Twisting devices for filaments

Claim 2

Twisting device for textile filaments, comprising at least one rotary ring against which the filament must be applied so as to be driven in rotation by the inner edge of the rotary ring to undergo twisting, said rotary ring being driven by a single drive roller, said rotary ring comprising an outer edge of magnetic material and being held supported on said single drive roller by a fixed support roller and by a magnetic device inserted between the fixed support roller and the single drive roller.

Claim 3

Device according to claim 1, wherein the magnetic device is arranged to draw the rotary ring against the single drive roller and the fixed support roller.

Claim 4

Twisting device for filaments, comprising several rotary rings against which the filament must be applied so as to be rotated by the inner edge of said rotary rings to undergo twisting, these rotary rings being staggered along a rectilinear path and distributed into two overlapping groups so that in following said rectilinear path there is alternately encountered a ring of one group and a ring of the other group, these two groups being able to undergo relative displacement in a direction perpendicular or substantially perpendicular to said rectilinear path, this relative displacement being effected by pivoting around the axis of a single drive roller against which the rotary rings of the two groups are kept supported, each rotary ring comprising an outer edge of magnetic material, and being held supported on the single drive roller by a fixed support roller and by a magnetic device arranged between the fixed support roller and the single drive roller.

Claim 5

Twisting device for filaments, comprising several rotary rings against which the filament must be applied so as to be rotated by the inner edge of said rotary rings to undergo twisting, these rotary rings being staggered along a rectilinear path and distributed into two overlapping groups so that in following said rectilinear path there is alternately encountered a ring of one group and a ring of the other group, these two groups being able to undergo relative displacement in a direction perpendicular or substantially perpendicular to said rectilinear path, this relative displacement being effected by pivoting around the axis of a single drive roller against which the rotary rings of the two groups are kept supported, each rotary ring comprising an outer edge of magnetic material, and being held supported on the single drive roller by a fixed support roller and by a magnetic device arranged between the fixed support roller and the single drive roller.

Claim 6

Device according to claim 3, wherein the magnetic device is arranged to draw the rotary ring concerned against the single drive roller and the fixed support roller.

Claim 7

Device according to claim 1, wherein the magnetic device is constituted by a permanent magnet.

Claim 8

Device according to claim 1, wherein the rotary rings form a fixed group (A) and a movable group (B) and the single drive roller comprises drive discs cooperating respectively with the rotary rings which each comprise a groove formed in the outer edge and in which the corresponding drive disc becomes positioned, the one or more fixed support rollers and the one or more magnetic devices being carried by a fixed support when it relates to a rotary ring of the fixed group (A) and by a movable support when it relates to a rotary ring of the movable group (B).

Claim 9

Device according to claim 1, wherein the one or more drive discs and the one or more fixed support rollers are provided with an outer edge constituted of flexible material enabling the driving of the rotary rings in rotation.

Claim 10

Device according to claim 1, wherein each rotary ring comprises on the inside one or several rings with a rounded inside edge and constituted of a flexible or rigid material enabling the driving of the filament.