Double-sided electroplating hanger

Abstract

The utility model relates to a double-sided electroplating hanger which comprises a first clamping plate, a second clamping plate and a conductive component, and the first clamping plate and the second clamping plate are respectively provided with a first window and a second window. When the electroplating clamp is used for workpiece electroplating, a to-be-electroplated workpiece is firstly arranged between the first clamping plate and the second clamping plate, and then the first clamping plate and the second clamping plate are attached to clamp the to-be-electroplated workpiece. At the moment, the two surfaces, needing to be electroplated, of the to-be-electroplated workpiece can be exposed through the first window and the second window respectively, and the supporting piece makes contact with the to-be-electroplated workpiece and is communicated with the to-be-electroplated workpiece. The double-sided electroplating hanger and the clamped workpiece to be coated are integrally arranged in an electroplating bath, and the electrodes are electrified, so that the two surfaces of the workpiece to be electroplated can be coated. Moreover, as the supporting sheet is annular, the supporting sheet can be in conductive contact with a circle of the workpiece to be electroplated, so that the current can be uniformly distributed around the workpiece to be electroplated, and the uniformity of a coating on the surface of the workpiece to be electroplated is further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electroplating, in particular to a double-sided electroplating hanger. Background Art

[0002] In common electroplating processes, the workpiece to be plated is usually clamped with an electroplating clamp, and then the workpiece to be plated is placed in the electroplating solution as a whole, so that the workpiece is evenly plated on all sides. Since the contact area between the electroplating clamp and the workpiece to be plated is small, the current is unevenly distributed on the surface of the workpiece to be plated, resulting in an uneven coating formed by electroplating. Utility Model Content

[0003] Based on this, it is necessary to provide a double-sided electroplating rack that can improve the uniformity of the coating in order to solve the above problems.

[0004] A double-sided electroplating hanger includes a first clamp, a second clamp and a conductive component, wherein the first clamp can be detachably attached to the second clamp and clamp a workpiece to be electroplated between the first clamp and the second clamp, the first clamp and the second clamp are respectively provided with a first window and a second window exposing the workpiece to be electroplated, the conductive component includes an electrode and a support sheet electrically connected to the electrode, the support sheet is located between the first clamp and the second clamp and extends along the circumference of the first window or the second window, and the workpiece to be electroplated clamped between the first clamp and the second clamp abuts against the support sheet.

[0005] In one embodiment, a first sealing ring extending along the circumference of the first window is provided on the side of the first clamping plate facing the second clamping plate, and a second sealing ring extending along the circumference of the second window is provided on the side of the second clamping plate facing the first clamping plate. The workpiece to be electroplated clamped between the first clamping plate and the second clamping plate presses the first sealing ring and the second sealing ring.

[0006] In one embodiment, a third sealing ring is disposed between the first clamping plate and the second clamping plate. The third sealing ring is disposed along the periphery of the first clamping plate and the second clamping plate and is clamped between the first clamping plate and the second clamping plate.

[0007] In one embodiment, the first clamping plate, the second clamping plate and the clamped workpiece to be electroplated are fitted together to form a sealed cavity, and the double-sided electroplating hanger also includes an interface component connected to the sealed cavity, through which negative pressure can be formed in the sealed cavity, so that the first clamping plate and the second clamping plate remain in contact under the action of negative pressure.

[0008] In one embodiment, the interface assembly includes a valve block and a shutoff valve connected to the valve block, and the valve block is installed on the first clamping plate or the second clamping plate and communicates with the sealing cavity.

[0009] In one of the embodiments, a limiting member is installed on a side of the second clamping plate facing the first clamping plate, and the limiting member is surrounded to form a limiting portion for accommodating a workpiece to be electroplated.

[0010] In one embodiment, the conductive component further comprises a conductive sheet mounted on the first clamping plate on a side facing the second clamping plate, and the supporting sheet is mounted on the conductive sheet and can elastically float relative to the conductive sheet along a thickness direction of the first clamping plate.

[0011] In one embodiment, the conductive sheet is ring-shaped and extends along the extension direction of the supporting sheet.

[0012] In one of the embodiments, a plurality of floating spring seats are provided between the conductive sheet and the supporting sheet, and the floating spring seats can elastically expand and contract along the thickness direction of the first clamping plate.

[0013] In one embodiment, a side of the first clamping plate facing away from the second clamping plate and a side of the second clamping plate facing away from the first clamping plate are both provided with fool-proof structures.

[0014] When the above-mentioned double-sided electroplating rack is used for electroplating of workpieces, the workpiece to be electroplated is first placed between the first clamping plate and the second clamping plate, and then the first clamping plate and the second clamping plate are fitted together to clamp the workpiece to be electroplated. At this time, the two surfaces of the workpiece to be electroplated that need to be electroplated can be exposed through the first window and the second window respectively, and the support sheet is in contact with and conductive to the workpiece to be electroplated. By placing the above-mentioned double-sided electroplating rack and the clamped workpiece to be plated as a whole in the electroplating tank and energizing the electrodes, coating can be achieved on both surfaces of the workpiece to be electroplated. Moreover, since the support sheet is ring-shaped, the support sheet can be in conductive contact with a circle of the workpiece to be electroplated, so that the current can be evenly distributed around the workpiece to be electroplated, thereby improving the uniformity of the surface coating of the workpiece to be electroplated. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 This is a schematic diagram of the structure of a double-sided electroplating rack in a preferred embodiment of the utility model;

[0017] Figure 2 for Figure 1 A schematic diagram of the structure of the first clamping plate in the double-sided electroplating rack shown;

[0018] Figure 3 for Figure 2 A schematic diagram of the other side of the first splint shown;

[0019] Figure 4 for Figure 3 A cross-sectional view of the first splint along AA;

[0020] Figure 5 for Figure 4 An enlarged schematic diagram of a section B in the cross-sectional view of the first splint shown;

[0021] Figure 6 for Figure 1 A schematic diagram of the structure of the second clamping plate in the double-sided electroplating rack shown;

[0022] Figure 7 for Figure 6 A schematic diagram of the other side of the second splint is shown. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0025] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0026] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0028] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0029] See also Figure 1 The double-sided electroplating rack 100 in the preferred embodiment of the present invention includes a first clamping plate 110 , a second clamping plate 120 and a conductive component 130 .

[0030] The first clamping plate 110 and the second clamping plate 120 are generally formed of non-metallic materials such as plastics and resins, and their outlines can be rectangular, circular, etc., and can be specifically designed according to the shape of the workpiece 200 to be electroplated. Among them, the first clamping plate 110 can be detachably attached to the second clamping plate 120 and clamp the workpiece 200 to be electroplated between the first clamping plate 110 and the second clamping plate 120. The workpiece 200 to be electroplated is generally in the form of a sheet, and can be an FPC board.

[0031] Specifically, the first clamping plate 110 and the second clamping plate 120 can be detachably connected by means of buckles, threaded fasteners or other quick-release structures, and the two can be completely separated after being disassembled. In addition, the first clamping plate 110 and the second clamping plate 120 can also be rotatably connected by means of hinges or rotating shafts, and the two can be attached or separated by rotating relative to each other. The purpose of the detachable first clamping plate 110 and the second clamping plate 120 is to facilitate the clamping of the workpiece 200 to be electroplated before electroplating and the removal of the workpiece after electroplating, and the specific installation method is not limited.

[0032] In addition, a foolproof structure 103 is provided on the side of the first clamping plate 110 facing away from the second clamping plate 120 and on the side of the second clamping plate 120 facing away from the first clamping plate 110 (see Figure 2 and Figure 7 The foolproof structure 103 may be a special-shaped groove, which can effectively prevent the first clamping plate 110 and the second clamping plate 120 from being reversed during installation.

[0033] Please also read Figure 6 In this embodiment, the first clamping plate 110, the second clamping plate 120 and the workpiece 200 to be electroplated are fitted together to form a sealed cavity (not shown), and the double-sided electroplating rack 100 also includes an interface component 140 connected to the above-mentioned sealed cavity. The interface component 140 can form a negative pressure in the sealed cavity so that the first clamping plate 110 and the second clamping plate 120 remain in contact under the action of the negative pressure.

[0034] The interface assembly 140 can be connected to an external exhaust assembly (not shown) so that the sealed cavity can be evacuated. After the workpiece 200 to be electroplated is placed between the first clamping plate 110 and the second clamping plate 120, the interface assembly 140 is first evacuated to form a negative pressure in the sealed cavity, so that the first clamping plate 110 and the second clamping plate 120 can be mutually attracted and clamped under the negative pressure. After the electroplating is completed, the sealed cavity can be broken by connecting the interface assembly 140 to positive pressure or atmosphere. At this time, the first clamping plate 110 and the second clamping plate 120 can be separated and the workpiece 200 to be electroplated can be taken out. It can be seen that the first clamping plate 110 and the second clamping plate 120 can be attached and separated by evacuating or inflating the interface assembly 140, which is convenient to operate.

[0035] Furthermore, in this embodiment, the interface assembly 140 includes a valve block 141 and a cut-off valve 142 connected to the valve block 141. The valve block 141 is mounted on the first clamping plate 110 or the second clamping plate 120 and communicates with the sealed cavity. After the sealed cavity is evacuated, the cut-off valve 142 can be switched to a closed state, so that a negative pressure state can be maintained in the sealed cavity for a long time to ensure smooth electroplating.

[0036] In this embodiment, a limiting member 170 is installed on one side of the second clamping plate 120 facing the first clamping plate 110, and the limiting member 170 is surrounded to form a limiting portion for accommodating the workpiece 200 to be electroplated. Before clamping the workpiece 200 to be electroplated, the workpiece 200 to be electroplated can be placed in the limiting portion of the limiting member 170, and then the first clamping plate 110 and the second clamping plate 120 can be attached. In this way, under the restriction of the limiting portion, the position of the workpiece 200 to be electroplated can be better maintained stable.

[0037] Specifically, the limiting member 170 is generally annular, and is formed with a plurality of limiting protrusions (not shown) protruding along the thickness direction of the second clamping plate 120. The plurality of limiting protrusions are arranged at intervals along the extension direction of the limiting member 170 to enclose the above-mentioned limiting portion. A pressing plate 180 may also be provided on the second clamping plate 120, and the limiting member 170 is mounted on the pressing plate 180. When the first clamping plate 110 and the second clamping plate 120 are in contact with each other, the pressing plate 180 presses the workpiece in the limiting portion onto the first clamping plate 110.

[0038] Please also read Figure 2 , Figure 3 and Figure 7 The first clamping plate 110 and the second clamping plate 120 are respectively provided with a first window 101 and a second window 103, and the first window 101 and the second window 103 can expose the workpiece 200 to be plated clamped between the first clamping plate 110 and the second clamping plate 120. Moreover, the shapes of the first window 101 and the second window 103 can be rectangular or circular, and can be specifically designed according to the shape of the surface of the workpiece 200 to be plated.

[0039] The conductive component 130 includes an electrode 131 and a support sheet 132 electrically connected to the electrode 131. The support sheet 132 is located between the first clamping plate 110 and the second clamping plate 120 and extends along the circumference of the first window 101 or the second window 102. The workpiece 200 to be electroplated clamped between the first clamping plate 110 and the second clamping plate 120 abuts against the support sheet 132. The electrode 131 is used to connect to an external power source and can be installed on either the first clamping plate 110 or the second clamping plate 120. When the first clamping plate 110 and the second clamping plate 120 are attached, the electrode 131 extends between the first clamping plate 110 and the second clamping plate 120. The support sheet 132 is formed of a conductive material, such as metal, and can also be installed on either the first clamping plate 110 or the second clamping plate 120. Specifically, the electrode 131 and the support sheet 132 in this embodiment are both installed on the first clamping plate 110, so the support sheet 132 extends along the edge of the first window 101.

[0040] During electroplating, the workpiece 200 to be electroplated is first placed between the first clamping plate 110 and the second clamping plate 120, and then the first clamping plate 110 and the second clamping plate 120 are attached to clamp the workpiece 200 to be electroplated. At this time, the two opposite surfaces of the workpiece 200 to be electroplated are exposed through the first window 101 and the second window respectively. Then, the double-sided electroplating rack 100 and the clamped workpiece 200 to be electroplated are placed in the electroplating tank as a whole and the electrode 131 is energized, so that the coating can be simultaneously achieved on the two opposite surfaces of the workpiece 200 to be electroplated.

[0041] Furthermore, since the support sheet 132 is annular, when the workpiece 200 to be plated clamped between the first clamping plate 110 and the second clamping plate 120 abuts against the support sheet 132, the support sheet 132 can be in conductive contact with a circle of the workpiece 200 to be plated. In this way, the contact area between the support sheet 132 and the workpiece 200 to be plated can be increased, and the current conducted from the support sheet 132 to the workpiece 200 to be plated can be evenly distributed around the workpiece 200 to be plated, thereby improving the uniformity of the coating on the surface of the workpiece 200 to be plated.

[0042] In this embodiment, a first sealing ring 150 extending along the circumference of the first window 101 is provided on the side of the first clamping plate 110 facing the second clamping plate 120, and a second sealing ring (not shown) extending along the circumference of the second window 102 is provided on the side of the second clamping plate 120 facing the first clamping plate 110. The workpiece 200 to be electroplated clamped between the first clamping plate 110 and the second clamping plate 120 presses the first sealing ring 150 and the second sealing ring.

[0043] The first sealing ring 150 can achieve sealing between the workpiece 200 to be plated and the edge of the first window 101, thereby preventing the plating solution in the plating tank from entering the interior of the single-sided coating rack 100 through the gap at the edge of the first window 101. The second sealing ring can achieve sealing between the workpiece 200 to be plated and the edge of the second window 102, thereby preventing the plating solution in the plating tank from entering the interior of the single-sided coating rack 100 through the gap at the edge of the second window 102.

[0044] It should be pointed out that in other embodiments, sealing steps may be machined at the edges of the first window 101 and the second window 102, or sealant may be pre-coated on the surface of the workpiece 200 to be electroplated, so as to achieve sealing between the workpiece 200 to be electroplated and the edges of the first window 101 and the second window 102.

[0045] In addition, in this embodiment, a third sealing ring 160 is disposed between the first clamping plate 110 and the second clamping plate 120 . The third sealing ring 160 is disposed along the periphery of the first clamping plate 110 and the second clamping plate 120 and is clamped between the first clamping plate 110 and the second clamping plate 120 .

[0046] The third sealing ring 160 can be installed on any edge of the first clamping plate 110 and the second clamping plate 120, or the third sealing ring 160 can be installed on both the first clamping plate 110 and the second clamping plate 120. The third sealing ring 160 can form a seal between the first clamping plate 110 and the second clamping plate 120, thereby preventing the electroplating liquid in the electroplating tank from entering the interior of the single-sided coating rack 100 through the gap between the first clamping plate 110 and the second clamping plate 120. Obviously, the first clamping plate 110 and the second clamping plate 120 can also be sealed by processing a sealing step or the like.

[0047] The sealed cavity is formed in the area between the third sealing ring 160 and the first sealing ring 150 and the second sealing ring, and has good sealing performance. When the double-sided electroplating rack 100 is placed in the electroplating tank as a whole, the electroplating liquid will not be able to enter the sealed cavity. Optionally, the support sheet 132 is arranged in the sealed cavity to avoid contact with the electroplating liquid, so that the surface of the support sheet 132 can be kept clean during the electroplating process, and the formation of an electroplating film layer on its surface can be avoided, which leads to a decrease in conductivity.

[0048] Please also read Figure 4 and Figure 5 In this embodiment, the conductive component 130 also includes a conductive sheet 133 installed on the side of the first clamping plate 110 facing the second clamping plate 120, and the supporting sheet 132 is installed on the conductive sheet 133 and can elastically float relative to the conductive sheet 133 along the thickness direction of the first clamping plate 110.

[0049] The support sheet 132 is electrically connected to the electrode 131 through the conductive sheet 133. When the first clamping plate 110 and the second clamping plate 120 are attached and clamped to the workpiece 200 to be electroplated, the elastically floating support sheet 132 can play a buffering role, thereby avoiding damage to the workpiece 200 to be electroplated. In addition, the elastically floating support sheet 132 can also provide a pre-tightening force acting on the workpiece 200 to be electroplated, so that the support sheet 132 can maintain good conductive contact with the workpiece 200 to be electroplated during the electroplating process.

[0050] Specifically, in this embodiment, the conductive sheet 133 is ring-shaped and extends along the extension direction of the support sheet 132. Since the conductive sheet 133 and the support sheet 132 extend in the same direction, the support sheet 132 can be better supported.

[0051] Furthermore, in this embodiment, a plurality of floating spring seats 134 are disposed between the conductive sheet 133 and the supporting sheet 132 , and the floating spring seats 134 can elastically expand and contract along the thickness direction of the first clamping plate 110 .

[0052] Specifically, the floating spring seat 134 can be fixed to the first clamping plate 110 by screws and the conductive sheet 133, and the support sheet 132 is installed above the conductive sheet 133 and the floating spring seat 134 and abuts against the floating spring seat 134. The floating spring seat 134 applies an elastic force to the support sheet 132 so that the support sheet 132 can float elastically relative to the conductive sheet 133.

[0053] It should be noted that, in other embodiments, the conductive sheet 133 and the supporting sheet 132 may also be provided with elastic mechanisms such as springs and compression springs, so that the supporting sheet 132 can float elastically.

[0054] When the double-sided electroplating rack 100 is used for electroplating a workpiece, the workpiece 200 to be electroplated is first loaded between the first clamping plate 110 and the second clamping plate 120, and then the first clamping plate 110 and the second clamping plate 120 are attached to clamp the workpiece 200 to be electroplated. At this time, the two surfaces of the workpiece 200 to be electroplated can be exposed through the first window 101 and the second window 102 respectively, and the support sheet 132 is in contact with and conductive to the workpiece 200 to be electroplated. The double-sided electroplating rack 100 and the clamped workpiece 200 to be plated are placed in the electroplating tank as a whole and the electrode 131 is energized, so that the coating can be achieved on the two surfaces of the workpiece 200 to be electroplated. Moreover, since the support sheet 132 is annular, the support sheet 132 can be in conductive contact with a circle of the workpiece 200 to be electroplated, so that the current can be evenly distributed around the workpiece 200 to be electroplated, thereby improving the uniformity of the surface coating of the workpiece 200 to be electroplated.

[0055] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0056] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A double-sided electroplating rack, characterized in that: It includes a first clamp, a second clamp and a conductive component, the first clamp can be detachably attached to the second clamp and clamp the workpiece to be electroplated between the first clamp and the second clamp, the first clamp and the second clamp are respectively provided with a first window and a second window exposing the workpiece to be electroplated, the conductive component includes an electrode and a support sheet electrically connected to the electrode, the support sheet is located between the first clamp and the second clamp and extends along the circumference of the first window or the second window, and the workpiece to be electroplated clamped between the first clamp and the second clamp abuts against the support sheet.

2. The double-sided electroplating rack according to claim 1, characterized in that: A first sealing ring extending along the circumference of the first window is provided on the side of the first clamping plate facing the second clamping plate, and a second sealing ring extending along the circumference of the second window is provided on the side of the second clamping plate facing the first clamping plate. The workpiece to be electroplated clamped between the first clamping plate and the second clamping plate presses the first sealing ring and the second sealing ring.

3. The double-sided electroplating rack according to claim 1, characterized in that: A third sealing ring is arranged between the first clamping plate and the second clamping plate. The third sealing ring is arranged along the periphery of the first clamping plate and the second clamping plate and is clamped between the first clamping plate and the second clamping plate.

4. The double-sided electroplating rack according to claim 1, characterized in that: The first clamping plate, the second clamping plate and the clamped workpiece to be electroplated are fitted together to form a sealed cavity. The double-sided electroplating hanger also includes an interface component connected to the sealed cavity. Negative pressure can be formed in the sealed cavity through the interface component to keep the first clamping plate and the second clamping plate fitted together under the action of negative pressure.

5. The double-sided electroplating rack according to claim 4, characterized in that: The interface assembly includes a valve block and a cut-off valve connected to the valve block. The valve block is installed on the first clamping plate or the second clamping plate and is communicated with the sealing cavity.

6. The double-sided electroplating rack according to claim 1, characterized in that: A limiting member is installed on one side of the second clamping plate facing the first clamping plate, and the limiting member is arranged to form a limiting portion for accommodating a workpiece to be electroplated.

7. The double-sided electroplating rack according to claim 1, characterized in that: The conductive assembly further comprises a conductive sheet mounted on the first clamping plate facing the second clamping plate, and the supporting sheet is mounted on the conductive sheet and can elastically float relative to the conductive sheet along the thickness direction of the first clamping plate.

8. The double-sided electroplating rack according to claim 7, characterized in that: The conductive sheet is ring-shaped and extends along the extending direction of the supporting sheet.

9. The double-sided electroplating rack according to claim 7, characterized in that: A plurality of floating spring seats are arranged between the conductive sheet and the supporting sheet, and the floating spring seats can elastically expand and contract along the thickness direction of the first clamping plate.

10. The double-sided electroplating rack according to claim 1, characterized in that: A fool-proof structure is provided on a side of the first clamping plate facing away from the second clamping plate and on a side of the second clamping plate facing away from the first clamping plate.

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