Power transmission tower main material replacing device

Abstract

The utility model relates to power transmission engineering equipment technical field especially relates to power transmission tower main material replacement device, its including support subassembly, and with the support subassembly both ends of detachable mode connection of joint component, support subassembly and joint component have the docking mechanism of mutual cooperation, joint component can with detachable mode fixed to with the main material of upper and lower adjacent on the main material of waiting for replacing, support subassembly is equipped with length adjusting module, be used for adjusting the total length of support subassembly, joint component and support subassembly are the modularization design, and both realize detachable connection through docking mechanism, the high altitude transportation, assembly and quick dismounting of convenient device, have improved construction efficiency and convenience, length adjusting module carries out the accurate length adjustment, guarantees the smooth operation of load transfer, the system that joint component and support subassembly constitute can realize the safe, controllable transfer and bearing of load.

Description

Technical Field

[0001] This utility model relates to the field of power transmission engineering equipment technology, and in particular to a device for replacing the main materials of power transmission towers. Background Technology

[0002] During long-term operation, the main materials of power transmission towers are subject to complex stresses such as wind loads and their own weight, and are also susceptible to corrosion or impact. After long-term operation, the main materials are prone to damage such as rust and deformation, thus requiring replacement of damaged main materials. For example, the support assembly for replacing the main materials of power transmission towers disclosed in patent number CN201310151949.7 often uses large ground-mounted supports for temporary support to bear all the loads on the main materials to be replaced. However, such large equipment is bulky and heavy, making transportation difficult and costly, and it also has requirements for the terrain near the power transmission tower. Existing technologies also use wire ropes and chain hoists for temporary support to bear all the loads on the main materials to be replaced, but the fixing points of wire ropes and chain hoists need to be repeatedly tested, the installation process is cumbersome, and the efficiency is low.

[0003] Based on this, the applicant is considering designing a power transmission tower main material replacement device that can be quickly disassembled and precisely adjusted. Utility Model Content

[0004] In view of the shortcomings of the prior art, the technical problem to be solved by this utility model is: how to provide a power transmission tower main material replacement device that can be quickly disassembled and precisely adjusted.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A power transmission tower main material replacement device includes a support assembly and a snap-fit ​​assembly detachably connected to both ends of the support assembly; the support assembly and the snap-fit ​​assembly have a mating mechanism that cooperates with each other. The snap-fit ​​assembly can be detachably fixed to the main material that is vertically adjacent to the main material to be replaced; The support component is equipped with a length adjustment module, which is used to adjust the total length of the support component, thereby transferring the load borne by the main material section to be replaced to the support component and the snap-fit ​​component.

[0006] The working principle and advantages of the power transmission tower main material replacement device in this technical solution are as follows: First, securely install at least two snap-fit ​​components onto the main material above and below the section to be replaced. Then, using the docking mechanism, quickly connect both ends of the support component to the two snap-fit ​​components above and below. Operate the length adjustment module in the support component to increase its total length. As the length of the support component increases, all structural loads originally borne by the main material to be replaced are transferred to the system consisting of the support component and the snap-fit ​​components. Next, remove the main material to be replaced and install a new main material. Then, operate the length adjustment module to shorten the total length of the support component, allowing the load to be smoothly transferred to the newly replaced main material. Finally, disconnect the docking mechanism and remove the snap-fit ​​components. The snap-fit ​​components and support components are modularly designed, and the two are detachably connected through the docking mechanism, facilitating high-altitude transportation, assembly, and rapid disassembly of the device, improving construction efficiency and convenience. The length adjustment module performs precise length adjustments to ensure smooth load transfer. The system consisting of the snap-fit ​​components and support components enables safe and controllable load transfer and bearing.

[0007] Furthermore, the docking mechanism includes a connector on the snap-fit ​​assembly and connectors disposed at both ends of the support assembly; the connector includes a limiting sleeve, and an end connecting rod that can be elastically extended and retracted within the limiting sleeve. When the free end of the end connecting rod is inserted into the connector, the elastic locking structure inside the connector automatically locks the free end of the connector.

[0008] Furthermore, the elastic locking structure includes a locking block that is elastically telescopically disposed within the connector receiving cavity, and the outer wall of the free end of the end connecting rod is provided with a locking protrusion that cooperates with the locking block.

[0009] Furthermore, a locking rod is fixedly connected to the free end face of the end connecting rod, and a through hole is provided on the connecting head for the locking rod to pass through. The outer side wall of the end of the locking rod that passes through the through hole is threaded.

[0010] Furthermore, a closure is detachably provided at the bottom of the limiting sleeve, and a limiting rod extending into the limiting sleeve is fixedly connected to the closure. The limiting rod is used to limit the end connecting rod.

[0011] Furthermore, the length adjustment module includes a lead screw, a lead screw sleeve that is threadedly engaged with the lead screw, and a drive mechanism for driving the lead screw sleeve to rotate, so that the lead screw extends or retracts along the axial direction of the lead screw sleeve.

[0012] Furthermore, the drive mechanism includes a worm gear fixed to the lead screw sleeve and a worm gear meshing with the worm gear; the length adjustment module also includes a mounting box, in which the worm gear and the lead screw sleeve are rotatably mounted.

[0013] Furthermore, the connector is detachably connected to the length adjustment module, and the support assembly further includes at least one adapter segment, the two ends of which are detachably connected to the connector and the length adjustment module, respectively.

[0014] Furthermore, the snap-fit ​​assembly includes an adapter and a snap-fit ​​component detachably connected thereto. The snap-fit ​​component includes a first snap plate and a second snap plate. The connector head is hinged to the adapter. The first snap plate is detachably connected to the adapter. The second snap plate is detachably connected to the first snap plate. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the power transmission tower main material replacement device according to an embodiment of the present utility model; Figure 2 This is a front view structural diagram of the main material replacement device for power transmission towers according to an embodiment of this utility model; Figure 3 This is a three-dimensional structural diagram of the connector and length adjustment module according to an embodiment of the present utility model; Figure 4 This is a three-dimensional structural diagram of the snap-fit ​​assembly according to an embodiment of the present utility model; Figure 5 This is a three-dimensional structural diagram of the adapter according to an embodiment of the present utility model; Figure 6 This is a three-dimensional structural diagram of the first and second card plates in an embodiment of the present utility model; Figure 7 This is a top view of the first and second card plates according to another embodiment of the present invention; Figure 8 This is a three-dimensional structural diagram of the connector according to an embodiment of the present utility model; Figure 9 This is a three-dimensional structural diagram of the end connecting rod in an embodiment of the present utility model; Figure 10 This is a cross-sectional structural diagram of the connector in an embodiment of the present utility model; Figure 11 This is a cross-sectional structural diagram of the end connecting rod and the connector in an embodiment of the present utility model; Figure 12 This is a three-dimensional structural diagram of the length adjustment module according to an embodiment of the present invention; Figure 13 This is a partial cross-sectional structural diagram of the length adjustment module according to an embodiment of the present invention; Figure 14 This is a cross-sectional structural diagram of a connector according to another embodiment of the present invention; In the above attached figures: 100. Snap-fit ​​assembly; 110. Adapter; 111. First through hole; 112. Connecting stud; 113. Connector; 1131. Receiving cavity; 1132. First spring; 1133. Locking block; 1134. Connecting hole; 120. Snap-fit ​​component; 121. First locking plate; 1211. Second through hole; 1212. Connecting hole plate; 122. Second locking plate; 200. Support components; 210. Connector; 211. Restricting sleeve; 2111. Observation hole; 212. End connecting rod; 2121. Locking rod; 2122. Snap-fit ​​protrusion; 213. Closure; 214. Restricting rod; 215. Second spring; 216. Load sensor; 217. Disc spring; 220. Length adjustment module; 221. Lead screw; 222. Lead screw sleeve; 2221. Worm gear; 223. Mounting box; 2231. Worm; 2232. Bearing; 230. Adaptation segment. Detailed Implementation

[0016] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0017] Refer to together Figures 1 to 13 This embodiment provides a main material replacement device for power transmission towers, which includes a support component 200 and a snap-fit ​​component 100 detachably connected to both ends of the support component 200; the support component 200 and the snap-fit ​​component 100 have a mating mechanism that cooperates with each other. The snap-fit ​​assembly 100 can be detachably fixed to the main material that is vertically adjacent to the main material to be replaced; The support component 200 is equipped with a length adjustment module 220, which is used to adjust the total length of the support component 100, thereby transferring the load borne by the main material section to be replaced to the support component 200 and the snap-fit ​​component 100.

[0018] In this embodiment, at least two snap-fit ​​components 100 are first securely installed on the main material above and below the section to be replaced; then, through a docking mechanism, the two ends of the support component 200 are quickly connected to the two snap-fit ​​components 100 above and below; the length adjustment module 220 in the support component 200 is operated to increase the total length of the support component 200. As the length of the support component 200 increases, all the structural load originally borne by the main material to be replaced is transferred to the system composed of the support component 200 and the snap-fit ​​components 100; then the main material to be replaced is removed and a new main material is installed; after that, the operation... The length adjustment module 220 shortens the overall length of the support component 200, allowing the load to be smoothly transferred to the newly replaced main material. Finally, the connection of the docking mechanism is released and the snap-fit ​​component 100 is removed. The snap-fit ​​component 100 and the support component 200 are modularly designed, and the two are detachably connected through the docking mechanism, which facilitates high-altitude transportation, assembly, and quick disassembly of the device, improving construction efficiency and convenience. The length adjustment module 220 performs precise length adjustment to ensure smooth load transfer. The system consisting of the snap-fit ​​component 100 and the support component 200 enables safe and controllable load transfer and bearing.

[0019] Preferably, such as Figures 7 to 11 As shown, the docking mechanism includes a connector 113 on the snap-fit ​​assembly 100 and connectors 210 disposed at both ends of the support assembly 200. Connectors 210 include a limiting sleeve 211, within which an end connecting rod 212 is elastically extendable. When the free end of the end connecting rod 212 is inserted into the connector 113, the elastic locking structure within the connector 113 automatically locks the free end of the connector 113. When connecting the support assembly 200 to the snap-fit ​​assembly 100, the operator aligns the end connecting rod 212 of the connector 210 with the connector 113 on the snap-fit ​​assembly 100. Since the end connecting rod 212 is elastically extendable within the limiting sleeve 210, the connection mechanism automatically locks the free end of the connector 113. Within 11, it ensures that both ends of the support component 200 can be smoothly connected to the two snap-fit ​​components 100, and can provide buffering and compensation for some installation deviations; when the free end of the end connecting rod 212 is inserted into the connector 113 to a certain depth, the elastic locking structure inside the connector 113 automatically completes the locking, allowing the two to be quickly connected; improving the efficiency of replacement, even if there is a small installation deviation, it can be compensated by the adaptive elastic expansion and contraction, reducing the accuracy requirements during installation and increasing fault tolerance; specifically, a second spring 215 is installed inside the limiting sleeve 211 to act on the end connecting rod 212 to realize the elastic expansion and contraction of the end connecting rod 212.

[0020] Preferably, such as Figures 7 to 11As shown, the elastic locking structure includes a locking block 1133 elastically telescopically disposed within the receiving cavity 1131 of the connector 113. A locking protrusion 2122, which mates with the locking block 1133, is provided on the outer wall of the free end of the end connecting rod 212. The locking protrusion 2122 has contact slopes on its top and bottom sides, and the locking block 1133 has mating slopes on its top and bottom sides. A first spring 1132, acting on the locking block 1133, is provided within the receiving cavity 1131 to achieve elastic telescopic movement of the locking block 1133. When the free end of the end connecting rod 212 is inserted... When the connector 113 receives the cavity 1131, the contact slope of the snap-fit ​​protrusion 2122 will contact the mating slope of the snap-fit ​​block 1133. Under the insertion force, the snap-fit ​​block 1133 is pushed and the first spring 1132 is compressed. After the snap-fit ​​protrusion 2122 stops pushing the snap-fit ​​block 1133, the compressed first spring 1132 is reset, and the snap-fit ​​block 1133 is inserted into the groove of the end connecting rod 212, realizing automatic locking. Specifically, there are at least four snap-fit ​​protrusions 2122 and at least four snap-fit ​​blocks 1133, which can lock more firmly.

[0021] Preferably, such as Figures 7 to 11 As shown, a locking rod 2121 is fixedly connected to the free end face of the end connecting rod 212. A connecting head 113 has a through hole 1134 for the locking rod 2121 to pass through. The outer side wall of the end of the locking rod 2121 that passes through the through hole 1134 is threaded. When the end connecting rod 212 is inserted into the connecting head 113, the locking rod 2121 will pass through the through hole 1134 on the connecting head 113 while automatically locking. A nut can be connected to the threaded section of the locking rod 2121 according to the actual situation. By tightening the nut, the end connecting rod 212 and the connecting head 113 are firmly fixed together. This improves the reliability of the connection and provides double insurance for the connection between the connecting head 113 and the end connecting rod 212.

[0022] Preferably, such as Figures 7 to 11As shown, a detachable closure 213 is provided at the bottom of the limiting sleeve 211. A limiting rod 214 extending into the limiting sleeve 211 is fixedly connected to the closure 213. The limiting rod 214 is used to limit the end connecting rod 212. The limiting rod 214 can limit the maximum retraction distance of the end connecting rod 212. The end connecting rod 212 reaches its end point of travel when it abuts against the limiting rod 214. Specifically, at least one observation hole 2111 is provided on the limiting sleeve 211. When adjusting the length of the support assembly 200, the operator can... The observation hole 2111 allows observation of whether the end connecting rod 212 and the limiting rod 214 are in contact. Contact between the connecting rod and the limiting rod 214 is a prerequisite for the support assembly 200 to be properly supported. The observation hole 2111 provides visual reference for the staff, avoiding blind operation and minimizing the possibility of load transfer failure due to the support assembly 200 not being properly supported, thus improving the safety of replacement operations. More specifically, the contacting ends of the end connecting rod 212 and the limiting rod 214 can be coated with an easily identifiable paint to improve the convenience of observation.

[0023] Specifically, such as Figure 14 As shown, multiple stacked disc springs 217 are arranged inside the aforementioned limiting sleeve 211. The specific number and stacking method can be adjusted according to the actual situation. When the end connecting rod 212 is compressed and retracted, it will compress the stacked disc springs 217. The disc springs 217 can withstand a large load within a very small deformation range, and have high stiffness, fatigue strength and load-bearing capacity, long service life and stable performance.

[0024] More specifically, such as Figure 14 As shown, a load sensor 216 is fixedly connected to the bottom of the aforementioned end connecting rod 212. The detection end of the load sensor 216 faces the aforementioned disc spring 217 or limiting rod 214. When the end connecting rod 212 is subjected to pressure, the pressure is directly transmitted to the load sensor 216 through the detection end. The load sensor 216 converts this pressure into an electrical signal, which is then processed and transmitted to the terminal for display. This enables visualization of load transfer, allowing operators to understand the pressure borne by the end connecting rod 212 in real time, thereby understanding the progress of load transfer and carrying out construction according to the progress. The aforementioned load sensor 216 can directly adopt the existing wireless load sensor 216, such as the SM34CWB wireless load sensor. The information detected by the load sensor 216 can be directly transmitted to the mobile terminal wirelessly, which is more convenient.

[0025] Preferably, such as Figure 12 and Figure 13As shown, the length adjustment module 220 includes a lead screw 221, a lead screw sleeve 222 threadedly engaged with the lead screw 221, and a drive mechanism for driving the lead screw sleeve 222 to rotate, so that the lead screw 221 extends or retracts along the axial direction of the lead screw sleeve 222; the lead screw 221 and the lead screw sleeve 222 are threadedly engaged with each other, and when the drive mechanism drives the lead screw sleeve 222 to rotate, the lead screw 221 will extend or retract along the axial direction of the sleeve, thereby adjusting the length of the support assembly 200 in its natural state.

[0026] Preferably, such as Figure 12 and Figure 13 As shown, the drive mechanism includes a worm gear 2221 fixed to the lead screw sleeve 222 and a worm 2231 meshing with the worm gear 2221; the length adjustment module 220 also includes a mounting box 223, in which the worm 2231 and the lead screw sleeve 222 are rotatably mounted; when the worm 2231 is driven to rotate, since the worm 2231 meshes with the worm gear 2221 fixed to the lead screw sleeve 222, the rotational motion of the worm 2231 is transmitted to the worm gear 2221. With the cooperation of the worm 2231 and the worm gear 2221, the lead screw sleeve 222 can be controlled to rotate precisely within the mounting box 223, thereby accurately and smoothly adjusting the length of the support assembly 200; and when the worm gear 2221 and the worm 2231 are generally engaged, it has the characteristic of reverse self-locking. The worm gear 2231 can only drive the worm wheel 2221, and the worm wheel 2221 cannot drive the worm gear 2231 in the opposite direction. When the rotation of the worm gear 2231 stops, the position of the lead screw 221 can be firmly locked, improving the stability of the support assembly 200. Specifically, the mounting box 223 includes a top cover and a bottom plate. The lead screw sleeve 222 is rotatably mounted on the bottom plate. The top cover and the bottom plate are detachably connected for easy maintenance. The outer wall of the mounting box 223 is equipped with a bearing 2232 connected to the worm gear 2231 to ensure the reliability of the rotation of the worm gear 2231. The mounting box 223 provides a protective space to protect the components inside. More specifically, the end face of the worm gear 2231 is provided with a hexagonal hole, which allows the operator to drive the worm gear 2231 to rotate using a wrench or other electric rotating equipment.

[0027] Preferably, such as Figures 1 to 3As shown, the connector 210 is detachably connected to the length adjustment module 220. The support assembly 200 also includes at least one adapter section 230, with both ends of the adapter section 230 detachably connected to the connector 210 and the length adjustment module 220, respectively. The adapter section 230 is an independent rigid module. By increasing or decreasing the number of adapter sections 230, or by replacing adapter sections 230 with different lengths, the support assembly 200 can meet the operational requirements of different situations, thereby improving the versatility and applicability of the device. Specifically, both ends of the adapter section 230 are connected between the connector 210 and the length adjustment module 220 via flanges. The aforementioned sealing member 213 is detachably connected to the limiting sleeve 211 and the adapter section 230 via flanges. Furthermore, flanges are provided at the top of the aforementioned screw 221 and the bottom of the mounting box 223 to facilitate the connection of various components.

[0028] Preferably, such as Figures 4 to 7 As shown, the snap-fit ​​assembly 100 includes an adapter 110 and a snap-fit ​​member 120 detachably connected thereto. The snap-fit ​​member 120 includes a first snap-fit ​​plate 121 and a second snap-fit ​​plate 122, which together form a clamping space. A connector 113 is hinged to the adapter 110. The first snap-fit ​​plate 121 is detachably connected to the adapter 110, and the second snap-fit ​​plate 122 is detachably connected to the first snap-fit ​​plate 121. The connector 113 is hinged to the adapter 110, allowing it to swing freely within a certain angle range. When the support assembly 200 is connected to the snap-fit ​​assembly 100, it can be used for main materials that are vertical or tilted at different angles, improving applicability. By designing the clamping surfaces of the first snap-fit ​​plate 121 and the second snap-fit ​​plate 122 into different shapes, for example... Figure 6 V-shape applicable to main angle steel material, or as Figure 7 The design is suitable for curved round tubes, improving applicability. The second clamping plate 122 and the first clamping plate 121 can be connected by bolts to clamp the main material. An elastic layer can be provided on the side of the first clamping plate 121 and the second clamping plate 122 that contacts the main material to increase friction. Specifically, when assembling the clamping assembly 100, at least one pair of connecting hole plates 1212 on the first clamping plate 121 are passed through the first through hole 111 on the adapter 110, and then the first clamping plate 121 and the adapter 110 are connected together by bolts. At the same time, the connecting stud 112 on the adapter 110 is passed through the second through hole 1211 on the first clamping plate 121 and locked with a nut, so that the adapter 110 and the first clamping plate 121 are firmly locked together. Different first clamping plates 121 and second clamping plates 122 can be replaced according to different types of main materials.

[0029] A method for replacing the main components of a power transmission tower, which uses the aforementioned power transmission tower main component replacement device, includes the following steps: Step 1: Install snap-fit ​​components 100 on the upper and lower main materials of the main material section to be replaced respectively; Step 2: Connect the two ends of the support component 200 to the upper and lower snap-fit ​​components 100 respectively through the docking mechanism; Step 3: Operate the length adjustment module 220 of the support component 200 to extend the length of the support component 200 until the load borne by the main material to be replaced is completely transferred to the support component 200 and the snap-fit ​​component 100. Step 4: Remove the main material section to be replaced; Step 5: Install the new main material section; Step 6: Operate the length adjustment module 220 to shorten the length of the support component 200, disconnect the docking mechanism, and release the snap-fit ​​component 100 on the main material.

[0030] The above method optimizes the process and shortens the construction period through rapid docking and precise adjustment; it also ensures the reliability of high-altitude load transfer; specifically, when using this solution, multiple transmission tower main material replacement devices can be deployed simultaneously on different upper and lower main materials to improve the reliability of replacement.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A device for replacing a main member of a power transmission tower, characterized by, It includes a support component and snap-fit ​​components that are detachably connected to both ends of the support component; the support component and the snap-fit ​​components have a mating mechanism that cooperates with each other; The snap-fit ​​assembly can be detachably fixed to the main material that is vertically adjacent to the main material to be replaced; The support component is equipped with a length adjustment module for adjusting the total length of the support component, thereby transferring the load borne by the main material section to be replaced to the support component and the snap-fit ​​component.

2. The power transmission tower main member replacement device according to claim 1, characterized by The docking mechanism includes a connector on the snap-fit ​​assembly and connectors at both ends of the support assembly; the connector includes a limiting sleeve, and an end connecting rod that can be elastically extended and retracted inside the limiting sleeve. When the free end of the end connecting rod is inserted into the connector, the elastic locking structure inside the connector automatically locks the free end of the connector.

3. The power transmission tower main member replacement device of claim 2, wherein The elastic locking structure includes a locking block that is elastically telescopically disposed within the connector receiving cavity, and a locking protrusion that cooperates with the locking block is provided on the outer side wall of the free end of the end connecting rod.

4. The power transmission tower main member replacement device of claim 2, wherein A locking rod is fixedly connected to the free end face of the end connecting rod. A through hole is provided on the connecting head for the locking rod to pass through. The outer side wall of the end of the locking rod that passes through the through hole is threaded.

5. The power transmission tower main member replacement device of claim 2, wherein The bottom of the limiting sleeve is detachably provided with a closure, and a limiting rod extending into the limiting sleeve is fixedly connected to the closure. The limiting rod is used to limit the end connecting rod.

6. The power transmission tower main member replacement device of claim 1, wherein The length adjustment module includes a lead screw, a lead screw sleeve that is threaded to the lead screw, and a drive mechanism for driving the lead screw sleeve to rotate, so that the lead screw extends or retracts along the axial direction of the lead screw sleeve.

7. The power transmission tower main member replacement device of claim 6, wherein The drive mechanism includes a worm gear fixed to the lead screw sleeve and a worm gear meshing with the worm gear; the length adjustment module also includes a mounting box, in which the worm gear and the lead screw sleeve are rotatably mounted.

8. The transmission tower main material replacement device as described in claim 2, characterized in that, The connector is detachably connected to the length adjustment module, and the support assembly further includes at least one adapter segment, the two ends of which are detachably connected to the connector and the length adjustment module, respectively.

9. The power transmission tower main member replacement device of claim 2, wherein The snap-fit ​​assembly includes an adapter and a snap-fit ​​component detachably connected thereto. The snap-fit ​​component includes a first snap plate and a second snap plate. The connector head is hinged to the adapter. The first snap plate is detachably connected to the adapter. The second snap plate is detachably connected to the first snap plate.

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