Apparatus for producing cement sheets

Claim 2

Apparatus for forming into sheet form a flowable hardenable material such as a cement mix, comprising: a. a cylindrical mould mounted for rotation on a horizontal axis and having a removable end plate, said mould and end plate being such that a cylindrical body formed within the mould can be extracted by sliding without dimensional change after removal of said end plate; b. means for feeding said material directly onto the inner surface of a liner held within said mould; c. a mandrel movable axially into the mould through the end of the mould having the removable end plate, said mandrel having a cylindrical surface engageable with the inside surface of a hollow cylindrical body of the material formed within the mould by spinning; d. mounting means for said mandrel allowing movement thereof axially into the mould and also allowing rotation thereof after removal from the mould and allowing relative transverse movement between the mandrel and a receiving surface for the sheet; e. a flexible liner dimensioned to fit within the cylindrical inner surface of the mold, the edges of said liner which are adjacent each other when in the mould being provided with radially extending elements; f. releasable connecting means for holding said radially extending elements to prevent separation thereof after removal of said mandreal, with said hollow cylindrical body and said liner, from the mould, and g. means for forming a longitudinal division in said cement body, to allow the body to be unrolled from the mandrel after removal from the mould.

Claim 3

Apparatus according to claim 1, wherein said radially extending elements are inwardly directed flanges which are of greater radial extent than the radial difference in dimensions between the curved outer surface of the mandrel and the curved inner surface of the mould, whereby said flanges also constitute said means for forming a longitudinal division in said cement body.

Claim 4

Apparatus according to claim 1, wherein said radially extending elements are outwardly directed flanges which flanges are spaced apart while the liner is in the mould so that after extraction from the mould the cylinder of material can be slit while the liner is still in place.

Claim 5

Apparatus according to claim 3, further including clip means adapted to engage said outwardly directed flanges of the liner when the cylinder is being removed from the mould, said clip means being removable to allow slitting means for forming the longitudinal division in said cement body to pass between the liner edges.

Claim 6

Apparatus according to claim 1, wherein said mould includes an annular member situated in said mould so as to define an end of said cylinder remote from that end adjacent the removable end plate, said annular member being movable axially of the mould and away from the end of said cylinder formed therein, and wherein said means for holding the cylinder on the mandrel includes extracting means contractible to the internal diameter of a cylinder formed within the mould and expandible into a space formed between said annular member and the cylinder on movement of said member away from the formed cylinder, whereby the said extracting means can engage the end of the cylinder remote from the removable end plate to hold the cylinder on the mandrel while the mandrel is withdrawn from the mould.

Claim 7

Apparatus according to claim 2, wherein said releasable connecting means includes hook members movably mounted on said mandrel and engageable with said inwardly directed flanges.

Claim 8

Apparatus according to claim 6, wherein said mandrel includes hook members engageable selectively with one or other or both of the flanges of said liner, whereby both edges of the liner are individually attachable to the mandrel.

Claim 9

Apparatus according to claim 7, wherein said liner flanges are provided with elements engageable by locking means carried by the mould.

Claim 10

Apparatus according to claim 8, wherein said liner edges include flanges having apertures, and wherein said apertures of each flange are engageable by a series of hooks carried on a shaft rotatably mounted on the mould, said hooks of each series being simultaneously engageable with said apertures of one flange by rotation of the respective shaft.

Claim 11

Apparatus for forming into sheet form a flowable hardenable material such as a cement mix, comprising: a. a cylindrical mould mounted for rotation on a horizontal axis and having a removable end plate, said mould and end plate being such that a cylindrical body formed within the mould can be extracted by sliding without dimensional change after removal of said end plate; b. means for feeding said material directly onto the inner surface of a liner held within said mould; c. a mandrel movable axially into the mould through the end of the mould having the removable end plate, said mandrel having a cylindrical surface engageable with the inside surface of a hollow cylindrical body of the material formed within the mould by spinning; d. mounting means for said mandrel allowing movement thereof axially into the mould and also allowing rotation thereof after removal from the mould and allowing relative transverse movement between the mandrel and a receiving surface for the sheet; and e. a flexible liner dimensioned to fit within the cylindrical inner surface of the mould, the edges of said liner which are adjacent each other when in the mould being provided with radially extending flanges, said flanges extending inwardly by an amount greater than the radial difference in dimensions between the curved outer surface of the mandrel and the curved inner surface of the mould, whereby said flanges constitute means for forming a longitudinal division in said cement body, to allow the body to be unrolled from the mandrel after removal from the mould;

Claim 12

Apparatus for forming into sheet form a flowable hardenable material such as a cement mix, comprising: a. a cylindrical mould mounted for rotation on a horizontal axis and having a removable end plate, said mould and end plate being such that a cylindrical body formed within the mould can be extracted by sliding without dimensional change after removal of said end plate; b. means for feeding said material directly onto the inner surface of a liner held within said mould; c. a mandrel movable axially into the mould through the end of the mould having the removable end plate, said mandrel having a cylindrical surface engageable with the inside surface of a hollow cylindrical body of the material formed within the mould by spinning; d. mounting means for said mandrel allowing movement thereof axially into the mould and also allowing rotation thereof after removal from the mould and allowing relative transverse movement between the mandrel and a receiving surface for the sheet; and e. a flexible liner dimensioned to fit within the cylindrical inner surface of the mould, the edges of said liner which are adjacent each other when in the mould being provided with radially extending flanges, said flanges extending inwardly by an amount greater than the radial difference in dimensions between the curved outer surface of the mandrel and the curved inner surface of the mould, whereby said flanges constitute means for forming a longitudinal division in said cement body, to allow the body to be unrolled from the mandrel after removal from the mould;

Claim 13

Apparatus according to claim 1, wherein said cylindrical surface of the mandrel is constituted by a cylindrically curved, flexible plate, and wherein said mandrel includes means for expanding said plate after insertion of the mandrel into a cylinder in the mould.

Claim 14

Apparatus according to claim 11, wherein said plate includes an outwardly directed flange at the outer end of the mandrel, said expanding means being capable of causing radial expansion of said plate by an amount at least equivalent to the radial extent of said flange, whereby said flange can be caused to engage the end of a cylinder of material formed in the mould to assist in sliding the cylinder from the mould.

Claim 15

A mandrel for use in removing a hollow cylinder of material centrifugally formed within a mould, comprising:-a cylindrically curved, flexible plate. a shaft extending axially of said plate and being mounted for continuous rotation in a support, expanding means including a linkage connecting said shaft with said plate, and also including a pneumatic cylinder connected to said linkage in such manner as to cause said linkage to expand said plate when the cylinder is supplied with pressurized gas, a gas reservoir contained within the mandrel and rotatable therewith, connector means being provided so that said reservoir can be pressurized with compressed gas at least when the mandrel is stationary, conduit means connecting said reservoir to said pneumatic cylinder, shut-off valve means interposed in said conduit means, and a valve actuator for operating said valve means, whereby said reservoir can be charged with compressed gas via said connector means while the mandrel is stationary, and whereby said valve actuator may be operated upon insertion of the mandrel into a mould to cause compressed gas in said reservoir to operate said expansion means while the mandrel is rotating.

Claim 16

A mandrel for use in removing a hollow cylinder of material centrifugally formed within a mould, comprising:-a cylindrically curved, flexible plate. a shaft extending axially of said plate and being mounted for continuous rotation in a support, expanding means including a linkage connecting said shaft with said plate, and also including a pneumatic cylinder connected to said linkage in such manner as to cause said linkage to expand said plate when the cylinder is supplied with pressurized gas, a gas reservoir contained within the mandrel and rotatable therewith, connector means being provided so that said reservoir can be pressurized with compressed gas at least when the mandrel is stationary, conduit means connecting said reservoir to said pneumatic cylinder, shut-off valve means interposed in said conduit means, and a valve actuator for operating said valve means, whereby said reservoir can be charged with compressed gas via said connector means while the mandrel is stationary, and whereby said valve actuator may be operated upon insertion of the mandrel into a mould to cause compressed gas in said reservoir to operate said expansion means while the mandrel is rotating.

Claim 17

A mandrel according to claim 13, wherein said plate includes an outwardly directed flange at the outer end of the mandrel, said expanding means being capable of causing radial expansion of said plate by an amount at least equivalent to the radial extent of said flange, whereby said flange can be caused to engage the end of a cylinder of material formed in the mould to assist in sliding the cylinder from the mould.

Claim 18

A mandrel according to claim 13, wherein said reservoir is a hollow space within said shaft.

Claim 19

A mandrel according to claim 13, wherein said valve actuator extends outwardly beyond the cylindrical surface of said plate, whereby said valve actuator may be operated to open the valve means by a means on said mould which engages said valve actuator when the mandrel is almost fully inserted into the mould.