Test fixture for external gap line arresters

Abstract

The present disclosure provides a test fixture for an external gap line arrester, the external gap line arrester comprising a first part comprising an arrester electrode and a second part comprising an arc initiation electrode, the arrester electrode and the arc initiation electrode together defining a discharge gap, the test fixture comprising: a main body provided with a plurality of mounting interfaces, the first part and the second part being mounted to the main body via the mounting interfaces; an adjustment assembly comprising: a guide rail provided on the main body; and a slide engaging the guide rail and configured to move along the guide rail relative to the main body; and a suspension element for connection to a crane via a rope, the suspension element being fixedly connected to the slide such that, after the test fixture has been hoisted by the crane, the position of the suspension element on the main body can be changed by moving the slide along the guide rail to adjust the pitch attitude of the main body and thereby the discharge gap, thereby allowing an insulation coordination test to be performed on the external gap line arrester.

Description

Technical Field

[0001] This disclosure pertains to the field of surge arresters, specifically relating to a test fixture for external gap line surge arresters. Background Technology

[0002] An external gap line arrester (EGLA) is a type of surge arrester used for overhead lines. Before installing an EGLA on an overhead line, an insulation coordination test is required. During the test, a crane (e.g., a single crane) is typically used to lift the first part, which includes the arrester electrodes, and the second part, which includes the arc-starting electrodes, so that the first and second parts are suspended.

[0003] One requirement of insulation coordination testing is to ensure that the discharge gap between the surge arrester electrode and the arc-starting electrode is within a predetermined value. However, due to differences in weight, length, etc., between the first and second parts, the suspended structure is prone to tilting, causing the discharge gap to deviate from the predetermined value. In such cases, the operator has to repeatedly lift the structure to adjust the lifting position until the discharge gap reaches the predetermined value. This results in low test efficiency. Utility Model Content

[0004] This disclosure provides a test fixture for an external gap line arrester, the external gap line arrester including a first part and a second part, the first part including an arrester electrode, and the second part including an arc-initiating electrode, the arrester electrode and the arc-initiating electrode jointly defining a discharge gap. The test fixture includes: a main body having a plurality of mounting interfaces, the first part and the second part being mounted to the main body through the mounting interfaces; an adjustment assembly including: a guide rail disposed on the main body; a slider engaging the guide rail and configured to move relative to the main body along the guide rail; and a suspension element for connection to a crane via a rope, the suspension element being fixedly connected to the slider, such that after the test fixture is lifted by the crane, the position of the suspension element on the main body can be changed by moving the slider along the guide rail to adjust the pitch attitude of the main body and thereby adjust the discharge gap, thereby allowing insulation coordination tests on the external gap line arrester.

[0005] In this disclosure, by setting an adjustment component, the test fixture can remain connected to the crane while adjusting the lifting position by operating the adjustment component, so that the test device does not need to be repeatedly lifted, thereby improving the test efficiency.

[0006] Furthermore, the main body includes a crossbeam, and the guide rail is arranged parallel to the crossbeam on the crossbeam; and the crossbeam is divided into multiple segments in its length direction, and two adjacent segments of the multiple segments are detachably connected to each other.

[0007] In this disclosure, by dividing the crossbeam into multiple sections, the main body can be disassembled into multiple smaller parts, making the test fixture easy to store and transport.

[0008] Furthermore, at least two of the plurality of segments correspond to the same guide rail.

[0009] In this disclosure, by having at least two of the multiple sections correspond to the same guide rail, each of the multiple sections can have a shorter length, thereby facilitating the storage and transportation of the test fixture. Furthermore, this also distributes the load across multiple sections, preventing excessive concentration of load on the main body, thus improving the reliability of the test fixture.

[0010] Furthermore, the main body is provided with a connection interface, and two adjacent sections among the plurality of sections are connected to each other through the connection interface; and the mounting interface and the connection interface have the same structure.

[0011] In this disclosure, by setting a connection interface with the same structure as the mounting interface, the structure of the test apparatus can be simplified, thereby reducing the manufacturing cost of the test tooling. Furthermore, when the mounting interface and connection interface need to be used with other components, this configuration allows the same component to be used for both the mounting interface and the connection interface, thereby improving the operator's user experience.

[0012] Furthermore, the main body and the guide rail are formed as a whole.

[0013] In this disclosure, by making the main body and the guide rail an integral unit, the main body and the guide rail can be arranged compactly, thereby facilitating the miniaturization of the test device.

[0014] Furthermore, the adjustment assembly further includes: a screw connected to the body and configured to rotate relative to the body; a nut engaged with the screw and fixedly connected to the slider, the nut being configured to convert the rotational motion of the screw into movement of the slider along the guide rail; and an actuator connected to the screw, enabling the screw to perform the rotational motion by operating the actuator.

[0015] In this disclosure, by providing a screw, nut, and actuator, the operator can easily and accurately adjust the position of the suspension element by operating the actuator, making the test fixture easy to use.

[0016] Furthermore, the main body is provided with an attachment interface, through which the screw is connected to the main body; and the mounting interface and the attachment interface have the same structure.

[0017] In this disclosure, by setting an attachment interface with the same structure as the mounting interface, the structure of the test apparatus can be simplified, thereby reducing the manufacturing cost of the test fixture. Furthermore, when the mounting interface and attachment interface need to be used with other components, this configuration allows the same component to be used for both the mounting interface and the attachment interface, thereby improving the operator's user experience.

[0018] Furthermore, the regulating assembly also includes a transmission configured to switch between multiple gear ratios, and the actuator is connected to the screw via the transmission.

[0019] In this disclosure, by setting up a gearbox, the operator can select a suitable gear ratio as needed, thereby improving the operator's user experience.

[0020] Furthermore, the test fixture includes two adjustment components, with the slider of each adjustment component fixedly connected to the corresponding suspension element.

[0021] In this disclosure, by setting two adjustment components and two corresponding suspension elements, the test fixture can provide multiple lifting positions, so that the test fixture can remain stable after lifting.

[0022] Furthermore, the test fixture also includes a clutch configured to selectively engage or disengage the screws of one of the adjusting components and the screws of the other adjusting component.

[0023] In this disclosure, by setting up a clutch, the operator can operate the clutch as needed, allowing the test fixture to switch between different operating modes, thereby improving the operator's user experience. Attached Figure Description

[0024] The accompanying drawings, which are included to provide a further understanding of this disclosure and form part of this disclosure, illustrate exemplary embodiments of the present disclosure and are used to explain the disclosure, but do not constitute an undue limitation of the disclosure. In the drawings:

[0025] Figure 1 This is a schematic diagram of a test fixture for an external gap line arrester according to an embodiment of the present disclosure, wherein a first part and a second part of the external gap line arrester are installed on the test fixture.

[0026] Figure 2 yes Figure 1 A three-dimensional view of the test fixture used for external gap line arresters, viewed from one direction;

[0027] Figure 3 yes Figure 1 A three-dimensional view of the test fixture used for external gap line arresters, viewed from another direction.

[0028] List of reference numerals in the attached diagram:

[0029] 100. Part One;

[0030] 110. Surge arrester electrodes;

[0031] 120. Discharge gap;

[0032] 130. Lightning arrester body;

[0033] 140. Insulating components;

[0034] 200. Part Two;

[0035] 210. Arc-starting electrode;

[0036] 220. Line insulators;

[0037] 230. Metal tools;

[0038] 300. Test fixtures;

[0039] 10. Main body;

[0040] 11. Install the interface;

[0041] 12. Crossbeam;

[0042] 12a, Section;

[0043] 12b, Section;

[0044] 12c, Section;

[0045] 13. Connection interface;

[0046] 14. Attachment interface;

[0047] 15. Connectors;

[0048] 20. Adjustment components;

[0049] 21. Guide rail;

[0050] 22. Slider;

[0051] 23. Screw;

[0052] 24. Nuts;

[0053] 25. Actuator;

[0054] 26. Support components;

[0055] 30. Suspension components;

[0056] G, Discharge gap;

[0057] L represents the length direction. Detailed Implementation

[0058] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0059] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this disclosure. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise.

[0060] The following is for reference. Figures 1 to 3 This invention describes a test fixture for an external gap line arrester according to an embodiment of the present disclosure.

[0061] Figure 1 This is a schematic diagram of a test fixture for an external gap line arrester according to an embodiment of the present disclosure, wherein a first part and a second part of the external gap line arrester are installed on the test fixture. Figure 2 yes Figure 1 A three-dimensional view of the test fixture used for external gap line arresters, viewed from one direction. Figure 3 yes Figure 1 A three-dimensional view of the test fixture used for external gap line arresters, viewed from another direction.

[0062] refer to Figures 1 to 3This disclosure provides a test fixture 300 for an external gap line arrester. The external gap line arrester includes a first part 100 and a second part 200. The first part 100 includes an arrester electrode 110, and the second part 200 includes an arc-starting electrode 210. The arrester electrode 110 and the arc-starting electrode 210 together define a discharge gap G. The test fixture 300 includes a main body 10, an adjustment assembly 20, and a suspension element 30. The main body 10 is provided with a plurality of mounting interfaces 11, through which the first part 100 and the second part 200 are mounted to the main body 10. The adjustment assembly 20 includes a guide rail 21 disposed on the main body 10, and a slider 22 engaged with the guide rail 21 and configured to move relative to the main body 10 along the guide rail 21. The suspension element 30 is used to connect to the crane (not shown) via a rope (not shown). The suspension element 30 is fixedly connected to the slider 22, so that after the crane lifts the test fixture 300, the position of the suspension element 30 on the body 10 can be changed by moving the slider 22 along the guide rail 21 to adjust the pitch attitude of the body 10 and thereby adjust the discharge gap G, thus allowing the insulation coordination test of the external gap line arrester.

[0063] Here, the pitch attitude of the main body 10 can be characterized by the angle between the longitudinal axis of the main body 10 and the horizontal plane.

[0064] As an example, such as Figure 1 As shown, the first part 100 of the external gap line arrester may further include a gap insulator discharge gap 120 and an arrester body 130, etc., and the second part 200 of the external gap line arrester may further include a line insulator 220, etc. For example, the external gap line arrester may have the same or similar configuration as the arrester for transmission lines disclosed in Chinese Utility Model Patent CN222940367U. In other words, the aforementioned discharge gap 120 may be the first discharge gap described in CN222940367U, and the aforementioned discharge gap G may be the second discharge gap described in CN222940367U. Here, the entire contents of CN222940367U are incorporated herein by reference.

[0065] As an example, a test method using test fixture 300 may include: mounting the first part 100 and the second part 200 of the external gap line arrester to test fixture 300; and orienting the body 10 horizontally, such as making the length direction L of the crossbeam 12 (which will be described in detail below) parallel to the horizontal direction.

[0066] As an example, the main body 10 may be provided with multiple mounting interfaces 11, and the first part 100 and the second part 200 of the external gap line arrester may be mounted to the main body 10 through different mounting interfaces 11. For example, the first part 100 may also include an insulating member 140, which may engage with one mounting interface 11 to fix the arrester electrode 110 to the main body 10. The second part 200 may also include a fitting 230, which may engage with another mounting interface 11 to allow the arc-starting electrode 210 to be oscillatingly mounted to the main body 10. Alternatively, the first part 100 and the second part 200 may be mounted to the main body 10 through the same mounting interface 11.

[0067] As an example, the mounting interface 11 may include two sets of mounting holes for mating with fasteners, and these two sets of mounting holes may have opposite orientations. For example, the mounting holes may be threaded holes for threaded connection with bolts. Alternatively or additionally, the mounting interface 11 may include a snap-fit ​​portion or a pin hole for receiving a pin, etc.

[0068] As an example, the suspension element 30 can be a hanging ring. For instance, the suspension element 30 can be threadedly connected to the slider 22. Alternatively, the suspension element 30 can be a hook, etc.

[0069] In this disclosure, by setting the adjustment component 20, the test fixture 300 can maintain its connection with the crane while adjusting the lifting position by operating the adjustment component 20, so that the test device does not need to be repeatedly lifted, thereby improving the test efficiency.

[0070] refer to Figure 2 and Figure 3 The main body 10 includes a crossbeam 12, and a guide rail 21 is arranged parallel to the crossbeam 12 on the crossbeam 12. The crossbeam 12 is divided into multiple segments 12a, 12b, and 12c in its length direction L, and two adjacent segments of the multiple segments 12a, 12b, and 12c can be detachably connected to each other.

[0071] As an example, each of the multiple segments 12a, 12b, 12c can be identical. Alternatively, some or all of the multiple segments 12a, 12b, 12c can be different, for example, these different segments can have different lengths.

[0072] As an example, each of the multiple sections 12a, 12b, and 12c can be provided with multiple mounting interfaces 11. For example, each section can be provided with three to six mounting interfaces 11, which can be evenly spaced along the length direction L.

[0073] As an example, the longitudinal axis of the main body 10 can be parallel to the central axis of the crossbeam 12. For instance, the longitudinal axis of the main body 10 can approximately coincide with the central axis of the crossbeam 12.

[0074] In this disclosure, by dividing the crossbeam 12 into multiple sections 12a, 12b, and 12c, the main body 10 can be disassembled into multiple smaller parts, making the test fixture 300 easy to store and transport.

[0075] refer to Figure 2 At least two of the multiple sections 12a, 12b, and 12c correspond to the same guide rail 21.

[0076] Here, a section corresponding to a guide rail means that at least a portion of the guide rail is disposed on the section.

[0077] As an example, sections 12a and 12b can correspond to an adjustment component 20. Figure 2 The guide rail 21 in the left-hand adjustment component 20, sections 12b and 12c can correspond to another adjustment component 20. Figure 2 The guide rail 21 in the right-hand adjustment component 20. In other words, a portion of the guide rail 21 of one adjustment component 20 and a portion of another adjustment component 20 can be set on the same section 12b.

[0078] In this disclosure, by having at least two of the multiple sections 12a, 12b, and 12c correspond to the same guide rail 21, each of the multiple sections 12a, 12b, and 12c can have a shorter length, thereby facilitating the storage and transportation of the test fixture 300. Furthermore, this also distributes the load across the multiple sections 12a, 12b, and 12c, preventing excessive load concentration on the main body 10, thereby improving the reliability of the test fixture 300.

[0079] refer to Figure 2 and Figure 3 The main body 10 is provided with a connection interface 13, and two adjacent sections among the multiple sections 12a, 12b, and 12c are connected to each other through the connection interface 13. The mounting interface 11 and the connection interface 13 have the same structure.

[0080] As an example, the connection interface 13 can be located at the end of each of the multiple segments 12a, 12b, and 12c. For example, for the middle segment 12b, two connection interfaces 13 can be located at both ends of the segment 12b; for the segments 12a and 12c located on both sides of the segment 12b, the connection interface 13 can be located at the end of the segments 12a and 12c closer to the segment 12b.

[0081] As an example, the main body 10 may also include a connector 15, which can engage with a connection interface 13 to connect two adjacent segments together. For example, a portion of the connector 15 can engage with a connection interface 13 on one of the two segments, and another portion of the connector 15 can engage with a connection interface 13 on the other of the two segments.

[0082] It is important to note that, in Figure 2 and Figure 3 Since the connection interface 13 is obscured by the connector 15 and cannot be observed, the lead of the reference numeral 13 does not actually point to the connection interface 13, but rather to the part of the connector 15 that covers the corresponding connection interface 13.

[0083] In this disclosure, by providing a connection interface 13 with the same structure as the mounting interface 11, the structure of the test apparatus can be simplified, thereby reducing the manufacturing cost of the test fixture 300. Furthermore, when the mounting interface 11 and the connection interface 13 need to be used with other components (e.g., fasteners), this configuration allows the same components to be used for both the mounting interface 11 and the connection interface 13, thereby improving the operator's user experience.

[0084] refer to Figure 2 The main body 10 and the guide rail 21 are formed as a whole.

[0085] As an example, the guide rail 21 can take the form of a slot provided on the body 10, which can receive at least a portion of the slider 22 to guide the slider 22 to move. For example, each of the multiple segments 12a, 12b, 12c can be provided with a slot, and two adjacent slots can be aligned with each other to form the whole or part of the guide rail 21.

[0086] In other embodiments, the guide rail 21 may be a separate component independent of the main body 10. For example, the guide rail 21 may be laid along the crossbeam 12. Preferably, the guide rail 21 may be divided into multiple track segments in the length direction L, and two adjacent track segments may be detachably connected to each other.

[0087] In this disclosure, by forming the main body 10 and the guide rail 21 as a whole, the main body 10 and the guide rail 21 can be arranged compactly, thereby facilitating the miniaturization of the test device.

[0088] refer to Figure 2 and Figure 3The adjustment assembly 20 further includes: a screw 23 connected to the body 10 and configured to rotate relative to the body 10; a nut 24 engaged with the screw 23 and fixedly connected to the slider 22, the nut 24 being configured to convert the rotational motion of the screw 23 into movement of the slider 22 along the guide rail 21; and an actuator 25 connected to the screw 23, enabling the screw 23 to perform rotational motion by operating the actuator 25.

[0089] As an example, the screw 23 can be arranged parallel to the guide rail 21. For instance, the screw 23 can pass through the slider 22.

[0090] As an example, actuator 25 may include a handle or handwheel that an operator can grip and apply torque to actuate screw 23. Alternatively, actuator 25 may include a motor connected to screw 23.

[0091] In other examples, the adjustment assembly 20 may also include a gearbox configured to switch between multiple gear ratios, through which the actuator 25 can be connected to the screw 23. This allows the operator to select the appropriate gear ratio as needed, thereby improving the operator's experience.

[0092] In this disclosure, by providing screw 23, nut 24 and actuator 25, the operator can easily and accurately adjust the position of suspension element 30 by operating actuator 25, making test fixture 300 easy to use.

[0093] refer to Figure 2 and Figure 3 The main body 10 is provided with an attachment interface 14, through which the screw 23 is connected to the main body 10. The mounting interface 11 and the attachment interface 14 have the same structure.

[0094] As an example, the attachment interface 14 can be provided on at least one of the multiple segments 12a, 12b, and 12c. For example, for the middle segment 12b, the attachment interface 14 can be provided in the middle part of the segment 12b; for the segments 12a and 12c arranged on both sides of the segment 12b, the attachment interface 14 can be provided at the ends of the segments 12a and 12c that are away from the segment 12b.

[0095] As an example, the adjustment assembly 20 may also include a support 26, which can engage with the attachment interface 14 to connect the screw 23 to the body 10. For example, the screw 23 may be rotatably supported on the support 26 by means of a bearing, etc.

[0096] It is important to note that, in Figure 2 and Figure 3Since the attachment interface 14 is obscured by the support member 26 and cannot be observed, the lead of the reference numeral 14 does not actually point to the attachment interface 14, but rather to the part of the support member 26 that covers the corresponding attachment interface 14.

[0097] In this disclosure, by providing an attachment interface 14 with the same structure as the mounting interface 11, the structure of the test apparatus can be simplified, thereby reducing the manufacturing cost of the test fixture 300. Furthermore, when the mounting interface 11 and the attachment interface 14 need to be used with other components (e.g., fasteners), this configuration allows the same components to be used with both the mounting interface 11 and the attachment interface 14, thereby improving the operator's user experience.

[0098] refer to Figure 2 and Figure 3 The test fixture 300 includes two adjustment components 20, and the slider 22 of each adjustment component 20 is fixedly connected to the corresponding suspension element 30.

[0099] As an example, the two adjustment components 20 can be arranged in a mirror-symmetric manner about a plane (virtual plane) perpendicular to the length direction L. For example, the actuator 25 of one adjustment component 20 can be located at the end of the corresponding screw 23 away from the other adjustment component 20. However, it should be understood that even if the two adjustment components 20 are arranged in a mirror-symmetric manner, the threads on the screws 23 in the two adjustment components 20 can still have the same direction of rotation.

[0100] As an example, the two suspension elements 30 can be connected to the same rope. For instance, the two suspension elements 30 can be positioned at opposite ends of the rope, and the crane hook can be positioned in the middle of the rope (the portion between the two ends), so that the rope is approximately inverted V-shaped. Preferably, the rope can be a wire rope. Of course, in other examples, the two suspension elements 30 can be connected to the crane via different ropes.

[0101] In other examples, the test fixture 300 may also include a clutch, which can be configured to selectively engage or disengage the screws 23 of one adjusting component 20 and the screws 23 of another adjusting component 20. In other words, when the clutch is engaged, the two screws 23 can be actuated synchronously; when the clutch is disengaged, the two screws 23 can be actuated individually. This allows the operator to operate the clutch as needed, enabling the test fixture 300 to switch between different operating modes, thereby improving the operator's experience.

[0102] It should be understood that the test fixture 300 is not limited to having two adjustment components 20. For example, in other embodiments, the test fixture 300 may have only one adjustment component 20.

[0103] In this disclosure, by setting two adjustment components 20 and two corresponding suspension elements 30, the test fixture 300 can provide multiple lifting positions, so that the test fixture 300 can remain stable after lifting.

[0104] The above are merely preferred embodiments of this disclosure. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this disclosure, and these improvements and modifications should also be considered within the scope of protection of this disclosure.

Claims

1. A test fixture (300) for an external gap line arrester, the external gap line arrester comprising a first part (100) and a second part (200), the first part (100) comprising an arrester electrode (110), the second part (200) comprising an arc-initiating electrode (210), the arrester electrode (110) and the arc-initiating electrode (210) jointly defining a discharge gap (G), characterized in that, The test fixture (300) includes: The main body (10) is provided with multiple mounting interfaces (11), and the first part (100) and the second part (200) are mounted to the main body (10) through the mounting interfaces (11); Adjustment component (20), including: Guide rail (21), disposed on the main body (10); and A slider (22) engages with the guide rail (21) and is configured to move relative to the body (10) along the guide rail (21); and A suspension element (30) is used to connect to a crane via a rope. The suspension element (30) is fixedly connected to the slider (22) so that after the crane lifts the test fixture (300), the position of the suspension element (30) on the body (10) can be changed by moving the slider (22) along the guide rail (21) to adjust the pitch attitude of the body (10) and thereby adjust the discharge gap (G), thus allowing insulation coordination tests to be performed on the external gap line arrester.

2. The test fixture (300) according to claim 1, characterized in that, The main body (10) includes a crossbeam (12), and the guide rail (21) is arranged parallel to the crossbeam (12) on the crossbeam (12); and The crossbeam (12) is divided into multiple segments (12a, 12b, 12c) along its length direction (L), and two adjacent segments (12a, 12b, 12c) are detachably connected to each other.

3. The test fixture (300) according to claim 2, characterized in that, At least two of the plurality of sections (12a, 12b, 12c) correspond to the same guide rail (21).

4. The test fixture (300) according to claim 2, characterized in that, The main body (10) is provided with a connection interface (13), and two adjacent segments of the plurality of segments (12a, 12b, 12c) are connected to each other through the connection interface (13); and The mounting interface (11) and the connection interface (13) have the same structure.

5. The test fixture (300) according to any one of claims 1 to 4, characterized in that, The main body (10) and the guide rail (21) are formed as a whole.

6. The test fixture (300) according to any one of claims 1 to 4, characterized in that, The adjustment component (20) further includes: A screw (23) is connected to the body (10) and configured to rotate relative to the body (10); A nut (24), engaging with the screw (23) and fixedly connected to the slider (22), the nut (24) being configured to convert the rotational motion of the screw (23) into the movement of the slider (22) along the guide rail (21); and An actuator (25) is connected to the screw (23) so that the screw (23) can perform the rotational motion by operating the actuator (25).

7. The test fixture (300) according to claim 6, characterized in that, The main body (10) is provided with an attachment interface (14), and the screw (23) is connected to the main body (10) through the attachment interface (14); and The mounting interface (11) and the attachment interface (14) have the same structure.

8. The test fixture (300) according to claim 6, characterized in that, The regulating assembly (20) also includes a transmission configured to switch between multiple gear ratios, and the actuator (25) is connected to the screw (23) via the transmission.

9. The test fixture (300) according to any one of claims 1 to 4, characterized in that, The test fixture (300) includes two adjustment components (20), and the slider (22) of each adjustment component (20) is fixedly connected to the corresponding suspension element (30).

10. The test fixture (300) according to claim 9, characterized in that, The test fixture (300) also includes a clutch configured to selectively engage or disengage the screw (23) of one of the adjustment components (20) and the screw (23) of the other adjustment component (20).

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