GB2153858A - Jacks selecting device for knitting machine - Google Patents

Abstract

A jacks selecting device in a circular knitting machine comprises jacks selecting levers (6) assigned to individual butts of the jacks, and further levers (3) assigned to a programme means (1), the further levers (3) being assigned by one (34) of their arms to the selecting levers (6) and by the other arms (31) to rockable pawls (9), the teeth of which are assigned to detents (63) of the selecting levers (6). When a pin (2) pivots a lever (3) to allow the associated lever (6) to move to an inoperative position the pawl (9) engages in the detent (63) to limit the return motion of the lever (6) and thus to avoid inaccuracy of selection caused by inertia. In an alternative embodiment the programme means comprises a ribbed drum which acts on the levers (3) in cooperation with electromagnets. <IMAGE>

Description

SPECIFICATION Jacks selecting device This invention relates to a jacks selecting device in a circular knitting machine, especially for the production of hosiery and the like goods.

Known small diameter single-cylinder and double-cylinder knitting machines for the production of hosiery goods are provided in each knitting feed with patterning drums to select the needles, the pattern in said pattern drum being set-out by means of pins or similar elements arranged in individual rows one above the other. The pattern is sensed by a set of levers located one above the other, the other ends of the levers control directly the jacks located in longitudinal grooves of the needle cylinder. The pattern drum is driven by a racking device, the motion of which is derived from the cam arranged on the needle cylinder of the machine. In case of high speed of the needle cylinder, the effect of inertial masses causes retarded swing of selecting levers from the needle cylinder and thus faults in needle selection.

The object of the invention is to eliminate the above mentioned disadvantage.

The present invention provides a jacks selecting device in a circular knitting machine, especially for the production of hosiery and the like goods, comprising jacks selecting levers assigned to individual butts of the jacks, and further levers assigned to a programme means, the further levers being assigned by one of their arms to the selecting levers and by the other arms to rockable pawls, the teeth of which are assigned to detents of the selecting levers.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a plan view of a pattern drum with illustrated selecting and sensing means for jacks selection, in selecting position; Figure 2 shows the same as Fig. 1 but with the selecting means in the position where there is no selection; and Figure 3 shows the same as in the foregoing Figures, but instead of a pattern drum, the control is by means of an electromagnet and ribbed drum.

A known small dimater circular knitting machine is in the knitting feed provided with patterning drum 1 on the cylindrical surface of which are in a known way arranged programme elements in individual rows one above the other, in the exemplary embodiment they are pins 2. To patterning drum 1, or to inidvidual rows of pins 2 are assigned levers 3 located rockably on a vertical rod 4.

Each lever 3 is on one arm 31 provided with a sensing lug 32 and to the same arm 31 is fixed one end of a tension spring 33, the other end of which is fixed to a holder 5. The second arm 34 of lever 3 is assigned to a selecting lever 6. Selecting levers 6 are located rockably on a vertical rod 7. Each selecting lever 6 is provided with a nose 61 designed to press the not shown jacks in the needle cylinder. At the end of each selecting lever 6 is fixed one end of a tension spring 62, the other end of which is fixed to a holder 5'. Further each selecting lever 6 is provided with a detent 63 to which is assigned a tooth of a pawl 9. Pawls 9 are located rockably on a vertical rod 8, tension springs 91 are fixed to pawls 9, and the other ends of springs 91 are fixed to arms 31 of sensing levers 3.

The above described device operates as foilows. When knitting a patterned fabric, the patterning drum rotates in the direction S.

Before the moment when lever 3 runs on pin 2, as illustrated in Fig. 1, sensing lug 32 is on the surface of patterning drum 1, towards which it is forced by the action of tension spring 33. Arm 34 of sensing lever 3 bears against the selecting lever 6, the nose 61 of which is held at the needle cylinder by the action of the tooth of pawl 9, which bears against lever 6 beyond the detent 63 and secures the lever 6 in this position. Nose 61 presses the jack into the groove of the needle cylinder so that the jack cannot be raised by a cam. Position of the pawl 9 is fixed by the position of arm 31, towards which it is urged by spring 91.

When the sensing lug 31 runs on pin 2, as illustrated in Fig. 2, lever 3 is swung in the direction against the action of tension spring 33. At the same time its arm 34 swings away from the selecting lever 6 and the arm 31 presses the pawl 9. Pawl 9 swings in anticlockwise direction and its tooth passes over the edge of detent 63 of selecting lever 6. In this moment the tension spring 62 swings the selecting lever 6 so, that its detent 63 engages the tooth of the pawl 9. Thus the nose 61 of selecting lever 6 is withdrawn from the needle cylinder and no pressing of the jack takes place. The jack is then raised by the cam and selects the needle. The moment of engagement of the pawl 9 in the detent 63 precisely determines the return motion of selecting lever 6 and the effect of inertia forces of rotating patterning drum and hence inaccuracy of selection at high speeds is avoided.

Within the extent of the invention, the programming means of a mechanical type, i.e.

the patterning drum may be replaced even by an electromechanical control. Instead of a patterning drum a longitudinally ribbed drum 1' (Fig. 3) is used, ribs 2' of the drum 1' controlling the swing of levers 3. Individual electromagnets E are assigned to the ends of arms 31 of levers 3. The device may be used in all types of circular knitting machines.

Claims (8)

1. Jacks selecting device in a circular knitting machine, especially for the production of hosiery and the like goods, comprising jacks selecting levers assigned to individual butts of the jacks, and further levers assigned to a programme means, the further levers being assigned by one of their arms to the selecting levers and by the other arms to rockable pawls, the teeth of which are assigned to detents of the selecting levers.

2. Jacks selecting device according to Claim 1, wherein the selecting levers are single-arm and spring-loaded, so that they act against the further levers assigned to the programme means which further levers are also spring-loaded so that they act reversely on the selecting levers.

3. Jacks selecting device according to Claim 1 or 2, wherein the pawls are springloaded by tension springs, the other ends of which are fixed to the arms of the further levers assigned to the programme means, while they also bear against said arms.

4. Jacks selecting device according to Claim 3, wherein the programme means is assigned to the arms of the further levers against which the pawls bear.

5. Jacks selecting device according to any preceding Claim, wherein the programme means is a patterning drum.

6. Jacks selecting device according to Claim 4, wherein the programme means is at least one electromagnet assigned to one side of the arms of the further levers and a rotary drum assigned to the other side of the arms.

7. Jacks selecting device in a circular knitting machine, substantially as hereinbefore described with reference to Figs. 1 and 2 of the accompanying drawings.

8. Jacks selecting device in a circular knitting machine, substantially as hereinbefore described with reference to Fig. 3 of the accompanying drawings.