HK1049030B - Sliding-tongue compound needle for a knitting machine - Google Patents

Description

Sliding latch compound needle for knitting machine

Technical Field

The invention relates to a sliding latch compound needle for knitting machines, comprising a knitting needle and a sliding latch at least partially straddling the knitting needle: the needle is provided with a hook, the sliding latch is provided with at least one butt and has an end and a shoulder; the bottom of the sliding latch is slotted longitudinally in its distal region, comprising the end and the shoulder, so as to allow the end to be separated by the needle or by an opposite sliding latch, which can be moved with respect to the needle so as to close and open the hook of the needle and drive a loop through the shoulder of the sliding latch.

Prior Art

A knitting needle is described in patent application EP0881315 of the applicant. In the embodiment described in this document, the bottom of the sliding latch and the upper edge of the knitting needle are rectilinear and parallel to the direction of travel of the knitting needle. The movement of the latch is therefore also rectilinear and parallel to the direction of travel of the needle. Thanks to this structure, when the needle advances with respect to the sliding latch into a position ready to transfer a loop, the loop to be transferred will have to ride on a slope on the needle until it has practically the same height as the bottom of the sliding latch. The result is that an upward pulling force is exerted on the coil and has the effect of enlarging the coil. This effect is further enhanced when the sliding latch advances and carries the loop on the hook of the knitting needle, the end and the shoulder of which pass very much on the hook of the knitting needle. The fineness of the stitches that can be knitted is limited.

In conventional composite needles of the earlier type, the needle is equipped with a hook in the form of a slider, said needle being located below a sliding channel which closes and opens said hook. In patent FR2652593 a device for raising and lowering the sliding channel with respect to the bottom of the groove of the needle has been proposed, in order to reduce the friction and the tension on the loop carried by the needle and to obtain a more uniform stitch. These devices have, on the one hand, a supporting effect at the bottom of the groove of the needle and, on the other hand, an action of exerting a lever effect by means of the needle pusher. However, the path of the ends of the sliding channel cannot be controlled sufficiently tightly and, in addition, because of the overall design of the knitting needle, the sliding channel cannot be moved beyond the hook of the knitting needle but can only be moved back and forth relative to the bottom of the sliding latch between a lower position and a raised position.

Summary of The Invention

The aim of the invention is to achieve a finer and more uniform knitting of the stitches and to make it easier to transfer the stitches to one or more receiving elements.

To this end, the composite needle with sliding latch according to the invention has means for positioning and vertical guiding the sliding latch at all positions of its movement with respect to the needle, these means for guiding and vertical positioning all being constituted only by the particular shape of the needle and of the sliding latch, so that the sliding latch moves along a non-linear path controlled at all points and with a raising and lowering motion.

By guiding the sliding latch in a well-controlled manner, these guiding means have the effect of reducing the vertical tension acting on the coil and thus reducing coil enlargement as much as possible. So that finer and more uniform loops can be knitted.

According to a preferred embodiment of the invention, the bottom of the sliding latch opens between the butt and the vicinity of the midpoint of the sliding latch, and the needle has an arm extending from the rear forward substantially parallel to the body of the needle; the arm passes through the sliding latch through its open bottom and extends above a solid portion of the sliding latch so as to form, together with the body of the needle, a fork in which the sliding latch is guided.

For the purpose of guidance, the internal dimensions of the fork and the bottom and back of the solid part of the sliding latch advantageously have the shape of cams (cam) to provide a non-linear movement of the sliding latch, i.e. to raise and lower the latch with respect to the knitting needle.

According to one embodiment, the sliding latch has at least one support point at its rear portion, which cooperates with the body of the needle to prevent the sliding latch from accidentally swinging and/or causing the rear portion of the sliding latch to move in a vertical plane with respect to the needle. In this last example, at least one side of the needle body against which the support point abuts is in the form of a cam.

Brief Description of Drawings

The drawings show, by way of example, one embodiment of the invention.

FIG. 1 is a side view of the sliding latch compound needle.

Fig. 2 shows the knitting needle and the sliding latch separated from each other.

Fig. 3 shows an enlarged view of the front part of the sliding latch as seen from above.

Figures 4 to 11 show eight successive positions of the sliding latch with respect to the needle moving from one extreme position to another, in particular to the case of transferring the loops.

Description of the preferred embodiments

The shape of the knitting needle and the sliding latch will be described first with reference to fig. 1 to 3.

The compound needle comprises ｃA needle 1 and ｃA sliding latch 2, the sliding latch 2 straddling the needle 1 in ｃA manner similar to that of the sliding latch needle described in document EP- ｃA-08881315. For this purpose, the sliding latch 2 has an inverted U-shaped profile, but for reasons that will become apparent later, only over a part of the length of the latch 2.

The needle 1 is equipped with a hook 3 in a conventional manner. In the illustrated embodiment, the knitting needle 1 is equipped with a butt 4, which butt 4 is intended to be driven by the cam of a carriage. However, the needles can be driven by a drive screw. Said needle is provided, near its middle, with a forwardly extending arm 5, which forwardly extending arm 5 is above the needle body, parallel to the longitudinal axis of said needle; that is to say parallel to the direction in which the needles travel in their needle beds. The needle 1 and the arm 5 form a fork 6, the inner flanks 7 and 8 of which have a non-linear cam-like profile. The cam-like side 7 extends beyond the fork 6 to a point where it has a recess 9, after which recess 9 a ramp 10 rises forward. The needle is inclined in a known manner in a manner tapering in the forward direction of the bevel 10, forming a downward bevel 11 up to the hook 3.

The sliding latch 2 has in front of it an end 12, which end 12 is located in front of a shoulder 13, and is equipped with a butt 14 at the rear of the sliding latch 2 for driving it. The bottom of the sliding latch 2 is removed at two points; at its distal end, on the one hand, in a portion in front of a point 15 located slightly behind the shoulder 13, and at its rear half 16, on the other hand, between the butt 14 and a point 17, said point 17 being located substantially at the midpoint of said sliding latch.

The distal end of the sliding latch, seen from above, is shown in fig. 3. The interruption of the U-shaped profile of said sliding latch forms a slot 18 which narrows at the end of the sliding latch to form the end 12; the sides of the slot 18 meet at the end of the end 12. The two sides of the groove 18 may be resiliently separated from each other.

The interruption 16 at the bottom of the sliding latch forms a cut whose width corresponds to the thickness of the needle. The arm 5 of the knitting needle passes through said cut and extends over the sliding latch body, that is to say over the bottom uninterrupted region 29 of said sliding latch. The region 29 has a bevel 19 on the front outer portion terminating in a nose 20 and a small protrusion 21 on the rear portion. The sliding latch has a first projection 22 at the bottom, inside the front, and a second projection 23 at the rear. The bottom of the sliding latch has a slight depression between the two projections.

The sliding latch 2 has, at its rear part, at the level of the butt 14, two support points 33 and 34 respectively cooperating with the upper 35 and lower 36 sides of the bottom of the needle, to prevent accidental swinging of the sliding latch. In addition, these support points can be used to cause an additional movement of the sliding latch with respect to the knitting needle, for example to retract the butt 14 with respect to the cam of the carriage, or to obtain a finer and more precise movement of its end 12. In this case, at least one of the side faces 35, 36 of the needle body is non-linear, i.e. in the form of a cam. The support point 33 is formed by a projection in the bottom of the sliding latch, while the support point 34 is formed, for example, by upsetting the material of the side wall of the sliding latch.

As regards the internal profile of the fork 6 of the needle, it has, starting from the end of the arm 5, a disengaging bevel 32, followed by a protuberance 24, then a slight depression and a second protuberance 25, which is not very marked, and an upper portion 26 on the needle body, which upper portion 26 has a constant height between the depression 9 and a bevel 27 ending in the depression 28.

As can be seen from fig. 1, when the needle is assembled, the region 29 of the sliding latch is located in the fork 6 of the needle, the latter providing a non-linear guide when the sliding latch 2 is moved. In fig. 1, the sliding latch is shown in its rearmost position on the knitting needle. In this position, the projection 24 of the arm 5 of the needle rests on the nose 20 of said sliding latch, which has the effect of positioning the end 12 of the sliding latch in a lower position with minimum height with respect to the needle. In this position, the two sides of the end 12 are separated by the needle 1, so that the end 12 and all the points of the recess behind it are below the upper edge of the needle.

The complete movement of the sliding latch on the knitting needle is described below with reference to fig. 4 to 11, in which 8 successive positions of the sliding latch with respect to the knitting needle are represented starting from the position shown in fig. 1, which is the same as the position shown in fig. 4, in fig. 4 to 11.

The sequence shown represents the transfer of one coil.

In the position shown in fig. 4, the sliding latch 2 is positioned in the fork 6 by its nose 20 and projection 22. The end 12 of the sliding latch is open and is located below the upper edge of the needle 1. The two sides of the end 12 rest against two milled surfaces 30 on the sides of the needles, which reduce the thickness of the needles and thus reduce the extent of opening of the end 12 so as not to exceed the width of the sliding latch. The loop 31 to be transferred is carried by the knitting needle so as not to exert pressure on the sliding latch 2 supported in cantilever fashion and to avoid slowing down of the latter. The end 12 is at this moment at a height H1 with respect to the lower edge of the needle, that is to say at this height H1 with respect to the bottom of the needle slot of the needle holder in which the needle slides. This height H1 is the minimum height of the end portion 12 in the path of the sliding latch.

When the sliding latch 2 advances, its projection 22 rises from the needle bevel 27 onto the upper portion 26 (fig. 5). The sliding latch is held and guided towards the top by the projection 24 of the arm 5 of the knitting needle. The sliding latch rises just enough to have the recess at the rear of the end 12 of the sliding latch slightly above the level of the needle. During the raising of the sliding latch, the end 12 is closed again and carries the loop 31 with the shoulder 13 of the sliding latch. The height H2 reached by the end 12 of the sliding latch is the highest level reached by the sliding latch during its movement with respect to the knitting needle.

The sliding latch 2 continues to advance, resting on the top 26 of the constant height of the needle, i.e. remaining at height H2, as shown in fig. 6.

The projection 22 of the sliding latch then leaves the portion 26 of the needle, so that the end 12 of the sliding latch falls towards the hook 3 of the needle, as shown in figure 7.

During its further lowering, the sliding latch 2 covers the hook 3 of the knitting needle with its end 12, as shown in fig. 8. This movement corresponds to the closing movement of a conventional latch needle by its latch.

As the sliding latch continues to move, its projection 22 reaches the needle bevel 10, so that the sliding latch 2 and its end 12 start a lifting movement (fig. 9) which continues until the end 12 reaches a height H4 (fig. 10). The purpose of this raising movement is to prevent the hook 3 of the knitting needle from hooking the filament of the loop 31 resting on the sliding latch.

Once having passed the hook 3, the projection 22 of the sliding latch 2 falls back along the bevel 11 of the needle and leaves it, while the projection 23 occupies above the surface 26 of the needle and the end 12 reaches a lower height H5 and remains at this height until the end of its stroke. The effect of this falling movement is to avoid deformation of the coil 31 under tension (fig. 11).

In the position shown in fig. 11, the loop 31 can be gripped by the opposite needle (transfer) or by a sliding latch (transfer between adjacent needles), as described in EP 0881315; that is to say by introducing the needle or sliding the latch into the end 12.

In a further embodiment, the sliding latch can completely straddle the knitting needle and can be equipped with two or more butts. Such a sliding latch may have a single support point, such as support point 34 (fig. 2), at its rear.

Claims (8)

1. Sliding latch compound needle for knitting machines, comprising a needle (1) equipped with a hook (3) and a sliding latch (2) straddling the needle at least partially and equipped with at least a butt (14), an end (12) and a shoulder (13), the bottom of which is slotted longitudinally (18) in its distal area comprising the end (12) and the shoulder (13) so as to allow the separation of the ends, which can be moved with respect to the needle in order to close and open the hook of the needle and to actuate a loop (31) through its shoulder, characterized in that it has the particular shape of a cam (24-28) interacting with the particular shape (22) of the sliding latch, when the sliding latch (2) has a raising and lowering motion with respect to the needle (1) and moves in a controlled manner at all points, the particular shape of these cam shapes constitutes completely and individually the positioning and non-linear path guide (6) for the sliding latch (2).

2. Composite needle as in claim 1, characterized in that the bottom of the sliding latch (2) opens (16) between its butt (14) and the vicinity of the midpoint (17) and in that it has an arm (5) extending forward from its vicinity of the center and substantially parallel to the body of the needle, this arm extending through its open bottom (16) above the solid portion (29) of the sliding latch, forming with the body of the needle a device (6) in which the sliding latch is guided.

3. Composite needle according to claim 2, characterized in that the internal dimensions (28) of the device (6) and the bottom and back of the solid part (29) of the sliding latch are cam-shaped to provide a non-linear movement of the sliding latch, i.e. to raise and lower it with respect to the needle.

4. Composite needle according to claim 3, characterised in that the needle (1) has two lateral milling surfaces (30) for reducing the opening of the end (12) of the sliding latch separated by the needle when the end is lowered below the upper edge of the needle.

5. Composite needle as in any claim from 1 to 4, characterized in that the particular shape of the cam shape of the needle is such that, when the sliding latch is at its maximum with respect to the needle (1), its end (12) is below the upper edge of the needle, so that in this position of preparation for transfer, the loop is supported by the needle.

6. Composite needle as claimed in claim 5, characterized in that the particular shape of the cam shape of the needle and of the sliding latch cooperating therewith are such that: when the sliding latch (2) moves forward with a loop starting from its position of maximum retraction, it is first raised to carry the loop on its shoulder, then lowered again to the position in which the hook of the needle is closed, then raised slightly again to avoid the hook catching the thread of the loop, and finally lowered again to reduce the tension acting on the loop.

7. Composite needle as in any claim from 1 to 4, characterized in that said sliding latch has at least one support point (33, 34) at its rear portion to cooperate with the body (35, 36) of the needle to prevent accidental swinging of the sliding latch and/or to cause movement of the rear portion of the sliding latch with respect to the needle in a vertical plane.

8. Composite needle according to claim 7, characterized in that at least one of the sides (35, 36) of the needle body against which the support points (33, 34) bear is cam-shaped.