US3378435A - Felt and fabric press type papermaking machine - Google Patents

Description

J. LOYND April 16, 1968 FELT AND FABRIC PRESS TYPE PAPERMAKING MACHINE 5 Sheets-Sheet 1 Filed Feb. 19, 1965 April 16, 1968 J. LOYND 3,378,435

FELT AND FABRIC PRESS TYPE PAPERMAKING MACHINE Filed Feb. 19, 1965 5 Sheets-Sheet April 16, 1968 .1. LOYND 3,37

FELT AND FABRIC PRESS TYPE] PAPERMAKING MACHINE Filed Feb. 19, 1965 5 Sheets-Sheet 3 J. LOYND April 16, 1968 FELT AND FABRIC PRESS TYPE PAPERMAKING MACHINE 5 Sheets-Sheet 4 Filed Feb. 19, 1965 April 16, 1968 J. LOYND 3,378,435

FELT AND FABRIC PRESS TYPE PAPERMAKING MACHINE Filed Feb. 19, 1965 5 Sheets-Sheet Q H 9&

m ca aa o VHQ/ 3o/ w 3? 2 NH 2 United States Patent 3,378,435 FELT AND FABRIC PRESS TYPE PAPERMAKING MACHINE James Loynd, Neenah, Wis., assignor to Kimberly-Clark Corporation, Neenah, Wis., a Corporation of Delaware Filed Feb. 19, 1965, Ser. No. 433,934 7 Claims. (Cl. 162-273) ABSTRACT OF THE DISCLOSURE A papermaking machine including a forming fabric supported by a set of rolls and a felt supported by a second set of rolls including a forming roll around which both the felt and fabric travel and a carriage for mounting the set of rolls for the forming fabric so as to allow the forming fabric to be moved away from and disassociated from the felt.

My invention relates to papermaking machines and more particularly to such machines of the type in which substantial dewaterin-g of the stock in forming the web is accomplished by applying tension on the forming fabric or wire carrying the paper web to be dewatered as the forming fabric passes about a curved surface.

It has previously been proposed in the application of Charles A. Lee et a1, Ser. No. 161,058, filed Dec. 21, 1961, now Patent No. 3,224,928 and in the patent application of John B. Graham, Ser. No. 419,765, filed Dec. 21, 1964, that a paper web may be formed by directing a paper stock slurry between two rolls which carry a forming wire. One of the rolls, which may be termed a forming or slice roll, also carries a top felt that is disposed between the wire and the peripheral surface of the roll and the arrangement is such that the paper web being formed lies between the wire and felt on this roll; and the web is dewatered primarily by the force of the wire bearing on the latter roll and on the web and felt which is due to the tension of the 'wire around the latter roll. The felt carries the newly formed web on its lower surface for subsequent additional dewatering and drying, and the machines thus are particularly satisfactory for lightweight webs, since these webs do not have sufficient weight to break their bonds with the under surface of the felt and fall off the felt.

It is an object of the present invention to provide an improved machine of this general type which is so arranged that the newly formed web is carried on the top surface of the felt instead of the under felt surface, so that the machine may be particularly advantageous for use with heavier webs.

It is also an object of the invention to provide an improved machine of this general type having a movable section, particularly a movable wire section, so that the wire section may be separated from the remainder of the machine for easy replacementof the forming wire.

In brief, preferred forms of the invention include movable carriages on which wire supporting rolls are rotatably mounted. A wire is disposed about the supporting rolls, and the supporting rolls include a roll pair embracing a separately mounted forming roll, so that the wire travels about the exterior surface of the forming roll. Except for the forming roll, the wire supporting rolls are all disposed within the loop of the wire, and the carriage on which the latter rolls are mounted may be moved away from the forming roll with the wire being disposed in the form of a loose loop about the rolls mounted on the carriage. The Wire may thus be easily replaced on the Wire supporting rolls on the carriage after such movement of the wire section away from the remainder of the machine has occurred. In one form of the invention, a paper stock inlet discharges beneath a forming roll and between the top felt carried by the forming roll and the overlying portion of the forming wire. The web is initially dewatered about the forming roll and leaves the roll on an upper surface of the felt coming off the upper peripheral surface of the forming roll, so that this embodiment of the invention' is particularly advantageous for heavier webs.

The invention consists of the novel constructions, arrangements and devices to be hereinafter described and claimed for carrying out the above stated objects, and such other objects, as Will be apparent from the following description of preferred forms of the invention, illustrated with reference to the accompanying drawings, wherein:

FIG. 1 is a diagrammatic side elevational view of a papermaking machine embodying principles of the invention;

FIG. 2 is a fragmentary side elevational view of the machine, particularly the wet end portion of the machine;

FIG. 3 is a sectional view taken on line 3-3 of FIG. 2;

FIG. 4 is a side elevational view, partly schematic, of the wet end portion of a papermaking machine embodying features of the invention; and,

FIG. 5 is a schematic side elevational view of the remainder of the machine illustrated in FIG. 4.

Like characters of reference designate like parts in the several views.

Referring now to the drawings, the illustrated papermaking machine may be seen to comprise an endless Fourdrinier forming fabric or wire 15. The wire is of the conventional type having interstices therethrough for draining a slurry of paper stock deposited thereon for forming a paper web. The wire 15 is supported by means of rolls 16, 17, 18, 19, 20, 21 and 22. All of these rolls may be solid rolls, and all of them, except roll 22, are within the loop of wire 15. The rolls 16 to 21 are supported by means of side frame members 23 and 24, and the roll 22 is supported by means of a pair of standards 25. The standards 25 are disposed on a base or floor 26, and the side frame members 23 and 24 are supported on the floor 26 through intermediate supporting mechanism, hereinafter described, which allows movement of the frame members 23 and 24 together with the rolls 16 to 21 so that these parts basically make up a movable wire section or carriage K. The roll 22 may be termed a forming or slice roll; the roll 16 may be termed a breast roll; theroll 17 is a guide roll; the rolls 18 and 20 are simple turning rolls; the roll 19 is a stretch roll; and the roll 21 may be termed a transfer roll.

The rolls 16, 18, 20 and 21 are respectively supported on fixed axes with respect to the frame members 23 and 24 by means of bearings 27, 28, 29 and 30 fixed to the frame members 23 and 24. The roll 17 is supported on the members 23 and 24 by means of bearing assemblies 31, one of which includes adjustable mechanism for moving the respective end of the roll 17 for the purpose of changing the path of the wire 15 about its supporting rolls as desired. A hand wheel 32 is provided to actuate the adjusting mechanism. The roll 19 is disposed in bearings 33 which are fixed in the ends of arms 34, and the arms 34 are swingably disposed about shafts 35 which are carried by the side frame members 23 and 24. An arm 36 is located adjacent to each of the arms 34, is swingably disposed on the associated shaft 35, and is connected with the adjacent arm 34 by means of a yieldable connecting device 37 of conventional construction. A jack screw 38 is connected to the end of each of the arms 36 and extends through a motor driven screw device 39 for swinging the arms 36 and for thereby swinging the arms 34 for the purpose of tightening or loosening the wire about its supporting rolls.

Each of the side frame members 23 and 24 includes trunnions 40, and relatively small diameter wheels 41 are mounted between the trunnions by means of beaiings 42. Each of the side frame members 23 and 24 is supported by means of four wheels 41, and the wheels are disposed or rails 43 laid on the floor 26. A pair of the wheels 41 on the two opposite side frame members 23 and 24 are drivingly connected together by means of a shaft 44, and a motor mechanism 45 of any suitable conventional type is provided for driving the shaft 44 and thereby driving these wheels 41 so as to cause the frame assembly, including the side frame members 23 and 24, to move across the floor 26.

The frame member 23 includes a pair of blocks 46 and 47, each of which is disposed between plane faced surfaces 48 and 49. Toggle bolts 50 swingably mounted at their lower ends on the member 23 extend through slots 51 in flanges 52 carried by the member 23 for the purpose of fixing the blocks 46 and 47 between the plane faced surfaces 48 and 49. A pair of toggle bolts 53 are swingably mounted in the floor 26, and one of these toggle bolts is adapted to extend through a slot 54 in a flange 55 provided in each of the side frame members 23 and 24 for the purpose of locking the carriage K along the rails 43.

A pair of cantilever beams 56 and 57 extend through the side frame members 23 and 24 and are fixed with respect to the side frame members. The beams are each adapted to enter into the slot 58 of a hook 59 which is fixed on a standard 60 that in turn is fixed on the floor 26. The standards 60 are so disposed that the cantilever beams 56 and 57 enter the slots 58 when the rolls 16 and 21 have been substantially separated from the roll 22 and the frame assembly, including the members 23 and 24, is at the limit of its movement to the right as seen in FIG. 2 along the rails 43.

A white water saveall pan 61 is disposed between the side frame members 23 and 24 and is fixed with respect to each of these members 23 and 24. This pan 61 is connected through a large diameter conduit 62 with the pulp supply system of the machine. The conduit 62 is held together by means of tie bolts 63 along a flange 64, and these bolts may be released so as to allow the upper portions of the conduit 62 to move along with the frame members 23 and 24 as the beams 56 and 57 are moved into the slots 58 of the hooks 59.

As will be hereinafter described, the blocks 46 may be removed for stringing a replacement wire 15 over the wire supporting rolls, and a pair of hydraulic jacks 65 are provided for supporting the carriage K for this operation. Each of the jacks 65 is supported on the floor 26 and engages in a socket member 66 fixed on the lower side of one of the cantilever beams 56 and 57.

The roll 22 is rotatably supported by means of a pair of bearings 67, each of which is disposed on a bracket 68 that in turn is fixed to the side of one of the standards 25. A support block 69 is disposed between each of the bearings 67 and the associated bracket 68, and toggle bolts 70 are swingably mounted on each of the brackets 68 and are adapted to enter into slots in the side of the associated bearing 67 for the purpose of removably fixing the bearing 67 with respect to the associated block 69 and bracket 68.

A paper stock inlet 71 is mounted on the standards 25. The inlet 71 comprises a stock conduit 72 tapering from one end to the other so as to have a large diameter inlet and a relatively small diameter outlet 72a. The inlet 71 comprises a pair of parallel plates 73 which are slightly spaced to have a narrow stock discharge slot between them, the slot being connected with the interior of the conduit 72 by means of a perforate flow distributor 74.

A pair of arms 75 are fixed with respect to the inlet 71 and the standards 25 and each of these arms over- 4 lies one of the bearings 67 for the roll 22, as shown in FIG. 2.

As will be observed, the wire 15 extends in looped form about the outer surfaces of the rolls 16 to 21, and the roll 22 is positioned between the rolls 16 and 21, which are positioned one above the other, so as to cause the wire to have a concavity in it as it passes over roll 22. Any of the rolls 16 to 22 may be driven by any suitable driving mechanism (not shown) for thepurpose of driving the wire in the direction indicated by the arrow A. The roll 22 is spaced by less than an inch from each of the rolls 16 and 21, and thee is a portion of the wire 15 that bridges from the roll 16 to the roll 22. The plates 73 extend between the rolls 16 and 22 and the inlet 71 thus is adapted to discharge paper stock on to the portion of the wire 15 bridging the rolls 16 and 22.

A top felt 76 also extends around the roll 22 and for a geater arc than that for the wire 15 and the felt underlies the wire 15 for the portion of the wire supported by the roll 22. The paper stock thus is discharged from the inlet 71 between the wire 15 and the felt 76, and as will appear from a following, more detailed description of the operation of the machine, a paper web is formed between the portions of the wire 15 and felt 76 supported by the roll 22, and the paper web follows the felt 76 for subsequent dewatering and drying of the web, with the wire 15 separating from the felt 76 and web between the rolls 21 and 22.

The web dewatering and drying apparatus may utilize more or less conventional components, such as those illustrated in FIG. 1. In this figure, the felt 76 is illustrated as being supported by rolls 77, 78, 79, 80, 81, 82, 83, 84 and 85. The roll 78 constitutes one roll of a wringer 86, the other roll of the wringer being a roll 87, and the roll 82 is a pressure roll having a pressure nip with a steam heated Yankee drier 88. The roll constitutes one roll of a main press 89, the other roll of which is the roll and the roll 84 constitutes one roll of a second main press 91, the other roll of which is the roll 92. A bottom felt 93 passes through the nip between the rolls 85 and 90 along with the felt 76, and a bottom felt 94 passes through the nip between the rolls 84 and 92 along with the felt 76. The bottom felts 93 and 94 are suitably supported by appropriate rolls disposed in conventional arrangements.

In operation, a slurry of paper stock which is a suspension of paper fibers in water, is supplied to the conduit 72 of the inlet 71; and the suspension passes through the flow distributor 74 and through the slot defined by the parallel plates 73. The stock discharges from the ends of the plates 73, after having been given a fine scale turbulence by these plates, into the gap between the rolls 16 and 22 and onto the portion of the Wire 15 bridging the rolls 16 and 22.

The wire 15 moves in the direction A about the rolls 16 to 22, passing downwardly over the roll 22; and the felt moves in the direction B about the rolls 22 and 77 to 85 and also passes downwardly over the roll 22. The felt 76 has a greater are of contact on the forming roll 22 than does the wire 15 and first contacts and leaves the roll 22 along lines 95 and 96, respectively, extendmg longitudinally of the roll; and the Wire 15 first contacts and leaves the roll 22 on similar lines 97 and 98, respectively. The paper stock that is discharged between the rolls 16 and 22 enters between the felt 76 and wire 15, between the lines 95 and 97, and travels around the roll 22 in a sandwich between the wire 15 and felt 76, being dewatered during this travel.

The dewatering of the paper stock being formed into a web about the periphery of the forming roll 22 is due primarily to the tension that is maintained on the wire 15 due to the action of the devices 38 in swinging the roll 19. The roll 22 is disposed between the wire supporting rolls 16 and 21, which are located one above the other; and the roll 22 has its wire carrying surface protruding beyond (to the right of, as seen in FIGS. 1 and 2) a line 99 tangent toboth of the rolls 16 and 21 on the peripheral surfaces of these rolls in contact with the wire 15. The wire thus wraps the periphery of the roll 22 for an arc of about 140, so that the tension maintained on the wire 15 causes the wire to bear forcefully against the surface of the roll 22 for this are, with the felt 76 lying between the wire 15 and the roll surface. Thus, as the paper web being formed on the surface of the roll 22 passes in a wire-web-felt sandwich about the surface of the roll 22, the paper web being formed is squeezed due to the force with which the wire 15 bears on the felt and roll, and the paper web is dewatered. Centrifugal force also helps in this dewatering action, since the roll 22 is rapidly rotating as the wire passes around it; and centrifugal force, in particular, is effective for throwing water from the web, which enters the interstices of the wire 15, outwardly from the wire. The saveall pan 61 is supported by and between the side frame members 23 and 24, and the pan 61 is so located that water jetting through the wire 15 directly from the plates 73, as well as the Water which is squeezed from the paper web as it passes about the roll 22, passes into the saveall pan 61. The conduit 62 conducts this white water from the saveall pan 61 and returns it to the stock supply system for the inlet 71.

The wire 15 leaves the surface of the roll 22 on the line 98 and passes to the roll 21; and, subsequently during the rotation of the roll 22, the felt 76. leaves the roll 22 on the line 96 and passes in a generally horizontal direction to the press 89. The formed paper web separates from the wire 15 along the line 98 and follows the felt 76, being carried on the lower surface of the felt, due to the fact that the felt-76 is more dense than is the wire 15. The felt 76 passes through the presses 89 and 91, around the roll 83 to the pressure roll 82; and the paper web remains on the lower surface of the felt during this travel and transfers at the roll 82 onto the external surface of the drier 38. The presses 8-9 and 91 function to additionally 'dewater the felt and web by squeezing the felt and web, and the bottom felts 93 and 94 assist in this dewatering action and carry away water squeezed from the top felt 76 and the paper web within the presses 8-9 and 91. The wringer 86 functions to dewatcr the felt 76 after the web has been transferred onto the drum 88 at the nip between the pressure roll 82 and drum.

-It will be noticed that the forming roll 22 is mounted on the fixed standards which are located on one side of the roll 22 and that the wire 15 is supported by the frame members 23 and 24 of the carriage K located on the other side of the forming roll 22. In order to disengage the wire 15 from the forming roll 22, as for a wire change, it is only necessary to break the conduit 62 at the flange 64 with respect to the remainder of the conduit 62 and energize the motor mechanism so as to drive two of the wheels 41 to cause the carriage K carrying the wire 15 to move away from the roll 22 and the standards 25 (to the right as seen in FIGS. 1 and 2). This movement of the wire 15 away from the forming roll 22 is without disturbing the inlet 71 in any way, inasmuch as the inlet 71 is also mounted on the standards 25. When this movement of the wire section has been completed, the ends of the cantilever beams 56 and 57 have entered into the slots 58 of the stationary hooks 59, thus supporting the ends of the beams 56 and 57, and the jacks 65 are now located beneath the socket members 66. The jacks 65 are then raised so as to support the carriage K through the cantilever beams and 57; the toggle bolts 50 are released; and the spacer blocks 46 and 47 are removed from between the parallel surfaces 48 and 49. The wire 15 extends loosely about its supporting rolls 16 to 21 and the wire may then be removed from the frame, including the members 23 and 24, sim ly by moving it off of these rolls and through the spaces between the parallel surfaces 48 and 49. A new wire 15 may then be moved onto the rolls 16 to 21. For convenience sake, the new wire may be supported by a wire stretcher (not shown) holding the wire generally in the looped shape it needs in order to pass over the rolls 16 to 21; and the new wire is slid from the stretcher through the gaps between the parellel surfaces 48 and 49 onto the external surfaces of the rolls 16 to 21.

After the new wire is in place on the rolls 16 to 21, it may be tightened, with the carriage K remaining in its detached position from the roll 22 and standards 25, by actuating the jack screws 38 by means of the motor driven screw devices 3 9 in order to swing the arms 34 and roll 19 outwardly. One of the rolls 16 to 21 may then be driven so as to cause the wire 15 to move about the rolls 16 to 21 to check the new wire to be sure that it is correctly centered on these rolls and remains in a desired path about them. As previously mentioned, the roll 17 may be adjusted by means of the hand wheel 32 for the purpose of changing the pa h of the wire 15 about the rolis 16 to 21 as desired. After the wire has been properly installed about its supporting rolls, the carriage K may be moved back into operative position with respect to the roll 22, as illustrated in FIGS. 1 and 2.

The felt 76 may also be changed when the carriage K is in its position separated from the forming roll 22 and inlet 71. A used felt 76 is removed from, and a new felt 76 is replaced in, the presses =89 and 91 and the wringer 86, as well as from and into the nip between the pressure roll 82 and drier 88 by conventional methods. In order to remove a felt 76 from about the forming roll 22, the toggle bolts are first released and the bearings 67 are raised slightly so that the blocks 69 may be withdrawn from position. The brackets prevent the roll 22 from being raised more than a small amount determined by the slight spacing between the brackets 75 and the bearings 67 so that the roll 22 cannot contact the lower plate 73 of the inlet 71 and damage the lower plate 73. With the roll 22 in raised position, the used felt is then moved from beneath the roll 22 through the gap between a bearing 67 and a bracket 68. The used felt is removed rom about the top of the roll 22 by lowering the roll 22 with the blocks 69 remaining out of position, and the felt is then moved outwardly from the roll 22 between one of the brackets 75 and the adjacent bearing 67. A new felt 76 may be installed in the same manner, except that the new felt is moved onto the roll 22 instead of being taken from it. The new felt may first be moved underneath the roll 22 by moving it between one of the brackets 68 and the adjacent bearing 67, and then the felt may be passed between one of the brackets '75 and the adjacent bearing 67 after the roll 22 has been lowered so as to bring the felt onto the upper peripheral surface of the roll 22.

The embodiment of the invention illustrated in FIGS. 4 and 5 comprises a 'Fourdrinier wire suported by rolls 101, 102, 103, 104-, 105 and 106. The rolls 102 to 106 are carried by a frame 107 having a plurality of wheels 108 rotatably mounted thereon by means of trunnions 109. The wheels 108 may be disposed on rails which are similar to the rails 43 shown in the first embodiment.

The roll 102, which may be termed a breast roll, is rotatably disposed in bearings 110 which are fixed to the frame 107. The roll 103 is rotatably disposed in the ends of arms 111 which are swingably mounted with respect to the frame 107, and a screw 112 is connected to the end of each of the arm-s 111 and is actuated by a motor driven screw device 113 for moving the roll 103 outwardly with respect to the frame 107. The roll 104 is similarly swingably mounted on the frame 107 by means of arms 114. A jack screw 115 is connected to the end of each of the arms 114, and each jack screw 115 is actuated by a motor driven screw device 116.

The roll 105 is the guide roll for the Fourdrinier wire 100 and is rotatably mounted in bearings 117 carried by the frame 107. A shifting device 118 is connected with one of 7 the bearings 117 and functions to shift one end of the roll 105 so that the path of the wire 100 may be shifted as desired or necessary.

The roll 106, which may be termed a transfer or pickup roll, is rotatably mounted in bearings 119, each of which is carried on an arm 120 swingably mounted with respect to the frame 107. An adjusting screw device 121 of conventional design may be provided for swinging each of the arms 120 and holding it in a selected position.

The roll 101, which may be termed a forming roll, is mounted by means of bearings 122 on standards 123. The rolls 102 and 101 are disposed to have a small gap between them, which may be less than an inch, and a paper stock inlet 124 is provided for directing stock between the rolls 101 and 102.

The stock inlet 124 comprises a pair of spaced parallel plates 125, which are adapted to carry stock between them and from which stock is discharged, a manifold 126 connected with the passage between the plates 125, and a pair of headers 127 and 128 which are adapted to be supplied with stock and which are connected to the manifold 126 for supplying stock thereto. The inlet 124 is quite similar to the inlet 71, except for details, since each of these inlets includes a pair of closely spaced parallel plates between which stock is discharged; and, if desired, an inlet of the same type as the inlet 71 could be substituted for the inlet 124 in the embodiment illustrated in FIGS. 4 and 5, as is apparent.

A top felt 129 also extends around the roll 101 and underlies the wire 100. As in the first embodiment, the stock inlet discharges stock between the felt and wire and formation of the paper web takes place between the felt and wire on the surface of the forming roll. The felt 129, in addition to extending around the roll 101, also extends around rolls 130, 131, 132, 133, 134, 135 .and 136. The rolls 130 to 136 may be suitably supported in any conventional manner, and the rolls 133 and 134 may be respectively guide and stretch rolls for the felt. The roll 135 may be one roll of a wringer 137, the other roll of which is a roll 138 having a nip with the roll 135. The roll 136 is one roll of a transfer press 139, the other roll in which is a roll 140 having a nip with the roll 136.

A second felt 141 extends through the nip between the rolls 136 and 140 along with the felt 129, and the paper sheet transfers to the felt 141 in the transfer press 139. The felt 141 extends around a plurality of rolls including the roll 140 and rolls 142, 143, 144, 145, 146, 147, 148 and 149. The rolls 147 and 148 may respectively be stretch and guide rolls for the felt 141 and the roll 144 is a pressure roll with respect to a steam heated Yankee drier 150. The roll 142 constitutes one roll of a press 151, the other roll of which is the roll 152 having a nip with the roll 142. A bottom felt 153, along with the felt 141, passes through the nip between the rolls 142 and 152, and the bottom felt 153 may be supported in looped form by a plurality of rolls in accordance with conventional practice.

The second embodiment of the invention shown in FIGS. 4 and operates much like the first described embodiment. Paper stock is discharged from the inlet 124 between the rolls 101 and 102, and the paper web forms and is dewatered around the surface of the forming roll 101 in a sandwich between the wire 100 and the top felt 129. Dewatering of the paper web being formed takes place primarily due to the tension being maintained on the wire 100 because of the action of the stretch rolls 103 and 104 and screw devices 113 and 116, although centrifugal force is also effective in this respect. The wire 100 leaves the surface of the forming roll 101 as the wire passes from the roll 101 to the roll 106 at the upper surface of the roll 101. In this connection, it may be mentioned that prerefably there is a slight gap between the rolls 101 and 106, and the adjusting screw device 121 may be effective for adjusting the position of the roll 106. As will be observed, the wire travels about the rolls 101to 106 in the direction indicated by the arrows C, and the direction of the wire about the forming roll 101 is in the upward direction, which is just opposite to the downward direction that the wire 15 takes about the forming roll 22 in the first described embodiment.

The felt 129 moves in the direction indicated by the arrows D and passes through the press 139, the wringer 137 and around the rolls 101 and 131 to 134. The wire separates from the felt 129 on the upper surface of the forming roll 101, and the formed web continues along with the felt 129 from the roll 101 and is disposed on the upper surface of the felt. The formed paper web travels with the felt 129 through the press 139, and in the press the paper web transfers from the felt 129 onto the felt 141. The press 139 helps in dewatering the paper web, and the wringer 137 functions to dewater the felt 129 after it leaves the press 139. The felt 141 is more dense than the felt 129; and, therefore, the web makes this felt to felt transfer; and suitable suction devices may also be provided in the roll 140, if desired, in order to effect this transfer.

The felt 141 travels in the direction E about the rolls and 142 to 149; and the paper web travels along with the felt 141 on its lower surface, through the press 151, and into the nip between the pressure roll 144 and the drier 150. The paper web transfers in the nip between the pressure roll 144 and the drier 150 onto the surface of the drier for subsequent drying. The press 151 with the bottom felt 153 functions to additionally dewater the paper web prior to the nip of the pressure roll 144 and drier 150.

This embodiment of the invention includes the frame 107 of the wire section supported by the wheels 108 by means of which the wire 100 may be separated from the forming roll 101 simply by moving the frame 107 away from the forming roll, the felt 129 and the inlet 124. The wire 100 may be replaced in substantially the same manner 0n the frame 107 and its wire supporting rolls as is described in connection with the wire 15 and the supporting rolls for the wire 15.

The second embodiment of the invention shown in FIGS. 4 and 5, in which the inlet 124 directs stock beneath the forming roll 101 rather than above the forming roll, provides a sheet on the upper surface of the felt 129 leaving the forming roll rather than a sheet on the lower surface of this felt. Since the paper web is on the top surface of the felt 129, this embodiment of the invention is particularly advantageous for use in connection with the heavier sheets, such as newsprint, which may have a basis weight, for example, of about 30 pounds per 3,000 square feet. This basis weight may be compared with tissue for which the first embodiment is particularly adapted, and which, for example, may have a basis weight of about 8 pounds per 3,000 square feet. The paper web, subsequent to its initial dewatering about the forming roll 101, is relatively weak; and therefore, a heavier sheet may well be supported more than a lighter sheet, and preferably through the first press 139 for the web.

It may be mentioned in connection with both embodiments of the invention that the forming rolls 22 and 101 may be suction rolls instead of solid rolls, if desired, and by suitably positioning the suction area within such a suction roll, the web being formed about the roll may be sucked off the wire onto the felt, thus utilizing a so-called vacuum pickup. The diameters of the rolls 22 and 101 may well be varied within wide limits. The rolls 22 and 101 may, for example, be about 3 feet in diameter, but they may also be substantially enlarged to about 6 feet in diameter, for example. In view of the fact that the dewatering action on the forming rolls 22 and 101 is dependent to some extent on the time during which the sheet being formed is subjected to the force due to the associated wire; particularly in connection with higher speeds and thicker webs, it may be desirable to utilize greater diameter forming rolls 22 and 101.

Both embodiments of the invention advantageously provide thorough dewatering of the webs being formed in the sandwiches between wire and felt as they pass around the forming rolls 22 and 101, due particularly to the tension kept on the wires. In each case, the wire is withdrawn from the surface of the forming roll, leaving the web and felt remaining on the roll for a slight additional distance; and there is thus no necessity for a separate couch roll. The felt, as it carries the web away from the forming roll, is in a substantially planar form and is not bent reversely from its condition about the forming "roll, which could cause undue disturbances of the newly formed web. The inlets 71 and 124, the forming rolls 22 and 101, and the wires 15 and 100 are so disposed that none of the water, which is drained from the webs being formed about the forming rolls, is drawn back onto the newly formed sheets causing possible damage.

In both embodiments, the wire section is all on one side of the forming roll (rolls 22 and 101). Each wire section is movably mounted, and it may thus-be moved as a unit away from the forming roll and the felt carried by the forming roll without disturbing the stock discharge inlet (inlets 71 and 124). The wires in the wire sections may thus be easily replaced, and the new wires may be preliminarily placed on appropriate stretchers in looped condition, so that the new wires may simply be slide into position on the supporting rolls of the wire sections after the wire sections have been retracted from their operating positions. Also, the independently movable wire sections allow the new wires to be run on their supporting rolls for inspection and trial purposes before the wire sections are moved back again into operative positions with respect to the remainder of the machines. In this connection, it should be noted that all of the supporting rolls for the wires in the movable wire sections are inside the loops of the wires.

I wish it to be understood that the invention is not to be limited to the specific constructions, arrangements and devices shown and described, except only insofar as the claims may be so limited, as it will be understood to those skilled in the art that changes may be made without departing from the principles of the invention.

What is claimed is:

1. In a paper web forming machine, the combination of an endless paper web forming fabric having interstices therethrough for draining paper stock deposited thereon, a set of forming fabric carrying rolls about which said fabric is movably disposed, an endless felt fabric, a set of felt fabric carrying rolls about which said felt fabric is movably disposed and including a forming roll so positioned that said forming fabric passes around the roll and overlies said felt fabric on the roll, a paper stock inlet positioned to direct paper stock between said fabrics as they come together in passing around said forming roll so as to form a paper web between said fabrics which subsequently follows said felt fabric, a carriage for one of said sets of rolls, and means for movably mounting said carriage so that the carriage with the set of rolls carried thereby together with the fabric carried by the set of rolls may be moved away from the other fabric so as to disassociate the two fabrics passing around said forming roll.

2. In a paper Web forming machine, the combination of an endless paper web forming fabric having interstices therethrough for draining paper stock deposited thereon, a plurality of fabric carrying rolls about which said fabric is movably disposed, a carriage carrying said rolls, an endless felt, a plurality of felt carrying rolls about which said felt is movably disposed and including a forming roll so positioned that said forming fabric passes around the roll and overlies said felt on the roll, a paper stock inlet positioned to direct paper stock between said fabric and felt as they come together in; passing around said forming roll so as to form a paper web between said fabric and felt which subsequently follows said felt, and means for movably mounting said carriage so that the carriage may be moved away from said felt and said forming roll with the forming fabric remaining positioned about said forming fabric carrying rolls.

3. In a paper web forming machine, the combination of an endless paper web forming fabric having interstices therethrough for draining paper stock deposited thereon, a plurality of fabric carrying rolls about which said fabric is movably disposed and including a pair of rolls disposed oppositely with respect to each other and spaced from each other, a carriage carrying said rolls, an endless felt, a plurality of felt carrying rolls about which said felt is movably disposed and including a forming roll positioned between said two last named fabric carrying rolls so that said fabric passes around the forming roll and overlies the felt on the forming roll, a paper stock inlet positioned to direct paper stock between said fabric and felt as they come together in passing around said forming roll so as to form a paper web between the fabric and felt which subsequently follows said felt, and means for movably mounting said carriage so that the carriage together with said forming fabric carried thereby may be moved away from said felt and said forming roll. I

4. In a paper web forming machine, the combination of an endless paper web forming fabric having interstices therethrough for draining paper stock deposited thereon, a plurality of fabric carrying rolls about which said fabric is movably disposed and including a pair of spaced rolls mounted substantially one above the other, a carriage carrying said rolls, an endless felt, a plurality of felt carrying rolls about which said felt is movably disposed and including a forming roll positioned between said two spaced fabric carrying rolls whereby said fabric passes around the forming roll and overlies said felt on the forming roll, a paper'stock inlet positioned to direct stock between said fabric and felt as they come together in passing around said forming roll so as to form a paper web between said fabric and felt which subsequently follows the felt, and a plurality of supporting wheels for said carriage for allowing the carriage to be horizontally moved so as to move said fabric off of said forming roll and disassoeiate the fabric from the felt about the forming roll.

5. In a paper web forming machine, the combination of an endless paper web forming fabric having interstices therethrough for draining paper stock deposited thereon, a plurality of fabric carrying rolls about which said fabric is movably disposedand including a pair of rolls which are spaced and are located one above the other, a carriage carrying said rolls, an endless felt, a plurality of felt carrying rolls about which said felt is movably disposed and including a forming roll, standards for pcsitioning said forming roll on a stationary axis between said two spaced fabric carrying rolls so that said fabric passes around the forming roll and overlies said felt on the forming roll, a paper stock inlet positioned to direct stock between the uppermost of said spaced fabric carrying rolls and said forming roll so that a paper web is formed between said fabric and felt as they pass around said forming roll and which subsequently follows said felt, and means for movably mounting said carriage for horizontal movement so that the carriage together with said spaced rolls and the fabric between said spaced rolls may be moved away from said forming roll to disassociate the fabric and felt as they pass around the forming roll.

6. In a paper web forming machine, the combination of an endless paper web forming fabric having interstices therethrough for draining paper stock deposited thereon, a plurality of fabric carrying rolls about which said fabric is movably disposed and including a pair of rolls which are spaced and are located one above the other, a carriage carrying said rolls, an endless felt, a plurality of felt carrying rolls about which said felt is movably disposed and including a forming roll, standards for posi tioning said forming roll on a stationary axis between said two spaced fabric carrying rolls so that said fabric passes around the forming roll and overlies said felt on the forming roll, a paper stock inlet positioned to direct paper stock between the lowermost of said two spaced fabric carrying rolls and said forming roll so that a paper web is formed between the felt and fabric as they pass around said forming roll which subsequently follows said felt, and means for movably mounting said carriage for horizontal movement so that said two spaced fabric carrying rolls together with the fabric between the latter two rolls may be moved away from said forming rolls to thereby disassociate said fabric from the felt passing around the forming roll.

7. In a paper web forming machine, the combination of an endless paper web forming fabric having interstices therethrough for draining paper stock deposited thereon, a set of forming fabric carrying rolls about which said fabric is movably disposed, a second endless fabric, a set of carrying rolls for said second fabric about which the 12 second fabric is mo-vably disposed and including a forming roll so positioned that said first named fabric passes around the forming roll and overlies said second fabric on the forming roll, a paper stock inlet positioned to direct paper stock between said fabrics as they come together in passing around said forming roll so as to form a paper web between said fabrics, a carriage for one of said sets of rolls, and means for movably mounting said carriage so that the carriage with the set of rolls carried thereby together with the fabric carried by the set of rolls may be moved away from the other fabric so as to disassociate the two fabrics passing around said forming roll.

References Cited UNITED STATES PATENTS 3,236,724 2/1966 Wahlstrom 162-317 S. LEON BASHORE, Primary Examiner.

DONALL H. SYLVESTER, Examiner.

A. HODGSON, Assistant Examiner.

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