Method and apparatus for forming yarn

Claim 3

A method according to claim 1, comprising firstly feeding fibrous material to a preceding continuous moving surface, transferring said fibrous material therefrom to one of said two surfaces forming said nip, the nature of said preceding surface and said one surface and the manner of feeding and transferring enabling the fibrous material to approach the preceding surface in a generally endwise manner but finally to lie in discrete lengths on said one surface generally transversely to its direction of movement, and drawing off the fibrous material continuously from said one surface, in the form of a yarn or like fiber assembly from said location thereof at whiCh said discrete lengths of material are caused to accumulate at an appropriate rate and become twisted together as said one surface moves relative thereto.

Claim 4

A method according to claim 2, in which the material is transferred from said preceding to said one surface entrained in a moving fluid.

Claim 5

A method according to claim 3, in which said preceding surface and said one surface are cylindrical, said material being fed generally radially to said preceding surface and generally tangently to said one surface and being withdrawn off said one surface in a direction parallel to the axis of the cylinder.

Claim 6

A method according to claim 2, in which the yarn or fiber assembly is subsequently consolidated.

Claim 7

A method according to claim 1, including the step of reducing the fiber length to approximately one inch before twisting.

Claim 8

A method according to claim 1, in which the yarn or fiber assembly is subsequently treated with polyvinyl alcohol to improve its handling properties.

Claim 9

A method according to claim 1, in which the fibers comprise carbon fibers.

Claim 10

Apparatus for making a yarn or like fiber assembly comprising two continuously movable surfaces arranged to form a nip and to move in substantially opposite directions in the region of the nip, means for feeding fibrous material to a location in the nip with the fiber axes lying substantially at right angles to the directions of movement of the two surfaces so that the fibers are engaged by the surfaces, means for providing a fluid flow at the location to assist in twisting the fibers together, and means for drawing off the material as a continuous strand of twisted fibers transversely to the directions of movement of the surfaces.

Claim 11

Apparatus for making a yarn or like fiber assembly comprising two continuously movable surfaces arranged to form a nip and to move in substantially opposite directions in the region of the nip, means for feeding fibrous material to a location in the nip with the fiber axes lying substantially at right angles to the directions of movement of the two surfaces so that the fibers are engaged by the surfaces, means for providing a fluid flow at the location to assist in twisting the fibers together, and means for drawing off the material as a continuous strand of twisted fibers transversely to the directions of movement of the surfaces.

Claim 12

Apparatus according to claim 9, including a preceding continuous movable surface to which said material is fed before said nip and means for transferring the fibrous material from said preceding surface to one of said two surfaces forming said nip.

Claim 13

Apparatus according to claim 10, in which said preceding surface is that of a taker-in cylinder, and said one of said two surfaces is that of a perforate cylinder, said means for transferring the fibrous material from one cylinder to the other being a fluid.

Claim 14

Apparatus according to claim 11, in which the peripheries of the two cylinders approach closely to each other, said fluid being air which entrains the material struck down by the taker-in cylinder and carries the material to the region where the cylinder peripheries approach each other for transfer of the material to the surface of the perforate cylinder, the air passing away through the perforations.

Claim 15

Apparatus according to claim 12, in which the fluid flow is controlled in a manner to produce the desired orientation of fibers of the material deposited on said perforate cylinder.

Claim 16

Apparatus according to claim 10, including a cross conveyor adapted to move in a direction transverse to the direction of movement of said preceding movable surface where the material is drawn off, the fibrous material being fed over said cross conveyor whereby the fibrous material is moved transversely during feeding.

Claim 17

Apparatus according to claim 9, including means for consolidating the yarn or fiber assembly after same has been drawn off.

Claim 18

Apparatus according to claim 15, wherein the consolidating means comprises cooperating endless conveyors which move at the same speed in the direction of yarn travel and are simultaneously oscillated transversely relative to one another.

Claim 19

Apparatus as claimed in claim 9, in which one of the two surfaces forming said nip is a roller arranged to prevent movement of the fibers over the other of the two surfaces.

Claim 20

Apparatus for making a yarn or like fiber assembly comprising a cylinder having a perforate surface, a roller having a surface arranged to define a nip with the perforate surface, means for feeding fibers to the nip for engagement by the surfaces with the fiber axes substantially parallel to the axes of the cylinder and roller, means for rotating the cylinder and roller surfaces in opposite senses at the nip, means for providing a fluid flow in the region of the nip to assist twisting together of the fibers, and means for drawing off the twisted fibers as a continuous strand of twisted fibers transversely to the direction of rotation of the cylinder surface at said nip.

Claim 21

Apparatus for making a yarn or like fiber assembly comprising a cylinder having a perforate surface, a roller having a surface arranged to define a nip with the perforate surface, means for feeding fibers to the nip for engagement by the surfaces with the fiber axes substantially parallel to the axes of the cylinder and roller, means for rotating the cylinder and roller surfaces in opposite senses at the nip, means for providing a fluid flow in the region of the nip to assist twisting together of the fibers, and means for drawing off the twisted fibers as a continuous strand of twisted fibers transversely to the direction of rotation of the cylinder surface at said nip.