False twisting apparatus

Claim 2

A rotary twisting member for imparting a twisting force to threads in contact with the twisting member when it rotates, comprising: flange means extending in the plane of rotation of said twisting member; an annular thread contacting surface having a plurality of annular segments peripherally disposed on said flange means including: an annular segment formed from material having a relatively high coefficient of friction, adapted to impart twisting forces to thread in contact with said segment; an annular segment formed from material having a relatively low coefficient of friction adapted for guiding a thread in contact with said segment.

Claim 3

A rotary twisting member according to claim 1 wherein the annular segment formed from material having relatively high coefficient of friction is disposed on the thread contacting surface at the point of maximum velocity of said thread contacting surface as it rotates.

Claim 4

A rotary twisting member according to claim 2 wherein said annular segments formed from material having relatively low coefficient of friction are disposed on opposite sides of said annular segment formed from material having a relatively high coefficient of friction.

Claim 5

A rotary twisting member according to claim 3 wherein said contacting surface is symmetrically shaped with relation to the annular segment formed from material of a relatively high coefficient of material.

Claim 6

A rotary twisting member according to claim 2 wherein said contacting surface is convex in cross section.

Claim 7

A rotary twisting member according to claim 2 wherein said contacting surface is cylindrical in cross section.

Claim 8

A rotary twisting member according to claim 2 wherein said rotary twisting member includes a friction disc comprising: flange means extending in the plane of rotation of said rotary twisting means; said contact surface being formed on the peripheral edge of said flange means.

Claim 9

A rotary twisting member according to claim 7 wherein said annular segments formed from material having relatively low coefficient of friction are disposed on opposite sides of said annular segment formed from material having a relatively high coefficient of friction.

Claim 10

A rotary twisting member according to claim 8 wherein said contacting surface is symmetrically shaped with relation to the annular segment formed from material made of relatively high coefficient of material.

Claim 11

A rotary twisting member according to claim 7 wherein said contacting surface is convex and is asymmetrically formed with respect to said annular segment formed from material having a relatively high coefficient of friction.

Claim 12

A rotary twisting member for imparting a twisting force to threads in contact with the twisting member when it rotates comprising: a tubular section for the passage of thread to be twisted; a mouth at each end of said tubular section; an annular thread contacting surface having a plurality of annular segments formed on each of said mouths; said annular thread contacting surface including: an annular segment formed from material having a relatively high coefficient of friction, adapted to impart twisting forces to thread in contact with said segment; an annular segment formed from material having a relatively low coefficient of friction adaptEd for guiding a thread in contact with said segment; means rotatably supporting said tubular section; thread guide means disposed adjacent each mouth of said rotary twisting member; said thread guide means connected to said means rotatably supporting said tubular section.

Claim 13

A rotary twisting member for imparting a twisting force to threads in contact with the twisting member when it rotates comprising: a tubular section for the passage of thread to be twisted; a mouth at each end of said tubular section; an annular thread contacting surface having a plurality of annular segments formed on each of said mouths; said annular thread contacting surface including: an annular segment formed from material having a relatively high coefficient of friction, adapted to impart twisting forces to thread in contact with said segment; an annular segment formed from material having a relatively low coefficient of friction adaptEd for guiding a thread in contact with said segment; means rotatably supporting said tubular section; thread guide means disposed adjacent each mouth of said rotary twisting member; said thread guide means connected to said means rotatably supporting said tubular section.

Claim 14

A rotary twisting member according to claim 11 wherein said annular segments formed from material having relatively low coefficient of friction are disposed on opposite sides of said annular segment formed from material having a relatively high coefficient of friction.

Claim 15

A rotary twisting member according to claim 12 wherein said contacting surface is convex in cross section.

Claim 18

The device for false twisting threads according to claim 14 wherein: said plurality of friction disc comprise: at least three mutually overlapping friction discs; the axis of rotation of said three mutually overlapping friction discs disposed to form the corners of a substantially equilateral triangle; the contact surfaces of said plurality of friction discs coacting to cause thread passing through said false twisting device to travel on a substantially helical path.

Claim 19

The device for false twisting threads according to claim 15 further comprising: a spindle; said plurality of rotary twisting members disposed in spaced relation on said spindle; and means to synchronously drive said plurality of rotary twisting members on said spindle.

Claim 20

The device for false twisting threads according to claim 16 wherein said plurality of rotary twisting members are disposed on three spindles positioned to form, in the plan view, a substantially equilateral triangle.

Claim 21

The device for false twisting threads according to claim 16 wherein the coefficient of friction of said annular segments formed from material of a relatively high coefficient of friction varies in predetermined relationship for said friction discs spaced along said spindle.

Claim 22

The device for false twisting threads according to claim 17 wherein the spacing between said friction discs spaced on said spindle varies in a predetermined relationship.

Claim 23

The device for false twisting threads according to claim 17 wherein the thickness of said flange means of said friction discs mounted in spaced relation on said common spindle varies along the spindle in accordance with a predetermined relationship.