55results about How to "Avoid connection failure" patented technology

The invention provides a power line carrier and wireless communication combined power data transmission method and system, and the method comprises the steps: collecting the operation data of terminal power equipment in real time through terminal collection equipment in a power distribution area, and adding a timestamp for the data; and the hybrid communication sub-equipment transmits the operation data with the timestamp to the hybrid communication main equipment of the substation by using the power line carrier. And after receiving the data, the main device calculates the communication distance between the power distribution area and the transformer substation according to the timestamp information, and selects a proper communication mode. And the master device continues to monitor and calculate the bit error rate, obtains parameters such as the signal-to-noise ratio, the attenuation value and the interference intensity of the communication channel, and inputs the parameters into the pre-trained support vector machine to predict the current bit error rate. And based on a prediction result, a communication distance, a load and other factors, a pre-trained reinforcement learning model is adopted to adaptively select an optimal communication mode, and the communication mode is dynamically adjusted to optimize a data transmission effect.

This invention provides a highly stable plug-in structure, including a connector, a connector sleeved on the connector, a wire on the connector, and a plug-in component on the connector and connected to the wire. The plug-in component includes an arc-shaped conductive element with at least one opening along its axial direction. The conductive element and the at least one opening create one or more independent elastic contact points. When the connector is mated to the connector, the conductive element is deformed by the pressure of the internal electrical contacts of the connector, ensuring stable and sufficient radial contact pressure with each insertion. After removal, the conductive element springs back to its original curvature, effectively preventing connection failure caused by permanent enlargement of the connector's inner diameter.

The wire harness comprises a main plug, a plurality of connecting holes and a plurality of conductive sleeves are arranged on the plug, each conductive sleeve comprises a vertical connecting part and a plurality of elastic sheets, the elastic sheets are annularly arranged outside the vertical connecting part at intervals and connected with the vertical connecting part, and the sides, close to orifices of the connecting holes, of the elastic sheets incline outwards. The conductive sleeve is inserted into the connecting hole, and the elastic sheet deforms under the action of the outer wall of the connecting hole and abuts against the outer wall of the wire harness core. When the conductive sleeve and the wire harness are synchronously inserted into the connecting hole, the elastic sheets deform towards the inner side of the connecting hole under the action of the hole wall of the connecting hole and are pressed on the wire harness core, so that the wire harness is locked by using the plurality of elastic sheets, the mechanical locking capability of the conductive sleeve on the wire harness is optimized, and the connection reliability is improved; and the plurality of elastic sheets enclose to form the side wall matched with the hole wall of the connecting hole under the action of the connecting hole, so that the contact area between the elastic sheets and the wire core is increased, and the electrical performance is improved.

The invention discloses a high-luminous-efficiency LED lighting device and a manufacturing method thereof, and relates to the technical field of lighting, the high-luminous-efficiency LED lighting device comprises a shell, a heat dissipation module used for avoiding light attenuation acceleration is arranged in the shell, the heat dissipation module comprises a ceramic heat dissipation plate and an aluminum substrate which are arranged in the shell, and concave-convex textures are arranged on the heat dissipation surface of the ceramic heat dissipation plate; the aluminum substrate is provided with a multi-channel assembly used for preventing the overall lighting effect from being reduced, and the opening of the shell is provided with an anti-glare assembly used for restraining glare under low light loss. Convection heat transfer is enhanced through concave-convex textures on the surface of the ceramic heat dissipation plate so as to delay light attenuation, the multi-channel assembly independently adjusts driving current through a power management system so as to achieve spectrum refined reconstruction, and the anti-dazzle assembly achieves dazzle suppression under low light loss through microstructure textures on the light-emitting face of a lens and light diffusion particles filled in the center area.

The utility model discloses a kind of connectors for inverter, including connector shell and the electric conductor being set in the connector shell, the one end of electric conductor is connected with the internal electrical element of plate end assembly, the other end of electric conductor is connected with external photovoltaic module;The connector shell includes connector main body and nut, connector main body is provided with boss, boss is located plate end assembly inside and is abutted with plate end assembly, so that the outside end of connector main body protrudes the through-hole of plate end assembly, the outside end of connector main body is provided with screw thread, when nut and the outside end of connector main body are cooperated screw thread connection, connector main body is fixedly connected with plate end assembly;It further includes the anti-back pad for preventing nut back rotation between plate end assembly and nut, in the structure, by the setting of anti-back pad, effectively prevent nut loosening and falling off in use process, to enhance the stability of connector for inverter, avoid the connection failure problem caused by nut loosening.

The invention relates to the technical field of power motors, in particular to a base and end cover sealing structure and a motor, and the base and end cover sealing structure comprises a base, a shell, an outer end cover, an inner end cover and a sealing element; the inner end cover is detachably arranged at the first end of the base, the second end, opposite to the inner end cover, of the base is rotationally connected with a rotary connecting assembly, and the rotary connecting assembly is connected with the shell. One end of the outer end cover is connected with the shell, the other end of the outer end cover is opposite to the inner end cover, and the sealing piece is arranged between the inner end cover and the outer end cover and seals the opposite space between the inner end cover and the outer end cover; a connecting buckle is arranged at the end, facing the rotary connecting assembly, of the inner end cover, and an assembling clamping groove matched with the connecting buckle is formed in the base. The problems that traditional threaded connection is low in efficiency and prone to failure are solved, and efficient assembly and reliable sealing are achieved while the stability of the overall structure after connection with external accessories is guaranteed.

The invention relates to the technical field of civil engineering, in particular to a steel sheet pile supporting device. The steel sheet pile supporting device comprises a pile plate body, an enclosing purlin assembly and a steel pipe support, and the pile plate body is fixedly connected with the enclosing purlin assembly through a hanging piece; the enclosing purlin assembly comprises a front plate, a rear plate and I-shaped steel, the front plate and the rear plate are connected through at least two sets of first bolts, and the length of the first bolts is larger than the distance between the front plate and the rear plate. The I-shaped steel is inserted between the front plate and the rear plate, and the number of the I-shaped steel is 2-3; the steel pipe support is a steel pipe, the steel pipe support is connected with the front plate, at least two sets of first stiffening ribs are arranged at the end of the side, close to the front plate, of the steel pipe support, and the steel pipe support is in threaded connection with the supporting piece through the first bolt holes. According to the supporting device, the assembling procedure is greatly simplified, the connection between the steel pipe support and the enclosing purlin assembly is firmer and more reliable, the load effect under the full working conditions of supporting tension, pressing and the like can be effectively resisted, and the overall stability and the bearing capacity of the supporting device are further improved.

The present application relates to the technical field of welding control, in particular to a large plate welding equipment control system, comprising a space normalization module, an address generation module, a path screening module, a structure verification module and an interconnection output module.In the present application, in the multi-machine collaborative working environment under strong electromagnetic interference of arc welding, the three-dimensional coordinates of the welding torch contact point are collected with high precision and space normalization processing is performed, which fundamentally eliminates the process data differences caused by different welding postures, a unified sequence number is constructed in combination with the starting timing of the core equipment of the welding power source and the wire feeder, a unique control address is generated by fusing the sequence identifier, the accurate mapping of the physical location of the equipment and the network address is realized, the logical connection sequence is intelligently constructed according to the proximity of the coordinate space, the node and path binding is completed synchronously, the rationality of the connection path and the stability of the communication structure are significantly improved, and the logical order, spatial clarity and control uniformity of the arc welding equipment group collaborative work are ensured.

This utility model relates to the technical field of thermal insulation structures, and discloses a rooftop thermal insulation reinforcement structure, including a thermal insulation layer laid on the rooftop. The thermal insulation layer has an extruded polystyrene (XPS) board inside, and a wire mesh layer is laid on the XPS board. The XPS board and the wire mesh layer are wrapped inside the thermal insulation layer. The wire mesh layer has multiple mesh openings, and there are intersections between adjacent mesh openings. An insert strip is provided at the intersection, and the insert strip passes through the XPS board. By setting the XPS board and the wire mesh layer inside the thermal insulation layer, and setting the insert strip at the intersection of the wire mesh layer, the connection strength of the internal materials of the thermal insulation layer is improved.

This application relates to a male connector and connector assembly. The male connector includes a housing and a male connector member. The housing includes a connection channel and an injection hole. The connection channel extends through the housing, and the injection hole is formed on the housing and communicates with the connection channel. The male connector member is disposed within the connection channel and has a recessed portion. The injection hole and the recessed portion communicate with each other. By filling the connection channel inside the housing with adhesive through the injection hole, the housing and the male connector member are secured, thus solving the problem of connection failure caused by connector slippage in automotive connectors.

The utility model relates to the technical field of furniture metal connection, in particular to an adjustable furniture metal connecting foot which comprises a cross plate, bottom plates are symmetrically arranged at the upper end of the cross plate in a sliding mode, buffer springs are fixedly connected to the middles of the upper ends of the bottom plates, and buffer bases are fixedly connected to the upper ends of the buffer springs. An adjusting structure is fixedly installed at the upper end of the buffering base, a supporting plate is fixedly connected to the upper end of the adjusting structure, the opposite corners of the supporting plate are of an arc-shaped structure, and a fence is fixedly installed on the edge, away from the arc-shaped corners, of the supporting plate. The adjustable furniture can adapt to adjustment of various road surfaces, the use comfort can be improved, the stability of the furniture in the adjustment process is guaranteed, balance combination of the stable structure, convenient operation and multiple functions is achieved, and the requirements for high-precision adjustment and high-adaptability connection in the furniture industry are met.

The utility model relates to the technical field of machine manufacturing, and discloses a ladder manufacturing positioning tool which comprises a supporting frame body and a plurality of connecting pieces, at least one pair of first positioning plates distributed at intervals in the first direction is arranged at the top of the supporting frame body, a first positioning hole is formed in each first positioning plate, and a second positioning hole is formed in each first positioning plate. A plurality of pairs of second positioning plates distributed at intervals in the first direction are arranged on one side of the supporting frame body in the height direction at intervals, each second positioning plate is provided with a second positioning hole, and the first direction is perpendicular to the height direction of the supporting frame body. Every two connecting plates located on different main frames can correspond to at least one pair of first positioning plates or at least one pair of second positioning plates, and the first positioning holes and the second positioning holes are used for assisting in positioning the positions of through holes to be formed in the corresponding connecting plates. Each connecting piece is detachably connected with a through hole formed in the connecting plate and the first positioning hole or the second positioning hole corresponding to the through hole. And the ladder stand manufacturing yield is high, and the universality is good.

The utility model discloses a track fastener which comprises a bottom plate, check blocks are fixedly connected to the two sides of the upper surface of the bottom plate, a track body is arranged between the check blocks, fixing rings are fixedly connected to the two ends of the upper surface of each check block, a C-shaped connecting plate is arranged between the fixing rings, and fixing bolts are arranged between the C-shaped connecting plate and the check blocks. A limiting assembly is arranged above the fixing bolts, and the two ends of the limiting assembly are connected with the corresponding fixing rings in a clamped mode. According to the track, the track body is supported through the bottom plate, the two sides of the track body are limited through the check blocks, the upper surfaces of the two sides of the track body can be limited through the C-shaped connecting plates and the check blocks which are fixed through the fixing bolts, the limiting assemblies are clamped to the fixing bolts through the clamping blocks, and the two ends of each limiting assembly are clamped to the fixing rings; and the fixing bolts can be limited, and threaded connection failure caused by loosening of the fixing bolts is avoided.

The utility model discloses a diesel engine fuel injection pump speed regulator control handle structure, which relates to the field of diesel engine speed regulation structures, and comprises a control handle body arranged between a control shaft and a pull rod, the control handle body comprises a connecting part, the top of the connecting part is connected with the pull rod, a U-shaped regulating part is arranged at the bottom of the connecting part, and a control handle folding edge is arranged on the regulating part. The control handle folding edge and the bottom of the connecting part are arranged in parallel, a connecting groove is formed among the bottom of the connecting part, the adjusting part and the control handle folding edge, a spline is arranged in the connecting groove and fixedly connected with the control shaft, and an adjusting part is arranged on the adjusting part; according to the diesel engine fuel injection pump speed regulator control handle structure, when the contact portion of the opening and the spline is abraded, the size of the connecting groove can be adjusted through the adjusting piece, so that the control handle body is fixedly connected with the spline, connection failure caused by abrasion of the contact portion of the opening and the spline is avoided, and the adjusting effect is guaranteed.

This utility model relates to a drill string processing system for oil drilling rigs, including a two-tier manipulator, a drill platform manipulator, a powered slip device, a steel drill bit, a thread cleaning device, and a traveling crane system. The two-tier manipulator is installed on the second tier of the derrick, and the traveling crane system is vertically and movably installed on the derrick. The drill platform manipulator and the steel drill bit are installed on the drill platform, allowing them to operate close to the wellhead. The powered slip device is installed at the wellhead. The thread cleaning device includes a male thread cleaning assembly and a female thread cleaning assembly. Both are installed on the drill platform; the male thread cleaning assembly cleans the male threads of the drill string located at the wellhead, and the female thread cleaning assembly cleans the female threads of the drill string located at the wellhead. Its advantages include a high degree of mechanization, significantly improved operational efficiency and safety.

This utility model belongs to the field of offshore wind power and discloses a quick unhooking device for towing floating wind turbines. It includes a housing, a piston, and an oil tank. The housing and piston are respectively used to connect to corresponding cables. The housing has an inner cavity with an opening on one side. The piston slides and inserts into the inner cavity. Multiple first separation plates are spaced apart on the inner wall of the inner cavity opposite the piston. Multiple second separation plates are spaced apart on the outer wall of the piston facing the inner cavity. The first and second separation plates are staggered, forming a serpentine channel. The serpentine channel is connected to the oil tank via a liquid inlet pipe. A seawater interface is provided on one side of the liquid inlet pipe, and a water inlet valve is installed on the seawater interface. The dual buffering principle of this utility model not only effectively copes with high-frequency, low-amplitude vibrations but also stores energy through the oil compression effect when facing strong impacts, significantly reducing the impact peak value, minimizing damage to connecting parts, and improving system stability.

This utility model belongs to the technical field of injection molding, and particularly relates to a protective ring mold and molding device, including an upper mold assembly, a lower mold assembly, and a mold core. When the upper mold assembly and the lower mold assembly are closed, the upper mold plate and the positioning assembly form an injection cavity, and the outer shell of the protective ring is formed by injection molding through the injection port on the periphery of the fiber rod. This utility model solves the problems of low efficiency and poor product consistency in manual operation. The replaceable design of the mold core adapts to the processing requirements of fiber rods of different specifications. The injection molding process makes the outer shell and the fiber rod form an integral structure, avoiding connection failure caused by insufficient glue curing. The cooperation between the positioning assembly and the upper and lower molds ensures the dimensional accuracy of the outer shell and eliminates the positioning misalignment defects common in manual operation.

The embodiment of the utility model relates to the technical field of electronics, in particular to a circuit board and electronic equipment. The embodiment of the utility model aims to solve the problem that the flexible circuit board is easily damaged by pulling force of two printed circuit boards. According to the circuit board provided by the embodiment, the second printed circuit board and the first printed circuit board are arranged at an interval, one end of the flexible circuit board is connected with the first printed circuit board, the other end of the flexible circuit board is connected with the second printed circuit board, and the rigid limiting piece is connected with the first printed circuit board and the second printed circuit board. The rigid limiting piece is used for preventing the second printed circuit board from moving relative to the first printed circuit board so as to prevent the first printed circuit board and the second printed circuit board from pulling the flexible circuit board, and then the flexible circuit board is prevented from being damaged by pulling force.

A display device is disclosed. The display device may include the following elements: a substrate; a light shielding layer disposed on the substrate; a first insulating layer disposed on the light shielding layer; a transistor including a source electrode or a drain electrode, the source electrode or the drain electrode having an extension overlapping each of the first insulating layer and the light shielding layer; a second insulating layer disposed on the extension; and a pixel electrode disposed on the second insulating layer. The first insulating layer and the second insulating layer may include a contact hole, the contact hole exposing a portion of the light shielding layer and exposing a portion of the extension. The pixel electrode may directly contact each of the portion of the extension and the portion of the light shielding layer.

The utility model relates to the technical field of operation machinery, and discloses a mounting device and operation machinery, the mounting device comprises a main body, the main body comprises a connecting part and a mounting part, the connecting part is fixedly connected with the mounting part, the connecting part is provided with a connecting structure matched with a vehicle body of a cleaning vehicle, and the mounting part is provided with a mounting structure for mounting a water spraying frame; according to the utility model, the main body and the supporting assembly form the integral mounting device together, the main body is provided with a structure connected with the vehicle body and the water spraying frame at the same time, the water spraying frame can be directly mounted only by a single mounting device, the integral main body is better in integrity, and the water spraying frame is more convenient to mount. The number of components is reduced, redundant reinforcing structures at the connecting positions of the components can be omitted, the strength of the main body is further improved through the supporting assemblies, and the water spraying frame can be reliably supported while the overall structure of the mounting device is simple.

The application relates to the technical field of wireless screen projection, in particular to an Airplay directional screen projection method and device, which are applied to a proxy server configured with double network cards, the proxy server is arranged between a guest network and a screen projection device network and respectively accesses the two networks; after an mDNS query packet of a user mobile phone terminal is acquired through a guest network card, a simplified mDNS response packet is replied to induce the mobile phone terminal to send a unicast query packet; the unicast query packet is forwarded to a screen projection device network multicast address, only a multicast response packet of a screen projection service bound with the mobile phone terminal is received; a service address in the response packet is modified into a guest network card IP and is fed back to the mobile phone terminal, and a NAT network channel is simultaneously established. The application solves the screen projection service discovery difficulty and the screen projection service discovery difficulty caused by VLAN isolation in a hotel and the like scene, does not need to change an existing network topology, realizes directional screen projection, the screen projection service can be flexibly arranged, adapts to different scene requirements, and has high connection stability.

The utility model discloses a self -locking card formula nut mechanism, including nut body, joint piece and stop device, joint piece is by side wall and located the baffle and fender of both ends constitute, and the cavity is formed among three, and nut body is along the axial sliding of screw hole in the accommodation cavity, and baffle sets up the perforation corresponding with screw hole, and the accommodation cavity has the starting end and the terminal end, and nut body is in the starting end with baffle abuts, in the terminal end with fender abuts, limit device is located in the side wall of accommodation cavity. In this mechanism, the joint piece can act as a wrench, limiting the nut body rotation, without the traditional tool screw, overcome the obstruction of limited space to installation, improve the installation efficiency in the limited space, avoid affecting production progress and equipment assembly. When the bolt is screwed into the nut body, the nut body moves from the starting end to the terminal end under stress until it contacts with the limiting device. Because the joint piece cannot be deformed due to environmental influence, it can lock and fix the nut body, effectively preventing it from loosening in vibration, impact and other environments.

The utility model discloses a knob, which is applied to a kitchen range and comprises a knob shell, a knob cover, a plurality of fixed ribs and a plurality of fixed ribs, the knob shell comprises a knob ring and an opening for sealing one end of the knob ring, and the inner wall of the knob ring is provided with a plurality of fixed ribs which are parallel to the central axis of the knob shell and are arranged at intervals along the circumferential direction; and the knob inner core is located in the knob shell, and a plurality of fixing grooves which correspond to the fixing ribs and are clamped and matched with the fixing ribs are formed in the peripheral surface of the knob inner core. The utility model further discloses a kitchen range with the knob. The beneficial effects of the utility model lie in that the fixation of the knob housing and the knob inner core is firm and stable.

This utility model relates to the field of FC socket technology and discloses a combined FC socket module, including an FC plug, an FC socket, and an FC jumper. A mounting block is fixedly disposed on one side of the FC socket, and a mounting groove is formed on one side of the FC plug. The mounting block and the mounting groove cooperate to connect the FC plug and the FC socket. The FC jumper is fixedly connected inside the FC plug. A pin is fixedly connected inside the FC socket and connects to one end of the FC jumper. A connecting component is provided between the FC plug and the FC socket. The connecting component includes a magnetic post and an adsorption groove. The magnetic post is fixedly disposed inside the mounting groove, and the adsorption groove is formed on the outer wall of the mounting block. The magnetic post slides against the adsorption groove, and the magnetic post adsorbs the adsorption groove, stably connecting the mounting block inside the mounting groove. This solves the problem of the laborious disassembly and assembly of existing equipment.

The application discloses a kind of based on substructure pre-stabilization ultra-high multilayer printed circuit board manufacturing method, suitable for the number of layers N greater than 20 ultra-high multilayer board manufacturing.The method divides the whole manufacturing process into three stages, and sequentially forms inner core, intermediate and final substructure.The core is: after each manufacturing stage is completed, the complete encapsulation process of metalization, resin filling, grinding and copper cap plating of interconnection hole is carried out, so that the mechanical and electrical stability of the current substructure is realized before entering the next stage of pressing.Meanwhile, for each substructure, its pressing process parameters are independently set to match its material and structural characteristics.The application effectively solves the core problems of poor interlayer alignment accuracy, poor high aspect ratio hole plating uniformity and low overall yield caused by thermal-mechanical stress accumulation in traditional manufacturing of ultra-high multilayer board, significantly improves the reliability and manufacturing efficiency of the product.

The invention discloses a connecting structure of an air inlet pipe in furnace tube type equipment and a fixing method of the connecting structure, and belongs to the technical field of pipe joint and pipe supporting, the connecting structure comprises a reaction cavity, an exhaust manifold arranged at the bottom of the reaction cavity and an air inlet pipe arranged in the reaction cavity, and further comprises an air inlet pipe fixing structure; the air inlet pipe fixing structure comprises an air outlet short pipe, a positioning ring and a clamping ring. A stepped cylindrical surface is arranged at the upper part of the air outlet short pipe; the positioning ring comprises a ring piece and a positioning column arranged on the ring piece; the clamping ring is of an annular structure with the span larger than 180 degrees. By means of the multi-point insertion matching design of the positioning columns and the positioning holes, accurate centering and powerful radial constraint of the air inlet pipe in the air outlet short pipe are achieved, and the possibility that the air inlet pipe shakes in the radial direction in the operation process is fundamentally eliminated. Due to the matching design of the arc-shaped clamping grooves and the protrusions, double mechanical locking in the axial direction and the circumferential direction is provided, the reliability is far better than that of traditional welding, and connection failure caused by thermal stress is completely eradicated.

The invention discloses a processing method of an aluminum oxide electrostatic chuck, and aims to overcome the defect that the connection failure is easy to occur when the electrostatic chuck is used for a long time. The method comprises the following steps: S1, selecting two substrates, and processing a high-voltage electrode groove on one substrate; s2, coating bonding slurry on the surface of a substrate close to the edge, and drying; s3, the two substrates are attached together and assembled into a furnace, diffusion welding is achieved after the slurry is heated, the two substrates are connected into a disc body, and an electrode cavity is formed in the high-voltage electrode groove; s4, conducting resin is poured into the electrode cavity in a vacuum mode. According to the processing of the electrostatic chuck, high-strength integration of the aluminum oxide ceramic and the internal conductive adhesive functional layer is realized, the problem of connection failure of the electrostatic chuck caused by decomposition or aging of an adhesive at a high temperature is avoided, the overall performance of the electrostatic chuck is improved, and the service life of the electrostatic chuck is prolonged.

The invention belongs to the technical field of cable connectors, and particularly relates to a center alignment integrated cable connector for a vacuum corrugated pipe and a connection method, and the center alignment integrated cable connector comprises a first connector, a second connector and a third connector; the third connector coaxially connects and wraps the first connector and the second connector which are horizontally mounted, and the central axes of the first connector, the second connector and the third connector are aligned; according to the connector, the first connector body, the second connector body and the third connector body are tightly combined in a threaded rotation mode, connection faults are effectively prevented, circuit safety is ensured, the first electric conductor and the second electric conductor are reliably connected, poor contact is completely eradicated, and the connector is simple in structure and convenient to use. Interference of external deformation factors can be blocked, stability of current transmission can be guaranteed, exchange of internal and external airflow is blocked, rotation of the third connector can be prevented, looseness between the connectors is avoided, and contact hidden dangers of the connectors are eliminated fundamentally.

This utility model relates to the field of martial arts props technology and discloses a martial arts performance prop, including two sticks, a connecting ring, and a metal chain. Each stick has a threaded hole at one end, and a connecting post is threadedly connected to the inner cavity of the threaded hole. Two rotating plates are symmetrically arranged radially in the inner cavity of the connecting post. The rotating plates are rotatably connected to the connecting post via pins. A locking block is fixedly connected to one side of each rotating plate. An annular groove matching the locking block is formed on the inner wall of the threaded hole. A return spring is provided between each rotating plate and the connecting post. One end of the return spring abuts against the rotating plate, and the other end is fixed to the inner wall of the connecting post. Two clearance grooves are formed at one end of the connecting post. The free end of the rotating plate extends into the clearance groove and slides in cooperation with the clearance groove. A rectangular groove is formed on the top of each rotating plate.