss and the associated post 42 at the back of the machine, these reinforcements 50 being arranged atan acute angle to the main cross members 44. A covering roof 'of stainlesssteel or other suitable sheet material is inturn supported on the truss members, and it is formed of curved section with its sideportions inclined downwardly in overhanging relation with the ends ofthe truss men1-.

bers.

The supporting structure of the machine includes a pair of

base members

60 and 61 which extend along the front and back of the machine similarly to the usual sole plates but which are shown as formed of generally trough shape in section to receive water draining from the sides of the roof 55, and each base member has a plurality of openings 62 for directing water therefrom into the usual wire pit (not shown). With this construction, all the water draining from the newly formed web on the upper run of the wire as it passes from the breast roll to the suction boxes is received initially on the upper surface of roof 55. This water therefore drains off at the side of the machine so that it is unnecessary to provide saveall trays or like members between the upper and lower runs of the wire such as are usually employed to prevent contamination of the lower run by fiber carried with the white water from the web on the upper run, and the water is discharged laterally from between the upper and lower runs of the wire. Also, this roof arrangement provides for continuous drainage over lips extending the full length of the table roll section and thus gives maximum capacity for rapid and complete drainage. In addition, with the drainage spread over the full area of the table section, the resulting film of water is correspondingly thin to reduce the tendency for accumulation of entrapped air in the return water system, and also the roof is easy to clean by simple washing with a hose or the like.

In the usual Fourdrinier construction, the saveall trays and their supporting structure constitute a major proportion of the total weight of the wire section, and since these parts are unnecessary in the present machine, it is also possible and practicable in accordance with the invention to construct this section of the machine of substantially lighter parts without sacrificing any necessary strength or rigidity. Also with this truss roof arrangement described, materials usually considered too costly for this purpose but which are nevertheless highly desirable, such as stainless steel, can be used at economical cost because of the greatly reduced weight and requirements with respect to quantity of material.

This greatly lightened overall structure in accordance with the invention is also readily adaptable to a cantilever mounting for the wire section facilitating wire changing. Referring to Figs. 2, 5 and 6, the rear base member 61 includes a plurality of rib-like stand portions 65, and the posts 42 at the back of the machine are secured at their lower ends to a shaft 66 journaled in these stands and extending the full length of the machine. A pad portion 67 of the front base member 60 serves in the operative position of the machine as the support for the plurality of blocks 68 which are secured to the front ends of the truss members 40, and the entire frame can thus pivot with the shaft 66 to raise the blocks 68 away from the pad 67 and so that the front of the frame is supported in cantilevered position as shown in Fig. 6.

Movement of the frame for wire changing as described is shown as effected by a plurality of fluid pressure cylinders 70 mounted at the back of an upstanding portion of each of the stands 65, and each having a piston rod 71 connected with a bracket 72 at the back of the adjacent post 42. The arrangement is such that when pressure is applied to cylinders 70, the posts 42 are pulled rearwardly of the machine so that the entire main frame rocks with the shaft 66, raising 'blocks 68 away from pad 67, and in this position the wire is readily removed and a new wire mounted in place from the front of the machine as indicated diagrammatically at 30a in Fig. 6. In order to cause the entire frame to move as a unit and to prevent premature movement of one or more of the posts 4-2, the latter may be bolted or otherwise secured to shaft 66 so that this shaft will act as a torque rod.

The frame may be readily held in raised position by means such as a loop-shaped latch member 75 (Figs. 8 and 9) pivoted to each stand 65 and adapted to slip over the cooperating latch portion 76 at the upper end of the adjacent'post 42. Disengagement of each latch75 is shown as effected by means of a fluid pressure cylinder 1 77 carried by stand 65 and having its piston rod pivoted in aslot 78 in the latch 75. The cylinders 77 may be double acting to operate the latches in both directions, or they may be single acting to disengage the latches, with engagement of the latches being effected by gravity after the frame has been raised a 'sufiicient distance. A shield 80 is shown as secured to the roof 55 adjacent each of the posts 42 to protect these parts against splashing by the water draining from the roof.

Fig. 1 shows the general location of the several guide rolls for the lower run of the wire 30. The guide roll 85 is mounted as shown in'Fig. 2 on the base member 60 at the front of the machine and on a stand 86 carried by the other base member 61, and if desired this roll may be supported in conjunction with a suit-able wire guide for movement angularly of the direction of travel of the wire to maintain travel of the wire in the proper direction, as shown for example in Staege Patent No. 2,484,- 473 issued October 11, 1949, to the assignee of this application. One or more inside rolls 88 above the lower run of the wire are carried by the posts 42 and blocks 68 for tilting with the truss roof, as best seen in Fig. 6. The guide roll 90 next to the couch is also an inside roll and is carried by supports 91 extending downwardly from one of the suction boxes 34'and tiltable therewith as shown. in Fig. 16. This provides the important advantage in operation that the wire passes below roll 90 after leaving the couch roll so that any particles of fiber adhering thereto tend to be forced out. This cleaning action is further aided by showers 95 located between roll 90 and the couch roll which promote effective cleaning by maintaining a flooded condition at the nip of roll 90 and the wire.

The breast roll 31 and the table rolls 32 are all carried by a pair of rails 99 which extend the full distance from the breast roll to the suction boxes, and which are adapted for connection to any suitable shaking mechanism (not shown). These rails 99 are shown as of rectangular hollow section for reduced weight, and they have flexible mountings on the truss roof providing for shaking the table rolls. For example, the rails 99 are shown as bolted at 98 to the upper ends of a plurality of plates 100 each of which has its lower end welded or otherwise secured to a sleeve 101 mounted by means of an internal rubber sleeve 102 on a bolt or rod 103 which is in turn supported by yoke-shaped bracket 105 similarly secured to the roof 55, preferably directly above one of the top members 45 for adequate rigidity. This type of mounting unit, in which the rubber sleeve is bonded whom the metal sleeve 101 and the rod 102, provides for the desired vibration of the plates 100 and the. parts supported thereby, and similar results are obtainable by constructing the plates 100 as leaf springs having their lower ends fixedly secured in the brackets 105. If desired, ,the rails 99 may be formed of multiple separate sections each connected with a shaking mechanism for shaking independently of each other.

The breast roll 31 is shown as mounted directly on the shake rails 99 by means of a pair of brackets 110 welded or otherwise secured to the ends of the rails 99' and equipped'with means for effecting controlled sliding movement of the breast roll away from the slice to provide suflicient clearance for ready wire changing. Referring to Figs. 3 and 4, each of these brackets includes a surface-111 forming a slideway for the square'bearing blocks 112 for the breast roll journals. Each bracket 110 is also provided with a complementary member 115 which is bolted thereto to enclose the bearing blocks 112 and which includes a slideway 116 and a face 117 limiting upward movement of the bearing block, and the members are shown as provided with eye bolts 1187to aid in their 'removal when it is desired to replace the breast roll.

"The sliding movement of bearing'blocks 112 in the

slideways

111 and 116 is effected and controlled by a pair of fluid pressure cylinders 120 mounted on the brackets 110 and having their piston rods 121 connected T to the bearing blocks. Bolts 123 are also threaded'in the brackets 110 for engagement with the pad portions on I the lower sides of the bearing blocks to lock them in their uppermost position. Thus when it is desired to change the wire, it is merely necessary to release thebolts 123 and permit the breast roll to move downwardly through the sliding movement of its bearing blocks 112 on the slideways 111. After the wire has been changed, the breast roll is returned to its uppermost position by means of cylinders 120 and is locked therein by the bolts 123;.

Figs. 11-15 illustrate the construction and operation of the stretch roll arrangement which maintains proper ten-- sion in the wire 30 during operation of the machine and may be mounted directly on the base member 60 similarly to the guide roll 85. The arm 133 is similarly mounted for pivotal movement about its center by means of a shaft I 137 carried by a stand 138 on base member 61. The

shaft carries a gear 140 meshing with a large gear 141 on a shaft 142 extending across the width of the machine and shown as mounted on the base members by means of stands 143, and at the back of the machine, the;

shaft 142 carries a large gear 145 meshing with a ge 146 on shaft 137.

During operation of the machine, the wire 13. Rotation of

arms

132 and 133 will cause roll 130 to move about the axis of

shafts

135 and 137 in a path passing between

rolls

88 and 131, and similarly the path of roll 131 will pass between

rolls

85 and 130, thus varying the extent of wrap of the wire on the stretch rolls and correspondingly increasing or decreasing the tension in the wire depending upon the direction of movement of A motor operated control is accordingly prothe rolls. vided for effecting rotation of the stretch roll arms in response to variations of the tension in the wire in order to maintain substantially constant tension. This control includes a motor 150 driving a worm 151 meshing with a worm gear 152 mounted for free rotation on shaft 142 by means of .a sleeve or hub portion 153. The sleeve 153 I also carries an arm 154 supporting a small air cylinder 1 i 155, and the piston rod 156 from cylinder 155 is positioned to abut an arm 157 projecting axially from the gear 141.

It will thus be apparent that if arm 154 moves in clockwise direction as viewed in Fig. 12, it will act through cylinder 155 and rod 156 to force arm 157 and gear 141 similarly in clockwise direction. This movement will be transmitted through gear 140 to cause counterclockwise movement of the stretch roll arms and tightening of wire 30, and correspondingly movement of arm 154 in counterclockwise direction will cause clockwise movement of the stretch roll arms and resulting decrease in the tension of the wire. To control this movement automatically in such manner as to maintain predetermined tension conditions in the wire, a pressure switch 160 is provided which is connected with the cylinder 155 as indicated diagrammatically in Fig. 12 and which in turn controls a reversing switch 161 for motor 150. The switch 160 is adjustable to respond to a change in the pressure in cylinder 155 above or below a predetermined desired range, and since such change will be causedby increase or decrease of the tension in the wire, transmitted through the contact between piston rod 156 and arm 157, when a a change occurs the motor 150 will be actuated to effect the proper correcting movementof the stretch roll arms; r 2,

30 wraps both of the stretch rolls 130 and 131 as shown in Figs. 1 and 14arr'd 15 show the operation of the stretch roll mechanism for releasing the wire for changing. The journals of 'roll 131 are releasably carried in the

arms

132 and 133 by means of a releasable bearing portion 165 pivoted jonthe armat 166 and provided with a releasable locking bolt 167, which may also be pivoted to the arm as shown for easyhandling. At each side of the machine, a hook 170 is pivoted at 171 to the machine frame and is normally' held in retracted position by a suitable releasable latch mechanism indicated diagrammatically at 172. The hooks 170 are so arranged that when they are released and dropped to their downwardly hanging positions they are in position to receive the journals of roll 131 as the stretch roll arms rotate. Thus in order to release the wire for changing, it is merely necessary to rotate the arms sufficiently to deposit the journals of roll 131 in books 170, release the bearing portions 165, and then continue'tlie movement of the arms until they are approximately horizontalas shown in Fig. 14. In this position of the parts, the roll 131 is supported from the cantilevered portion of the machine frame while the roll 13'0 remains supported on the base structure, and the wire is accordingly free for lateral movement as shown in Fig. 14. Then after the Wire has been removed and replaced, the reverse operation will return the stretch roll mechanism to its operating position shown in Fig. 13.

'This 'ten sioning mechanism for the wire offers outst'andingadvantag'es for convenience of wire changing as well as 'during operation of the paper machine. It is compact anddoes not require changing of the basic machine frame, and at the same time it provides adequate slack for wire changing without requiring a well or other special structure for receiving the slack after the wire has been tightened on the machine. In addition, since it is constructed foradjustrnent through a comparatively wide range, the initial length of the wire is not critical, and the stretch rolls can be operated to compensate for a range of wire lengths without adjustment other than the required movement of these rolls to their positions wherein the desired tension in the wire is established.

Thesu'ction boxes 34 are provided with a cantilevered mounting similar to that for the table roll section in order to facilitate wire changing. Referring to Fig. 16, eachsuction box includes a main enclosure 250 having a supportingend portion 251 at the back of the machine which is rotatably mounted on a shaft 252 carried by a stand 253. Tilting of the suction boxes with the table roll section is simplified'if the shaft 252 is coaxial with the supporting shaft 66 for the table roll section, and shaft 252 is shown as hollow to provide a convenient connection from the several suction boxes to the pump or :other suction source. The hollow shaft 252 may be slotted at 254 ('Fig. 18) to connect with the interior of the supporting portion .251 of each suction box and may be welded or otherwise secured to the boxes to provide suction-tight connections. The open end of hollow shaft 252 is connected with an elbow 255 by a rotatable seal indicated generally at 256, and the closed end of the shaft is shown as rotatably supported at 257 on a suitable end stand 258, and elbow .255forrns a convenient connection to the suction pump (not shown).

The-portions 251 of the suction boxes are tiltable on the axis of the hollow shaft 252, and the mechanism for effecting their tilting movement is shown as similar to that describedfor the table roll section and includes a cylinder 260 mounted on the stand 253, a latch member 262 and an-operating cylinder 263 for the latch similar to the corresponding parts described in connection with Figs. .8 and 9. Atthe front side of the machine, each sucstructure, providing for movement of the frame 267 out of the way when the suction 'box is tilted as described to raise its'frontend for wire changing.

The suction boxes 34 are shown in the drawings as of the construction disclosed in detail in the copending application of 'Farhang Iavid, Serial No. 264,090, filed of even date herewith and assigned to the same assignee as this application, now Patent No. 2,728,273. Each suction boxcontains a plurality of continuously driven endless belts 270 arranged transversely of the direction of wire travel, with the belts forming the supporting surface for the underside of the wire and with the effective suction being applied through slots formed by spacing adjacent belts. As shown in Fig. 17, the belts are supported at the front end of the suction box on sheaves 271 carried by a shaft 272, and the belts are driven continuously at slow speed to present a constantly changing surface to the wire.

If all the belts 270 were driven in the same direction, they would tend to cause sidewise movement of the wire, and in order to provide for driving adjacent belts in opposite directions and thus to counteract such tendency, every other sheave 271 is freely rotatable on shaft 272 while the remaining sheaves are keyed to the shaft as shown. The reverse arrangement is employed at the opposite end of the suction box, with the belts which are driven from shaft 272 being supported on sheaves 273 freely rotatable on the shaft 274 and vice versa. Separate motors are provided for driving the

shafts

272 and 274, one of these motors 275 being shown in Fig. .1 at the front of the machine, and the second motor being sim'ilary mounted at the back of the machine. In order to provide for slow movement of the belts, for example at speeds of the order of one foot per minute, the motors 275 should be of the gearhead type or otherwise provided with suitable speed reduction means. Couplings 276 may be provided as indicated to facilitate individual removal of the suction boxes for repair or replacement.

The suctioncouchroll 35 is also provided with a cantilever type mounting for tilting with the rest of the wire section. Referring to Figs. 19 and 20, the bearing housing 280 at the back end of the couch roll is pivoted at 281 to the upper end of a stand 282, and the journal 283 extends through a further stand 285. A fluid pressure cylinder 286 is mounted at the upper end of stand 285 and operates through a lever 287 pivoted in the stand to depress the journal 283 and thus to rock the couch roll about its pivots 281 and raise its forward end.

The suction connection to the interior of roll 35 provided at the front of the machine, through a stand 290 and a removable section 291 bolted at 292 to the stand 290 and to the end housing 295 of the couch roll, which includes a passage 296 communicating with the suction chamber within the couch roll. For wire changing it is merely necessary to loosen the bolts 292 and remove the section 291, after which the application of pressure in cylinder 286 will cause the roll to tilt as described.

Figs. 21-25 show a modified construction of Fourdrinier machine constructed in accordance with the invention in which special provision is made to cause all the water draining from the web through the table rolls to be discharged at the back of the machine. The truss roof structure which supports the breast roll and the table rolls includes truss members 300 which are shown as constructed of tubing as described in connection with Figs. 5-7, with the top and bottom members in each truss arranged to incline upwardly and to converge towards thefront of the machine so that the sheet metal roof 301 supported thereon is inclined from the front of the machine towards the back throughout its entire lateral extent. Also the front of the roof is flared upwardly at 302, and its side at the back of the machine includes a depending skirt 303 to direct the water draining from the web into the base member 305, which is shown as generally similar in construction to the base member 61 as previously described.

Each of the truss members 300 is secured at the back of the machine to a post 310 pivoted by means of a shaft 311 in ribbed portions 312 of the base.member 305,,

and a tilting assembly indicated generally at 313 corresponds to the similar mechanism described in connection with Figs. 8 and 9. A leg 315 is secured in depending relation to the front of each truss member and is adapted to seat on the upper end of a correspondingly spaced base member 316, with the engaging ends of these parts being shown as formed with tongue and groove portions for increased stability, and the lower ends of the legs 315 are provided with bracing struts317.

The shake rails 320 are supported on the posts 315 and the truss members 300 by flexible mountings 321, which may be of substantially the same construction described in connection with Fig. 10, and a shield 322 surrounds each mounting 321 at the back of the machine as shown. The table roll units indicated generally at 323 are also shown as of the construction previously described, and the mounting 324 for the breast roll 325 is also of substantially the same construction described in connection with Figs. 3 and 4. A shake mechanism 326 is shown as mounted on the base member 305 and connected through rods 327 with the shake rail at the back of the machine. are shown as of essentially the same construction previously described in connection with Figs. 1, l9 and 20. A shield 329 may be provided along the back of the machine to deflect wash water directed across roof 301 from'a wash-up hose at the front of the machine.

The suction box indicated generally at 330 is shown as similar to the suction box construction previously described in connection with Figs. l6-18, but instead of a plurality of boxes each containing a relatively small number of continuous belts, Fig. 2l shows themachine as including only a single box 330 incorporating a corresponding large plurality of continuous belts. The suction box 330 may be mounted at the back of the machine in substantially the same manner as described, and it is preferably'connected with the longitudinal bracing of the truss frame as described in connection with suction boxes 34. At the front of the machine, suction box 330 includes a pair of depending legs 331 fitting corresponding supporting base members 316, and one ofthe legs 331 also cooperates with the rearward portion of the suction boxto support the guide rolls 333. The legs 315 similarly cooperate with the posts 310 to support the guide rolls 335 and 336, while the lower guide roll 337 is supported by fixed stands 338.

The Fourdrinier machine of Fig. 21 .also incorporates a modified construction of wire tensioning mechanism in accordance with the invention. Referring particularly to Figs. 23-25, a shaft 340 is supported on the base of the machine below the guide roll 335, and this shaft extends from front to back of the'machine and supports a pair of elongated curved arms 341 at its opposite ends which are secured thereto for rotation'there'with and in turn carry a stretch roll 343; A- worm gear 345 is free on shaft 340 and is driven by a-worm 346 from a motor 347. The gear'345 includes a hub portion 348 which carries an arm 3 50, and this arm is operatively connected with the adjacent arm 341 through 'apressure cylinderor bellows 355 which corresponds structurally and functionally with the cylinder 155 as described in connection with Fig. 12 and correspondingly controls motor 347.

As shown in Fig. 24, the arms 341 may be swung downwardlyv to a retracted position in which the wire is released for lateral movement between

rolls

335 and 343 for changing, and this arrangement does not require release of any of these parts in any other way. During operation of the machine, the arms 341 normally carry the roll 343 in approximately the position shown in Fig. 25 in which roll 343 cooperates with roll 335 and the adjacent roll 336 to maintain the proper tension in the wire, with the actual operating position at any given time being controlled by the tension in the wire acting through the pressure unit 351 in the same manner as described The suction couch roll 328 and'its' mounting in connection with Fig.;12.". it will also be noted that since in this arrangement the roll 335 which acts as a stretch roll is also one of the guide rolls and is fixed with relation to the main frame of the machine, it may readily be driven as desired in properly synchronized relation with the couch roll to assist in proper driving of the wire, as by a separate synchronized motor or a belt drive from the couch roll as indicated diagrammatically at 360 in Fig. 24. v

It will be apparent that this Fourdrinier machine as shown in Figs. 21-25 provides substantially the same advantages of structure and mode of operation as described in connection with Figs. l20, especially from the standpoint of light and rigid construction eliminating the usual heavy side beams and saveall trays. The machine of Figs. 21 and 22 also oifers the additional advantage that all the water draining from the web as it crosses the table rolls is discharged to the back of the machine, and the front of the machine is maintained free of structural supports and the like other than the simple leg arrangement shown so that the attendants have unobstructed forming wire, the combination of aplurahty of truss tion being especially adapted for cantilevered mounting, without the necessity for jacks or other heavy temporary or permanentstructural supports.

While the forms of apparatus herein described constitute a preferred embodiment of the invention, it is to v be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

i. in a Fourdrinier paper machine having a continuous forming wire, the combination of a plurality of truss members arranged in spaced relation transversely of the direction of wire travel and each including a plurality of structural members connected together to form such truss member, a covering roof supported on the tops of said truss members and cooperating therewith to form a mainframe, a plurality of table rolls for supporting the wire, means on said frame for supporting said table rolls above said roof to cause water to drain from said wire onto 'said roof, said roof being inclined laterally of said machine 'and extending laterally beyond the sides of the wire ,to deflect said water laterally of said machine and outwardly from between the upper and lower runs .of the wire, means including a first shaft forming a horizontal mounting for the back side of said frame, at least one suction box located beyond said table rolls in the path of travel of the wire, means including a second shaft substantially coaxial with said first shaft forming a horizontal pivotal mounting for each said suction box, and means for tilting said frame and said suction box on said mountings to support the opposite side of said frame and said suction box in cantilevered position for changing the wire.

2. In a Fourdrinier paper machine having a continuous members arranged in spaced relation transversely of the direction of wire travel and each including a plurality of structural members connected together to form such truss member, a covering roof supported on the tops of said truss members and cooperating therewith to form a main frame, a plurality of table rolls for supporting the wire, means on said frame for supporting said table rolls above said roof to cause water to drain from said wire onto said roof, said roof being inclined laterally of said ma chine and extending laterally beyond the sides of the wire to deflect said water laterally of said machine and out wardly from between the upper and lower runs of the wire, means including a shaft forming a horizontal mount-.

box'located beyond said table rolls in the path of travel of the. wire, means including a tube forming a horizontal pivotal mounting for each said suction box, said tube having a suction connection between the interior thereof and the'interior of each said suction box mounted thereon, means for connecting said tube to'a source of suction tofapply suction through each said box to the wire pass ing thereover, and means for tilting said frame and said suction box on said mounting means to support the front side of said frame and said suction box in cantilevered position for changing the wire.

3. In a Fourdrinierpaper machine having a continuous forming wire, the combination of a main frame, a plurality of table rolls carried .by said frame for supporting the wire, means including a shaft forming a horizontal mounting for the back side of said frame, at. least one suction box located beyond said frame in the path of travel of the wire, means including a tube forming a horizontal pivotal mounting for each said suction box, said tube having a suction connection between the interior thereof and the interior of each said suction box mounted thereon, means for connecting said tube to a source of suction to apply suction through each said bot; to the wire passing thereover, and means for tilting said frame and said suction box on said mounting means to support the front side of said frame and said suction box in cantilevered position for changing the wire.

4. In a Fourdrinier paper machine, apparatus for supporting the forming wire comprising means forming a base, a plurality of truss members extending transversely of the direction of wire travel and each including a pair of top and bottom structural members secured together in vertically spaced relation by a plurality of bracing members spaced from each other transversely 'of said wire to provide a rigid truss member of essentially open and lightweight construction, reinforcing members extending in the direction of wire travel intermediate the ends. of said truss members and connecting said truss members together in spaced relation lengthwise of said wire'to form a unitary framework, a plurality of spaced posts secured to the ends of said truss members respectively and cooperating with said base to support said framework free of side beams a roof supported on said framework in covering relation therewith, a plurality of table rolls for supporting said wire, means carried by said framework for mounting said table rolls above said roof to cause waterto drain from said wire onto said root, and said roof being inclined laterally of said machine and extending laterally beyond both sides of said who to deflect such water laterally of said machine and outwardly from between the upper and lower runs of said wire. 7

5. In a Fourdrinier paper machine, apparatus for supporting the forming wire comprising means forming a base, a plurality of truss members extending transversely of the direction of wire travel and each including a pair of top and bottom structural members secured together in vertically spaced relation by a plurality of bracing members spaced from each other transversely of said wire to provide a rigid truss member of essentially open and lightweight construction, reinforcing members extending in the direction of wire travel intermediate the ends of said truss members and connecting said truss members together in spaced relation lengthwise of said wire to form a unitary framework, a plurality of spaced posts secured to the ends of said truss members respectively and cooperating with said base to support said framework free of side beams, a roof supported on said framework in covering relation therewith, a plurality of table rolls for supporting said wire, means carried by said framework for mounting said table rolls above said roof to cause water to drain from said wire onto said roof, said roof being inclined laterally of said machine and extending laterally beyond both sides of said wire to deflect such water laterally of said machine and outwardly from between the upper and lower runs of said wire, and means formingcoaxial pivotal mountings for saidposts on said base along one side of said framework for tilting of said framework to a cantilevered position for changing said wire. H

6. In a Fourdrinierpaper machine, apparatus for supporting the forming wire comprising means forming a base, a plurality of truss members extending transversely of the direction of wire travel and each including a pair of top and bottom structural members secured togetherin vertically spaced relation by a plurality of bracing members spaced from each other transversely of said wire to provide a rigid truss member of essentially open and lightweight construction, reinforcing members extending in the direction of wire travel intermediate the ends of said truss members and connecting said truss members together in spaced relation lengthwise of said wire to form a unitary framework, a plurality of spaced posts secured .to the ends of said truss members respectively and cooperating withsaid base to support said framework free of side beams, a roof supported on said framework in covering relation therewith, a plurality of table rolls for supporting said wire, a. pair of shake rails extending longitudinally of said framework adjacent opposite ends of said truss members, flexible means securing said rails to saidframework, brackets on said rails supporting said table 'rolls above said roof to cause water todrairrfrom said wire onto said roof, and said roof being inclined laterally of said machine and extending laterally beyond both sides of said wire to deflect such water laterally of said machine and outwardly from between the upper and lower runs of said wire.

References Cited in the file of this patent UNITED STATES PATENTS