TWI401347B - Magnetic actuator, particularly for selection devices in hosiery knitting machines or the like, and selection device for hosiery knitting machines or the like - Google Patents

Description

Magnetic actuator for selecting a device in a knit knitting machine or the like and a selection device for a knit knitting machine or the like

The present invention relates to a magnetic actuator, particularly a magnetic actuator for a selection device in a knit weaving machine or the like.

Magnetic actuators for use in a knit knitting machine or the like are well known.

In general, the magnetic actuators are basically constructed by: a main magnet having two poles arranged side by side and separated by a breakpoint; and a selection electromagnet provided with a ferromagnetic core, The ferromagnetic core has at least one pole located at a discontinuity between the two poles of the main magnet. The selection electromagnet is provided with a coil for supplying electrical power to the coil in order to eliminate or significantly reduce the magnetic attraction of the pole of the core of the electromagnet selected by the main magnet.

The selection device using the magnetic actuators generally includes a plurality of selection elements made of a material that is magnetically attractable, the plurality of selection elements being movable relative to the magnetic actuator in a direction of motion and as they move The pole facing the main magnet and the pole of the core of the electromagnet are selected.

The magnetic actuator is arranged on the machine such that the poles are arranged sequentially along the actuating direction of the selection element such that when the elements move in the actuating direction, one of the faces successively faces the main first One of the poles of the magnet, then facing the discontinuity and the pole of the core of the electromagnet, and finally the other pole of the main magnet.

Moreover, the selection elements can be moved from a first position in which they are adjacent or even in contact with the poles to a second position in which they are in phase with the poles. This mobility of the selection elements at the two locations corresponds to two different actuations of the components (typically knitting needles) in the machine that must be selected by means of the selection device.

In practice, in many cases, the movement of the selection elements from the second position to the first position is counteracted by an elastic element that tends to maintain the corresponding selection element in the second position. Upstream of the magnetic actuator, a support, usually constituted by a cam, acts on the selection elements such that they all directly adjoin the first pole of the main magnet or just at the first pole of the main magnet Upon reaching the first position, the first pole of the main magnet will hold the selection element at that position until the discontinuity begins. At the discontinuity, if the coil is supplied with electric power, the attractive force of the selected electromagnet core generated by the main magnet is eliminated or significantly reduced to such an extent that the attraction is insufficient to resist the transfer of the selected component to the first The force of the two-position spring element is also maintained in the second position when the attraction force itself is insufficient to transfer the selection element from the second position to the first position during passage through the second pole of the main magnet. If, conversely, the coil of the selected electromagnet is not powered, selecting the core of the electromagnet will keep the selection element in the first position, the selection element will remain in this position and during the passage through the second pole of the main magnet Stay in this first position.

Depending on whether the selection element is in the first or second position, and thus does not engage the other elements in the machine, the selection of the elements causes the components associated with the machine (usually the knitting needles) to be actuated differently, Thereby achieving the desired choice.

In this type of magnetic actuator, it has been found to be difficult to determine the size of the selected electromagnet coil and to feed the coil because of the precise effect on the selected component, at the discontinuity, ie at the extreme end of the electromagnet core The strength of the magnetic field generated by the coil power supply must be substantially equal to and opposite to the strength of the permanent magnetic field generated by the main magnet in the core of the selected electromagnet. If the strength of the magnetic field generated by the coil power supply is significantly lower or higher than the strength of the permanent magnetic field generated in the selected electromagnet core, then selecting the pole of the electromagnet core still exerts an attractive force on the selected component, thereby obtaining The desired effect runs counter to the effect.

In a conventional type of magnetic actuator, the specification and power supply of the coil of the electromagnet are quite complicated, because the strength of the magnetic field generated at the pole of the electromagnet is selected, and thus the attraction force applied from the pole to the selection element is Depending on the number of selected components adjacent to or in contact with the pole of the main magnet, the selected component may cause a change in the magnetic field of the main magnet due to its presence, which in turn is located inside the main magnet and at each pole thereof. A change in the magnetic field is caused in the selection of the electromagnet core at the discontinuity.

In a conventional type of magnetic actuator, in order to avoid selection errors, it is necessary to provide a coil for selecting an electromagnet whose current can vary depending on various selection conditions, thereby greatly increasing the actuation of the magnetic actuator. management.

In addition, the magnetic actuators, when specifically applied to the selection device, must not interfere with the positioning of other components required for the operation of the machine. To this end, the design of such magnetic actuators always targets the entire space occupied by the magnetic actuator. In a conventional type of magnetic actuator, the target is achieved by using a small main magnet (which has a correspondingly low power) with the consequence of being extremely small compared to processing tolerances and assembly tolerances. Clearance.

This fact forces high precision in the manufacture and assembly of magnetic actuators, which increases the corresponding cost and makes it difficult to achieve a constant performance between magnetic actuators of equal power.

On the other hand, in order to have a larger gap and thus solve the problem, one may consider increasing the power of the main magnet, but due to the design of the magnetic actuator of the conventional type, this will force the selection of the coil of the electromagnet. The size is increased to cause other problems in the space occupied by the magnetic actuator.

It is an object of the present invention to solve the above problems by providing a magnetic actuator, particularly for use in a knit knitting machine or the like, which is magnetically actuated relative to conventional types. It is easier to manufacture and actuate.

Within this aim, an object of the present invention is to provide a magnetic actuator that is significantly affected by various selection conditions to a degree that is significantly smaller than conventional types of magnetic actuators and thus ensures high operational reliability and accuracy. Excessive accuracy is not required in terms of the specifications of the power supply and the electrically actuated components.

Another object of the present invention is to provide a magnetic actuator that can be provided with significantly larger dimensional tolerances and assembly tolerances than conventional types of magnetic actuators.

Another object of the present invention is to provide a magnetic actuator that can better utilize the magnetic properties of the material from which it is made.

This object and these and other objects (which will become more apparent hereinafter) are achieved by a magnetic actuator, particularly for use in a knit knitting machine or the like, the magnetic actuator comprising a main magnet having at least two poles arranged side by side and separated by a breakpoint, characterized in that it comprises a selection electromagnet provided with at least one pole, the at least one pole being aligned with the discontinuity The selection electromagnet is actuatable to create or eliminate or reduce the magnetic attractive force at the pole of the selection electromagnet disposed transversely with respect to the discontinuity.

Referring to the drawings, a magnetic actuator according to the present invention (indicated generally by reference numerals 1a and 1b in the two embodiments) includes a main magnet 2 and a selection electromagnet 3a, 3b.

In both of the illustrated embodiments, the main magnets 2 each have at least two poles 4, 5 and 6, 7 arranged side by side and separated by a break point 8, 9.

The selection electromagnets 3a, 3b are provided with at least one pole 11a, 11b, 12b which is aligned with the breakpoints 8, 9 between the main magnets 2.

The selection electromagnets 3a, 3b comprise a permanent magnet 13a, 13b and at least one control or actuation coil 14a, 14b for supplying electrical power to the at least one control or actuation coil 14a, 14b, thereby reducing or eliminating the selection of the electromagnet 3a The magnetic attraction of the poles 11a, 11b, and 12b of 3b.

The poles 11a, 11b, 12b of the electromagnets 3a, 3b are selected to be spaced apart from each other in the lateral direction with respect to the breakpoints 8, 9 between the main magnets 2.

Conveniently, the entire selection electromagnets 3a, 3b are spaced apart from each other in the lateral direction with respect to the main magnet 2.

More specifically, in both of the illustrated embodiments, the main magnets 2 each include a permanent magnet 20 sandwiched between two yokes 21, 22, the ends of which are by their ends The two pairs of poles are formed as a first pair of poles 4, 5 and a second pair of poles 6, 7 respectively, wherein the poles 4, 6 are formed by the yoke 21 and the poles 5, 7 are formed by the yoke 22. The poles 4, 6 of the yoke 21 are separated by a corresponding break point 8, and similarly, the poles 5, 7 of the yoke 22 are separated by a corresponding break point 9.

Each of the two yokes 21, 22 of the main magnet 2 is substantially U-shaped, and the discontinuities 8, 9 are formed between the two free ends of the U-shape.

The permanent magnet 20 of the main magnet 2 is placed between the two yokes 21, 22 near the ends of the two arms of each U-shaped shape of the two yokes.

In the first embodiment, the selection electromagnet 3a includes a permanent magnet 13a connected to a yoke 25a, the yoke 25a is formed with a pole 11a by one end thereof, and the poles 11a are aligned with the breakpoints 8, 9 between the main magnets 2 But spaced apart in the horizontal direction.

The permanent magnet 13a of the electromagnet 3a is preferably connected to the yoke 25a and close to the yoke end portion opposed to the end portion of the forming pole 11a.

The end portion of the yoke 25a forming the pole 11a is preferably folded toward the main magnet 2.

The yoke 25a is disposed on the side of the yoke 22 of the main magnet 2, and the permanent magnet 13a of the selection electromagnet 3a is disposed at a distance from the yoke 22, which makes it possible to use the yoke 22 to close the magnetic circuit of the selection electromagnet 3a. . In practice, the yoke 22 is "connected" to a permanent magnet 13a of the electromagnet 3a by a gap 28a and serves as a second yoke for selecting the electromagnet 3a.

If necessary, the yoke 25a can be further away from the yoke 22 by applying a connecting member 27a made of a ferromagnetic material to the surface of the permanent magnet 13a of the selection electromagnet 3a facing the main magnet 2, the connecting member. The 27a "connects" the selection electromagnet 3a to the yoke 22 of the main magnet 2 close to the selection electromagnet 3a across or through the gap 28a.

In the second embodiment, the selection electromagnet 3b includes a permanent magnet 13b sandwiched between the two yokes 29b, 30b, the two yokes 29b, 30b forming two poles 11b, 12b by their ends, which The two poles 11b, 12b are aligned with each other and aligned with the breakpoints 8, 9 between the main magnets 2, but are spaced apart in the lateral direction relative to the discontinuities 8, 9.

The two poles 11b, 12b of the selection electromagnet 3b are preferably arranged side by side in a direction substantially perpendicular to the direction in which the poles formed by each of the yokes 21, 22 of the main magnet 2 are arranged side by side.

The coil 14b of the electromagnet 3b is preferably wound around the permanent magnet 13b between the two yokes 29b, 30b.

Conveniently, in the two embodiments of the magnetic actuator of the present invention, there is a support member 31 made of a diamagnetic material, which is preferably applied to the direction selecting electromagnets 3a, 3b of the main magnet 2. On the yoke 22 or 21.

The support member 31 is a contact surface that must be actuated by means of an actuator to form a contact surface, thereby preventing it (although attracted) from directly contacting the main magnet 2 and selecting the poles of the electromagnets 3a, 3b, which will become hereinafter At a glance.

The magnetic actuators 1a, 1b according to the invention are designed to be preferably used in a knitting machine or the like, wherein the two poles of the main magnet 2 or the two poles are indicated by an arrow 32. The actuation direction is sequentially disposed at a substantially coplanar position such that it faces the selection element 33 made of a material that is magnetically attractable, the selection elements 33 being selectable relative to the magnetic actuators 1a, 1b Moves in the actuation direction 32. In this manner, the selection element 33 sequentially faces the first pole or the first pole 4, 5 of the main magnet 2, then faces the discontinuities 8, 9 and the pole 11a of the selection electromagnet 3a or selects the electromagnet 3b. The pair of poles 11b, 12b then face the second pole or the second pole pole 6, 7 of the main magnet 2.

The selection element 33 can be moved from a first position in which the poles are held close to the poles by a magnetic attraction applied by the poles to a second position in which it is further spaced from the poles relative to the first position .

Each of the selection elements 33 moves from the first position to the second position and vice versa, and is movable in a plane perpendicular to the actuation direction 32, and is resisted by the elastic member from the second position to the first The elastic member may be constituted by a spring 34 in a positional movement.

The fact that the magnetic actuator according to the invention can also be used with other types of selection devices will not be changed, and the magnetic induction according to the invention will be explained hereinafter with reference to a device by way of example only and merely to clarify its actuation. The operation of the actuator for selecting a needle 35 of a dial 36 in a circular knitting machine of the type disclosed in U.S. Patent No. 6,014,875, the entire disclosure of which is incorporated herein by reference. Using a plurality of levers as selection elements 33, the levers being pivoted about an axis of rotation 37 to the opposite end of the corresponding needle relative to the tip end and oscillating about the axis of rotation 37, from which the first position Move to the second position.

For the magnetic actuator 1a according to the invention in the first embodiment, each of the selection elements 33 is moved in the actuation direction 32 with respect to the magnetic actuator 1a. Before reaching the first pole or the first poles 4, 5 of the main magnet 2 or here, a support, for example by a cam, acts on the selection element 33, thereby moving it from the second position to the first position That is, it is pushed toward the poles 4, 5, and the poles 4, 5 are held in the first position by their magnetic attraction, as shown in Figs.

When the selection element 33 reaches the discontinuities 8, 9 which face the other part of the pole 11a of the selection electromagnet 3a, if the coil 14a is not supplied with power, the attraction of the pole 11a by the permanent magnet 13a causes the selection element 33 remains in the first position as shown in FIG. The selection element 33 then faces the second or second counter 6, 7 of the main magnet 2, and the main magnet 2 holds the selection element 33 in the first position, as shown in FIG.

It should be noted that the selection element 33 rests against the support element 31 in the first position, which prevents it from directly contacting the poles.

On the contrary, if the coil 14a is supplied with power, the attraction force of the pole 11a of the selection electromagnet 3a is canceled and the selection element 33 is moved to the second position by the action of the spring 34, that is, moved away from the pole 11a, as shown in FIG.

Subsequently, during the passage through the second or second counter 6, 7 of the main magnet 2, the selection element 33 remains in the second position, as shown in FIG.

The different positions of the selection element 33 after passing through the discontinuities 8, 9 and the pole 11a of the selection electromagnet 3a are used to engage or disengage the selection element 33 with an actuating element, such as a cam, thereby forming a pair of elements. Different actuations, in the illustrated example, the element is formed by a needle 35 that is coupled to the selection element 33 and is thus selected by a selection device.

The operation of the magnetic actuator in its second embodiment is similar to that described above with reference to the first embodiment, except that in the first embodiment, since the selection electromagnet 3a has a single yoke 25a In fact, the magnetic circuit of the electromagnet 3a is selected to be closed on the selection element 33 by using the yoke 22 of the main magnet 2, and in the second embodiment, the magnetic circuit of the electromagnet 3b is selected only by selecting the electromagnet. The two yokes 29b, 30b of 3b are closed on the selection element 33.

The magnetic actuator according to the invention may also be provided in the form of other embodiments encompassed within the scope of the invention, for example by means of a simple core made of a ferromagnetic material rather than by means of A permanent magnet is provided to select the electromagnets 3a, 3b. The fact that the core of the selection electromagnets 3a, 3b can have other shapes is not changed, and the selection electromagnets 3a, 3b can be provided substantially as described and illustrated with reference to the drawings, but only by a ferromagnetic material. The core is replaced by a permanent magnet as described with reference to the figures. The core of the electromagnets 3a and 3b may be selected integrally with the yoke 25a or the yokes 29b and 30b as needed.

In other embodiments in which the selection of the electromagnets 3a, 3b does not have a permanent magnet, the operation of the magnetic actuator differs from the magnetic actuator described above in that when the selection element 33 is to be in the main magnet 2 When the discontinuous points 8, 9 are maintained in the first position, the coils 14a, 14b of the selection electromagnets 3a, 3b are powered to generate an attractive force at the poles 11a, 11b, 12c, and when the selection element 33 is to be from the first position When moving to the second position, power is not supplied to the coils 14a, 14b of the selection electromagnets 3a, 3b.

In the magnetic actuator according to the present invention, since the poles 11a or the poles 11b, 12b of the electromagnets 3a, 3b are selected and the discontinuity point 8 between the poles or pole pairs 4, 5 and 6, 7 of the main magnet 2, The fact that 9 are spaced apart in the lateral direction avoids or at least significantly reduces the interference of the magnetic field of the main magnet 2 with the selection of the electromagnets 3a, 3b. In this manner, the selection of the electromagnets 3a, 3b is not affected by the change in the magnetic field of the main magnet 2 due to the different selection conditions of the selection element 33, or at the most least. Therefore, it is easier to determine the specifications of the coils 14a, 14b of the selection electromagnets 3a, 3b and to correctly determine the strength of the current supplied to the coils 14a, 14b in order to cancel or reduce or produce the selection of the electromagnets 3a, 3b. The attractive force formed on the selection element 33.

Furthermore, also due to the fact that in the magnetic actuator according to the present invention, a stronger permanent magnet having a significantly larger gap than the main magnet of the conventional type of magnetic actuator can be used for the main magnet, thereby making it possible Accepting greater manufacturing and assembly tolerances and thus simplifying their manufacture and reducing their manufacturing costs without the need to oversize the coil, which can be kept small.

The small coil size and its fact that it is arranged outside the main magnet also allows us to better utilize the space available on the machine for which the magnetic actuator is to be used for mounting the magnetic actuator.

Finally, it should be noted that the significantly larger gap of the magnetic actuator of the present invention enables the magnetic material used to operate in a linear (i.e., away from saturation) curve B (magnetic induction) - H (magnetized field strength) region, thereby The actuator is made less sensitive to any changes in the state of supply of the materials.

It has been found in practice that the magnetic actuator of the present invention achieves its intended purpose in its entirety, as it ensures high operational accuracy and reliability and is simpler to manufacture and actuate than conventional types of magnetic actuators. .

In the examples of the embodiments described above, various characteristics given in accordance with specific examples may be interchanged with other different characteristics present in the examples of other embodiments.

The magnetic actuators thus conceived are susceptible to numerous modifications and variations, all of which are within the scope of the accompanying claims; all details may be further replaced by other technically equivalent elements. .

In practice, the materials used (as long as they are compatible with the particular application) and the dimensions can be arbitrarily determined according to requirements and the latest technology.

1a. . . Magnetic actuator

1b. . . Magnetic actuator

2. . . Main magnet

3a. . . Select electromagnet

3b. . . Select electromagnet

4. . . pole

5. . . pole

6. . . pole

7. . . pole

8. . . Intermittent point

9. . . Intermittent point

11a. . . pole

11b. . . pole

12b. . . pole

13a. . . permanent magnet

13b. . . permanent magnet

14a. . . Actuating coil

14b. . . Actuating coil

20. . . permanent magnet

twenty one. . . Yoke

twenty two. . . Yoke

25a. . . Yoke

27a. . . Connecting element

28a. . . gap

29b. . . Yoke

30b. . . Yoke

31. . . Supporting element

32. . . Actuation direction

33. . . Selection component

34. . . Elastic member

35. . . Knitting needle

36. . . Dial

37. . . Rotation axis

Further features and advantages of the present invention will become more apparent from the description of two preferred but non-exclusive embodiments of a magnetic actuator of the present invention, which is shown by way of non-limiting example in the accompanying drawings. FIG. A side elevational view of a magnetic actuator of the present invention in a first embodiment, the magnetic actuator being applied to a device for selecting a needle in a dial of a circular knitting machine; a perspective view of the magnetic actuator in the first embodiment; FIG. 3 is a top plan view of the magnetic actuator in the first embodiment; and FIGS. 4 to 6 show the original in the first embodiment in a front view Inventive magnetic actuator, a sequence of actuation of a selection element; FIGS. 7 to 9 show, in a front view, another actuation sequence of a selection element for the magnetic actuator of the present invention in the first embodiment; FIG. A side elevational view of a magnetic actuator of the present invention in a second embodiment, the magnetic actuator being applied to a needle selection device of a dial of a circular knitting machine; FIG. 11 is a magnetic actuator a perspective view in the second embodiment; Fig. 12 is a magnetic actuator in A top plan view in the second embodiment.

1a. . . Magnetic actuator

2. . . Main magnet

3a. . . Select electromagnet

4. . . pole

5. . . pole

6. . . pole

7. . . pole

8. . . Intermittent point

9. . . Intermittent point

11a. . . pole

13a. . . permanent magnet

14a. . . Actuating coil

20. . . permanent magnet

twenty one. . . Yoke

twenty two. . . Yoke

25a. . . Yoke

27a. . . Connecting element

31. . . Supporting element

33. . . Selection component

Claims (19)

A magnetic actuator for a selection device in a knit knitting machine, comprising a main magnet having at least two poles arranged side by side and separated by a breakpoint, comprising a selection electromagnet, the selection electromagnet The iron is provided with at least one pole, the at least one pole being aligned with the discontinuity point and laterally spaced relative to the discontinuity point, the selection electromagnet being actuatable to generate or eliminate or reduce the pole of the selection electromagnet A magnetic attraction at the place. The magnetic actuator of claim 1, wherein the selection electromagnet is laterally spaced relative to the main magnet. The magnetic actuator of claim 1, wherein the selection electromagnet comprises: a core made of a ferromagnetic material, wherein the one end portion forms the at least one pole of the selection electromagnet; A coil wound around the core and capable of being powered to generate the magnetic attraction at the at least one pole of the selection electromagnet. The magnetic actuator of claim 3, wherein the selection electromagnet comprises: a permanent magnet magnetically coupled to the at least one pole to thereby generate the magnetic attraction force at the at least one pole of the selection electromagnet; and An actuating coil that can be powered to eliminate or reduce the magnetic attraction at the at least one pole of the selective electromagnet. A magnetic actuator according to claim 1, wherein the main magnet comprises a permanent magnet sandwiched between the two yokes, the two yokes being formed by their ends to form two pairs of poles separated by the discontinuity. The magnetic actuator of claim 5, wherein the two yokes of the main magnet are Each of the plurality is generally U-shaped, wherein the discontinuity is formed between the two free ends of the U-shaped shape. A magnetic actuator according to claim 6, wherein the permanent magnet of the main magnet is placed between the two yokes in a region close to the two arms connecting the U-shapes of the two yokes. A magnetic actuator according to any one of claims 3 to 7, wherein the permanent magnet or the core system of the electromagnet is composed of or connected to a yoke, the yoke being formed by one end thereof The at least one pole. A magnetic actuator as claimed in claim 8, wherein the coil is disposed around the yoke of the selection electromagnet. The magnetic actuator of claim 8, wherein the permanent magnet or the core of the selection electromagnet is spaced apart from the yoke of the main magnet adjacent to the selection electromagnet by a gap, thereby using the main magnet The yoke serves as a second yoke of the selection electromagnet. The magnetic actuator of claim 8, comprising an element for connecting the permanent magnet or the core of the selection electromagnet to the yoke of the main magnet adjacent to the selection electromagnet by a gap . The magnetic actuator of claim 4, wherein the permanent magnet of the electromagnet or the core is connected to two yokes, the two yokes being formed by their ends to be aligned with each other and with the discontinuity The point is aligned. A magnetic actuator according to claim 12, wherein the two poles of the selection electromagnet are arranged side by side in a direction substantially perpendicular to a direction along which the at least two poles of the main magnet are arranged side by side. The magnetic actuator of claim 12, wherein the coil surrounds the selection electromagnetic The permanent magnet of the iron or the core is arranged. A magnetic actuator according to claim 1 comprising a support member made of a diamagnetic material, said support member being a member actuatable by said magnetic actuator to form a contact surface and adapted to avoid The actuated element is in direct contact with the poles. A selection device for a knit weaving machine or the like, comprising: a magnetic actuator as claimed in one or more of the preceding claims, wherein the at least two poles of the main magnet are in a direction of motion And a selection element that is magnetically attracted and movable relative to the selection actuator in the actuation direction, thereby sequentially facing a first one of the poles of the main magnet, and then facing the selection The discontinuity of the electromagnet and the at least one pole, and then facing a second one of the at least two poles of the main magnet; the select elements are engagable from a magnetic attraction applied by the poles Moving to a first position near the poles to move to a second position in which it is further spaced from the poles relative to the first position; the coil can be powered by a source whereby each selection element remains The first position or each of the selection elements is moveable from the first position to the second position as it passes the discontinuity point and the at least one pole of the selection electromagnet. The device of claim 16, wherein in the first position, each of the selection elements rests on the support member. A device according to claim 16 or 17, wherein the selection member is movable in a plane substantially perpendicular to the actuation direction due to the action of the resilient member as moved from the first position to the second position. The device of claim 16 or 17, wherein the poles of the main magnet and the selection electromagnet are directed substantially coplanar with respect to the faces of the selection elements.