JPH05214643A - Needle selecting apparatus of knitting machine - Google Patents

Abstract

PURPOSE: To provide a needle-selection device, capable of selecting needles at a very high speed, and, at the same time, preventing risk of any damage that could lead to accidents of the device. CONSTITUTION: This device, mounted on a carriage of knitting machine, directly selects a jack 3 or needle. This selection is performed by magnetic lamps 9, 10, facing each other and forming, in-between, a region in which a magnetically neutral electrical magnet 12 works for the selection. The needle is kept inactive, when supply of current to the magnet is stopped.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a flat knitted fabric with needles and preferably a carriage carrying at least one needle bed provided with jacks (keys) for pressing the needles and a needle selection device. In a machine, said device is an electromagnetic needle selection device of a flat knitting machine, wherein said device comprises a selection electromagnet for selecting a selected channel and a knitting needle.

[0002]

Various types of electromagnetic selection devices are known. One class of these devices is European Patent No. 0,
249,203 and Swiss Patent 622,5.
No. 66. These devices act on independent jack and needle selection members. In these, the movement by magnetic attraction to the excited lamp is amplified according to a known principle. A mechanical member is attached to each needle and its only function is to mechanically transmit a selection command to a jack, which is typically attached to the needle.

[0003]

The device of this classification therefore consists of a number of parts which are not necessary for the knitting function to be fulfilled. These devices are further characterized by the use of two opposed electromagnets so that the selection member can be tilted between two positions corresponding to the inactive position and the active position. Now, when a current is not flowing through the electromagnet due to a technical defect, the needle is unexpectedly brought into the working position, which usually causes the needle to break and often causes machine failure. obtain. However, in these devices the mass to be moved and the friction are low and thus the excitation conditions of the selection member are clear and reproducible, but at the expense of a large number of additional components.

Directly selecting a jack or needle is
In this case, the frictional forces are very variable and therefore difficult to control and therefore even more difficult to implement.

[0005]

2. Description of the Prior Art An example of another class of selector is described in German Patent 2,938,835, in which the actuation on the jack is more direct. In the technique employed, mechanically reinforced springs engage each jack. In one embodiment, the reinforced jack is held inactive by magnetic attraction to the electromagnet.

[0006]

When the electric current is cut off, the needle is activated. The accidental interruption of the current supply to the electromagnet has the same catastrophic consequence as in the first class of devices described above. To avoid such accidents, additional mechanical parts are needed. in addition,
In these devices, the springs fatigue, wear, and break.

[0007]

2. Description of the Prior Art In other types of selection devices, selection is either associated with a jack or not associated with a jack, as described, for example, in U.S. Pat. No. 4,414,806. It has been proposed to operate by impact on a member. These devices employ one or more movable members, the movement of which is performed by a solenoid. The impact member is surely returned by a spring.

[0008]

These devices are delicate. The stroke of the displaceable member is very small, and its end, which impacts the displaceable member, is worn very rapidly. The service life of the selection member is therefore limited. Springs, bearings, or joints are similarly subject to wear. Incomplete actuation synchronization will cause the end of the impact member to fall into the path of the jack and damage it. Finally, the operating frequency (speed) is limited because the moving parts must reciprocate during each selection.

[0009]

OBJECTS OF THE INVENTION The object of the invention is to eliminate the disadvantages associated with the known selection device described above, to eliminate intermediate moving parts that are not directly involved in the knitting operation, and to be of great importance in the event of a technical failure of the selection device. It eliminates the risk of damage and increases the service life of the moving parts.

[0010]

In the selection device of the present invention, the needle or jack crosses the channel of the selection device, and each of the channel and the needle or jack is controlled by an electromagnet to excite the needle. Alternatively, the butt of the jack projects from the needle bed and constitutes a bistable system which is driven by the cam of the carriage.

The selection device of the invention can be very compact. The selection device of the present invention operates without moving parts that act directly on the jack or needle. If the current to the electromagnet is cut off, the needle will remain inactive and thus avoid any damage. This selection device allows very fast selection frequencies (speeds) and reduces power consumption.

Furthermore, since the number of parts can be greatly reduced, the cost of the flat knitting machine is greatly reduced and its reliability is enhanced.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 and 2 show in cross-section one of the needle beds 1 of a flat knitting machine, which needle bed has a needle groove 2.
A butt 4 is provided in the needle groove 2, and a jack 3 for pressing a needle (not shown here) by a known method is arranged. The member 3 may be a needle. A carriage with a cam 6 is shown schematically at 5. A selection device is attached to the carriage 5, which has a channel 8 through which the jack 3 crosses while the carriage 5 moves along the needle bed.

When the selector device 7 is not actuated (FIG. 1), the jack or needle 3 crosses the channel 8 without displacement and its butt 4 is not driven by the cam 6 of the carriage. On the other hand, when the selection device 7 is actuated (FIG. 2), the jack or the needle 3 is lifted and its butt 4 is driven by the cam 6.

The operating principle of the selection device 7 is shown in FIGS.

In this working principle, two opposite and continuous magnet lamps 9, 1 with a very high suction force
0, this magnet lamp has at least one region 11 called the neutral region where the magnetic attraction is lost. The selection is made by the electromagnet 12 in this neutral region. When directly selecting needles or jacks, the force required to displace them is very variable. One needle can lift several tens of grams, while the next one requires, for example, hundreds of grams or more. In all cases, there must be a magnetic field large enough to attract the needle or jack that has the highest friction. However, in these cases, the needle or jack near the selected jack or needle must stay in those positions. Since it is impossible to prevent the attraction force from acting on the adjacent jack, the magnet lamp of the device holds them with a high attraction force, and thus the needle or the needle located in the neutral region 11 Zero the suction force of Jack.

The neutral area 11 can be used in two different ways.

3 to 5 show the first method. The needle or jack 3 penetrating the selection channel 8 is aligned and then symmetrically drawn upwards against the lower magnet lamp 9. FB represents the attractive force when the jack is in contact with the lower magnet lamp 9, FH represents the attractive force when the jack is in contact with the upper lamp 10, and FE is the jack or needle in the lower lamp 9. The attraction force of the electromagnet 12 when it is still rising is shown.

4 and 5 illustrate the profile of these forces along the selected channel 8. These figures show that the electromagnet 12 acts on only one jack or needle at a time if there is a neutral zone 11 of appropriate width.

FIGS. 6-8 illustrate another method of utilizing the neutral zone 11. In this case, the electromagnet 12 selects the needle by actuation by attraction. The needles or jacks 3 at the selector inlet are first sucked against the lower ramp 9 to determine their position during a change in the machine running direction and then to the upper ramp 10. If electromagnet 1
If the two are excited over a path through the neutral zone 11, they will follow this ramp until they leave the selector. On the other hand, if the electromagnet 12 is not energized when the needle reaches the neutral zone 11, this needle will be attracted by the force FB '(FIG. 7) by the lower magnet ramp 9 and will be attracted to the lower ramp 9. ..

FIG. 8 shows that the contour of the suction force of the lower lamp 8 has a peak region at the neutral position, and the suction of the jack or the needle is surely performed.

In each case, the channel and each of the needles or jacks traversing the channel constitute an electromagnet controlled bistable system.

The force profiles shown in FIGS. 4, 5, 7 and 8 can be easily created in the magnet lamps shown in FIGS. 9-12. These figures show the lower lamp 9 as an example. The lamp comprises two pole members 12, 13 in the form of a hard metal for magnets, between which a specific number of permanent magnets 14, preferably made of rare earths, are arranged. The pole members 12, 13 are unobstructed in the neutral region. Jack or needle 3
Unlike the previously known magnet lamp system in which the selection member slides on the non-magnet hard metal member and the lamp is at an obstructed level with the selection electromagnet, the pole members 12, 1
It is in direct contact with 3. The thickness of the strips 12, 13 and the size of the magnet 14 are calculated so that the portion of the pole member in contact with the jack or needle 3 is magnetically saturated. This allows the jack or needle 3 to be independent of the distribution of these jacks or needles on the two lamps 9, 10.
Secure the suction force of.

The neutral region 11 is made by arranging the magnets 14 so that the directions of the magnetic fluxes φI and φII are reversed on both sides of the neutral region 11, as shown in FIGS. 11 and 12. In this case, a part of the magnetic flux φIII is short-circuited by the pole member in the region where the pole member near the neutral region has the thin portion 15. The magnitude of this magnetic flux φIII is 1
2, 13 depending on the cross-sectional area in the neutral region 11. This provides a means to select the width of this neutral area. The larger the cross-sectional area, the more the magnetic short circuit occurs in the larger part of the magnet and the wider the neutral area 11. With proper selection of this cross-sectional area, it is actually needed in a fine gauge with a pitch on the order of two jack widths (16 gauge with a pitch of 1.588 mm and 0.8
It is possible to obtain a neutral area 11 comparable to the width of a jack or needle (corresponding to a jack width of 2 mm). Furthermore,
Due to the bias of the magnetic flux passing through the pole members 12, 13, the neutral region 11
The lateral suction force between the passages across can be minimized.

Other methods of creating neutral regions are possible.

13 and 14 show an embodiment in which the neutral region is magnetically short-circuited in the neutral region by the metal member 16 in the neutral region.

The two pole members 12, 13 can have different shapes to modify the force profile shown in FIGS. 4, 5, 7 and 9. For example, if one of the two pole members is not taller than the other, an air gap is created, which in turn reduces the attractive force. Such an embodiment is illustrated in FIGS.

15 and 16 show another embodiment of the magnet lamp. For example, the lamp 9 comprises a U-shaped pole member 13 'between which is located a strip 12' forming the other pole member of the magnet 14.

The attractive force of the magnet lamp is also shown in FIG.
In this case, it may be reinforced by an additional magnet arranged next to the lamp.

In addition to the neutral area in which the selection takes place, another neutral area can be made by the same principle, especially at the entrance of the selector to ensure that the jack or needle sticks to the desired lamp.

17 to 19 illustrate an actual embodiment of the selection device.

The selection device is carried on an angle bracket mounted on the carriage 5 of the machine. Two supports 18, 19 are screwed onto this angle bracket 17. The support 18 supports the upper lamp 10 and the electromagnet 12. The lower magnet lamp 9 is attached to the support 19. The magnet lamp is made as shown in Figures 9 to 12 with the difference that at the entrance of the selection station the pole member 12a of the upper lamp 10 extends below the member 13a of the same lamp. And this occurs substantially by moving away from the neutral zone. The jack or needle approached to contact the upper lamp 10 thus contacts only a single pole member,
Therefore, it is retained by the reduced magnetic force. Pole member 12
a can thus serve the function of a cam bringing the jack or needle in the vicinity of the lower magnet ramp 9 which attracts the jack or needle.

The coil of the electromagnet 12 has a low inductance so that the jack or needle can be attracted at a very high frequency.

[0034]

In the selecting device of the present invention, the needle or the jack crosses the channel of the selecting device, and each of the channel and the needle or the jack is controlled by the electromagnet, and the butt of the needle or the jack is excited by exciting the electromagnet. Is protruding from the needle bed and constitutes a bistable system which is driven by a cam of a carriage.

The selection device of the invention can be very compact. The selection device of the present invention operates without moving parts that act directly on the jack or needle. If the current to the electromagnet is cut off, the needle will remain inactive and thus avoid any damage. This selection device allows very fast selection frequencies (speeds) and reduces power consumption.

Furthermore, since the number of parts can be greatly reduced, the cost of the flat knitting machine is significantly reduced and its reliability is enhanced.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a selection device showing an inactive jack.

FIG. 2 is a schematic cross-sectional view showing the same jack in the operative position.

FIG. 3 is a schematic front view of a selector whose electromagnet operates by attraction.

4 is a diagram showing a magnetic attraction contour of the upper lamp of the selector shown in FIG.

5 is a diagram showing a magnetic attraction contour of a lower lamp of the selector shown in FIG. 3. FIG.

FIG. 6 is a schematic front view of a selector operated by suction.

7 is a diagram showing a magnetic attraction contour of the upper lamp of the selector shown in FIG.

FIG. 8 is a diagram showing a magnetic attraction contour of a lower lamp of the same selector.

9 is a front view of one of the magnet lamps of the selector shown in FIG. 3 or FIG.

FIG. 10 is a top view of the magnet lamp.

FIG. 11 is a diagram showing a magnetic flux generated in a magnet by a jack.

FIG. 12 is a diagram showing a magnetic flux generated by another magnet.

FIG. 13 is a front view of one of magnet lamps of a selector according to another embodiment.

FIG. 14 is a top view of the magnet lamp shown in FIG.

FIG. 15 is a front view of a magnet lamp of a selector of still another embodiment.

16 is a sectional view taken along line XVI-XVI of FIG.

FIG. 17 is a more detailed front view of an embodiment of a selection device.

FIG. 18 is a contour diagram of the same device as seen in the A direction.

FIG. 19 is a contour diagram of the same device as seen in the B direction.

[Explanation of symbols]

 3 needles 7 selection device 4 bat 5 carriage 9 magnet lamp 10 magnet lamp 12 electromagnet 11 neutral area

Claims (13)

[Claims] 1. A flat knitting machine with a carriage carrying a needle and preferably at least one needle bed provided with keys for pressing said needle and a needle selection device, said device comprising a selection channel and an actuation. In an electromagnetic needle selection device of a flat knitting machine consisting of a selection electromagnet for selecting the needle, the needle (3) or jack crosses the channel of the selection device (7) and Each of them is controlled by an electromagnet, and the butt (4) of the needle or the jack is projected from the needle bed by the excitation of the electromagnet to form a bistable system which is driven by the cam of the carriage. Characteristic knitting machine needle selection device. 2. Two opposed magnet lamps (9, 10)
At least one (10) of the lamps has a very low attraction force to the magnet lamp and one electromagnet (12)
At least one confined area (11) in which
2. The needle selecting device for a knitting machine according to claim 1, further comprising: a magnetically neutral forming region. 3. The magnet lamps (9, 10) are arranged one on top of the other, the shape of the channel (8) and the magnetisation of the magnet lamps being such that the needle or jack at the inlet of the channel is below the magnet lamp ( 9) upwards, being placed or attracted to a position corresponding to the inoperative position of the needle, as a result of which they are attracted by the electromagnet (12) in the magnetically neutral region (11) 3. The needle selection device for a knitting machine according to claim 2, wherein the needle is placed in an activated state. 4. The magnet lamps (9, 10) are arranged one on top of the other and the shape of the channel (8) and the magnetisation of the magnet lamps is such that the needle or jack is above the channel at the entrance of the channel (8). 10) to be placed or attracted to a position corresponding to their operating position, the needle being activated in the magnetically neutral region (11) as a result of interruption of the electromagnet's excitation current. The needle selecting device of the knitting machine according to claim 2, wherein the needle selecting device is placed. 5. The needle selecting device for a knitting machine according to claim 3, wherein the needle selecting device comprises a single electromagnet. 6. The needle selection device for a knitting machine according to claim 2, 3 or 4, wherein magnet lamps are continuous in the neutral selection region. 7. The magnet lamp comprises a plurality of permanent magnets (1
4) and a pole member forming the actual ramp, wherein the needle or the jack is in direct contact with these pole members. .. 8. Two permanent magnets (14) of different polarities are arranged on each side of said magnetically neutral region (11), part of the magnetic flux of these two magnets being a pole member (12, 1
The needle selecting device for a knitting machine according to claim 6, wherein the needle selecting device is closed by 3). 9. A magnetically neutral region (1) from the magnet lamp.
The needle of the knitting machine according to claim 7, characterized in that (1) is provided with a member (16) for magnetically short-circuiting the magnetic flux of a permanent magnet arranged on either side of the neutral region. Selection device. 10. The cross section of the pole members (12, 13) and the spacing of the permanent magnets (14) define a magnetically neutral region of width corresponding at most to the distance separating the two needles or jacks. The needle selection device for a knitting machine according to claim 6, wherein 11. A knit according to claim 10, characterized in that the pole members (12a, 13a) of the same magnet lamp (10) act as a cam and magnet lamp for the lamp to position the needle or jack. Machine needle selection device. 12. The needle selection device for a knitting machine according to claim 6, wherein the pole member is made of hard magnetic metal. 13. The needle selection device for a knitting machine according to claim 7, 8 or 9, wherein the pole member is magnetically saturated.