US2830503A

US2830503A - Paper machinery

Info

Publication number: US2830503A
Application number: US462093A
Authority: US
Inventors: Jr Joseph Baxter
Original assignee: Black Clawson Co
Current assignee: Black Clawson Co
Priority date: 1954-10-13
Filing date: 1954-10-13
Publication date: 1958-04-15
Anticipated expiration: 1975-04-15

Description

April 15,- 1958 Y J. BAXTER, JR 2,830,503

PAPER MACHINERY Filed Oct. 15,1954 e Sheets-Sheet 1 INVENTdR. JOSEPH BAXTER, JR.

Q W ATTORNEYS April 15, 1958 J. BAXTER, JR

PAPER MACHINERY 6 Sheets-Sheet 2 Filed 001;. 13, 1954 IN VEN TOR.

-w\ JOSEPH BAXTER,JR.

April 15, 1958 J. BAXTER, JR

PAPER MACHINERY 6 Sheets-Sheet 3 Filed Oct. 13, 1954 Ma T.

mm Mm ll/ T A we aw m m/ 5 mm mm m April 15, 1958 J. BAXTER, JR

PAPER MACHINERY 6 Sheets-Sheet 4 Filed 001;. 13, 1954 mm v M N E R VX 0 N T [B M H P E.,, SW mw VIM April 15, 1958 J. BAXTER, JR 2,830,503

PAPER MACHINERY Filed Oct. 13, 1954 6 Sheets-Sheet 5 Fl G 9 CLUTCH BRAKE on OFF TUBE TER 210 REJECT COUNTER IN VEN TOR.

JOSEPH BAXTER, JR.

ATTORNEYS April 15, 1958 J. BAXTER, JR 2,830,503

' PAPER MACHINERY Fil ed Oct. 15, 1954 s Sheets-Sheet e FIG-ll INVENTOR.

JOSEPH BAXTER, JR. BY

ATTOR NEYS PAPER MACHINERY Joseph Baxter, Jr., Franklin, Ohio, assignor to The Black Ciawson Company, Hamilton, Ohio, a corporation of io Application October 13, 1954, Serial No. 462,093

Claims. (CI. 92-66) This invention relates to the manufacture of tubes of paperboard and other web materials.

Among the primary objects of the invention is the provision of apparatus for continuously forming a series of tubes of predetermined length by winding a web of sheet material such as paper or plastic on successive mandrels which are indexed in caged position at a forming station, rotated to wind the web thereon until a tube of the desired thickness has been built up thereon, and then released and replaced by a new mandrel on which the next tube is formed.

A particular object of the invention is to provide such apparatus wherein the operation may be essentially automatic, with the apparatus performing according to a definite cycle which is automatically started by completion of the winding of a tube to the desired thickness and which includes automatic removal of each finished tube followed by delivery and indexing of each successive new mandrel to the forming station for winding of the next tube thereon.

An additional object of the invention is to provide such automatic tube forming apparatus which also includes selective controls for manual operation thereof and especially for selective interruption of the regular cycle of the apparatus in the event of improper formation of a given tube. I

Another object of the invention is to provide apparatus as outlined above for forming tubes of paperboard which includes a paperboard machine continuously forming and delivering a wet paper web to the forming station for the tubes, and particularly to provide such apparatus wherein the same belt which receives the paper web from the paper machine also delivers the paper web to the tube forming station and aids in the operation of windingthe paper web on successive mandrels at the forming station.

It is also an object of the invention to provide tube forming apparatus as outlined above which is quickly and easily adjusted as desired to vary the thickness of the tubes formed thereby without otherwise affecting the operation of the apparatus as a whole.

Many 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 somewhat diagrammatic view in the nature of a sectional perspective illustrating tube forming apparatus constructed in accordance with the invention;

Fig. 2 is a somewhat diagrammatic elevational view of a portion of the apparatus of Fig. 1 and looking in the opposite direction from Fig. 1;

Fig. 3 is an enlarged view of a fragment of one of the conveyors which carries the mandrels on which the tubes are formed; v

Fig. 4 is an enlarged fragmentary view showing certain of the limit switches which control operation of the apparatus;

Fig. 5 is an elevational view of the press section of United States Patent the apparatus of Figs. 1 and 2 which defines the formin station for the tubes;

Fig. 6 is a plan view of the press section of Fig. 5;

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

Fig. 8 is a fragmentary view looking in the direction indicated by the line 88 of Fig. 6;

Fig. 9 is a wiring diagram; and

Figs. 10-14 are fragmentary diagrammatic views illustrating successive steps in the tube forming operation of the apparatus of Figs. 1-9.

Referring to the drawings, which illustrate a preferred embodiment of the invention, Fig. 1 illustrates in diagrammatic fashion the general arrangement and mode of operation of the apparatus, and Fig. 2 illustrates in more detail the tube forming portions of the apparatus. The successive mandrels it on which the tubes 11 are formed are carried during operation of the apparatus by a pair of continuous sprocket chain conveyors 13 carried by sprockets 1 on a plurality of shafts 15 mounted on a framework identified generally as 16. An adjustable take-up unit 17 provides for maintaining proper tension of the chain conveyors 13. Each conveyor also has pivoted thereon a plurality of successive blocks 20 each having a slot 21 therein for receiving one end of a mandrel, and guiding angles 22 hold the mandrels in place in those portions of the travel of the conveyors wherein the slots 21 open downwardly.

The operation of this apparatus i such that the mandrels 10 are carried successively through a forming station which is defined by two pairs of press rolls 3033 mounted in pairs as parts of two presssections indicated generally at 34 and 35. These press sections are mounted for relative transverse movement between retracted positions opening the forming station and advanced positions in which the press rolls cage one mandrel in the forming station to wind a wet paper web thereon. In the retracted positions of the press sections, the conveyors 13 remove the wound tube from the forming station and deliver a new mandrel into position for the next cycle of the apparatus, the conveyors being supported by guide plates or brackets 36 mounted on the main framework at either side of the machine, having slots 37 therein receiving and providing for the reciprocating movements of the journals of the

press rolls

32 and 33. The successive mandrels having the wound tubes thereon are removed at the right hand end of the machine as viewed in Fig. l for drying and such other subsequent treatment as may be desired.

The press rolls 3i) and 31 cooperate with a continu ous felt web 40 which is threaded around a plurality tional construction, detailed "description thereof is be lieved unnecessary, and in operation they supply a continuous wet paper web 45' to the felt 40 for delivery to the forming station, the felt 40 being continuously driven in the direction of the arrows in Fig. l by the usual drive for the couch rolls and also the drive for the press rolis 3% and 31 as described hereinafter. The paper machines 44 are indicated as provided with stock inlets 46 of the construction disclosed in Staege Patent No. 2,347,717, issued May 2, 1944, to the assignee of this application.

'Means are provided for continuously tensioning and conditioning the felt 40 as well as for controlling the moisture content of the paper web 45. Thus the guide roll 41' is provided with a manually adjustable stretcher mechanism 50, and the guide roll 41" is automatically ad- A contin particles of fibers which may adhere to the felt as the latter leaves the forming station, and a suction box 53 dries the felt before it reaches the first couch roll 42. Moisture in the paper web is regulated by a suction box 55 over which the felt 40 travels just before reaching the forming station, and a shower pipe 56 provides for intermittently re-wetting the web to facilitate transfer from a completed tube to a new mandrel as described hereinafter, this shower pipe having a control valve 57 (Fig. 9) of the poweropening, spring-return type and a mounting bracket 58.

The

press rolls

32 and 33 in the press section 35 cooperate with a similar felt 60 which is arranged on guide rolls 61 within the continuous web formed by the mandrels and conveyors 13, and it is continuously driven by the driving action of the press rolls 32-33. All of these press rolls are driven in the same angular direction so that the felt 60 travels through the forming station in the opposite direction from the felt 40, namely in clockwise direction as viewed in Fig. l, and it is continuously conditioned by a whipper assembly 62 and suction box 65. Manual adjustment of the tension of felt 60 is effected by a stretcher assembly 66 for the guide roll 61, and the guide roll 61" is automatically adjustable to maintain tension in the felt 60 during movement of the press section 35.

The detailed construction and operation of the two press sections will be apparent from Figs. 6-8. At the wet end of the apparatus, the press section 34 is formed by front and

rear slides

80 and 81 connected by upper and

lower tie beams

82 and 83. Each of the

slides

80 and 81 is supported for movement lengthwise of the apparatus by rollers 84 on rails 85, and the slides are guided at the top by guides 86 suspended by brackets 87 from the main framework 88 of the apparatus. The

press rolls

30 and 31 are journaled in vertical alignment in the

slides

80 and 81, and they are provided with three backing rolls 90 carried by side frames 91 connected by a tie frame 92 and mounted for sliding movement with respect to the press rolls by means of side plates 93 slidable on brackets 94 secured to the tie beam 83. A pair of air cylinders 95 are mounted on an I-beam 96 and are connected at 97 with the backing roll frame parts 91-92 to vary the supporting pressure of the backing rolls against the press rolls as desired. The main base for this part of the apparatus is identified generally as 99.

The press section 35 at the right hand or tube end of the apparatus is of essentially the same construction, and it includes

slides

100 and 101 connected by

tie beams

102 and 103 and provided with similar rollers 104 running on the rails 85, with the upper ends of these slides being guided similarly to the slides 80-81 by guides 86. The press section 35 also includes backing rolls 105 mounted similarly to the backing rolls 90 as indicated by similarly identified parts provided with air cylinders 106 corresponding to the cylinders 95 and similarly mounted to supply controlled backing pressure through the rolls 105 to the

press rolls

32 and 33.

As stated, the two press sections are movable with respect to each other, and means are provided for effecting and controlling this movement and also for maintaining both sections in proper parallel alignment at all times. Each of the slides 80-81 and 100-101 is accordingly provided with a

fluid pressure cylinder

110, 111 mounted on the framework 88 and having its piston rod 112 connected to the associated slide. The

cylinders

110 and 111 are. double-acting to cause alternative power advance and retraction of the press sections and to maintain pressure thereon during formation of the tubes, and each cylinder is.provided witha double-acting solenoid valve 115.

Relative alignment of the press sections is maintained by sprocketv chain connections between opposed slides in cooperation with

torque shafts

120 and 121 which extend between the rearward ends. of the slides 80-91 and 100-101. respectively. Referringflto. Fig. 5, a chain. 123 runs around. a sprocket: 125 at thefrontend ofthetorque shaft 120, and the ends of this chain are connected by

rods

126 and 127 to the front slides and respectively. A similar chain 130 runs around a sprocket 131 on the forward end of the torque shaft 121, and its ends are similarly connected by

rods

132 and 133 to

slides

80 and 100. These chain arrangements are duplicated at the back side of the apparatus so that whenever one slide either advances or retracts, it will not only cause similar movement of its opposed slide, but these movements will be transmitted to the other side of the apparatus by the torque shafts to maintain both pairs of slides in proper relation at all times and thereby to maintain the several press rolls in effectively constant parallel relation.

All of the press rolls 30-33 are continuously driven in the same angular direction by the main drive motor through a gear transmission 151 from which a separate flexible coupling 152 connects with each press roll in order to maintain the drive throughout the operating movements of the press sections. Provision is also made for driving one felt guide roll 41a from the press roll 30. A sprocket chain 155 connects a sprocket on the shaft of press roll 30 with an idler sprocket 156 on the base structure 99, and a second sprocket chain 157 connects the idler sprocket 156 with a sprocket on the shaft of the felt guide roll 41a.

The tube conveyors 13 are provided with an adjustable intermittent drive which indexes successive mandrels 10 in the forming station. As shown diagrammatically in Fig. 1, a motor 160 is adapted to run continuously during operation. of the apparatus and to drive one sprocket shaft 15 through an air clutch 161, and the shaft 15' is also provided with an air brake 162. The arrangement is such that when clutch 161 is engaged, the shaft 15' is driven to advance the conveyors 13, and the brake 162 is engaged to stop the shaft 15 when clutch 161 is released. The brake,however, is of a type requiring power to operate it in either direction, and it is not coupled to the clutch. and can be released without reengagement of the clutch.

These operations of the clutch 161 and brake 162 are controlled. during operation of the apparatus through electrical circuits which include a limit switch 165 mounted on the framework 16 and operated by a cam 166 on a sprocket shaft 15". The switch 165 is shown as normally open, and since a relatively small amount of rotation of the shafts 15v is required to advance each successive mandrel into indexed position, the cam 166 is shown as having three high-points 167 for closing switch 165. The camv 166 is preferably mounted for angular adjustment on shaft 15" to assure proper indexing operation.

Three additional limit switches are operated by the

press sections

34 and 35 in the manner indicated in Fig. 3. The limit switch 170, which is mounted on the fixed base 99, controls the thickness of the tubes and is operated in response to movement of the press sections away from each other as the result of increasing thickness of the tube' being built up on the mandrel 10 caged in the forming station. The switch 170 is shown as normally closed, but it is held open in the closed position of the press sections by depression of its operating plunger 171 by a bracket 172 mounted on one of the press section slides, shown as the slide 100. The mounting of the bracket 172isadjustable as indicated at 173 to provide for the variation of the desired thickness of the tubes to be formed.

The other two limit switches and 181 are also mounted on the fixed base 99 and are operated in response to complete retractive movement of the press sections. The switch 180 is shown as associated with the wet end press section 34, and it is operated by an adjustable bracket 182 on the slide 80 in the fully retracted position of press section 34. The limit switch 181 is similarly operated. by an adjustable bracket 183 on the slide 100 in the fully retracted position of press section 35.

The sequential operationof the. apparatus is illustrated by the wiring diagram in Fig. 9, in which for the sake of simplicity, the two sides of the power circuit have been indicated by plus and minus signs. Operation of the apparatus is preferably automatic as pointed out, but provision is also made for manual control, by means of a selector switch 200 which effects alternative actuation of the relays RA and RM. Fig. 9 shows the control circuits as set for automatic operation and with all the parts in the positions which they occupy while a tubeis being formed in the forming station. Thus all of the

limit switches

165, 170, 130 and 181 are open, the clutch 161 and brake 162 are both released, relay RA is energized, but all of the other relays are open, and the solenoid valves 115 are set to supply pressure to the outer ends of

cylinders

110 and 111 to urge the press sections together.

This stage of the operation of the apparatus is also illustrated in Fig. 10, in which the partially wound tube 11b is shown on the mandrel 10b, and the last finished tube 11a is indicated as on the mandrel 10a. The next mandrel to be used is identified as 10c, and it is preferably arranged as shown for engagement with the felt 60 both to bring it up to the speed of the felt and especially to wet its surface by the moisture in the felt in order to promote a smooth start of the winding operation thereon by even addition of the wet web to the wetted mandrel. The mandrel 10b is continuously rotated by the felts 4t) and 60 as indicated by the arrow, and it will also be apparent that while the press rolls 3033 are each in pressure engagement with the tube 111; through their associated felts, they are out of engagement-with each other as required by their common angular direction of rotation.

As the thickness of the tube being wound on the caged mandrel 10b increases, the

press sections

34 and 35 are moved apart against the yielding pressure of

cylinders

110 and 111 until the bracket 172 releases the switch operating plunger 171, thus causing switch 170 to close. This immediately completes the energizing circuit for relay R1. Closing of relay R1 in turn completes the proper circuit to the solenoid valves 115 to cause the

cylinders

110 and 111 to retract the press sections, this circuit running through the line 202, the uppermost pair of contacts of relay R1, line 203, the back contacts of relay R6, and

lines

204 and 205, and this relative position is illustrated in Fig. 11. As the press sections reach their fully retracted positions, they act respectively to close the

limit switches

180 and 181, thus completing the respective energizing circuits for. the relays R2 and R3. It will also be noted that closing of relay R1 completed parallel circuits through the back contacts of relays R2 and R3 for releasing brake 162.

Closing of relays R2 and R3 opens the brake-releasing circuit just described leaving the brake released, and closes a circuit through the upper contacts of both of relays R2 and R3 and a line 206 to a tube counter 210 for counting the completed tubes. In addition, closing of relays R2 and R3 completes an energizing circuit for the relay R4, this circuit running through a line 211, the lowermost contacts of relay RA, line 212, the back contacts of relay R5, and line 213.

Closing of relay R4 completes the circuit for engaging clutch 161, this

circuit including lines

214 and 215, thereby causing the conveyor shaft to be driven for advancing the conveyors 13 and thus removing the completed tube on mandrel 10b from the forming station and advancing the next mandrel 10c and 141d toward the forming station. At the same time, shaft 15" will be rotated to drive the cam 166. In addition, closing of relay R4 completes the circuit turning on the shower 56 to cause momentary wetting of the paper web as it approaches the forming station and thus to facilitate pressure rupture of the web from the finished tube and starting of the web on the new mandrel.

This stage of the operation of the apparatus is, illustrated in Fig. 12, and it continues only for the partial revolution of cam 166 required to bring the next high point 167 into closing relation with the switch 165. When this occurs, both of relays R5 and R6 will be energized by circuits running through the middle contacts of both of relays RA and R1, line 216, switch 165, and

lines

217 and 218. Closing of relay R5 deenergizes relay R4 and thus shuts off the shower 56. In addition, closing of relay R5 breaks the engaging circuit for clutch 161 and completes a releasing circuit for the clutch through the line 212, the upper contacts of relay R5, and line 219.

Closing of relay R6 in efiiect reverses the pressure supply to the press section cylinders 10-111, by opening the circuit through line 204 to the solenoid valves and completing a new circuit to these valves through lines 216 and 220, thus causing the press sections to start advancing to close the forming station. Closing of relay R6 also closes a circuit causing engagement of brake 162, this circuit running through the line 212 and the lines 221, and finally relay R6 completes a hold-in circuit for itself in parallel with switch 165.

As soon as the press sections start to close, the

limit switches

180 and 181 again open, thus deenergizing relays R2' and R3. This in turn opens the brake-engaging circuit through the upper contacts of R2 and R3 and re-closes the parallel circuits through the back contacts of these relays for releasing brake 162, so that while the tube conveyors 13 have been stopped, they are free to move to the extent required for centering of the new mandrel 14 between the four press rolls in the forming station. In addition, the adjustment of the cam 166 should be such that the switch will be closed to cause engagement of brake 162 just in advance of complete movement of the mandrel 1190 into the forming station, and this stage of the operation is illustrated in Fig. 13.

With the new mandrel 10c stopped in the position shown in Fig. 13, the closing press rolls 30 and 31 and the felt 40 will press the wetted portion of the paper web against mandrel 100 with sufiicient pressure to cause the web to adhere thereto and to start winding thereon, thereby breaking the web from the finished tube 11b, as indicated by the tail 45 in Fig. 14. In addition, as the press sections complete their closing and centering action on the new mandrel, they will in effect pull the conveyors forward the necessary small distance to rotate the cam sufficiently to re-open the switch 165. As soon as this occurs, the relays R5 and R6 will be opened to re-close the back contacts of relay R6 in preparation for the next cycle. These conditions will continue only for the interval required for complete closing of the press sections and re-opening of the limit switch 176', which will in turnopen relay R1 to reestablish the conditions shown in Fig. 9.

Fig. 9 also illustrates provisions for partially or manual operation of the apparatus. For example, in place of the thickness limit switch 170, the push button switch 225 may be used to initiate the indexing cycle of the apparatus. The switch 225 is also useful in the event of a possibly faulty start of a new tube or if for any other reason the operator wishes to reject a tube and index the machine without waiting for operation of switch 1'79. In addition, Fig. 9 shows a reject counter 226 provided with a push button switch 227 for manual operation when a defective tube is rejected.

Completely manual operation of the apparatus is provided by shifting the main switch 20% from the energizing circuit for relay RA to the energizing circuit for relay RM. This supplies current to three additional manuallyoperated switches 231 231 and 232 for controlling respectively the solenoid valves 115, the clutch 161 and the brake 162. Opening and closing of the press sections to the extent required to actuate the tube counter 210 each time the indexing cycle is repeated. In addition, a switch 235 may be provided as shown for manually controlling the shower 56, this switch having On and Off manual positions in addition to an automatic position in -which its lower contacts are closed in series with the lower contacts of relay R4.

The invention accordingly provides reliable and efficient apparatus for the continuous high speed formation of tubes of paper board, and the invention also provides for accurately controlled variation of the thickness of the tubes produced by this apparatus. More specifically, the apparatus of the invention operates continuously to form a wet paper web from paper making stock and to wind this wet web directly into the desired tubes, which require only final drying and whatever finishing operations may be desired, such for example as impregnation with asphalt if the tubes are to be used as conduits for electric cable, sewer or soil pipe, and like purposes. In particular, the invention provides for accurate automatic control of the apparatus, including control of the moisture content of the paper web as well as of the dimensions of the fully wound tube, and all conditions affecting operation of the apparatus are also readily adjusted as desired to establish the final characteristics of the finished tubes.

While the forms of apparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparaus, 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:

1. Apparatus for continuously forming tubes of porous fibrous web material on mandrels, comprising a pair of press sections each including a pair of press rolls in substantially vertical alignment, means mounting said press sections for relative movement in a substantially horizontal plane with said pairs of rolls in opposed relation defining a forming station for receiving and caging a single said mandrel in substantially centered relation with all four of said press rolls, first and second endless felt webs associated with said press sections respectively and threaded between said pairs of rolls in engagement with the associated said pair of rolls, means for continuously rotating all of said rolls in the same direction to cause said felt webs to travel through said forming station in opposite directions, means for continuously supplying a wet fibrous web to said first felt for continuous delivery thereby to said forming station, means connected with said press sections for maintaining pressure engagement of said rolls with said caged mandrel causing said felt webs to wrap substantial portions of the periphery of said caged mandrel and thereby to rotate said caged mandrel with resulting winding thereon of said fibrous web into a tube, said pressure maintaining means including yieldable pressure applying means providing for continuous retraction of said press sections as the thickness of said tube increases, means responsive to increase of said tube to a predetermined total thickness for effecting relative retraction of said press sections to open said forming station for removal of said mandrel and said tube thereon and for insertion of a new mandrel, and means for advancing said press sections to close said forming station and to start said fibrous web winding on said new mandrel.

2. Apparatus for continuously forming tubes of porous fibrous web material on mandrels, comprising a pair of press sections each including a pair of press rolls in substantially vertical alignment, means mounting said press sections for relative movement in a substantially horizontal plane with said pairs of rolls in opposed relation defining a forming station for receiving and caging a single said mandrel in substantially centered relation with all four of said press rolls, a first and second endless felt webs associated with said press sections respectively and threaded between said pairs of rolls in engagement with the associated said pair of rolls, conveyor means for indexing successive said mandrels in said forming station, means for continuously rotating all of said' rolls in the same direction to cause said felt webs to travel through said forming station in opposite directions, means for continuously supplying a wet fibrous Web to said first felt for continuous delivery thereby to said forming station, reversible fluid pressure means for maintaining yieldable pressure engagement of said rolls with each successive said caged mandrel and causing said felt webs to wrap substantial portions of the periphery of said caged mandrel and thereby to rotate said caged mandrel with resulting winding thereon of said fibrous web into a tube, means responsive to increase of said tube to a predetermined total thickness for reversing the pressure supply to said fiuid pressure means to effect relative retraction of said press sections and opening of said forming station, means operable upon retraction of said press sections to cause said conveyor to remove said mandrel and said tube thereon from said forming station and to index a new mandrel in said forming station, and means for effecting advance of said press sections to close said forming station on said indexed mandrel and to start said fibrous web winding thereon.

3. Apparatus for continuously forming tubes of porous fibrous web material on mandrels, comprising a pair of press sections each including a pair of press rolls in substantially vertical alignment, means mounting said press sections for relative movement in a substantially horizontal plane with said pairs of rolls in opposed relation defining a forming station for receiving and caging a single said mandrel, first and second endless felt webs associated with said press sections respectively and threaded between said pairs of rolls in engagement with the associated said pair of rolls, means for conveying a plurality of said mandrels successively through said forming station, means for continuously rotating all of said rolls in the same direction to cause said felt webs to travel through said forming station in opposite directions, means for continuously supplying a wet fibrous web to said first felt web for continuous delivery thereto to said forming station, yieldable means for maintaining pressure engagement of said rolls with each successive said caged mandrel and causing said felt webs to rotate said caged mandrel with resulting winding thereon of said fibrous web into a tube, means responsive to increase of said tube to a predetermined thickness for effecting relative retraction of said press sections to open said forming station for removal of said mandrel and said tube thereon and indexing of a new mandrel by said conveying means, means for effecting advance of said press sections to close said forming station on said new mandrel and to start said fibrous web winding thereon, and means for causing said new mandrel to engage said second felt web in advance of indexing thereof in said forming station to initiate rotation of said new mandrel and to moisten the surface thereof for promoting a smooth start of the winding of said fibrous web thereon.

4. Apparatus for continuously forming tubes of porous fibrous web material on mandrels, comprising a pair of press sections each including a pair of press rolls in substantially vertical alignment, means mounting said press sections for relative movement in a substantially horizontal plane with said pairs of rolls in opposed relation defining a forming station for receiving and caging a single said mandrel in substantially centered relation with all four of said press rolls, first and second endless felt webs associated with said press sections respectively and threaded between said pairs of rolls in engagement with the associated said pair of rolls, means including an indexing conveyor arranged to carry a plurality of successive mandrels downwardly through said forming station, means for continuously rotating all of said rolls in the same direction to cause said felt Webs to travel through said formingstation in opposite directions, means for continuously supplying a wet fibrous web to said first felt for continuous delivery thereby to said forming station, yieldable means for maintaning pressure engagement of said rolls with each said caged mandrel and causing said felt webs to wrap substantial portions of the periphery of said caged mandrel and thereby to rotate said caged mandrel with resulting winding thereon of said fibrous web into a tube, sensing means responsive to increase of said tube to a predetermined total thickness for effecting relative retraction of said press sections to open said formin station, means responsive to retraction of said press sections for causing said conveyor to remove said mandrel and said tube thereon from said forming station and to index a new mandrel in said forming station, means for effecting advance of said press sections to close said forming station on said indexed mandrel and to start said fibrous web winding thereon, means for effecting continuous cleaning of said felt Webs at locations spaced from said forming station, and selectively operable means for effecting retraction of said press sections and the removal and replacement of said caged mandrel independently of said sensing means.

5. Apparatus for continuously forming tubes of porous fibrous Web material on mandrels, comprising a pair of press sections each including a pair of press rolls in substantially vertical alignment, means mounting said press sections for relative movement in a substantially horizontal plane with said pairs of rolls in opposed relation defining a forming station for receiving and caging a single said mandrel, first and second endless felt webs associated with said press sections respectively and threaded between said pairs of rolls in engagement with the associated said pair of rolls, means including a continuous conveyor for carrying a plurality of successive said mandrels downwardly through said forming station, means for continuously rotating all of said rolls in the same direction to cause said first and second felt webs to travel respectively downwardly and upwardly through said forming station, means for continuously supplying a Wet fiborus web to said first felt for continuous delivery thereto to said forming station, yieldable means for maintaining pressure engagement of said rolls with each successive said caged mandrel and causing said felt webs to rotate said caged mandrel with resulting winding thereon of said fibrous web into a tube, means responsive to increase of said tube to a predetermined thickness for effecting relative retraction of said press sections to open said forming station, means responsive to opening of said forming station for causing said conveyor to remove said caged mandrel and said tube thereon and to index the next said mandrel in said forming station, means for effecting advance of said press sections to close said formstation on said next mandrel and to start said fibrous web winding thereon, and means cooperating with said conveyor to cause said next mandrel to engage the surface of said second felt web moving upwardly from said caged mandrel in advance of indexing thereof in said forming station to initiate rotation of said next mandrel and to moisten the surface thereof for promoting a smooth start of the winding of said fibrous web thereon.

References Cited in the file of this patent UNITED STATES PATENTS Re. 17,335 Mattei et al June 25, 1929 1,147,262 Parker July 20, 1915 1,497,344 Parker June 10, 1924 1,786,215 Mazza Dec. 23, 1930 1,984,073 Mazza Dec. 11, 1934 2,366,999 Campbell Jan. 9, 1945 FOREIGN PATENTS 605,793 Germany Nov. 17, 1934