EP1197591B1 - Latch needle with resilient latch support - Google Patents

Description

The invention relates to a latch needle, in particular for knitting machines.

Both flat knitting machines and circular knitting machines Machine knitting needles are used. These have a needle body on which a hook (Head) is formed. The hook is a swivel stored tongue assigned between two end positions can be swung back and forth. In a final position the tongue lies with its spoon at the point of the hook and thus closes the hook interior. In her other End position is the tongue in reserve and gives the Hook interior free.

In some knitting machines, the tongues are desired the tongue needles near their two end positions each in a stable position. For example. becomes occasionally desired a stable tongue rest position, the the reserve (end position) is adjacent and in the tongue not abutting the needle shank. This should, for example. be achieved that the thread of a tongue closing Mesh in the space between the tongue and the needle shaft can slide, without the tip of the tongue (Tongue spoon) to be skewered.

Occasionally it is also required that the tongue has a stable rest position, the closed position (end position) is adjacent. This example., When the tongues by means of a provided on the knitting brush from her Closing position are transferred to their reserve. The brush finds a better attack on the tongues, if these of the Hooks are slightly splayed. They are not allowed though are spread too far, so as not to be damaged. By transferring the tongue from its locking system in their reserve the thread space is opened and Thus, a thread can be inserted for stitch formation.

To set stable resting positions of the tongue Feathers in use. For example. is from US-PS 3,050,968 like also from EP-A-0259563 a latch needle is known, which has a needle body with a end hook formed on the needle body and a arranged adjacent to the hook and pivotally has stored tongue. The tongue sticks out with hers Shank end in a tongue slot, the across of a Bearing pin is penetrated. This stores the tongue pivotable between a closed position in which the tongue with her spoon at the tip of the hook, and one Reserve in which the hook interior is open. By doing Tongue slot is also arranged a bending spring, which is in contact with the shaft end of the tongue. The Shank end has a flattened area or, in the case of EP-A0259563, two flattened areas, Serve contact surfaces and where the spiral spring with Abut pressure surfaces. As a result, one or two stable rest positions the tongue determines, in which the tongue spoon something of the Hook tip or the shaft is lifted.

To achieve the lifting of the tongue from the point of the hook, a relatively large restoring force must be provided what is very difficult with this type of spiral spring to achieve.

From practice and DE-A-1 410 312 are beyond tongue needles with spring-supported tongue known as in the figures 7 and 8 are illustrated. Such a latch needle 1 has a needle body (shank) 2 with an end-side Hook 3 and a hook tip 4 on. On the hook 3 joins a shaft area in which a tongue slot 5 is formed. In this is a tongue 6, e.g. pivotally mounted by means of a bearing pin 7. In the tongue slot 5, a spring 8 is arranged, which is with both ends 11, 12 at corresponding seats 10, 14th supported, which are formed in the slot 5. The feather (Leaf spring) 8 has on both sides of the journal 7 bending points 15, 16, which, as FIG. 7 illustrates, with a back 17 of the tongue 6 or, like Figure 8 illustrates with an inner side 18 of the tongue 6 can come into contact and thus pressure surfaces form.

With such a basic structure is that of the spiral spring 8 set rest position of the tongue 6 substantially from the positioning of the bearing pin 7 to the bending points 15, 16 dependent. Lowest tolerances in the spring production or influence in the formation of the journal 7 the rest position of the tongue 6 drastically. A tolerance the position of the journal 7 in the longitudinal direction of the latch needle 1 gives a significant positioning error in a quiet location. This can, when the tongue in the Reserve is located, a thread, during the withdrawal movement the needle, be impaled by the tongue spoon, or in Closing position, the brushes may be the tongue do not capture. The function of the latch needle is not more safely guaranteed.

In addition, a tolerance results in the position of the journal 7 between needle back 9 and needle breast 19 a significant deviation of the restoring forces of hers optimal value. If the restoring forces are too low, can the tongue can not be transferred to their rest positions are the restoring forces too high, the tongue moves (squirts) over this rest position and is possible damage exposed. The function of the latch needle is not more safely guaranteed.

Both the position of the tongue in their respective Resting position, as well as the force with which the tongue in this Rest position is transferred and held, which influences Quality of the stitch pattern of the knitted fabric to be produced.

It is an object of the invention to a latch needle create, with which to achieve an improved knitting pattern leaves.

This task is performed by the latch needle with the Characteristics of claim 1 solved.

The latch needle according to the invention has a spring on, the at least one stable, different from an end position Quiescent setting. Serve two contact surfaces on the tongue and two pressure surfaces on a spring, which is associated with the tongue. This succeeds both, the rest position of the tongue by interaction of the first Set pressure surface with the first contact surface, as also to bring out the tongue from the adjacent end position. For example, can the lifting of the tongue from the hook through the second contact surface and the second pressure surface brought about become. This has the advantage of taking off the tongue of the hook, for example, with a relatively large Return torque can be effected while adjusting the rest position e.g. with lower restoring moments he follows. This will ensure a safe lifting of the tongue from reached the hook and on the other hand it is achieved that a tongue sliding over the tongue very much the tongue easy to push on the hook. At least that's how it is long, until the tongue near its end position a larger one Receives counter moment. The tongue tends therefore in to a much lesser extent, the time passing over them To stretch mesh, as it is in the case of latch needles Figure 7 and 8 is the case where a single Investment and pressure surface of the tongue from its end position in the respective rest position transferred.

In addition, the latch needle according to the invention is essential less sensitive to manufacturing tolerances, as the latch needle according to Figure 7 or 8. The stable rest position is through the first print area and the first Fixed contact surface, with the first contact surface preferably arranged at the end of the tongue shaft is. The pressure surface of the associated spring is here preferably parallel to the longitudinal direction of the spring, i.e. parallel or in only a small point Angle arranged to a line connecting the two ends the compression spring connects together. This will be the Influence of manufacturing tolerances when bending the spring or in the positioning of the same relative to the tongue pushed back in the tongue slot largely.

In the latch needle according to the invention are the Pressure and contact surface for guiding the tongue out their respective end position of the pressure and contact surfaces separated (spaced), which serve the tongue in their respective rest position. This allows the Tongue with relatively low restoring forces in its rest position being held. This prevents the tongue with too much force and therefore too much speed jumps into its stable rest position and possibly over the Target shoots out. Such cases, in needles after the State of the art can occur and to a faulty Mesh image or possibly to damage the Needles or the tongues can, with the inventive Tongue needle avoided or largely excluded become.

It is considered advantageous, the latch needle form so that the first pressure surface and the first Contact surface are disengaged when the tongue in its end position is located and that the second pressure surface and the second contact surface are disengaged, when the tongue is in its rest position. These Measure separates the movement areas of the tongue, in which the first and second abutment surface pressure surface pair, respectively is effective. This allows the restoring moments of the tongue in the relevant ranges of motion independently of each other be set.

Preferably, the first contact surface of the tongue is in arranged a distance to the pivot axis, the lower is the distance of the second contact surface to the Pivot axis. This allows the achievement of relatively large, but for short-stroke restoring moments by the second contact surface. These great restoring moments can a particularly safe lifting of the tongue from the hook on the other hand, because of their Kurzhubigkeit not or hardly contribute to widen the mesh.

The first contact surface is preferably arranged such that that she defines a triangle with the axis of rotation, of the contact surface adjacent inner angle peak Angles are. As a result, every turn of the Tongue from its rest position, the spring spans, with what the rest position set stable in both pivot directions becomes. This also contributes to the rest position of the Adjust the tongue precisely.

In a possible embodiment of the latch needle is the pivoting range in which the second pressure surface with the second contact surface in operative engagement (at least linear, marginal or point contact), smaller than the swivel range in which the first contact surface or their shank-side or end-side edge with the printing surface is in contact.

The first contact surface is preferably a plane surface. Alternatively, however, can also be a concave or convex be provided curved surface. The contact surface acts as a cam surface. The training as a plane surface has the advantage of a precise adjustment of the desired Rest.

The latch needle according to the invention can also be designed in this way be that the tongue has two defined rest positions which are adjacent to their respective end positions. This is then served by a third and fourth contact surface the tongue and a third and fourth pressure surface at the Feather. The printing surfaces, especially the first and third Pressure surface of the spring, can be identical or each other at least partially overlap, i. a common Include surface area.

It has proved to be useful, the Pressure surface of the spring measured in the longitudinal direction at least twice as big as their thickness. This ensures sufficient stability of the desired rest position.

Further details of advantageous embodiments The invention will become apparent from the drawing, the description or subclaims.

Fig. 1 eine erfindungsgemäße Zungennadel, in teilweiser geschnittener schematisierter Darstellung, mit Zunge in Schließlage,

Fig. 2 die Zungennadel nach Figur 1, mit Zunge in einer ersten Ruhelage, in einer schematisierten und teilweise aufgebrochenen Darstellung,

Fig. 3 die Zungennadel nach Figur 1 und 2, mit der Zunge in einer zweiten stabilen Ruhelage, in einer schematisierten und teilweise aufgebrochenen Darstellung,

Fig. 4 die Zungennadel nach Figur 1 bis 3, mit Zunge in Rücklage (Endlage), in schematisierter und teilweise aufgebrochener Darstellung,

Fig. 5 die Zungennadel nach Figur 1 bis 4, in schematischer Darstellung, mit Veranschaulichung verschiedener Zungenpositionen, in schematisierter Darstellung,

Fig. 6 die auf die Zunge der Zungennadel nach Figur 1 bis 5 wirkenden Rückstellmomente, in Abhängigkeit von der Schwenklage der Zunge, in Prinzipdarstellung als Diagramm, und

Fig. 7 und

Fig. 8 eine Zungennadel nach dem Stand der Technik.

In the drawing, an embodiment of the latch needle according to the invention and a latch needle according to the prior art are illustrated. Show it:

1 shows a tongue needle according to the invention, in a partially cut schematized representation, with tongue in the closed position,

2 shows the latch needle according to FIG. 1, with tongue in a first rest position, in a schematized and partially broken view,

3 shows the latch needle of Figure 1 and 2, with the tongue in a second stable rest position, in a schematic and partially broken away representation,

4 shows the latch needle of Figure 1 to 3, with tongue in reserve (end position), in a schematic and partially broken view,

5 shows the latch needle according to FIGS. 1 to 4, in a schematic representation, with illustration of different tongue positions, in a schematic representation,

Fig. 6 acting on the tongue of the latch needle of Figure 1 to 5 restoring moments, in dependence on the pivotal position of the tongue, in a schematic diagram as a diagram, and

Fig. 7 and

Fig. 8 shows a latch needle according to the prior art.

FIG. 1 illustrates a latch needle 1, one shaft 2 and one end on the shaft 2 trained hook 3 has. The hook 3 runs in one Hook tip 4 off. Following the hook 3 is in the shaft 2, a tongue slot 5 is formed in which a Tongue 6 is pivotally mounted. For storage, e.g. an approximately cylindrical bearing pin 7, which has a pivot axis 7a defines. This is about right with its central axis match.

The tongue 6 is associated with a bending spring 8, which in the tongue slot 5 is arranged and on the journal 7 extends past. Their two ends 11, 12 are stored in corresponding seats 10, 14 which are in the tongue slot are formed. The bending spring 8 has two Bending 15, 16, where they are otherwise along their indicated in Figure 1 by a dash-dotted line L. Extends longitudinally. The bending points 15, 16 represent pressure surfaces to which the tongue 6 with its outside (back) 17 and its inside 18 when it swings to its final positions.

While the contact surfaces 21, 22 thus by substantially flat surface areas of the outside 17 or the inside 18 are formed, the pressure surfaces 15, 16 formed by curved portions of the spiral spring 8.

In addition to the contact surfaces 21, 22, on the Shaft of the tongue 6 are formed, the tongue has the sixth further contact surfaces 23, 24, which at the in the tongue slot 5 projecting end of the tongue 6 are arranged. This end has an opening 25 for receiving the journal 7 on. As the end of the tongue 6 of the opening 25 part of the shaft of the tongue 6 considered.

The contact surfaces 23, 24 are two substantially level pressure surfaces 26, 27 associated with the spiral spring. The Pressure surfaces 26, 27 are between the bending points 15, 16 arranged and, as shown in Figure 1, below the line L arranged, which are the support points of the ends 11, 12 in the seats 10, 14 interconnects. The Bending points 15, 16 are arranged above this line L.

The bending spring 8 is thus formed double cranked, where the bend is so flat that through the bending points 15, 16 pressure surfaces formed with the Contact surfaces 21, 22 do not come into contact when the Pressure surface 26 or 27 on the contact surface 23 or 24th is applied. This is e.g. from Figure 2 and Figure 3 can be seen. The lengths of the pressure surfaces 26, 27 are in the needle longitudinal direction preferably measured about two to three times as long as the thickness of the spiral spring 8.

The contact surfaces 23, 24 are at the end of the Tongue shaft arranged with the pivot axis 7a define a triangle with two acute angles. This is illustrated in Figure 1 based on the contact surface 24. Be the two opposite ends the contact surface 24 by connecting lines a, b with connected to the pivot axis 7a, a triangle is obtained, in which the between the connecting lines a, b and the Bearing surface 24 included angle W1, W2 smaller than 90 ° are. This measure serves the desired Resting position of the tongue 6 in both pivoting directions To stabilize restoring moments.

The pressure surfaces 26, 27 can merge into one another or overlap each other (Figure 4). They are through the Regions of a flat central portion 28 of the spiral spring 8 fixed, the corresponding pivotal positions with the respective contact surface 23, 24 of the tongue 6 in contact come. The flat central portion 28 of the spiral spring 8 is arranged below the bearing pin 7. The distance between the abutment surfaces 23, 24 and the opening 25 is preferably smaller than the pin diameter (diameter the tongue 25). By contrast, those by the bending points 15, 16 defined contact surfaces 21, 22 in one greater distance to the bearing pin 7 is arranged.

The spiral spring 8 lays in interaction with the tongue 6 two stable rest positions R1, R2 fixed, that of Figure 5 are visible and in which the tongue 6, the bending points 15, 16 of the spiral spring 8 is not touched. The tongue 6 is pivotable back and forth between two end positions E1, E2, wherein the end position E1 is determined by the fact that the Tongue 6 rests with its spoon on the hook tip 4. This end position E1 is the closed position.

The end position E2 is determined by the tongue 6 is transferred as far as possible in reserve and with their Outside 17 abuts the shaft 2.

The two rest positions R1, R2 are pivot positions, which are arranged between the two end positions E1, E2. The rest position R1 is a tongue position in which the tongue is lifted from the hook 3 and the hook tip 4. The Resting position R2 is a position of the tongue 6 near the End position E2, in which the tongue 6 of the needle shaft. 2 lifted off is. The distance is so great that a thread that moved by the shaft 2 in the direction of the hook 3 is formed in the between the tongue 6 and the shaft 2 can slip at an acute angle.

The tongue needle 1 described so far works as follows:

In Figure 2, the latch needle 1 with a thread 30th which belongs to a mesh and in which Hook interior is located. The tongue 6 is in her Quiet location R1. This is achieved and determined by the bending spring 8 with its pressure surface 27 under bias abuts against the contact surface 24. Accordingly becomes the contact surface 24 as a "first contact surface" and the Pressure surface 27 referred to as "first pressure surface".

The spiral spring 8 generates in cooperation with the Tongue 6 is a restoring moment M that the tongue 6 in her Resting position R1 stops. The restoring moment M is shown in FIG. 6 schematically visible. Is the tongue 6 in In its rest position R1, it is moment free. Even the smallest distractions the tongue 6 out of its rest position R1, produce but a restoring moment M1 or M2, the the deflection of the tongue 6 is directed against. The when deflected in the two directions were obtained repulsive Moments M1, M2 can be different be big, this depends for example on whether the angles W1, W2 are the same or different.

If the tongue 6 from its rest position R1 out in Direction towards the tip of the hook 4 moves, it leaves through the contact surface 24 and the pressure surface 27th fixed holding range for the rest position R1 and passes in its final position E1. In this is the contact surface 22nd with the pressure surface 15 (bending area) in plant. This is illustrated in Figure 1, in which to a mesh associated thread 30 presses the tongue 6 to the hook tip 4. In this end position, the pressure surface 22 engages at a relatively long lever on the tongue 6, anyway on a longer lever than the pressure surface 27th Accordingly, as illustrated in FIG comparatively larger restoring moment M3 generated. However, this only in a small swivel range B of the tongue just before putting her end on the hook tip 4.

The contact surface 22 is called "second contact surface" and the bending region 15 is referred to as "second printing surface". The pivoting area in which the second contact surface 22nd and the second pressure surface 15 are effective is shown in FIG 6 Area B. The area in which the first contact surface 24 and the first pressure surface 27 are effective is in FIG. 6 denotes A. The pivoting ranges A and B can be different sizes. The swivel range A in the example is greater than the swivel range B.

Accordingly, the restoring torque curve in terms the second end position E2 and the second rest position Get R2. The contact surface 23 and the pressure surface 26 form "the third bearing surface" and the "third pressure surface", the one illustrated in Figure 6 swivel range C with the restoring moments M5, M6. This can be greater or smaller than the pivoting range A as well as the swivel range B be.

The pressure surface formed by the bend 16 and the contact surface 21 form a "fourth pressure surface" and a "fourth abutment surface" illustrated in FIG Swivel range D near the end position E2 generate a restoring moment M4.

The restoring moments M3, M4 can be independent of the restoring moments M1, M2; M5, M6 can be adjusted and thus both larger and smaller than this chosen become. In particular, between the pivoting ranges B and A, and between the pivot areas C and D be an intermediate region by no appreciable Return torque is present or a low Return torque is generated. This e.g. by the Bending points 15, 16 of the spiral spring 8 only then with the Tongue 6 come into contact when the tongue 6 closer the relevant end position E1, E2 stands as at the respective Quiet location R1, R2. This can be achieved that the tongue 6 is not too violent from their respective end position E1, E2 is ejected, causing them to rest Reached R1, R2 safely and did not overshoot.

When the thread 30, as illustrated in Figure 2 is, when knitting a direction gem. an arrow 31 in FIG. 2, it moves as soon as it reaches the inside 18 the tongue 6 has started, this from its rest position R1 out. The generated here and counteracting the process Return torque M2 (diagram according to FIG. 6) is preferred low and less than that in opposite Direction acting return moment M1. This can be achieved by the contact surface 24 asymmetrical is arranged offset against the bearing pin 7. In FIG 2 it is offset from the journal 7 to the left, so that she barely towers to the right. To on the left, however, the contact surface 24 projects beyond the bearing journal 7th

The running in the direction of arrow 31 thread 30th leads the tongue 6 out of its rest position R1 and initially swings it towards its reserve. The tongue 6 thereby passes first into that in FIG. 3 illustrated position, i. in their rest position R2 gem. figure 3. In this presses the pressure surface 26 of the spiral spring 8 against the contact surface 23 of the tongue 6. Does the of The loop formed by the thread 30 now continues in the direction of Arrow 32 (Figure 3), the thread 30 comes gradually into the illustrated in Figure 4 position. Due to the here greater distance to the pivot axis 7a, the Thread with relatively low tension a swivel moment generate, which is greater than the relatively low restoring moment M6, that of the surface pairing of the contact surface 23 and the pressure surface 26 is formed. The tongue 6 becomes thus pressed into the illustrated in Figure 4 end position E2 or in a position in the area D (FIG. 6). The Mesh therefore only becomes much later Time expanded in the course of movement, with this widening is much lower than conventional Latch needles. In addition, the duration of stitch expansion significantly shortened, which causes this expansion has no lasting effect. The printing surface 16 and the contact surface 21 generate a relatively high counter torque M4 only in a very short swivel range. However, the thread 30 engages the longer lever and therefore can without a lasting widening of the mesh Moment to overcome the restoring torque M4 generate.

Is the thread 30 from the tongue 6 down to the Shaft 2 slid, the latch needle 1 begins its withdrawal movement. The tongue 6 stands in its rest position R2. As soon as the thread 30 touches its outer side 17, exercises the thread 30 has a pivoting force on the tongue 6. These is sufficient to the illustrated in Figure 6 low holding torque M5, that of the contact surface 23 and the pressure surface 26 is generated to overcome and the tongue 6 in to swing its rest position R1 back. Slides the thread 30 then, as Figure 1 illustrates, on the back 17 of the tongue towards the tongue spoon, the thread 30 can thanks to the tension of the mesh formed bring out the tongue 6 from the rest position R1 and first the relatively low holding torque M1 and then in a time-offset second step the restoring moment Overcome M3. The loop formed by the thread 30, is thus without lasting expansion over the hook knocked off the latch needle. The tongue reaches 6 the illustrated in Figure 6 swivel range B and assumes a position or in this swivel range B one. The mesh is not permanently widened to to slide over the tongue in rest position R1, but A small thread tension is sufficient to the tongue to the end position E1 or in the vicinity of the same.

Although the resting positions R1, R2 with only small Resetting forces is a sure one Lifting the tongue 6 from its end positions E1, E2 ensured. This is done by the restoring moments M3, M4, which however only in small swivel ranges B, D effective are.

The latch needle 1 according to the invention has a spring 8 on which serves the tongue 6 in one or two stable Rest conditions R1, R2 to fix and the moreover serves, the tongue 6 from their end positions E1, E2 out to to lead. In this case, the tongue 6 and the spring 8 are formed, that in the end positions E1, E2 and in the rest positions R1, R2 different restoring moments are applied can, with the restoring moments in the end positions by other pressure surface areas 15, 16 and contact surfaces 21, 22 are produced on the tongue, as in the rest positions R1, R2. The restoring moments M3, M4 are in the End positions E1, E2 by conditioning the tongue 6 with its inside 18 or its outer side 17 is generated on the spring 8. The restoring moments M1, M2, M5, M6 in the rest positions R1, R2 are by interaction of pressure surfaces 26, 27 the spring 8 with contact surfaces 23, 24 at the shaft end the tongue 6 generates containing the bearing bore 25.

Claims (9)

1. Latch needle (1), in particular for knitting machines,
   with a needle blade (2), on which a hook (3) with a hook point (4) is provided and which has a sawslot (5),
   with a latch (6), which is disposed in the sawslot (5) to swivel back and forth around a swivel axis (7a) between two end positions (E1, E2), wherein the latch (6) lies on the hook point (4) in one of the end positions (E1, E2) and is moved as far as possible into the retract position in its other end position (E1, E2),
   with a spring (8) for fixture of a resting position (R1) stabilised by repelling moments, which is adjacent to an end position (E1) and in which the latch (6) forms an acute angle with the blade (2),
   wherein the spring (8) has a first plane pressure surface (27) and the latch (6) has a first flattened abutment surface (24), which is associated with the first pressure surface (27) and abuts against this when the latch (6) is located in its resting position (R1),
   characterised in that
   the spring (8) has a second pressure surface (15) formed by a bending point, which is spaced from the first pressure surface (27), and wherein the latch (6) has a second abutment surface (22), which is spaced from the first abutment surface (24) and only abuts against the second pressure surface (15) when the latch (6) moves out of its resting position (R1) into the adjacent first end position (E1) in order to return the latch (6) to the first end position (E1).
2. Latch needle according to Claim 1, characterised in that the first pressure surface (27) and the first abutment surface (24) are not in engagement when the latch (6) is located in its end position (E1), and that the second pressure surface (15) and the second abutment surface (22) are not in engagement when the latch (6) is located in its resting position (R1).
3. Latch needle according to Claim 1, characterised in that the first abutment surface (24) is arranged at a shorter distance from the swivel axis (7a) than the second abutment surface (22).
4. Latch needle according to Claim 1, characterised in that with the rotational axis (7a) the first abutment surface (24) defines a triangle, of which the inside angles (W1, W2) adjacent to the abutment surface (24) are acute angles.
5. Latch needle according to Claim 1, characterised in that the spring (8), the abutment surfaces (24, 22) and the pressure surfaces (27, 15) are dimensioned and arranged such that in the end position (E1) a restoring moment (M3) is generated, which is greater than the restoring moment (M1, M2) in the resting position (R1).
6. Latch needle according to Claim 1, characterised in that the second pressure surface (15) and the second abutment surface (22) only come into contact with one another when the latch (6) is located between the resting position (R1) and the end position (E1).
7. Latch needle according to Claim 1, characterised in that for fixture of a further stable resting position (R2), the latch (6) has a third abutment surface (23) and a fourth abutment surface (21) spaced from this, and that the spring (8) has a third pressure surface (26) associated with the third abutment surface (23) and also a fourth pressure surface (16) associated with the fourth abutment surface (21).
8. Latch needle according to Claim 7, characterised in that the first and the third pressure surfaces (27, 26) of the spring (8) overlap one another at least partially.
9. Latch needle according to Claim 1, characterised in that the spring (8) is an elongated spiral spring, and that measured in its longitudinal direction (L), the pressure surface (27, 26) of the spring (8) is at least twice the dimension of its thickness.

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