The present invention concerns a combing machine and respective comber groups for cotton strip particularly downwards drawing machines.

This solution is conveniently applicable for the combing and the separation in stumps (example of 20-30 centimeters) of fibers aligned tape (cotton strip) successively rolled up, these stumps after drawed being rejoined in new in cotton strips that successively is twined in wire form.

In prior art these machines and respective comber groups and respective technology are known (Rif. "Pettinatura del cotone" Chapter III pag .250 and followings of the book in the name of Carlo Carminati "II filatore di cotone", editor U. Hoepli 1960, see also US PS 3562865 in the name of H. Heichenberger et al). These comber groups essentially comprise: - A combing roll of the end of the cotton strip or involving fringe circular sector of combing tips; - A nipper group with upper nipper jaw and lower nipper jaw movable with the cotton strip and an upper guide for the separation of the combed cotton from the continuous cotton strip. And this obviously for the successive operations as expressed and explained in introduction well known prior art means.

The drawbacks of this solution consist in the fact that for the operation of the two drawer roll couples, a very complex gearing transmission and inverter system is required in order to allow a perfect synchronized movement of the

rotation of the drawer rolls with the combing roll and the respective nipper group.

A gear transmission system as above exposed is bulky, complex and expensive and needs a container in closed box for the gears in bath of oil, with consequent frequent necessity of maintenance.

Scope of the present ^' invention is to obviate to said drawbacks.

This and other scopes are reached with the present invention as claimed, by means of a tearing combing roll couple group rotating in both directions and between said combing roll and said tearing group, a nipper group with upper nipper jaw and lower nipper jaw mobile with the cotton and an upper guide comb for separation of the combed cotton from the continuous cotton strip, Characterized in that: - in at least one axis of said tearing couple of tearing group a step by step reversible electric motor is connected for their rotation - an electric corresponding impulses emitter of respective angular rotational values is associated to the rotation axis of said combing roll; - said electric impulses emitter is connected to a programmable computer to elaborate said impulses connected to said step by step reversible electric motor, in order that with opportune software , - it is possible to allow movement in programmed mode said tearing rolls both in clockwise and in counterclockwise direction in function of the corresponding impulses to determined rotation angles of said combing roll.

With this solution we obtain the advantage to eliminate all the mechanical in oil bath gear transmission system previously necessary for synchronization of the movements of the combing roll and of the drawer roll couples,

eliminating even the mechanical complexity of a rotation inverter, and reducing the encumber to a minimum size required with this new solution that requires only a small electric motor to the end of one axis of only one of said drawer roll couples, being the second couple operated by a simple not expensive gear transmission using an intermediate idle gearing wheel for obtaining the same rotation with same angular speed. ^■ The invention is better understood with the joined description and drawings as an example, in which: Figure 1 represents a frontal schematic view of an operator group according to the invention. Figure 1 is a frontal schematic view of an operating group of the invention. Figures 2 ,3 ,4 represent in transverse section the schematic view of three successive phases of the displacement of the comber group.

Making reference to the drawings the invention concerns: . A combing machine and respective comber groups for cotton strip wherein each comber group includes: - a combing roll (5) of the cotton fringe (p) involving a circular sector of combing tips (51 ); - a tearing combing roll couple group rotating in both directions (1 ) and between said combing roll (5) and said tearing group (1) , - a nipper group with upper nipper jaw (.2) and lower nipper jaw (4) mobile with the cotton (p) and an upper guide comb (3) for separation of the combed cotton (p1) by the continuous cotton strip (p) , characterized in that: - in at least one axis (121 ) of said tearing couple of tearing group (12) a step by step reversible electric motor (6) is connected for their rotation; - an electric corresponding impulses emitter of respective angular rotational values is associated to the rotation axis of said combing roll (52) ;

- said electric impulses emitter is connected to one programmable computer to elaborate said impulses connected to said step by step reversible electric motor (6), in order that with opportune software , - it is possible to allow movement in programmed mode said tearing rolls (11 12) both in clockwise and in counterclockwise direction in function of the corresponding impulses to determined rotation angles of said combing roll ( 5 ) . Advantageously: - the drawer roll couples are two and each drawer roll couple involves a lower drawer motor toothed roll (112) and an upper idle smooth counterroll ( 1 1 1 ) . - the- step by step driving motor(6) involves a reducer in which the motor axis act by central pinion (61 ) that commands in the same rotation in mesh two driven gears (62) coaxial and keyed with the respective axes of the drawer rolls (121 ).

The working system of the comber group is indicated according to well known prior art in figures 2 to 4 in which: - in Figure 2 is illustrated the phase in which the cutting and guide group of the continuous cotton strip is portrayal and the combed stump (p1) is extracted to be conveyed to the throwing by means of rotation in counterclockwise sense of the drawer rolls 1 , while the combing roll (5) begins the combing of the cotton (p) advancing it by means of engagement with the own toothed sector (51 ); - in Figure 3 after combing that advanced the combed cotton being even in the same time advanced with the nipper guide group (2-3-4) toward the couples of the drawer rolls and after that these have taken the combed head of the cotton and advancement and when the combing roll (5) is disengaged from the cotton with the own combing sector (51 ), the respective rotation is inverted;

- in Figure.4 it is shown the following phase at the moment of the clamping of the cotton with the comb 3, being the drawer rolls (1 ) again made rotate in advancing direction.

The drawer rolls rotation synchronism in clockwise and in counterclockwise direction with the combing roll that before this invention was realized with gearing means, and now is carried out by means of the invented system above exposed, taking particularly in account the rotation angle of the combing roll corresponding to the hoop arch that covers the corresponding combing sector (51 ) which is the essential element that determines the rotational behavior of the drawer rolls . We understand so that with a pulse emitter programmed for rotation angles on the axis of the combing roll (5) and in collaboration with a computer, respective program and command to one electric step by step motor, we can transmit to the drawer rolls the desired movement (1 ) without expensive, bulky and complex mechanical transmissions.