GB1582536A - Selecting needles in circular knitting machines - Google Patents

Description

(54) SELECTING NEEDLES IN CIRCULAR KNITTING MACHINES (71) We, ELITEX - CONCERN ThXTILNLHO STROJ,IRENSTVI, a Corporate Body organised and existing under the laws of Czechoslovakia, of Liberec, Czechoslovakia, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to selecting needles in circular knitting machines.

Various types of electromechanical and electromagnetic needle selection methods and devices are known in both flat and circular knitting machines. One of the known types of electromagnetic selecting devices is based on the principle of pushing back the driven out selectors by swingable levers which are attached to all butts on the selectors. These swingable levers move in a plane, which might be horizontal or vertical, an electromagnet or electromagnets, respectively acting upon their other ends.

Another selecting principle consists in that the swingable levers or slide valves are controlled by electromagnets which only retain the levers in either an operative or inoperative position, and the swinging motion, or pushing out and pushing back being controlled by mechanical means, usually a cam and a spring.

The types of electromechanical selection devices as specified above are reliable in their operation. However, it is necessary for their correct operation to choose the appropriate dimension of the springs and to choose an optimum force of the retaining electromagnet in order to avoid selection failures due to fatigue, or dimensioning of springs, respectively, or due to the resistance of selectors against being shifted inside the tricks of the needle cylinder.

The purpose of the present invention consists in mitigating the above disadvantages and in forming such a device which would secure a safe and easily adjustable selection, particularly in small diameter circular knitting machines.

According to the present invention there is provided a circular knitting machine comprising tiltable selector jacks for controlling the selection of needles to take part in knitting, the selector jacks having butts arranged at different levels, selection elements associated with the selector jacks at the respective levels, the selection elements each having an operative end tiltable about an axis extending normally to the surface of the needle cylinder between an operative position for engagement with a selector jack butt and a rest position for nonengagement with a selector jack butt, mechanical means for tilting the selection elements from the rest position to the operative position, and electromagnets associated with the respective selection elements for retaining the respective selection element tilted from its rest position to its operative position in its operative position when the electromagnet is energised, the operative end of each selection element having a camming edge which leads the axis of tilting of the selection element in relation to the direction of rotation of the needle cylinder.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 represents diagrammatically the mechanical means for controlling selector jacks in the needle cylinder in axial section; Fig. 2 is a diagrammatic plan view of the mechanical means for controlling the selector jacks together with a representation of the location of retaining electromagnets.

Figs 3 and 4 show respectively the operative position and the rest position of a spring loaded selection element in side view, said element being controlled by an electromagnet and a lever of the mechanical transmission from the needle cylinder; Figs. 5 and 6 show respectively the operational position and the rest position of the operational selecting element in plan view; and Fig. 7 represents diagrammatically the distribution of control butts of adjacent selector jacks.

A one cylinder circular knitting machine is provided with a needle cylinder 1, in the tricks 2 which are mounted axially stationary but tiltable selector jacks 3 and above them intermediate jacks and thereabove needles (not shown). The needle cylinder 1 is mounted rotatably on bearing 4 in a lower flange 5.

The butts 6 of selector jacks 3 are distributed in four levels, one butt 6 being on each selector jack 3, as represented in Fig. 7.

Associated with butts 6 at various levels are in each feed selection elements 7, 8, 9, 10 (Fig.

1) which are tiltable about their longitudinal axes which are normal to the surface of needle cylinder 1 and intersect said cylinder at points located above the paths of the appurtenant butts 6, as shown in the example of the selecttion elements 7 relative to path a of butts 6 in Fig. 4.

The operative end of each selection element 7 to 10 is formed like a lever, on which is made a ramped edge for pressing back butts 6 and thus selector jacks 3 into tricks 2, as shown in Fig. 2. The selection elements 7 to 10 are mounted swingably in a block 11 mounted stationarily on the lower flange 5. At the other ends of selection elements 7 to 10 respectively are mounted sleeves with arms 12, 13, 14, 15 against which bear the lifted ends of levers 19, 18, 17, 16 in a normal position, said levers being loaded by tension springs, of which only one spring 16' appurtenant to lever 16, is represented in Fig. 2.The levers 16 to 19 are mounted swingably on pin 20 in block 11, and against their other ends which are swingable in horizontal planes, bear levers 21, 22, 23 and 24, which are loaded by not represented springs and are mounted swingably in stand 25 mounted stationarily on the lower flange 5. The ends of levers 21 to 24 bear against cam 26 mounted on the rotatable race of bearing 4.

The arms 12 to 15 of the sleeves are arranged between the ends of levers 19 to 16 and electromagnets E mounted on a not represented stand, as can be seen on the example of arm 15 in Fig. 3, said electromagnets being controlled from a not represented electronic programming device. Arms 12 to 15 are spring loaded by tension springs P likewise as in the example of Fig. 3 and 4 and their tilting motion, or the tilting motion of the operative ends of selection elements 7 to 19 into both the operative and inoperative position, respectively, is limited by stationary stops D, D' mounted in block 11.

The electromechanical selecting device operates as follows: The needle cylinder 1, and thus also cam 26 rotate in the direction S. The gauges between the scanning ends of levers 21 to 24 correspond to the gauges of needle tricks 2, or the gauges between the separate butts 6 of all selector jacks 3, respectively. Between butts 6 at the separate levels, gauges are made which correspond to the pitch of the teeth of cam 26, or gauges of a width including Sour tricks 2.

Thus, gradually are swung out, one after another, levers 2i to 21, which control levers 19 to 16 and said levers thereupon via arms 12 to 15 bring about the displacement of selection elements 7 to 10 into operative positions, in the space between the neighbouring butts 6 at separate levels.

On the example of controlling the selection element 7, the control operation between the operative and inoperative position is explained below. Before the claw of cam 26 contacts lever 21, the selection element 7 is in the inoperative position, as shown in Fig. 4, and thus above path a, along which pass butts 6. In that position, the selection element 7 is held by spring P, arm 15 bearing against stop D. As soon as the claw of cam 26 contacts lever 21, the selection element 7 is swung out via lever 16 and - arm 15 in the direction S, into the opera tive position as shown in Fig. 3. Arm 15 bears against stop D', and upon feeding current into electromagnet E, arm 15 is held fast, the selection element 7 remaining in its operative posi tion, and the ramped edge causing the selector jack 3 to be pressed back into trick 2, as shown in Fig. 5.

If no current is fed into electromagnet E, arm 15 and thus also selection element 7 are returned by spring P into their inoperative position, the butt 6 passing in the swung out position, as shown in Figs. 4 and 6, below the operative end of selection element 7. In both cases, after the claw of cam 26 bypassed lever 21, i.e. when into electromagnet either is or is not fed current, lever 16 by action of spring 16' and lever 21 by its spring are returned to their original positions, and upon releasing the pulse in electromagnet E, selection element 7 is again returned by spring P into the inoperative position.

In that manner proceeds the selection of each selector jack 3, the butt 6 of which is at the appurtenant level to the selection element 7.

In the same manner is performed also the selection of selector jacks 3, of which the butts are located at other levels, always one after the other, beginning with that selector jack 3, of which butt 6 is in a lowermost position as far as to the uppermost position, and again from the lowermost butt to the uppermost etc.

The selection of selector jacks 3 is performed in a reliable manner and the structural arrangement of the selection element has the advantage that the operative end is actually by action of butt 6 pressed against electromagnet E, its retaining force being thus minimal, its size reduced as well as the current value for its excitation. The selection elements are actually pressed by the butts of selectors into the operative position, as their axes are above the paths of the butts and behind the operative end of the selection element, whereby the reliability and efficiency of selection are substantially increased.

Claims (4)

WHAT WE CLAIM IS:

1. A circular knitting machine comprising tiltable selector jacks for controlling the selection of needles to take part in knitting, the selector jacks having butts arranged at different levels, selection elements associated with the selector jacks at the respective levels, the selection elements each having an operative end tiltable about an axis extending normally to the surface of the needle cylinder between an operative position for engagement with a selector jack butt and a rest position for nonengagement with a selector jack butt, mechanical means for tilting the selection elements from the rest position to the operative position, and electromagnets associated with the respective selection elements for retaining the respective selection element tilted from its rest position to its operative position in its operative position when the electromagnet is energised, the operative end of each selection element having a camming edge which leads the axis of tilting of the selection element in relation to the direction of rotation of the needle cylinder.

2. A circular knitting machine as claimed in Claim 1, wherein the selection elements are arranged relative to the needle cylinder in such a manner that their tilting axes are arranged apart from the path of the appurtenant selector jack butts.

3. A circular knitting machine as claimed in Claim 1 or 2, wherein each selection element is a two arm lever, and between the operative end forming one arm and the other arm oppositely to which are arranged the mechanical means for bringing about the tilting motion and the retaining electromagnet, is provided a pin for mounting tiltable the selection element.

4. A circular knitting machine, substantially as hereinbefore described with reference to the accompanying drawings.