US1304253A - Rotary screen for paper-stock - Google Patents

Description

C. 8. BIRD.

ROTARY SCREEN FOR PAPER sTocK. APPLICATION FILED SEPT. 1G. i918.

Patented May 2), 1919.

2 SHEETS-SHEET l.

61115.02 wmlr C. S. BIRD.

ROTARY SCREEN FOR PAPER STCK.

APPLICATION FILED SEPT- I6. i918.

'Patented May 2o, 1919.

2 SHEETS-SHEET 2.

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UNITED ysTATns PATENT OFFICE.

CHARLES S. BIRD, OF EAST WALPOLE, MASSACHUSETTS, ASSIG-NOR TO BIRD MACHINE COMPANY, A CORPORATION OF MASSACHUSETTS.

V ROTARY SCREEN Fon PAPER-STOCK. i

Specification of Letters iatent..

Patented May'zo, 1919.

Application filed September 16, 1918. Se'ra1No.254,308.

To all 'whom it may concern:

Be it known that I, CHARLES S. BIRD, a

citizen of the United States, residing at East Talpole, in the county of Xorfolk and State of Massachusetts, have'invented certain new and useful Improvements in Rotary'Screens for Paper-Stock, of which the following is aspeciication.

This inventlon pertains rotary screen for paper stock.

v The invention has for its main object, the

production of a screen that will insure a constant output of stock, and which by reason of its peculiarb construction will require but a minimum of power to operate` it, and at the same time is durable and consequently of long life.

A still further object is to provide means working in conjunction with the usual water cleaning jet orf spray to remove strings and snags from the screen surface.

Fig. 2 a transverse vertical sectional view,

and

Fig. 3 a longitudinal vertical 4sectional view.

In the drawings, 1 denotes a suitable' frame or standard at the head end and 2. a standard or frapie at the opposite end. The screening cylinder proper may be of any approved form and in that illustratedcomprises -a closed head 3, an open ring. shaped head 4 between which extend suitable tie rods 5, and screen supporting and attaching bars 6; rPhe screening surface 1s preferably formed of segmental perforated plates 7 produced from phosphor-bronze or `the like, which are attached by screws to the heads and bars.,

Head 3 has xedly secured thereto Ia stub shaft 8 which extends outwardlyvv through a stuing box 9 mounted inlstandard 1.

Said shaft has secured to it a gear 10 and.

derives its motion at a reduced speed,

through the gearing as shown, from a band wheel 11. Head 4, which is of ringform,

extends through and is supported at its to an improved outer end by suitable bearing blocks 12 preferablyY produced from lignum-vitae held in place in the standard 2 by a ring or collar 13. A discharge mouth 14 is secured to standard 2, and the screened pulp passes therefrom into a discharge box (not shown) which is connected to the head box ofthe paper machine. f

The vat of themachine is designated by 15 and is sustained in yoke-shaped frames 16 and 17 -which latter at one side are supported by laminated spring members 18.

the opposite side being pivotally supported from links 19, the pivots for the upper ends of which are sustained by standards 20. A

radius bar 21 is connected to one of the lower link pins and a pitman 22 isadjustably secured thereto, the opposite end of the pitman coacting with an eccentric 23 carried by 'a driven shaft 24. .Through this arrangement the tank or vat is vibrated, the ahflplitudev of vibration being regulated and determined by adjustment of the pitman with reference to the radius .bar orv arm 21.

A flexible connection. is effected between `each end of the vat and the adjacent standards 1 and 2 which, inA effect, form heads orends for the vat. -strips or bands of rubber, denoted by 25, Fig. 3, form an effective simple and durable connection and are preferably held in place by metallic straps 26 overlying the bands and .secured in place by screws passing .into the vat body and into iianges 27 formed on the respective standards.

The vat at its lower side is provided with av drain 28 into which settle the impurities that are held back by the screen, down- "comin-g unscreened stock assisting gravity' in this action. The impurities thus caught :are removed in a small constant stream to a l small auxiliary screen (not shown), where any good stuffis removed and returned to the How-box 29which discharges -into the vat, Fig. 2.

Projecting through the head 4 and eX- f tending .throughout the' length of the screen in the upper portion thereof` is a trough orV tray 30, and located above said tray' and within the screen is a spray pipe I have found that 31. The water forced from said pipe passes through the screen and acts to dislodge .any matter which is heldin the screen openings or perforations, the jet carrying such maposed portion of the screen surface is again submerged. Supported in suitable bearings on'the standards land 2 is a shaft 35 to which is imparted a rapid rotation. Said shaft carries a wiper or beater, the flexible elements 36 whereof contact the screen sur-y face and act to yremove any strings, snags or other adhering substances therefrom. Said elements will preferably be formed of feltthough bristles or wires may be employed. Felt, however, is found preferable,"as it does not weary away readily and moreover does not wear away the screen.

Preferably the'screen is rotated slowly in a direction the reverse of that of the wiper, which latter, asabove noted, has a relatively high speed. Any material which may pass the screen cleansing jet or spray will therefore be removed by the wiper, such removal being facilitated by the difference in 4speed of rotation between the screen and wiper. A hood or guard 37 overlies the wiper,- and prevents splashing' of the water and waste material which is removed thereby.

What is claimed isz Y l. In a machine of the character specified, the combination of a vat, means for vibrating the same; ya screen mounted for rotation withinsaid vat 1:' means 'for feeding the stuff to be'screened to the vat; and a rotatable beater contacting the outer `surface of the -screen land acting upon the exposed surface thereof. p

2. In amachine of the character specified, the combination of a vat; a screen mounted for rotation within said vat; means for feeding stuEv to the-vat and exteriorly of the screen,-said screen havingl an inward flow; ajet pipe located within the screen above the stuff level of lthe vat; a wiper contacting the exposed outer'face of the screen aftery it passes the jet; v wiper at a relatively high speed.

3. the combination of a vat; a screen mounted for rotation within said vat; means for feeding stuif to the vat and exteriorly of the and means' for rotatingv the screen, said screen havin an inward flow; a

jet pipe locatedwithin elscreen above the In a machine of the character specified,-

after it passes the jet; and means for rotating the wiper at a relatively high speed.

4. In a machine of the character specified, the combination of a pair of frames or standards; a vat; a flexible connection between the ends of said vat and frames, said frames forming the heads or ends of the vat; an inflow screen mounted for rotation inthe vat; means for vibrating the vat; a spray pipe located interiorly of the screen; and a flexible wiper acting upon the outer surface of the screen beyond the spray pipe.

5. In a machine of the character-specified, the combination of a U-shaped vat body;v a pair of frames or standards; a ange extending from each frame toward the body; a' rubber strip secured to 'each flange and to the adjacent end of the body and forming a closure between said parts; means vfor vibrating said body; an iniow screen mounted for rotation within said vatg a spray pipe located interiorly of the screen; and a fiexipoint beyond the spray .the adjacent end of the body and' forming a closure between saidY parts; means for vibrating said body; a screen mounted for rotation with said vat; and a rotary wiper embodying a 'series of flexible members adapted to contact the exposed surface of the screen.

7 In a machine of the character specified, the combination of a U-shaped vat body; a pair of frames located adjacent the ends thereof; a flexible connecting closure between the vat ends and the frames a drain ,located at the lower side of the vat; means for vibrating the vat transversely to its axis; a screen mounted in said vat, one end ,of the screen being open and discharging loutwardly therefrom; ta spray pipe located within the upper pa/rt of the screen; and a rotary-iexible beater working lagainst the ysurface of the screen in rearof the spray pipe, said beater rotating in a direction the reverse of that of the screen and having a peripheral speed in excess of that of the screen: t l

In testimony whereof I have signed my name to this specification.

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