KR20010087117A - Apparatus for Supporting Fabric in Loom - Google Patents

Abstract

PURPOSE: To make it possible to change the width of woven cloth without changing a cloth guiding member and prevent the damage of warps caused by jetting fluid attributable to the descent of a weaving start accompanied by the opening of the warps. CONSTITUTION: A woven cloth supporting apparatus comprising a pair of cloth end guides having a space between themselves in the direction of the cloth width, that is, a pair of cloth end guides having a guiding piece whose upper end touches the lower surface of one end of the woven cloth and a guiding piece whose upper end touches the lower surface of the other end of the woven cloth, respectively, and a cloth center guide which bridges both the cloth end guides, that is, a cloth center guide whose upper end touches the lower surface of the center of the woven cloth. Each of the cloth end guides extends from the outer end of a temple in the cloth width direction toward the center of the woven cloth beyond the inner end of the temple in the space between the temples and the weaving start, and the cloth center guide allows each of its ends in the cloth width direction to touch the guiding piece of a cloth end guide on the opposite side to the weaving start and to overlap the cloth end guide, and at least one of the cloth end guides and the cloth center guide are combined so that they can move relatively in the cloth width direction.

Description

Apparatus for Supporting Fabric in Loom

Field of invention

TECHNICAL FIELD This invention relates to the woven fabric support apparatus in the loom provided with the temple apparatus which makes shrinkage of a woven fabric small.

Background of the Invention

The upper type temple apparatus used for the loom presses each end (each end portion) of the woven fabric in the bombing direction by a temple composed of a plurality of links or the like having a plurality of needles, and moves the respective fabrics together with the advancement of the woven fabric. It is arrange | positioned at the both ends of a woven fabric so that a part may be pulled in the width direction. The temple is arranged on the woven end near the fastball, and therefore, the shrinkage of the woven cloth in the vicinity of the fastball is suppressed. Looms with such a temple device are provided with a woven support device for supporting the lower surface of the woven fabric against the pressing pressure from above the woven fabric. The woven support device is installed as close to the fastball as possible in a range that does not interfere with the body needle movement, in order to prevent the fastening of the fastener due to the inclined opening movement.

As one of the kinds of woven fabric support apparatuses, a fabric is provided with a pair of fabric guides (cloth guide members) spaced apart in the width direction from the widthwise end portion of the fabric, and the widthwise center portion of the fabric is disposed between the two fabric guides. There is a thing in the center guide (guide bar) (Japanese Patent Laid-Open No. 9-13250). The edge guide and the center guide of the cloth face each other in the width direction of the cloth width direction. When changing the woven width, the cloth center guide is replaced with a guide having a length corresponding to the new woven width.

Another woven fabric support device is to receive a woven fabric from a pair of left and right fabric guides (pelplates) that are stacked and connected, and to change the amount of overlap of the fabric guides when changing the woven fabric width (Japanese Patent Application Laid-Open No. 4-202833). 4 degrees).

However, in the former device, a plurality of fabric center guides having different lengths must be prepared, and each guide must be subjected to a machining for rounding off corners of the abutting cross sections to prevent the occurrence of scratches caused by the abutting cross sections. . In such a process, a woven fabric enters between abutting end faces of the guide, and small scratches also occur.

In the latter apparatus, since the fabric guide does not extend to the end of the woven fabric, it cannot support the fabric end provided with the temple. Further, even if the left and right guides are extended to the cutting edge, for example, the distance between the fastball and the gun guide is different in the left and right gun guides. Is damaged by the injection fluid for entrainment. The damage of the upper slope by the injection fluid is for the following reasons.

In fabrics in which the upper and lower inclination numbers differ greatly, the tension difference between the upper and lower inclinations becomes large, and the inclined straight ball moves up and down in accordance with the opening movement. At this time, the fall amount of the fastball of the fabric part supported by the fabric guide far from a fastball becomes larger than the fall amount of the fastball of the fabric part supported by the fabric guide near a fastball.

On the other hand, the state of the inclined opening when the injection fluid for gastric inflow passes is in the middle of opening at the weft supply side (emergency side) end, is the maximum opening in the center part, and is closed in the end of the weft inlet side (reflection side) end. For this reason, the opening amount of each part corresponding to the woven fabric end when the injection fluid passes through is thus small during the opening or during the closing opening.

As a result, in the latter apparatus, the injection fluid easily collides with the inclination of the top of the fabric end supported by the fabric guide away from the fastball, so that the inclination of the upper inclination is impaired, the injecting fluid is dispersed, and the movement speed of the weft is reduced and Cause further damage of the slope.

An object of the present invention is to support a woven fabric of a loom having a temple device which enables the woven fabric width to be changed without replacing the fabric guide member, and prevents the damage of the warp caused by the injection fluid caused by the fall of the fastball due to the opening motion of the warp. To provide a device.

The above and other objects of the present invention can be achieved by the present invention described below. Hereinafter, the content of the present invention will be described in detail.

1 is a plan view showing an embodiment of a woven fabric support device according to the present invention together with the main part of a loom.

Fig. 2 is a sectional view of the woven fabric support device shown in Fig. 1, (A) is a sectional view of the line 2A-2A of Fig. 1, (B) is a sectional view of the line 2B-2B of Fig. 1, and (C) is a 2C-2C of Fig. 1 It is a cross section of the line.

FIG. 3 is a plan view similar to FIG. 1 showing one embodiment in a state where the woven fabric width is changed in the embodiment shown in FIG.

Fig. 4 is a plan view showing another embodiment of the woven fabric support device according to the present invention together with the main part of the loom.

Fig. 5 is a sectional view of the woven fabric support device shown in Fig. 4, (A) is a sectional view taken along the line 5A-5A in Fig. 4, (B) is a sectional view taken on the line 5B-5B in Fig. 4, and (C) is a 5C-5C shown in Fig. 4 Line cross section.

* Explanation of major symbols *

10, 50: woven fabric support device 12: woven fabric

14: Slope 16: Body

20: fastball 22: temple

26: gun guide 26a: guide of the gun guide

28: gun center guide 28a: guide part of gun center guide

30: guide bar base

52: Semi-spherical side guide member of the fabric center guide

52a: guide portion of the semi-side spherical guide member

54: fastener guide member of the gun center guide

54a: Guide portion of the fastener side guide member

The woven fabric support apparatus according to the present invention is used for a loom having a temple disposed above one end of the woven fabric and a temple disposed above the other end.

Such a woven support device has a guide section having a guide section having a top edge in contact with the bottom surface of one end of the woven fabric and a guide edge having a top edge in contact with the bottom of the other end of the woven fabric in a pair of shroud guides spaced in the width direction of the fabric. And a cloth center guide having a guide portion having a guide portion having a top edge that is in contact with a central lower surface of the woven fabric with a cloth center guide spanning both of the cloth guides.

Each woven fabric guide extends between the temple and the fastball from the outer end of the temple in the bombing direction toward the woven fabric center rather than the inner end, and the guide portion of the fabric center guide extends each end in the woven fabric width direction. The guide part of the guide is connected to the semi-spherical side of the guide and overlaps both guide parts. At least one of the cutting guide and the center guide are combined to be relatively movable in the direction of the bomb width.

When changing the woven fabric width, the gun guide and the gun guide are relatively moved in the direction of the gun bomb, and the amount of overlap between the guide of the gun guide and the guide of the gun guide is changed. For this reason, it is not necessary to provide the some woven fabric guide member which has the different length according to the woven fabric width.

Each end of the guide portion of the fabric center guide overlaps the guide portion of the fabrication guide, and the guide portion of the fabrication guide and the guide portion of the fabrication center guide are not butted in the direction of the fabric width. For this reason, since the woven fabric is supported by at least one of the guide portion of the cutting guide and the guide portion of the cloth center guide over the entire width, scratches caused by the woven fabric entering between the end faces of both guides do not occur.

The guide portions of both cutting guides are located on the direct sphere side than the guide portions of the cloth center guides. For this reason, the following effects generate | occur | produce further.

At both ends in the bombing direction, since the fastball of the corresponding inclination does not go down than the fastball of the inclination of the central part in the bombardment direction, even when the opening amount of the corresponding inclination at the time of passage of the injecting injection fluid is not sufficient. Nevertheless, there is no problem of inclination of the inclination caused by the injecting fluid, such that the injecting fluid is in contact with the inclination and fluff occurs in the inclination. On the other hand, in the center portion in the bombing direction, the injection fluid does not contact the upper inclination even when the fastball is lower than the fastener at the end of the woven fabric because the opening amount of the inclination is large at the time of passage of the injection fluid. Therefore, there is no problem of inclination damage caused by the injection fluid throughout the woven fabric.

The fabric center guide may be formed of a single member. By doing so, the flaw due to connection does not arise compared with the case where the fabric center guide which supports a fabric center part is divided into two or more members, and they are connected. In addition, the fastball side of the guide part in the center of a cloth is equidistant from the fastball over the whole semi-spherical ball side of the guide part of a cutting guide, and is not located in the semi-fastener direction. Therefore, the lowering of the fastener due to the opening movement can be made as small as possible even in the woven fabric central portion where the lower surface is brought into contact with the guide portion of the fabric center guide.

The fabric center guide is a pair of semi-woven fabric side guide members spaced in the artillery direction, and the guide portion overlapping the semi-woven fabric side of the woven fabric central end of the guide portion of the guide of the fabrication guide corresponding to one end in the artillery direction. It has a pair of semi-spherical side guide members which have, and a guide part which overlaps with both semi-spherical side guide members, the guide part which contact | connects and overlaps with the fast-held side of the guide part of the said semi-semi-spherical side guide member in each edge part in the width direction. The fastener side guide member can be provided. In such a case, since the fastener side guide member of the cloth center guide also approaches the fastener like the edge guide, the fall of the fastener due to the opening movement can be suppressed also in the center part in the woven fabric width direction, and the woven fabric is the fastener side It does not enter between the cross section of a guide member and a semi-height-side guide member, and therefore a scratch does not arise by it.

The cutting guide and the center guide have a first plate portion having a guide portion having a top edge in contact with a lower surface of the woven fabric, and a second plate portion extending in a semi-height direction following the bottom edge of the first plate portion. This has an L-shaped cross section. By doing so, the second plate-shaped portion can be provided as an installation portion, and each guide to the loom can be easily installed, and the rigidity of each guide is increased due to the L-shaped cross-sectional shape to form each guide from a thinner material. Since it is possible to make the guide part of the cloth center guide closer to a fastener, the fall of the center fastener in the gunpo direction can be made smaller.

Example

Referring to Figures 1, 2 and 3, the woven fabric support device 10 is a loom, especially a jet loom, having a top-shaped temple device in which a temple assembly is disposed at each end in the width direction of the woven fabric 12. Is installed.

In such a loom, the inclination 14 is opened by an opening device not shown. The weft yarn enters the opening of the inclined 14 by an indentation apparatus, not shown, and is immediately hit by the body 16. The woven fabric 12 is wound on a winding device, not shown, through the cloth guide roll 18. The fastener 20 is in the vicinity including the intersection point of the upper inclination and the lower inclination in the inclined opening.

Each temple assembly supports the plurality of temples 22 so as to be rotatable to the temple case 24, and the temples 22 are provided at intervals in the moving direction of the woven fabric 12, and the width direction of the woven fabric (ie, It extends in the blast direction and is provided in the loom so that the width direction end part (that is, the fabric end part) of the woven fabric 12 is pressed from the top. The woven fabric 12 is passed between the temple 22 and the temple case 24, and the fabric end is rotated around an axis line extending in the bombing direction in accordance with the movement of the woven fabric 12. Pulled out, the shrinkage is suppressed.

The woven support device 10 includes a pair of left and right shoulder guides (left guide bar and right guide bar) 26 spaced in the direction of the bombing direction, and a cloth center guide (center guide bar) spanning the two gun guides 26 ( 28) and a guide bar base 30 installed on the frame of the loom.

Both of the cutting guides 26 and the center guide 28 extend horizontally in the semi-height direction following the lower edge of the first plate portion and the first plate portion extending in the vertical direction and the left and right directions (pore direction direction). The upper end edge of the guide part 26a, 28a which is formed of the single member which has an L-shaped cross-sectional shape by the said 2nd plate-shaped part, and the upper edge of the 1st plate-shaped part contacts the lower surface of the woven fabric 12. It is provided in the guide bar base 30 in the 2nd plate-shaped part so that it may act as a. The vicinity of both end portions of the upper edges of the guide portions 26a and 28a consists of an arcuate surface having a center at the bottom and tangential to the upper edge of the center portion, thereby suppressing the formation of scratches.

One edge guide 26 guides the widthwise one end region of the woven fabric 12, the other edge guide 26 guides the widthwise other end region of the woven fabric 12, and the cloth center guide 28 directs the woven fabric. Guide the widthwise central region of (12). Each shroud guide 26 is formed between the corresponding temple 22 and the fastball 20 from the outer end of the temple 22 in the bombing direction to the center of the woven fabric 12 rather than the inner end of the temple 22. It is extended.

The cell center guide 28 arrange | positions each edge part in the width direction of the woven fabric 12 of a 2nd plate-shaped part on the 2nd plate-shaped part of the cutting guide 26, and cut | disconnects a 1st plate-shaped part. It is in contact with the semi-preferred side of the first plate-shaped part of the guide 26. Thereby, the guide part 28a connects each end part to the semi-woven ball side of the guide part 26a, and is overlapped with the guide part 26a, and both the cutting guides 26 and the gun center guide 28 are the gunpo directions. Relatively moveable.

However, each of the cutting guides 26 is provided with an end portion in the widthwise direction on the lower surface of the case 24 by the screw member 32, and the overlapping portion with the center guide 28 is the bar holder 34 and the screw member. It is attached to the guide bar base 30 by 36. As shown in FIG. The fabric center guide 28 is fitted to the guide bar base 30 by the screw member 40 while fitting the adjustment plate 38 in the center in the fabric width direction.

In the woven fabric support device 10, each end of the guide portion 28a of the fabric center guide 28 overlaps the guide portion 26a of the cutting guide 26, and the guide portion of the cutting guide 26 ( 26a) and the guide part 28a of the fabric center guide 28 do not face each other. For this reason, since the woven fabric 12 is supported by at least one of the guide parts 26a and 28a over the full width, the flaw which arises because the woven fabric 12 enters between the cross sections of a cloth guide does not arise.

The distance between the fastener 20 and the cutting guide 26 is L. FIG. In contrast, the distance between the fastener 20 and the cloth center guide 28 is L + t larger than the distance L by the thickness t of the first plate-shaped portion of the cutting guide 26. If the tension difference between the up and down inclination 14 is large, the fastener 20 is pulled up and down in the direction of high tension in accordance with the opening movement of the inclination 14, and the maximum opening of the inclination 14 is indicated by the solid line and the dotted line in FIG. Move up and down to the position indicated by.

At this time, the descending amount of the portion of the fastener 20 of the cloth center portion supported only by the cloth center guide 28 distant from the fastener 20 is the fastener of the cut portion supported by the cutting guide 24 close to the fastener 20 ( 20) It is larger than the descending amount of the part.

On the other hand, the opening state of the inclination 14 when the injecting injection fluid passes through is in the middle of the opening at the end of the weft supply side (emergency side), and is the maximum opening in the center portion, and at the end of the weft inlet side (reflection side). It is during the closing. For this reason, the opening amount of each part corresponding to the cloth end when the injection fluid passes is small accordingly during the opening or during the closing opening.

However, in the woven fabric support apparatus 10, since the both guide parts 26a are located in the fastener 20 side rather than the guide part 28a, the following additional effects generate | occur | produce.

At each end part in the blasting direction of the woven fabric 12, the fastener 20 of the corresponding inclination 14 does not go down than the fastener 20 of the inclination 14 of the center part in a blasting direction, and therefore Damage of the incline 14 by the injecting fluid, even though the opening amount of the corresponding incline 14 is not sufficient at the time of passage of the injecting injecting fluid, the injecting fluid contacts the upper incline and fluffs are generated in the upper incline. The problem does not occur. On the other hand, in the center part of the woven fabric 12, since the opening amount of the inclination 14 at the time of passage of the injection fluid is large, even if the fastener 20 of the cloth center part descends below the fastener 20 of the cloth edge part, the injection fluid will be inclined upward. Do not touch Therefore, the problem of the damage of the inclination 14 by the injection fluid does not arise over the whole woven fabric.

When changing the woven fabric width, loosen the threaded member 36 on the semi-finished yarn side, move the cutting guide side 26 on the semi-finished yarn side in the bombing direction integrally with the temple 22 on the semi-finished yarn side and the temple case 24, and return the cloth. The amount of overlap of the guide parts 26a and 28a between the cutting edge guide 26 and the gun center guide 28 on the four sides is changed.

When the predetermined width value is not obtained, first tighten the screw member 36 on the semi-finished side, integrate the three cutting guides 26, the center guide 28 and the guide base 30 on the semi-finished side, Loosen the bolt (not shown) and the threaded member 36 on the steep side, which secure the guide base 30 to the loom. Subsequently, three cutting guides 26, the gun center guide 28, and the guide base 30 on the semi-employed yarn side are integrally moved in the gunpo direction, and the cutting guide 26 and the gun center guide 28 on the yarn feeding side are moved. ), The overlapping amount of the guide portions 26a and 28a is changed to obtain a predetermined woven width value.

In any case, the amount of overlap between the guide portion 26a of the cutting guide 26 and the guide portion 28a of the fabric center guide 28 is changed, and it is necessary to have a plurality of fabric guide members having different lengths according to the woven fabric width. none. Loose screw members are retightened after changing the fabric width. 3 shows a state in which the fabric guide width of the semi-finished yarn side is moved to the semi-finished yarn side with respect to the gun center guide 28 to change the woven fabric width.

According to the woven fabric support device 10, since the fabric center guide 28 is formed of a single member, the fabric center guide 28 supporting the fabric center portion is divided into two or more members and connected thereto. Thus, no scratch occurs due to the butt connection. In addition, the fastener side of the guide part of the cloth center guide 28 is the same distance from the fastener 20 over the whole with respect to the semi-fastener side of the guide part of the cutting guide 26, and is not located in the semi-fastener direction. Therefore, the lowering of the fastener 20 according to the opening movement can be made as small as possible even in the woven fabric central portion supported by connecting the lower surface to the guide portion of the fabric center guide 28.

Moreover, according to the said woven fabric support apparatus 10, the 1st plate-shaped part which has the guide part with the upper edge which both the edge guides 26 and the cloth center guide 28 abut on the lower surface of the woven fabric 12 at the upper edge. And each of the guides to the loom, having an L-shaped cross-sectional shape by the second plate-like portion extending in the semi-spherical direction following the lower edge of the first plate-shaped portion, and having the second plate-shaped portion as the attachment portion. Becomes easy. In addition, because of the L-shaped cross-sectional shape, the rigidity of each guide can be increased to form each guide with a thinner material, thus making the guide portion 28a of the fabric center guide 28 closer to the fastener 20. The fall of the central fastener 20 in the woven fabric width direction can be made smaller.

4 and 5, the woven fabric support device 50 includes a pair of semi-woven fabric side guide members 52 with the cloth center guides spaced in the width direction of the woven fabric 12, and both semi-woven fabric side guide members. It is comprised by the three guide members of the fastball side guide member 54 which straddled by 52.

The guide members 52 and 54, like all the cutting guides 26, are formed of members having an L-shaped cross-sectional shape by the first and second plate portions, and the upper edge of the first plate portion is formed. It is provided in the guide bar base 30 in the 2nd plate-shaped part so that it may act as the upper edge of the guide part 52a, 54a which contact | connects the lower surface of the woven fabric 12. As shown in FIG. The vicinity of both end portions of the upper edges of the guide portions 52a and 54a consists of an arcuate surface having a center at the lower end and tangential to the upper edge of the center portion, thereby preventing the occurrence of scratches.

Each semi-woven fabric side guide member 52 is arrange | positioned at the one end part in the width direction of the woven fabric 12 on the cloth center side end part of the cutting | disconnection guide 26 corresponding to it, and also in the width direction of the woven fabric 12. The other end of the first plate-shaped portion is disposed on the corresponding end of the fastener-side guide member 54, and the first plate of each of the cutting guide 26 and the fastener-side guide member 54, respectively. It is in contact with the upper half-height side. Thereby, each edge part of the guide part 52a is overlapped by the semi-spherical side of the guide part 54a, and the semi-spherical side guide member 52 and the straight side side guide member 54 are movable relatively in the width direction. .

However, each semi-woven side guide member 52 is provided with the overlapping portion with the corresponding cutting guide 26 in the guide bar base 30 by the bar holder 34 and the screw member 36, and at the same time The overlapping portion with the guide member 54 is provided in the guide bar base 30 by the bar holder 56 and the screw member 58.

The guide portion 54a of the fastener-side guide member 54 is maintained at a position where the position (distance) from the fastener 20 is substantially equal to the position of the guide portion 26a of the cutting guide 26. For this reason, the center area | region in the width direction of the woven fabric 12 is a fastball side at the position from the fastener 20 substantially the same as the guide part 26a of the cutting guide 26 in the moving direction of the woven fabric 12. It is supported by the guide portion 54a of the guide member 54.

In the woven fabric support device 50, the guide portion 52a of each semi-woven side guide member 52 and the guide portion 26a of the cutting guide 26 are end portions as in the embodiment shown in Figs. Is overlapping. Moreover, the edge part overlaps with the guide part 52a of each semi-height-side guide member 52, and the guide part 54a of the straight-side guide member 54. As shown in FIG. For this reason, since the woven fabric 12 is supported by at least one of the guide parts 26a, 52a, and 54a all over, the woven fabric 12 is the edge guide 26, the semi-woven side guide member 52, and the fastball side. Scratches resulting from entering between the end faces of the guide member 54 do not occur.

In addition, when the tension difference of the up-down inclination 14 is large, the fastball 20 will move up and down to the position shown by the solid line in FIG. 5, and the position shown by the dotted line according to the opening movement of the inclination 14. As shown in FIG. However, in the woven fabric support apparatus 50, since the center part in the width direction of the woven fabric 12 approaches the fastener 20 by the guide part 56a of the fastener side guide member 56, the woven fabric 12 The fall of the fastener 20 according to the opening movement can be prevented also in the width direction center area | region.

In the woven fabric support device 50, the woven fabric width can not only be changed as in the embodiment shown in FIG. 1, but also there are four overlapping portions of the guide portion, which is larger than the embodiment shown in FIG. Can be.

The present invention is not limited to the above embodiment. The present invention can be variously modified without departing from the spirit thereof.

The present invention provides a woven fabric support apparatus for a loom having a temple device that enables the woven fabric width to be changed without replacing the woven fabric guide member and prevents the damage of the warp caused by the injection fluid caused by the fall of the fastball due to the opening motion of the warp. Provided has the effect of the invention.

Claims (4)

In the woven fabric support apparatus of the loom with the temple 22 arrange | positioned above one end of the woven fabric 12, and the temple 22 arrange | positioned above the other end, The lower end of the cloth guide 26 and the other end of the woven fabric 12 having a guide portion 26a having an upper edge contacting the lower surface of the one end of the woven fabric 12 by a pair of cutting guides 26 spaced in the width direction. A woven end guide 26 having a guide portion 26a having an upper edge in contact with the Fabric center guide 28 having guide sections 28a, 52a, 54a with top edges abutting the central lower surface of woven fabric 12 with fabric center guides 28, 52, 54 spanning both woven fabric guides 26; 52, 54), Each cutting guide 26 extends between the temple 22 and the fastball 20 from the outer end of the temple 22 in the bombing direction toward the center of the woven fabric rather than the inner end thereof. The center guides 28, 52, and 54 are overlapped by connecting the respective ends of the guide parts 28a, 52a, and 54a in the direction of the bombardment to the half-height side of the guide part 26a of the cutting guide 26. There is, At least one of the cutting guide (26) and the center guide (28, 52, 54) of the weaving loom support device, characterized in that combined to be relatively movable in the woven width direction. 2. The woven support device of a loom according to claim 1, wherein the fabric center guide is formed of a single member (28). 2. The guide portion of the cutting guide (26) according to claim 1, wherein the cloth center guide is a pair of semi-woven ball guide members (52) spaced in the cloth width direction and corresponding at one end in the cloth width direction. A pair of semi-spherical side guide members 52 having a guide portion 52a overlapping the semi-dices side of the cloth center end portion 26a), and a fastener-side guide member spanning both semi-spherical side guide members 52 54) having a fastener-side guide member 54 having a guide portion 54a overlapping with the fastener side of the guide portion 52a of the semi-height-side guide member 52 at each end portion in the width direction. A woven fabric support device for a loom. 4. The fabrication guide (26) according to any one of claims 1 to 3, wherein the fabrication guide (26) and the fabrication center guides (28, 52, 54) are in contact with the lower surface of the woven fabric at the upper edge thereof. A woven fabric support of a weaving machine having an L-shaped cross-sectional shape by a first plate portion having a portion 54a) and a second plate portion extending in a semi-spherical direction following the lower edge of the first plate portion. Device.