RU2338018C2 - Needle selector for knitter - Google Patents

Abstract

FIELD: textile industry, paper industry.

SUBSTANCE: needle selector for knitter chooses working needle by using a piezoelectric device having a piezoelectric element, in which intermediate position between rear end and forward end of the piezoelectric device supported so that a body could move, the piezoelectric element is hung on so that the body rotates by using rotating element for stabilisation of piezoelectric device vibration. Section framework of the rotating element on the plane surface, which is perpendicular to the axis of the rotating element and the plane surface of the piezoelectric device, is formed so that a bend in the direction across the width of the piezoelectric device decreases to the value, which is less then one of a bend in longitudinal direction.

EFFECT: increase of vibration speed of the rotating element in the piezoelectric device and decrease of electric energy consumption.

6 cl, 27 dwg

Description

FIELD OF THE INVENTION

The present invention relates to a needle selector used in a knitting machine such as a circular knitting machine or a flat knitting machine. More specifically, the present invention relates to a needle selector for a knitting machine in which a piezoelectric knitting machine driver is actuated by suppressing a bending movement of the piezoelectric element in a predetermined direction for more efficient selection of working needles.

State of the art

In a knitting machine such as a circular knitting machine or a flat knitting machine, the vertical movement of the working needles is selected based on a knitting operation stored in a memory device such as a diskette to create an article having a predetermined knitting texture. Various types of needle selectors are used to select the vertical movement of the working needles.

This type of needle selector will be described. First of all, a diagram of the operation of selecting a needle in a knitting machine will be described for a circular knitting machine, schematically shown in FIGS. 14, 15A and 15B.

14 is a schematic perspective view illustrating a main knitting mechanism of a circular knitting machine. As shown in FIG. 14, in the circular knitting machine, the working needles 52 are slidably mounted in a plurality of vertical grooves (not shown) formed along the longitudinal axis on the outer surface of the knitting cylinder 51, which rotates as shown by arrow A. As shown in FIG. 15A and 15B, needle take-off pushers 53 are located under the working needles 52, which can abut against the lower parts of the working needles 52. The base 54a of the cylindrical cam stops is fixedly mounted under the knitting cylinder 51. A plurality of cam stops 54 each having a predetermined shape is disposed above the base 54a of the cam stops at a predetermined interval. The cam stops 54 push up the pushers 53 of the selection of needles to push the working needles 52 up.

The basic principle of knitting is as follows. When the working needle 52 on the rotary knitting cylinder 51 is pushed up by the needle pickup pusher 53, the working needle 52 protrudes from the upper surface of the knitting cylinder 51. The thread 56 fed from the bobbin 55 with thread is fed to the hook of the protruding working needle 52 to form a loop from the thread . Then the working needle 52 is moved down using a known mechanism (not shown) to form one loop. By selection, one way or another, vertical movement must be applied to the working needle 52, and a loop may or may not be formed, the process proceeding to the next knitting step, thereby creating the desired product. To actuate the working needles in this way in a knitting machine, the needle take-off pushers 53 are usually positioned under the working needles 52 so that they abut against the working needles 52. The needle take-off pushers 53 are selectively connected to the working needles 52 by using a needle selector 57 which is driven based on information from a control device 58, including a storage device that stores the knitting operation for the knitting texture and controls the vertical movement of the working needles 52.

A case in which a piezoelectric device is used as a needle pickup will be described below with reference to FIGS. 15A and 15B, which show the relationship between the working needle, needle pickup pusher and needle picker.

The piezoelectric device 2 may be bent as shown in FIG. 15A or bent as shown in FIG. 15B in the opposite direction to that of FIG. 15A, depending on what voltage is applied to the piezoelectric device 2. Finger 5 is for connecting to the front end of the piezoelectric device 2. The piezoelectric device 2, the pin 5 and the cam stop 54 are arranged as shown in FIGS. 15A and 15B. The working needle 52 and the needle pusher 53 move in a circle with the knitting cylinder 51 (not shown) down from the front side of the pattern sheet to the back side of the sheet (or in the opposite direction). The needle take-off pusher 53 can pivot about a support 53a, i.e., as around a center. The end face 69 of the needle selection and the end face 70 of the cam stop are protruding from the pusher 53 of the needle selection to the side, as shown in figa and 15B.

If the piezoelectric device 2 is bent as shown in FIG. 15A, then the needle pickup end 69 of the needle pickup pusher 53 that moves in a circle collides with the finger 5. Therefore, the end 70 of the cam stop of the needle pickup pusher 53 cannot be connected to the cam stop 54. Therefore, the needle pickup pusher 53 is not pushed up with the cam stop 54, and the working needle 52 is not pushed up.

If the piezoelectric device 2 is bent as shown in Fig. 15B, then the finger 5 at the front end of the piezoelectric device 2 does not collide with the needle picking end 69 of the needle pickup pusher 53, which moves in a circle with the knitting cylinder 51 and the needle pickup pusher 53 retains vertical position. Therefore, the end stop 70 of the cam stop at the lower end of the pusher 53 of the needle selection is pushed up along the inclined surface by the cam stop 54, and accordingly, the working needle 52 is pushed up.

When the needle take-off end 69 of the needle take-off pusher 53 and the finger 5 at the front end of the piezoelectric device 2 are selectively connected in this way, the working needle 52 can move freely upward on demand and an article having an arbitrary knitting texture can be knitted.

The most important characteristic when knitting is high productivity, that is, the ability to increase the rotation speed of the knitting cylinder. To increase the speed of rotation of the knitting cylinder 51, the needle selector 57, which controls the upward movement of the working needles 52, must operate at high speed. For this purpose, various types of knitting needle selectors that work at high speed have been developed and used.

For example, the present inventor has proposed a needle selector (see Japanese Patent Laid-open Publication No. 60-224845), which uses the force of attraction or repulsion of an electromagnet to rotate multiple fingers. This needle selector has a higher working speed and a smaller size than a conventional needle selector, thereby providing a reduction in energy consumption. The applicant of the present invention also proposed a piezoelectric needle selector (see Japanese Laid-open Publication No. 62-28451) to replace a needle selector using an electromagnet described above. According to this needle selector, the finger is actuated by bending the piezoelectric device to select the working needle. A higher working speed, smaller size and lower power consumption of the needle selector were achieved.

The applicant of the present invention also invented an improved device of the piezoelectric needle selector described above and filed it on October 5, 1988 as Japanese Patent Application No. 63-249967 entitled "Needle Selector for Knitting Machine". This invention is registered as Japanese Patent No. 1969970 (see Japanese Patent Publication No. 6-94619), and a similar US patent US 5027619.

FIG. 12A shows the piezoelectric needle selector described in Japanese Patent No. 1969970. As shown in FIG. 12A, in accordance with the improved needle selector, finger 5 is rotatably disposed on the piezoelectric device 2 containing the piezoelectric element. Power is applied to the piezoelectric element to actuate the finger 5. The working needle of the knitting machine is selected by operating the finger 5 (more specifically by means of a pusher) so that it is possible to knit an article having the texture of the desired pattern. In accordance with the distinguishing feature of this needle selector, a portion of the rear end of the piezoelectric device 2 is rotatably supported by the support A or the housing through the rotary element 1A. The front end portion of the piezoelectric device 2 is rotatably connected with a U-shaped groove in the rear end portion of the finger 5 through the rotational element 1B. The intermediate portion between the portion of the rear end and the portion of the front end of the piezoelectric device 2 is fixed by means of rotational elements 30 configured to rotate in the supporting device 13 or the housing. The finger 5 and the piezoelectric device 2 are located on the same straight line.

As shown in FIG. 12A, the intermediate portion of the piezoelectric device 2 is supported by the supporting device 13 through the rotary elements 30. When the piezoelectric device 2 is bent, it vertically moves the rear end 5A of the finger 5. Vertical movement of the rear end 5A vertically moves the front end 5B of the finger 5, which protrudes through the hole 19a of the support device 19. As a result, upward movement of the working needle 52 is selected.

It has been found that when the piezoelectric device 2 is rotatably supported in its predetermined position in this way, the piezoelectric device 2 can be freely bent. As a result, the speed of movement of the finger 5 increases significantly and the number of movements of the front end of the finger 5 increases. When a piezoelectric device with such a structure is used, damage to the piezoelectric device is reduced and the life of the needle selector is extended. In this improved piezoelectric needle selector, when the design of the finger driving the device that rotates the finger member is highly advanced, the needle selection ability is greatly improved.

Essentially, the piezoelectric device vibrates in all directions (360 °) in the plane when power is applied to it. This is understandable on the basis of the fact that the piezoelectric device is initially introduced as a vibration plate of the speaker. When a piezoelectric device that vibrates in all directions is formed in the form of a rectangular plate and one end of the long side of the plate is fixed, the plate forms a beam fixed at one end, the other end of which oscillates vertically. Even in this case, when the piezoelectric device vibrates in all directions, the vibration component in the width direction of the rectangular piezoelectric device is maintained. Typically, one of ordinary skill in the art will consider this vibrational component created in the width direction as an unavoidable fact.

In the conventional needle selector shown in FIG. 12A, the rotational element 30 that holds the piezoelectric device 2 in a predetermined position is a cylindrical element having a slot 32 extending from the end front surface of the rotational element 30 in the direction of the longitudinal axis to hold the piezoelectric device 2, as shown in the detailed view of FIG. 12B. The axis neck 31a at the end portion of the rotational element 30 having a circular cross-section is inserted into a circular hole (not shown) formed in the support device 13 to rotatably support the rotational element 30.

In the example shown in FIG. 12A, the rotational elements 30 secure the piezoelectric device 2 with the slots 32 on the left side and the right side. Alternatively, as shown in FIG. 13, one cylinder 40 may be used having a slot (not shown) in its central portion to secure the piezoelectric device 2.

In this case, also, the axle journals 40a and 40b, each of which has a circular cross section, are inserted and held in the circular holes of the support device 13 to support the piezoelectric device 2 with rotation.

In a conventional needle selector, as described above with reference to FIGS. 12B and 13, the cylinder that rotationally holds the piezoelectric device in an intermediate position is a cylindrical element of circular cross section.

As described above, although the present inventors are focused on increasing the operating speed, reducing the size and reducing the power consumption of the needle selector for the knitting machine and use different types of measurements for these purposes to achieve results, nevertheless, higher performance is required.

Taking this into account, the present inventors conducted comprehensive studies to obtain a more efficient oscillatory motion of the piezoelectric device and came to the following conclusion. That is, since a cylindrical element of circular cross section is used, it is difficult to provide a more effective vibration of the piezoelectric device in the longitudinal direction. In particular, with a further reduction in the size of the needle selector, the diameter of the cylinder, which holds the piezoelectric device rotatably in the intermediate portion, tends to decrease. The present inventors have found that the smaller the diameter of the cylinder, the more obvious vibration will occur in the width direction.

The aim of the present invention is to provide a needle selector of a new design for a knitting machine that can reduce the maximum number of losses during the oscillatory movement of the piezoelectric device of a conventional needle selector for a knitting machine.

SUMMARY OF THE INVENTION

In accordance with the present invention, a needle selector for a knitting machine is provided, comprising a plate piezoelectric device including a piezoelectric element and a finger aligned with the piezoelectric device and arranged to move, while the portion of the rear end of the piezoelectric device is rotatably supported in the groove of the support device or housing, the front end portion of the piezoelectric device is rotatably connected to the rear end portion and the finger, the intermediate position between the portion of the rear end and between the portion of the front end of the piezoelectric device is clamped by a rotational element configured to rotate in the supporting device or body, and the finger is actuated by applying a voltage to the piezoelectric element to select the working needle of the knitting machine, so that you can knit the product with the texture of a given pattern, characterized in that the rotational element contains the neck of the axis formed at its two ends, which are supported by bearings mounted in a support device or housing, and a central portion between two axle necks, and a slot that grips the piezoelectric device is formed on at least a portion of the central portion in the width direction of the piezoelectric device, and an axial sectional structure of the central portion on a plane that is perpendicular to the axis of the rotational element and perpendicular to the plane of the piezoelectric device, is formed so that a bend in the width direction non-piezoelectric device is reduced to a value less than the amount of bending in the longitudinal direction of the piezoelectric device.

More specifically, in accordance with a feature of the present invention, the reduction in bending in the width direction caused by the piezoelectric device of the needle selector of the knitting machine in accordance with the present invention is increased to exceed the reduction in bending in the width direction caused by the rotational element when the axial sectional structure of the central portion made of the same material and forms a circle.

In general, the present invention seeks to alter the cross-sectional design of a central portion of a rotational element to minimize as much as possible any movement other than oscillatory motion along the longitudinal direction of the piezoelectric plate that occurs when voltage is applied. As described above, the diameter of the rotational element in the needle selector is reduced as a result of using various other technologies, and the piezoelectric device can be bent freely in the width direction. Therefore, it is believed that the need for more damping of the bend in the width direction than the bend in the longitudinal direction of the piezoelectric device is increasing. These problems can be solved according to the present invention.

An example of the simplest construction as the construction of the central portion includes one construction in which the cross-sectional design of the rotational element that is perpendicular to the axis has an elliptical shape having a short side in the longitudinal direction of the piezoelectric device. The cross-sectional shape of the rotational element is not limited to an ellipse, but can be of any shape as long as the length of the central portion along the longitudinal direction of the piezoelectric device is less than the length along the perpendicular direction of the piezoelectric device (direction perpendicular to the surface of the piezoelectric device). In particular, if in the future the needle selector becomes smaller and the diameter of the rotational element decreases, the decrease in vibration in the direction along the width of the piezoelectric device will become insufficient. Therefore, to provide greater suppressive force against vibration in the width direction of the piezoelectric device, it is effective if the cross section of the rotational element that holds the piezoelectric device in the intermediate position of the needle selector is shaped like, for example, a train rail, that is, if the cross section has a rib-shaped protrusion on one or both of the upper and lower sides of the Central portion of the rotational element in a position remote from the slot.

According to another preferred embodiment, the central portion of the rotational element is formed of at least two layers of cross-sectional design that are made of materials having different bending stiffnesses, and a material having increased bending stiffness is used to form a portion remote from the slot compared with the material used in the area located near the slot. In this case, as materials of two layers, for example, plastics having different bending stiffnesses can be used. Alternatively, plastic can be used to form a portion close to the slot, and a metal such as steel can be used to form a portion remote from the slot.

Thus, the construction of the rotational element according to the present invention can be achieved in two ways, i.e. by changing the shape of the rotational element in a section perpendicular to the axis of the rotational element, and by partially replacing the material used in the perpendicular section, as well as by combining the two methods.

Other features and advantages of the present invention will be apparent from the following description, used in conjunction with the accompanying drawings, in which like reference numerals indicate the same or similar elements in the drawings.

Brief Description of the Drawings

The accompanying drawings, which are included and form part of the detailed description, illustrate embodiments of the present invention and, in combination with the description, explain the principles of the present invention. In the drawings:

Figure 1 is a perspective view showing the construction of a needle selector for a knitting machine in accordance with an embodiment of the present invention;

figure 2 is a Central longitudinal view in section of a needle selector for the knitting machine of figure 1;

FIGS. 3A and 3B are views showing an example of a rotational member in a needle selector for a knitting machine of an embodiment that holds the piezoelectric device in an intermediate position, FIG. 3A is a perspective view and FIG. 3B is a side view of the rotation axis ;

FIGS. 4A and 4B are views showing another example of a rotary element in a needle selector for a knitting machine of an embodiment that holds the piezoelectric device in an intermediate position, FIG. 4A is a perspective view and FIG. 4B is an axial view rotation

FIGS. 5A-5C are views showing another example of a rotary element in a needle selector for a knitting machine of an embodiment that holds the piezoelectric device in an intermediate position, FIG. 5A is a perspective view, FIG. 5B is a cross-sectional view along the AA line of FIG. 5A, and FIG. 5C is a cross-sectional view of a variant of the example shown in FIG. 5B;

6 is a view showing another example of a rotational element in a needle selector for a knitting machine of an embodiment that holds the piezoelectric device in an intermediate position, and illustrates the position shown from the side of the rotation axis;

FIGS. 7A and 7B are views showing another example of a rotational element in a needle selector for a knitting machine of an embodiment that holds the piezoelectric device in an intermediate position, FIG. 7A is a perspective view and FIG. 7B is a side view axis of rotation;

FIGS. 8A and 8B are views showing an example of a rotational element in a needle selector for a knitting machine in an embodiment that is known and rotatably supports a portion of a rear end of a piezoelectric device in a groove of a support device or body, FIG. 8A is a view in perspective view of the rotational element, and FIG. 8B is a view of the rotational element relative to the support;

Fig. 9A is a perspective view of a finger in a needle selector for a knitting machine in an embodiment that is known and rotatably coupled with a finger through a portion of a front end of a piezoelectric device;

FIG. 9B is a view showing movements of a portion of a front end of a piezoelectric device on a finger side in a needle selector for a knitting machine in an embodiment affected by a positional displacement of the rotational element in an intermediate position during bending movement of the piezoelectric device;

Fig. 9C is a schematic view showing an example of a housing in a needle selector for a knitting machine in an embodiment in which a plurality of piezoelectric devices are arranged to form layers;

10A-10C are perspective views showing examples of a rotational element in a needle selector in an embodiment and a conventional needle selector that holds the piezoelectric device in an intermediate position, FIGS. 10A and 10B are views showing conventional examples, and FIG. 10C is a view showing an example of the present invention;

11 is a graph illustrating the relationship between movement and torque, which depends on a change in the shape of the rotational element that holds the piezoelectric device in an intermediate position;

12A and 12B are views showing an example of a well-known knitting machine needle selector, with FIG. 12A being a perspective view and FIG. 12B is a perspective view showing an example of a rotational member that holds the piezoelectric in an intermediate position the device used in the needle selector of FIG. 12A;

13 is a perspective view showing another conventional rotary element used in a well-known knitting machine needle selector, relative to a piezoelectric device;

14 is a schematic view for explaining vertical movement of the working needles that are used with the knitting mechanism in a circular knitting machine; and

figa and 15B are schematic views showing the relationship between the bend of the piezoelectric device and the vertical movement of the working needle in the needle selector for the knitting machine, with figa is a schematic view showing the case when the working needle is not driven by a cam stop, and FIG. 15B is a view showing a case where the working needle is driven by the cam stop.

The best way to implement the present invention

Next, the present invention will be described in detail with reference to the accompanying drawings, which show a needle selector for a knitting machine in accordance with an embodiment of the present invention.

Figure 1 shows a perspective view of a needle selector for a knitting machine in accordance with an embodiment of the present invention, and Figure 2 shows a central longitudinal sectional view of a needle selector for a knitting machine of Figure 1.

As shown in FIGS. 1 and 2, the rear end portion 2A of the piezoelectric device 2 to which the spherical device 1A is attached is mounted in the groove 17 of the support portion 150 of the support device A that supports the rear end portion of the piezoelectric device 2. FIG. 8A shows a view perspective view of a spherical device 1A.

A groove is formed at the end portion of the spherical device 1A. The end portion of the piezoelectric device 2 is installed and fixed in this groove. As shown in FIG. 8B, since the spherical portion of the spherical device 1A can rotate in the groove 17 of the support device, the portion 2A of the rear end of the piezoelectric device 2 can be rotated up or down, as shown by arrows in FIG. 8B.

The spherical device 1B is similar to the spherical device 1A attached to the rear end portion of the piezoelectric device 2 and attached to the front end portion 2B of the piezoelectric device 2. The spherical device 1B is fixed and connected by the open end portion of the rear end portion 5A of the finger 5. The spherical device 1B can also rotate up or down in a portion 5A of the rear end of the finger 5, as shown by the arrows in FIG. 2.

As shown in FIG. 9A, the rear end portion 5A of the finger 5 has an opening in the widthwise direction of the finger 5, and the mounting portion 18 of the finger of the support device A also has a corresponding opening. The axis 6 is installed in two holes for attachment with the possibility of rotation of the finger 5 to the mounting section 18. The finger 5 is connected to the piezoelectric device 2 for alignment (in the same direction) with the rectangular piezoelectric device 2. Section 5B of the front end of the finger 5 protrudes from the hole 19A open wall 19 of the supporting device A, which is mounted vertically in a position remote from the mounting portion 18 of the finger.

The hole 19A is formed with a width and a height in accordance with the process that occurs when the finger 5 moves vertically. The finger 5 repeats the bending movement of the plate 8, caused by the piezoelectric element 9, to connect with or disconnect from the end of the pusher for the selection of needles, which is installed with emphasis in the working needle or the lower end of the working needle.

An intermediate portion Y (see FIG. 9B) between the rear end portion 2A and the front end portion 2B of the piezoelectric device 2 is secured by a rotary element 3 formed on the intermediate portion 13 of the support of the support device A. The piezoelectric device 2 is bent near the intermediate portion Y as the support . As shown in (A) in FIG. 9B, the closer to the side of the finger, the higher the vibration speed of the finger. In addition, although the amplitude of X decreases, the torque increases. As shown in (B) in FIG. 9B, when the piezoelectric device 2 moves away from the finger, the opposite phenomenon is observed. Although the amplitude of X increases, the torque decreases.

The intermediate section Y, where the piezoelectric device 2 is fixed by means of the rotational element 3, is preferably in a position from 1/3 to 2/3 of the entire length of the piezoelectric device 2 from the portion 2A of the rear end of the piezoelectric device 2.

As the rotational element 3, a rod-shaped element of circular cross section is usually used, as described above (see FIGS. 12B and 13). If it is necessary to use the rotational element only to provide intermediate support in the piezoelectric device 2 so that the bending movement becomes free, then any other rod-shaped element is suitable, since the neck of the axis of the rotational element is rotatable relative to the supporting device A and no restriction is imposed on the cross-sectional structure of the central plot of the rotational element. Therefore, it is natural that only a rod-shaped element with a circular cross section along its entire length, which was then easiest to use, was used as a rotational element.

Various types of examples of the construction of the rotary element 3 as the main element according to the present invention will be described with reference to FIGS. 3A, 3B, 4A, 4B, 5A, 5B, 5C, 6, 7A and 7B.

On figa (perspective view) shows a first example of a rotational element. 3B, it is shown on the axis side. The rotary member 3 according to the first example has axial journals 31a and 31b at its two ends, and its central portion 33 has an elliptical portion with a major axis L1 and a minor axis W1. A through hole 32 for securing the piezoelectric device 2 is formed on a side portion of the central portion 33.

As can be seen from figv, that section of the Central section 33 of the rotational element 3, which is perpendicular to the axial direction, is an ellipse. Based on the shape of the central portion 33 and the position of the through hole 32 shown in FIG. 3B, it can be seen that the larger axis of the ellipse extends along a section perpendicular to the axis of the rotational element 3 in a direction perpendicular to the plane of the piezoelectric device 2. Therefore, it is clear that with such In design, the bend of the piezoelectric device 2 along the width direction is suppressed to become smaller than the bend of the piezoelectric device 2 along the longitudinal direction. According to this example, the diameter R1 of the axis neck 31a is smaller than the minor axis W1 of the central portion 33.

FIG. 4A shows a perspective view of a rotary element 3a in accordance with a second example, and FIG. 4B shows a view of the same rotational element shown from the axis side. In the rotary element 3a, the diameter R2 of the axis neck 31a is equal to the minor axis W2 of the central portion 34.

In the first and second examples, the ratio of the major axis to the minor axis is selected depending on the extent to which the vibration of the piezoelectric device 2 should decrease in the width direction.

FIG. 5A is a perspective view of a rotational member 3b in accordance with a third example, and FIG. 5B is a cross-sectional view of the same rotational member. In this rotational element 3b, the two ends of the cylindrical element 31 form the axial journals 31a and 31b. Rod-shaped elements 35a and 35b made of metal, such as steel, having a higher stiffness than the material of element 31, are located on a section of element 31, which is parallel to the plane of the piezoelectric device 2, which should be installed in the through hole 32 in the Central section of the element 31. In according to the third example, the rod-shaped elements 35a and 35b may be located in a recessed position on the surface of the element 31. Alternatively, as can be seen from FIG. 5C, which shows a sectional view of the rotational element 3c According to a fourth example, rod-shaped elements 36a and 36b may be adhered to the outer surface of the member 31. The third and fourth examples of the rod-shaped member may be located, for example, only one side surface portion. More specifically, either the upper or lower rod-shaped element 35a or 35b (or rod-shaped element 36a or 36b) can be used. The material of the rod-shaped elements 35a, 35b, 36a and 36b is not limited to any material. A material having a higher bending stiffness than the material of the element 31 can be used to form parts 35a, 35b, 36a and 36b. When a material having a much higher bending stiffness than the material of the element 31 is used to form parts 35a, 35b, 36a and 36b, the proportion of the rod-shaped element can be reduced.

The rotational element 3d in accordance with the fifth example shown in FIG. 6 is formed by injection molding two materials having different bending stiffnesses using, for example, a common injection mold. In this case, polyacetal is preferably used to form part 31, and polymeric material having a higher bending stiffness than polyacetal is used to form parts 37a and 37b, for example, a composite polymer material obtained by reinforcing a polymer such as polyacetal with glass fiber or the like.

FIG. 7A is a perspective view of a rotational member 3e according to a fifth example, and FIG. 7B is a perspective view of the same rotational member shown from the axis of rotation. In the rotary element 3e, the central portion 38 is formed with an I-shaped rail-like cross-section, as shown in FIG. 7B, and the axis necks 31a and 31b are located at the two ends of the central portion 38. In this case, the central portion 38 and the axis necks 31a and 31b are preferably made of the same material by injection molding. As shown in FIG. 7B, the I-shaped section contains different sections in their shape. When the dimensions of the respective sections vary in different ways, the bending stiffness can vary greatly, as shown by the calculation examples described below.

As described above in detail in various examples, in accordance with the distinguishing feature of the needle selector for a knitting machine in accordance with this embodiment, the piezoelectric device is secured by the rotary element 3 only at one point in an intermediate position between the rear end portion and the front end portion of the piezoelectric device 2 and the axial section of the rotational element at this only one point has a specific design so that the piezoelectric bends in the width direction Cesky decreased devices.

The design of the rotary element 3 was changed for rotary elements with a conventional circular section, various types of elliptical shapes and various types of I-shaped sections of the present invention, and the results of calculations of changes in bending stiffness are shown below.

Calculation formula

Cross-sectional area

A circle πd ^2/4 Ellipse

{0,5

(большая ось)}

{0,5

(малая ось)}π

{0.5

(major axis)}

{0.5

(minor axis)} I form dt + 2a (s + n) (see Fig. 7B) Section inertia moment A circle I = πd ^4/64 Ellipse I = π

{0.5

(major axis)} ³

{0.5

(minor axis)} I form g = (h-1) ÷ (b-t)

Tables 1, 2 and 3 show the obtained calculation results.

Table 1 Calculation example Sectional shape Diameter R1 Radius r Minor axis Major axis Cross-sectional area The ratio of area to 1 Moment of inertia of the I section I to 1 ratio 1 (prior art) a circle 10 5 - - 78.5 - 490 - 2 ellipse - - 8 12.5 78.5 1,0 575 1.17 3 ellipse - - 6 16.7 78.5 1,0 1361 2.77 four ellipse - - 10 12 90,4 1.15 848 1.73 5 ellipse - - 10 fourteen 110 1.40 1346 2.74

Table 1 shows the cross-sectional area and the magnitude of the moment of inertia I of the cross section of the rotational element of the case in which the rotational element has a conventional circular cross section, and cases in which the rotational element has different types of elliptical cross-sections in accordance with the present invention. For convenience of calculation, suppose that the usual circular section has a diameter of 10 mm. The calculations were performed by comparing with this case.

As can be seen from table 1, in the case of a circle (prior art), the cross-sectional area is 78.5 mm ² , and I is 490. In cases with ellipses, assuming that the cross-sectional area is equal to the cross-sectional area of the circle when the minor axis is 8 mm (calculated Example 2), I is only 1.17 times larger than the circle. When the minor axis is 6 mm (calculation example 3), I becomes 2.77 times larger and the bending stiffness is significantly increased.

A test calculation (calculation examples 4 and 5) is carried out in relation to how much I increases with increasing the major axis while the minor axis is 10 mm, which is equal to the diameter of the circle (prior art). When the major axis is 12 mm, I becomes 1.73 times larger; when 14 mm, I becomes 2.74 times larger.

Table 2 shows the shapes and sizes of the three calculation examples 6, 7 and 8, when the rotational element has an I-shaped cross-section. Table 3 shows the corresponding cross-sectional areas and I values of the three calculated examples 6, 7 and 8.

table 2 Calculation example The dimensions of the respective sections of the rail-like I-shaped section (see figv) b T a d h one s n 6 8 four 2 12 6 four 3 four 7 10 6 2 12 6 four 3 four 8 10 6 2 fourteen 8 6 3 four

Table 3 Calculation example Cross-sectional area The ratio of area to 1 Moment of inertia of the I section I to 1 ratio 6 76 Essentially equal to 1109 2.26 7 one hundred 1.27 1396 2.84 8 112 1.42 2170 4.43

Calculated examples of rotational elements having I-shaped sections include the case (calculation example 6), in which the cross-sectional area is essentially equal to the cross-sectional area of calculation example 1 (circular cross-section), and cases (calculation examples 7 and 8), in which the value of b , that is, the width of the I-shaped section in the longitudinal direction of the piezoelectric device 2 is set equal to the diameter of calculation example 1.

From table 3 it can be seen that in any example when an I-shaped section is used, the value of I can be significantly increased compared with the case in which any other section was used.

Then, samples of rotary elements according to the prior art and samples according to the present invention were made. Each sample was made with a piezoelectric device for conducting a vibration test in accordance with the actual needle selection operation. 10A, 10B and 10C depict schematic perspective views of the rotational elements used.

The rotational element in FIG. 10A is the rotational element shown in FIG. 13, which is commonly used widely in the needle selector, and the rotational element in FIG. 10B is the rotational element that supports the piezoelectric device 2 shown in FIGS. 12A and 12B, c two sides. On figs shows an example of the present invention, a detailed design of which is shown in figs. The rod-shaped elements 36a are located on the two upper and lower sides of the central portion 31.

The experiment was carried out as follows. The rotating elements described above were made with piezoelectric devices for manufacturing three samples for each of comparative example 1, the construction of which is shown in FIG. 10A, comparative example 2, the construction of which is shown in FIG. 10B, and this example. The corresponding samples were tested for vibration. As the piezoelectric device 2, a piezoelectric device with a width of 10 mm and a length of 30 mm was used. The rotational element 30 was made of polyacetal with a diameter of 2.5 mm. The rod-shaped element 36a was made of stainless steel with a diameter of 0.3 mm.

Table 4 shows the test results obtained.

Table 4 Sample No. A
Torque up B Torque down C
Total movement D (AxC) E (BxC) F (D + E) / 2 The average value of F Difference Comparative Example 1 FIG. 10A one 0.39 0.31 1.14 0.445 0.353 0.399 0.420 0,090 2 0.41 0.36 1.27 0.521 0.457 0.489 3 0.38 0.34 1.20 0.456 0.408 0.432 Comparative Example 2 FIG. 10B four 0.28 0.26 1.00 0.280 0.260 0.270 0.268 0,021 5 0.32 0.23 1.01 0.323 0.232 0.278 6 0.29 0.25 0.95 0.276 0.238 0.257 Example FIG. 10C 7 0.44 0.35 1.29 0.568 0.452 0.510 0.508 0,028 8 0.42 0.37 1.32 0.544 0.488 0.521 9 0.43 0.34 1.28 0.550 0.435 0.493

A. Torque up: torque to support the piezoelectric device when pressed down from the upper amplitude position to the center position;

B. Downward torque: torque to support the piezoelectric device when pressed upward from the lower amplitude position to the center position;

C. Total displacement: the difference between the upper and lower amplitudes;

D. A × C: product of upward torque and total displacement;

E. B × C: product of downward torque and total displacement;

F. (D + E) / 2: average value of the products of the corresponding torques and the total displacements;

The average value of F: the average value of the F values of three samples;

Difference: The difference between the maximum and minimum F values of the three samples.

The larger the average value indicated by F in table 4 of the upper and lower products of the total displacements and torques, the more the vibration is damped in the direction along the width of the piezoelectric device, so that the vibration in the longitudinal direction of the piezoelectric device is more effective.

From table 4 it is seen that the average F value of the example increases by about 20% of the average F value of comparative example 1 and that the vibration among the three samples of the example is significantly increased compared to comparative example 1.

Based on this experiment, it was found that if the rotational element is interrupted in the width direction, as in comparative example 2, when the voltage is applied to the piezoelectric device, vibration damping in the width direction is significantly reduced when compared with comparative example 1, in which the rotational element is continuous in width direction.

During this experiment, the relationship between the torque and the movement of each sample was examined. 11 shows the result. Among the lines of which each represents the relationship between torque and movement, the broken line 1 shows comparative example 1, line 2, dotted with a dot, shows comparative example 2, and the solid line 3 shows an example.

11, the larger the area under a straight line representing the relationship between torque and displacement, the more vibration is suppressed in the widthwise direction of the piezoelectric device, so that the vibration in the longitudinal direction of the piezoelectric device is more effective. 11, a solid line 3 representing the relationship between the torque and the movement of the example is located in the uppermost position. This proves that the piezoelectric device provided with the rotational element in accordance with the present invention shows an excellent result in terms of vibration of the piezoelectric device, which usually cannot be obtained.

The new needle selector for a knitting machine in accordance with the present invention has been described in detail for a case in which a single piezoelectric device has been used. In fact, one of ordinary skill in the art will recognize that in a mass production knitting machine, one piezoelectric device is not held by the support device. As shown, for example, in FIG. 9C, a housing is used in which a plurality of piezoelectric devices (seven piezoelectric devices in the case of FIG. 9C) are located at a distance from each other to form a layer. Therefore, a needle selector for a knitting machine according to the present invention relates to a needle selector in which at least one piezoelectric device is housed in a support device or housing.

Although a needle selector for a knitting machine according to the present invention is described for a case in which a needle selector is used in a circular knitting machine, a needle selector according to the present invention can also be used in a flat knitting machine.

Industrial applicability

The knitting machine needle selector according to the present invention is based on a knitting machine needle selector, which is registered by the applicant of the present invention as Japanese Patent No. 1969970 (see Japanese Patent Publication No. 694619) and a similar US Patent No. 5027619 and is widely used as a reliable device. In addition, since the rotational element that holds the piezoelectric device in an intermediate position is obtained so that the bend in the width direction of the piezoelectric device is suppressed and becomes smaller than the bend in the longitudinal direction of the piezoelectric device, the piezoelectric device can vibrate more efficiently.

As a result, the vibration speed of the piezoelectric device can be increased and an increase in productivity of the knitting machine can be achieved.

The present invention is not limited to these embodiments, and various changes and modifications are possible without departing from the idea and scope of the present invention. Moreover, the scope of the present invention is determined by the attached claims.

Claims (6)

1. A needle selector for a knitting machine, comprising: a plate piezoelectric device including a piezoelectric element and a finger aligned with the specified piezoelectric device and arranged to move, while a portion of the rear end of the specified piezoelectric device is supported to rotate into the groove of the supporting device or housing, a portion of the front end of said piezoelectric device is rotatably connected to a portion of the rear end of said about the finger, the intermediate position between the indicated portion of the rear end and the portion of the front end of the specified piezoelectric device is clamped by a rotational element configured to rotate in the specified supporting device or housing, and the specified finger is actuated by applying voltage to the specified piezoelectric element to select the working needle of the specified knitting machine so that you can knit a product with the texture of a given pattern, characterized in that the said rotator The element contains axle necks formed at its two ends, supported by bearings installed in the indicated support device or housing, and a central section between the two axle necks, and a slot that clamps the specified piezoelectric device is formed on at least part of the specified the Central section in the direction along the width of the specified piezoelectric device, and the design of the axial section of the specified Central section on a plane perpendicular to the axis of the specified rotational of the element and perpendicular to the plane of said piezoelectric device is formed such that the bending in the width direction of said piezoelectric device is reduced to a value less than the magnitude of the bending in the longitudinal direction of said piezoelectric device. 2. The needle selector according to claim 1, characterized in that said central portion has a cross-sectional shape such that its length along a direction that connects said portion of the rear end and the portion of the front end of said piezoelectric device is less than the length along the thickness direction of said piezoelectric device. 3. The needle selector according to claim 2, characterized in that said cross-sectional shape of said central portion is an ellipse that has a short side in a direction connecting said portion of the rear end and a portion of the front end of said piezoelectric device. 4. The needle selector according to claim 1, characterized in that said cross-sectional shape of said central portion has a rib-shaped protrusion on one or both of the upper and lower sides of the central portion in a position remote from the slot. 5. The needle selector according to claim 1, characterized in that said central portion is formed of at least two layers in the construction of its cross section, which are made of materials having different bending stiffnesses, and a material is used to form a portion remote from the slot having a higher bending stiffness than the material used in the area near the slot. 6. The needle selector according to claim 5, characterized in that said portion remote from the slot is formed of a rod-shaped element made of metal, and the portion near the slot is made of plastic.

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