US2635508A - Apparatus for forming cement sheets - Google Patents

Description

A. MAGNAN|- APPARATUS FOR FORMING CEMENT SHEETS April 21, 1953 Filed Feb. 27. 1948 3 Shees-Sheet 1 INVENTOR @ffm A7-hau.; BY

MMM/1m( ATTORNEYS April 21, 1953 A. MAGNANI APPARATUS FOR FORMING CEMENT SHEETS 5 Sheets-Sheet 2 Filed Feb. 27, 1948 A 55' INVENTOR fsmullm,

,B Paw ATTOREYS April 21, 1953 A. MAGNANl APPARATUS FOR FORMING CEMENT SHEETS 3 Sheets-Sheet 15 Filed Feb. 27. 1948 mal Patented Apr. 21, 1953 APPARATUS FOR FORMING CEMENT SHE ETS

Alessandro Magnani, Broni, Italy Application February 27, 1948, Serial No. 11,653 In Italy August 5, 1941 Section 1, Public Law 690, August 8, 1946 Patent expires August 5, 1961 6 Claims.

This invention relates to apparatus for the production of asbestos cement sheet material and is concerned more particularly with improved apparatus of the type shown in my co-pending application, Ser. No. 367,476, led November 27, 1940, now Patent No. 2,592,518, issued April 8, 1952, of which application this is a continuationin-part. v

The apparatus disclosed in the patent comprises an endless chain of suction boxes having perforated outer faces and an endless waterpermeable belt encircling the chain. The chain and belt are guided, so that they have contacting upper horizontal stretches, and aqueous brous cement material is deposited upon the belt in contact with the boxes and is then distributed to form a sheet, from which water is removed through the belt by suction applied through the boxes. In the apparatus of the patent, the outer faces of the boxes are perforated throughout substantially their entire areas and each boxis provided with a transverse sealing strip along the lower edge of its forward face, the strip engaging the adjacent box in the upper stretch of the chain. The spaces between adjacent boxes above the sealing strips are, accordingly, not sealed by the strip. Also, the belt, after losing contact with the sheet, is led around cylindrical rollers until it returns to the upper stretch in contact with the boxes, and no means are provided for manipulating the belt to free adherent material therefrom or for shifting the belt transversely to correct mis-alignment thereof with the chain.

The present invention relates to apparatus as shown in the patent, which produces a sheet superior to that produced on the patented apparatus, in that it is denser and more homogeneous. The improved result stated is obtained by reason of the provision in the new apparatus of better sealing means between adjacent boxes, together with means tending to prevent spreading of the deposited material. In addition, means are provided for insuring a smoother travel of the belt, which is in correct alignment with the chain of boxes.

For a better understanding of the invention, reference may be made to the accompanying drawings, in which Fig. 1 is a side elevational view, with parts broken away, of one form of the apparatus of the invention;

Fig. 2 is a sectional view on the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary transverse sectional view of a suction box, showing the belt and sealing bands in operative position;

Fig. 4 is an end view of one of the guide rollers for the belt;

Fig. 5 is a perspective view of the roller;

Fig. 6 is a perspective view of a roller of modied form; and

Fig. '7 is a view in perspective of one of the suction boxes.

The apparatus shown in Fig. 1 comprises a framework I0, near opposite ends of which are mounted bearings for shafts I2, I3 carrying wheels Il. An endless chain of connected hollow boxes I5 is trained about wheels I4 and the outer face of each box is provided with an area I6 containing a multiplicity of perforations IBa. The perforated area on each box extends from one transverse edge to the other, but terminates short of the lateral edges of the box, so that the latter has solid lateral margins I1. The sectional shape of the outer faces of the boxes defines the profile of the bottom surface of the sheet to be produced and, as the apparatus illustrated is for producing a longitudinally corrugated sheet, the outer faces of the boxes have corrugations extending lengthwise of the chain of boxes. 'Ihe bottom of each box is provided near each end with a bottom opening in the form of a slot I 8 extending lengthwise of the chain. The forward transverse wall I9 of each box is also provided with a channel of U-shape, in which is inserted a rubber sealing strip 20, which projects out of the channel. The strip extends across the box below the corrugated surface thereof and its ends terminate flush with the outer face of the box in the solid areas II.

The boxes in the upper stretch 2I of the chain are supported with their top surfaces horizontal on a pair of chambers 22, which have longitudinal slots 23 in their top surfaces in position to register with the slots I8 in the bottom of the boxes and are connected by lines 22a to a suction system. The boxes in the upper stretch ZI form a suction support, which is moved to the right (Fig. 1) during the operation of the apparatus by rotation of wheels I4 on shaft I3. For this purpose, the shaft is driven by any suitable means. The boxes in a lower horizontal stretch 24 of the chain are supported on rails 25 attached to the framework.

A belt 26 of water-pervious fabric encircles the chain of boxes and lies in contact with the top surfaces of the boxes in the upper stretch 2 I. As the belt approaches the boxes in the upper stretch, it is shaped to corrugated form by passing between upper and lower sets of rollers 21, 28, the rollers in the two sets being offset. Beyond the stretch 2|, the belt passes over a xed support 29 and is then turned abruptly around an angle bar 30. The bar has corrugations corresponding to those on the boxes, on its top and side surfaces, over which the belt travels, and the two sets of corrugations are offset. Beyond the angle bar, the bar passes over idler rollers 3|, 32, 33. A nozzle 34 may be employed to spray water on the belt at any appropriate place between the idler rollers to clean it. l

Rollers 3|, 32, and 33 are polygonal in section and each face of each roller is formed with corrugations 35, which are of the same shape as the corrugations in the boxes. The corrugations on each face of each roller are offset from those on adjacent faces, so that a trough on one face is in alignment with crests on the adjacent faces. If desired, one of the rollers may be mounted for adjustment and, for this purpose, the roller is of the construction shown in Fig. 6. The roller 3l of Fig. 6 is similar in shape to roller 3|, for example, and its spindle 38 at one end extends into a bearing 39, which is mounted on aligned pins 40 in respective bearings 4|. Pins 40 serve as a pivot, which extends transverse to spindle 33 and about which the spindle may be swung. The other end of the spindle is mounted in a bearing 42, which may be moved positively to swing the roller. In the construction shown in Fig. 6, bearing l2 is attached to a rod 43 secured to a piston within the cylinder 44 of a hydraulic motor, which can be actuated to swing roller 3l in opposite directions about the axis through pins 40.

The use of the polygonal rollers described causes the belt to be manipulated in its travel about the rollers and the belt frees itself from material adhered thereto. Should the belt tend to become mis-aligned in relation to the chain of boxes, motor 44 can be operated to swing roller 3l in the appropriate direction to restore the alignment of the belt.

The aqueous fibrous cement used in forming the sheet is delivered through a nozzle 45 to a distributing device, which includes a pair of side plates 46, in which are mounted shafts 4l, 48 carrying flanged rollers 49 running on guides 53 lying on opposite sides of the belt and the boxes 1n the upper stretch 2|. 45, shafts 41, 48 are equipped with spreaders in the form of rollers having a corrugated shape corresponding to the shape of the corrugations in the top of the boxes. Rollers 5| are spaced above the surface of the belt a distance correspending to the thickness of the sheet to be produced. A motor 52, mounted on a cross-bar between plates 46, drives shaft 48 through suitable connections and the motor is of the reversing type and thus causes the distributing device to be reciprocated along guides 50 during the operation of the apparatus. During the travel of the distributing device, the aqueous material discharged upon the belt through nozzle 45 is spread out by rollers 5| to sheet form.

Beyond the ends of guides 50 in the direction of travel of the strip, the latter is compressed by a corrugated roller 53 on a shaft 54 in bearings on a carriage 55. Shaft 54 and a parallel shaft 55 on the carriage are provided with flanged wheels 57 running on guides 58 lying on opposite sides of the chain of boxes and a reversing motor 59 mounted on carriage 55 'and connected to shaft 54 by suitable connections causes carriage 55 to reciprocate on the guides. During such movement Between the side plates o of the carriage, roller 53 compresses and smooths the traveling cementitious sheet.

As shown in Fig. 3, the belt 26 is wider than the perforated areas I6 of the boxes, but narrower than the boxes. The belt, accordingly, partially overlies the solid portions of the outer faces of the boxes on opposite sides of the perforated areas. A pair of endless sealing bands 53, which are preferably of rubber, overlie the lateral margins of the belt and the solid areas of the outer faces of the boxes beyond the edges of the belt and contact with the ends of the vertical portions of the sealing strips 20. With this arrangement, the lateral edges of the belt are sealed by the sealing bands, so that there can be no leakage through the portions of the belt outside the area, on which the brous cement sheet 54 is formed. Also, the spaces between adjacent boxes are sealed by the strips 23. As a result, the full effect of the suction is applied to the deposited material through the belt by the boxes and there is no leakage through the edges of the belt, which would tend to produce sheets less dense along those edges than elsewhere.

The provision of the polygonal corrugated rollers, which serve to keep the belt clean, and of the improved sealing means consisting of the U- shaped sealing strips and the endless sealing bands, results in the production of sheets of improved quality, and defects, which might arise from mis-alignment of the belt with the boxes, are avoided by the adjustment of one of the polygonal rollers by means of motor 44.

I claim:

l. In apparatus for the production of longitudinally corrugated asbestos cement sheet material, such apparatus including an endless chain of suction boxes having perforated areas in their outer faces, said areas being corrugated lengthwise of the chain, and means for` advancing the chain of boxes along a path having a horizontal upper stretch, the combination of a water-permeable endless belt narrower than the boxes and wider than said areas encircling the chain of boxes, means for guiding the belt with a horizontal upper stretch thereof in contact with the upper stretch of the chain, said means including a roller of polygonal section having corrugations in its faces corresponding to those on the boxes and With the corrugations on each face offset from those on adjacent faces, endless sealing bands movable with the belt and overlying and engaging the lateral margins of the belt and of the boxes outside of said areas in the upper stretch of the belt and chain, and means for depositing aqueous fibrous cement material upon the belt in said upper stretch in contact with the boxes,

2. In apparatus for the production of longitudinally corrugated asbestos cement sheet material, such apparatus including an endless chain of suction boxes having perforated areas in their outer faces, said areas being corrugated lengthwise of the chain, and means for advancing the chain of boxes along a path having a horizontal upper stretch, the combination of a waterpermeable endless belt narrower than the boxes and wider than said areas encircling the chain of boxes, mea-ns for guiding the belt with a horizontal upper stretch thereof in contact with the upper stretch of the chain, said means including a roller changing the direction of the belt, said roller being of polygonal section and having corrugations in its faces corresponding to those on the boxes and with the corrugations on each face offset from those on adjacent faces, means for swinging the roller in a plane substantially transverse to the belt on one side of the roller about an axis at one end of the roller, endless sealing bands movable with the belt and overlying and engaging the lateral margins of the belt and of the boxes outside of said areas in the upper stretch of the belt and chain, and means for depositing aqueous fibrous cement material upon the belt in said upper stretch in contact with the boxes.

3. In apparatus for the production of longitudinally corrugated -asbestos cement sheet material, such apparatus including an endless chain of suction boxes having perforated areas in their outer faces, said areas being corrugated lengthwise of the chain, ,and means for advancing the chain of boxes along a path having `a horizontal upper stretch, the combination of a water-permeable endless belt narrower than the boxes and wider than said areas encircling the chain of boxes, means for guiding the belt with a horizontal upper stretch thereof in contact with the upper stretch `of the chain, said means including a roller of polygonal section having corrugations in its faces corresponding to those on the boxes and with the corrugations on each f-ace offset from those on adjacent faces, and means for depositing aqueous fibrous cement material upon the belt in said upper stretch in contact with the boxes.

4. In apparatus for the production of longitudinally corrugated asbestos cement sheet material, such apparatus including an endless chain of suction boxes having perforated areas in their louter faces, said areas being corrugated lengthwise of the chain, and means for `advancing the chain of boxes along a path having a horizontal upper stretch, the combination of a water-permeable endless belt narrower than the boxes and wider th-an said areas encircling the chain of boxes, means for guiding the belt with a horizontal upper stretch thereof in contact with the upper stretch of the ch-ain, said means including a roller of polygonal section having corrugations in its faces corresponding to those on the boxes and with the corrugations on each face offset from those on adjacent faces, positively operating means for swinging the roller about an axis at one end of the roller and lying in a plane substantially parallel to the plane of travel of the belt, and means for depositing aqueous fibrous cement material upon the belt in said upper stretch in contact with the boxes.

5. An apparatus for the production of asbestos cement sheet material, which comprises an endless chain of suction boxes having perforated areas in their outer faces inward from the lateral edges thereof, means for advancing the chain of boxes along a path having a horizontal upper stretch, a sealing strip on a transverse vertical Wall of each box engagea-ble with the opposed wall of the adjacent box in said upper stretch, each strip extending across the box below the outer face thereof and terminating at said face on opposite sides of the perforated area in said face, a water-permeable endless belt encircling the chain of boxes, the belt being narrower than the boxes and wider than the perforated areas in the outer faces thereof, means for guiding the belt to cause an upper horizontal stretch thereof to cover the perforated areas of the boxes in the upper stretch of the chain, endless sealing bands movable with the belt and having stretches overlying and engaging the lateral margins of the belt and of the outer faces of the boxes in the upper stretches of the belt and chain, the bands engaging the ends of the sealing strips on the boxes in said upper stretch, and means for depositing aqueous fibrous cement material upon the belt in said upper stretch in contact with the boxes.

6. An apparatus for the production of asbestos cement sheet material, which comprises an endless chain of suction boxes having perforated areas in their outer faces inward from the lateral edges thereof, means for advancing the chain of boxes along a path having a horizontal upper stretch, a water-permeable endless belt encircling the chain of boxes, the belt being narrower than the boxes and wider than the perforated areas in the outer faces thereof, means for guiding the belt to cause an upper horizontal stretch thereof to cover the perforated areas of the boxes in the upper stretch of the chain, endless sealing bands movable with the belt and having stretches overlying and engaging the lateral margins 0f the belt and of the outer faces of the boxes in the upper stretches of the belt and chain, sealing means on each box engageable with the adjacent box in the upper stretch of the chain and extending across the box from one sealing band to the other, and means for depositing aqueous fibrous cement material upon the belt in contact with the boxes in the upper stretch of the chain.

ALESSANDRO MAGNANI.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 200,209 Lewthwaite Feb. 12, 1878 476,153 Lee May 31, 1892 545,788 Fairbanks et al Sept. 3, 1895 723,257 Fairbanks Mar. 24, 1903 762,431 McGrath June 14, 1904 790,589 Parker et al May 23, 1905 1,297,773 Adams Mar. 18, 1919 1,303,493 Milne May 13, 1919 2,008,318 Ziegler July 16, 1935 2,041,967 Schroeder et al. May 26, 1936 2,297,504 Salvaneschi Sept. 29, 1942 FOREIGN PATENTS Number Country Date 109,444 Germany Apr. 11, 1900 374,936 Italy Sept. 8, 1939 376,993 Italy Dec. 4, 1939 379,889 Italy Apr. 11, 194'0

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