4386 results about "Tread" patented technology

The invention relates to a pneumatic vehicle tire comprising a tread with profile positives delimited by grooves, including profile positives which are provided with sipes, which in plan view run at least in certain portions at an angle of 0° to 50° to the axial direction and have a width of 0.4 mm to 1.6 mm and a depth at the deepest point that is at least the profile depth reduced by 4.5 mm and at most 100% of the profile depth, with the sipes in each case being involved in forming at least one wear indicator. The wear indicator is formed by a sipe portion of the sipe which in plan view has the form of a sun symbol or a snowflake symbol.

A multi-layer shock absorbing cushion sole for footwear includes four layers of material, assembled in such a way that air pockets are created within the sole to provide a shock-absorbing, cushioning effect for a wearer's feet. The top layer of the sole is a hard rubber layer, preferably made from a thermoplastic rubber. The second layer is preferably positioned directly beneath the top layer, and includes shaped surfaces forming ridges and grooves on a top and bottom portion thereof to create open air pockets within the sole. The third layer, positioned below the cushion layer, is also preferably formed from a thermoplastic rubber. The bottom layer is preferably formed from natural rubber, and preferably includes a tread design on the bottom surface thereof. A multi-layer shock absorbing cushion insert for pre-existing footwear is also provided in another embodiment.

The invention relates to the technical field of tire production, in particular to a method for identifying abnormal wear of a tire through color difference of an automobile tire tread, which comprises the following steps: determining scanning parameters; correcting scanning parameters; obtaining a point cloud picture; quantitative parameters are selected, and a wear state model is trained based on historical detection data; establishing a mapping relation; according to the detection data of the to-be-detected automobile tire and the wear state model, obtaining a quantization parameter value of the automobile tire; generating a quantization parameter point cloud picture; verifying whether the quantization parameter value is accurate or not according to the spectrogram of the reflected light and the quantization parameter point cloud atlas; and generating a visual quantization parameter point cloud picture. According to the method, scanning parameters are dynamically corrected according to the actual perimeter to ensure the accuracy of point cloud data, automatic calculation of quantization parameters is realized in combination with a machine learning model, and finally, abstract wear data are converted into a visual image through color mapping, so that the wear condition is directly obtained by observing colors, and the accuracy of the wear condition is improved. And the detection efficiency of abnormal wear of the tire is improved.

A multi-layer shock absorbing cushion sole for footwear includes multiple layers of material, assembled in such a way that air pockets are created within the sole to provide a shock-absorbing, cushioning effect for a wearer's feet. The top layer of the sole is a hard rubber layer, preferably made from a thermoplastic rubber. The second layer is preferably positioned directly beneath the top layer, and includes air pockets formed therein by various structures, methods and techniques. The optional third layer, positioned below the cushion layer, is also preferably formed from a thermoplastic rubber. The bottom layer is preferably formed from natural rubber, and preferably includes a tread design on the bottom surface thereof. A multi-layer shock absorbing cushion insert for pre-existing footwear is also provided in another embodiment.

The invention relates to a tire structure aging prediction method, in particular to a method, a system and a program product for predicting aging and damage risks of a tire multilayer structure. According to the method, nanoindentation testing is carried out on all layers (an airtight layer, a transition layer, a tread layer and the like) of the tire at different time points, elastic modulus data are obtained, and the modulus variation is calculated. And performing numerical solution on the diffusion behavior of oxygen in each layer in combination with a Fick diffusion equation, establishing a concentration-modulus coupling model, extracting an aging rate and a critical modulus change threshold, and realizing prediction of failure time of each layer, thereby evaluating the overall remaining life and safety risk of the tire. The system integrates a data acquisition module, a temperature control module and an automatic analysis module, has the advantages of high detection precision, quick response, accurate prediction and the like, and can provide a scientific basis for tire design optimization and maintenance management.

The invention discloses a temperature detection method and device for a mine engineering tire. The method comprises the following steps: acquiring a target thermal imaging image of a mine target area, and determining position information of each target tire on a target vehicle in the target thermal imaging image by using a target detection model; intercepting a tire area image including the target tire from the thermal imaging image according to the position information of the target tire, and dividing the tire area image into a tread area image and a sidewall area image by using a target segmentation model; the temperature information in the tread area image and the temperature information in the sidewall area image are subjected to statistics, the temperature states of the tread and the sidewall of the target tire are determined according to the statistical result, the temperature states are displayed, and the temperature states are used for reflecting whether the temperature of the tread or the sidewall is abnormal or not and the temperature abnormal area corresponding to the abnormal temperature. The technical problem that a traditional tire temperature detection scheme is not suitable for engineering tires working in the mine environment is solved.

The invention discloses a tire performance testing method and device. The method comprises the following steps: acquiring the initial depth and the post-grinding depth of each pattern groove on the tread of a target tire before and after grinding, and the initial temperature and the post-grinding temperature of each pattern block before and after grinding; determining an initial groove depth uniformity parameter, an initial temperature uniformity parameter, an after-grinding groove depth uniformity parameter and an after-grinding temperature uniformity parameter of the tread of the target tire before and after grinding based on the parameters; according to the initial groove depth uniformity parameter, the initial temperature uniformity parameter, the ground groove depth uniformity parameter and the ground temperature uniformity parameter, whether grinding of the target tire is qualified or not is evaluated; and if the grinding is qualified, testing the performance of the ground target tire. The technical problem that the accuracy of the performance test result of the polished tire is poor as the wear condition of the tread cannot be really reflected only according to the depth of the pattern groove is solved.

The invention provides a wheel tread derailment detection method and system for a railway vehicle. According to the method, jacking driving devices with jacking rotating wheels are symmetrically arranged on the two longitudinal sides of a track, a pressure sensing unit is arranged between the two jacking rotating wheels, optical detection units with orthogonal optical paths are installed on the outer sides, and displacement measurement units are integrated on the jacking rotating wheels, so that a three-dimensional detection network is formed. During detection, a top rotating wheel lifts a wheel step by step, a blocking signal, tread pressure and a vertical displacement parameter are synchronously collected, and a space mapping relation between a pressure decreasing path and a displacement abnormal point is established; converting the blocking signal into a blocking release rate, and calculating a displacement accumulated value in combination with a space mapping relation; and when the displacement accumulated value is continuously increased and the blocking release rate exceeds a threshold value, wheel-rail separation is judged, and jacking is controlled to be stopped. Through cooperative detection and analysis of multiple sensors, accurate judgment and self-adaptive jacking control of the wheel-rail separation state are achieved, and the problem of wheel diameter adaptability of a traditional fixed jacking mode is effectively solved.

A multi-layer shock absorbing cushion sole for footwear includes four layers of material, assembled in such a way that air pockets are created within the sole to provide a shock-absorbing, cushioning effect for a wearer's feet. The top layer of the sole is a hard rubber layer, preferably made from a thermoplastic rubber. The second layer is preferably positioned directly beneath the top layer, and includes shaped surfaces forming ridges and grooves on a top and bottom portion thereof to create open air pockets within the sole. The third layer, positioned below the cushion layer, is also preferably formed from a thermoplastic rubber. The bottom layer is preferably formed from natural rubber, and preferably includes a tread design on the bottom surface thereof. A multi-layer shock absorbing cushion insert for pre-existing footwear is also provided in another embodiment.

The invention discloses a tire finite element modeling and multidirectional rigidity optimization method and system based on characteristic lines. The method comprises the following steps: extracting tire section characteristic lines from a three-dimensional digital model; introducing the tire section characteristic line into a finite element analysis environment, generating a three-dimensional tire geometric model by rotationally scanning the characteristic line, and performing grid division on the model; setting tire material attributes, performing zoning setting on the model according to a tire crown, a tire shoulder and a tire side wall, and setting tire thickness based on zoning; applying a constraint boundary condition at the center of the tire, and establishing a contact form of the tread and the ground; a progressive inflation pressure load is applied, the deformation state of the inflated tire is calculated, and longitudinal rigidity, radial rigidity and lateral rigidity calculation and analysis steps are set; the tire elasticity modulus and the cord fabric thickness are used as design variables, and an optimization algorithm is adopted to solve a multi-objective optimization function. The method has the advantages of being simple in modeling method and high in practical operability, the tire modeling threshold can be lowered, and the fund and time cost of refined modeling is reduced.

The invention discloses a low-resistance and high-wear-resistance tire rubber composition as well as a preparation method and application thereof, and belongs to the technical field of rubber materials. The tire rubber composition comprises the following raw materials in parts by weight: 50-70 parts of natural rubber NR, 30-50 parts of solution polymerized styrene-butadiene rubber SSBR, 40-60 parts of modified white carbon black, 3-5 parts of zinc oxide, 1-2 parts of stearic acid, 1-3 parts of an anti-aging agent 6PPD and 2.5-3.5 parts of a vulcanization system. The prepared tire rubber material has the advantages that the rolling resistance is obviously reduced, the wear resistance is improved, the energy consumption is effectively reduced, and the requirements of new energy automobiles on high-performance tires are met. Through three-step modification treatment, the white carbon black is uniformly dispersed in a rubber matrix, and the interface bonding is firm, so that the prepared tire can reduce the rolling resistance of the tire using the tread rubber, and the tread rubber has higher wear resistance, tensile strength and elongation at break, and accords with the development direction of new energy automobiles in the future.

A wheel includes a boss, a rim, and a web. The rim includes a tread and a flange. A center of the rim in the axial direction of the wheel is disposed closer to the flange in the axial direction than a center of the boss in the axial direction is. The web has a plate-thickness center line that has a linear shape when the wheel is viewed in its longitudinal section. When an angle that the plate-thickness center line forms with the axial direction is denoted by a, a distance in the axial direction from a side face of the rim to an outer end of the plate-thickness center line is denoted by Pw, a length of the rim in the axial direction is denoted by Wr, and Pw / Wr is denoted by L, the wheel satisfies the expression L≥0.0223α−1.363. Where, the angle α is 90° or less.

A tire tread comprising a groove with a groove depth; a tread element adjacent to the groove; the tread element comprising a tread surface intended to engage a ground surface, a radial direction perpendicular to the tread surface, a sipe radially extending from the tread surface, along the radial direction the sipe exhibits an outer section parallel to the radial direction, an inner section parallel to the radial direction, the inner section comprising an even outer edge, an inclined section between the outer section and the inner section, the inclined section being inclined with respect to the radial direction of an inclination angle of at most 60°; the inclined section comprises undulations extending along the even outer edge.

The rubber composition for a tire tread according to the embodiment contains a rubber component containing a diene rubber and vegetable granules having a surface treated with a sulfonic acid-type surfactant. The rubber composition for a tire tread has excellent on-ice performance, excellent wet performance, and excellent low heat generation property.

A pneumatic tire that is an example of an embodiment includes a tread and a sidewall, and the sidewall has at least one side block. At an inner end of the side block in a tire radial direction, a protrusion is formed that protrudes outward in a tire axial direction. A height H2 of the protrusion is, for example, between 1.1 and 3.0 times a height H1 of a highest portion of the side block other than the protrusion.

The utility model discloses a pattern block with an exhaust channel and a tire vulcanization mold, the pattern block comprises stacked pattern sheets, and each pattern sheet is provided with an auxiliary groove forming part; the concave part of the end surface of the auxiliary groove forming part forms an auxiliary groove; each pattern sheet is also provided with an end face exhaust groove and a through hole; the through holes penetrate in the thickness direction of the pattern piece, the auxiliary grooves and the end face exhaust grooves are located in the same end face of the pattern piece, and the auxiliary grooves, the end face exhaust grooves and the through holes are sequentially communicated; an exhaust gap is formed between every two adjacent pattern pieces; the exhaust gap is connected with the inner circumferential face of the tire vulcanization mold and extends in the circumferential direction, and the auxiliary groove and the end face exhaust groove are both communicated with the exhaust gap. Through the arrangement of the exhaust gap, when a tire is manufactured, gas in the inner cavity of the tire vulcanization mold can be fully exhausted in time, and the tire production efficiency is improved; meanwhile, due to the arrangement of the auxiliary grooves, the exhaust gaps are prevented from being stuck with rubber materials, and the service life of the tire vulcanization mold is prolonged.

The invention discloses a four-wheel drive lifting type agricultural universal chassis with an adjustable wheel tread. The four-wheel drive lifting type agricultural universal chassis comprises a frame and four groups of leg-wheel assemblies, the vehicle leg-wheel assembly comprises a vehicle leg assembly, the vehicle leg assembly comprises a vehicle leg support and a wheel assembly, and a lifting adjusting mechanism is arranged between the vehicle leg support and a wheel; the vehicle leg support is in running fit with the vehicle frame through a fixed shaft, wheel track adjusting driving mechanisms are arranged on the vehicle frame in one-to-one correspondence with the vehicle leg assemblies, and the wheel track adjusting driving mechanisms are used for adjusting the wheel track between the wheel assemblies; the lifting adjusting mechanism comprises an electric cylinder and a sliding square tube guide structure, the sliding square tube guide structure comprises an outer square tube fixedly connected to the vehicle leg support and an inner square tube capable of sliding in the outer square tube, one end of the electric cylinder is connected with the vehicle leg support, and the other end of the electric cylinder is connected with a welding plate integrally welded with the inner square tube; a steering execution mechanism is arranged in the inner square tube; the wheel assembly comprises a wheel support and wheels installed on the wheel support, and hub motors are integrated in the wheels to achieve four-wheel independent driving.

The utility model relates to the technical field of tires, and discloses a four-season tire pattern which comprises a tire tread, the whole tire tread is cut through by a herringbone groove, and a reinforcing rib defined by four cylinders is arranged at the center of the herringbone groove. Through unequal numbers of through type inclined grooves and non-through type inclined grooves formed in the central pattern blocks and linear and wavy 3D guide grooves reasonably distributed in the central pattern blocks, the rigidity of patterns can be well balanced, the ground contact area of the tread is increased, and therefore the abrasion performance of the tire is improved, and the service life of the tire is prolonged. According to the tire, the dry ground gripping force and wet ground breaking water film of the tire are ensured, meanwhile, the gripping performance of the tire in ice and snow fields is guaranteed, and the tire patterns are arranged in a multi-layer variable-pitch arrangement mode when the tire patterns are arranged at all the pitches in the circumferential direction of the tread, so that the low-noise characteristic of the tire is achieved; and the center position of the herringbone groove is connected with the pattern block through the reinforcing rib formed by encircling four special cylinders, so that drainage and snow removal are facilitated, and the rigidity of the tread pattern block is ensured.

The invention discloses a preparation method of tread rubber, and belongs to the field of rubber processing. The preparation method comprises the following steps: pretreating aramid pulp, a coupling agent and a lubricant, and then adding the pretreated aramid pulp, the coupling agent and the lubricant into natural rubber to prepare aramid pulp master batch particles; the obtained aramid pulp master batch particles are added into raw materials for preparing tread rubber, and the prepared rubber material has excellent mechanical properties, wear resistance and low rolling resistance. According to the method, the dispersity and interface combination of the aramid pulp in the rubber are remarkably optimized, the comprehensive improvement of the mechanical property, the wear resistance and the rolling resistance of the tread rubber is realized, and the tread rubber has outstanding industrial application value.

The multifunctional deformable composite wheel comprises a hub, a positioning hole is formed in the center of the hub, a wheel face is arranged on the periphery of the hub, the wheel face comprises a plurality of track opening and closing bodies annularly arranged in the circumferential direction of the hub, and the track opening and closing bodies are rotationally connected with the outer end of the hub. A sliding block rocker mechanism is installed between the hub and the track opening and closing body, a power driving rotary disc is further installed on the side face of the hub, and the power driving rotary disc is used for driving the sliding block rocker mechanism to move to drive the track opening and closing body to be opened outwards in the circumferential direction of the hub to be in an inclined state and to be closed inwards in the circumferential direction of the hub to be in an annular state. By the adoption of the composite wheel and the wheel-track deformable structure, the composite wheel has good road holding force, anti-skid performance and obstacle crossing capacity, can be flexibly adjusted, can meet the use requirements of mobile equipment as long as a rolling place is involved, is simple in overall structure and convenient to operate, provides powerful support for development of the mobile equipment, and is worthy of popularization and application. Popularization and application are facilitated.

The invention provides a transporting device for a plastic fishing raft and an operation method of the transporting device. The transporting device comprises a plastic fishing raft body. The rail assembly is fixedly installed on a walkway plate of the plastic fishing raft body through a rail fixing frame, the rail assembly comprises a cross rail and a linear rail which are installed in a crossed mode, and a positioning groove and a climbing block are arranged at the crossed position; the cargo carrying assembly comprises a conveying frame, a handrail and a cargo body, the cargo carrying assembly is movably installed on the rail assembly through a power assembly, the power assembly comprises driving motors symmetrically arranged at the front end and the rear end of the bottom of the conveying frame, and each driving motor drives wheels on a wheel shaft to rotate through a driving gear; the treads of the wheels are matched with the track contact surfaces, and the rims of the wheels are matched with the side edges of the track assembly. The mechanical level of mariculture operation is remarkably improved, and the problems that traditional manual carrying is low in efficiency and poor in safety are solved.

The invention relates to the technical field of wheel performance testing, in particular to a laboratory testing method and system for representing the gripping performance of tire tread rubber on a wetland epoxy floor. According to the method, a thin water film of 10-100 microns is stably maintained on a representative epoxy substrate through online thickness measurement and closed-loop film control, a mu-slip rate curve is obtained at the slip rate of 0.1-10%, mu 0, mu max, delta mu and mu 10% are extracted and are subjected to in-situ fusion with British pendulum BPN under the same substrate and the same film thickness, and a wetland epoxy comprehensive grip index (WEGI) is formed. According to the method, the repeatability under the thin water film working condition and the comparability between laboratories are remarkably improved; embodiments show that the introduction of a small amount of LSBR and fine cutting grooves can synchronously improve [mu] max and BPN, while the repeatability of uncontrolled film, non-representative substrate or real vehicle test is poor. The method is suitable for rapid optimization of a new energy automobile tire tread formula.

The invention relates to the technical field of tire processing, in particular to a pattern and rolling resistance simulation evaluation method and system for a rubber engineering tire. The method comprises the following steps: acquiring tire pattern parameters; building a finite element model of tire-road surface contact according to the tire pattern parameters; according to the finite element model, determining deformation distribution, longitudinal tensile strain, grounding pressure distribution and pavement contact rigidity of the tire in the rolling process; and determining a rolling resistance evaluation value according to the deformation distribution, the longitudinal tensile strain, the grounding pressure distribution and the pavement contact rigidity. And rapid parameterization iteration is supported, and modeling errors caused by non-uniform geometric feature description are avoided. And the simulation accuracy and repeatability are ensured. The influence of the pattern structure on the rolling process is reflected, and a foundation is laid for a rolling resistance evaluation value. Quantitative evaluation of the tire rolling resistance is realized, data-driven design optimization is supported, and the simulation efficiency is improved.

The invention relates to the technical field of tire simulation design, in particular to a method, system and equipment for calculating contribution of tire parts to camber rigidity and a storage medium. The method is based on a finite element model and comprises the following steps: firstly, carrying out two-dimensional axial symmetry modeling and inflation analysis on a tire, rotating to generate a three-dimensional model, then establishing contact with a rigid road surface, applying rated inflation pressure and load, and carrying out steady-state rolling and camber working condition simulation to obtain reference camber rigidity comprising all parts; and then target parts such as a tread, a belted layer and sidewall rubber are selected, the Young modulus of the target parts is reduced to 0.01%-5% of a design value, the analysis is repeated on the premise that the Poisson's ratio of the target parts and other parts and boundary conditions are kept unchanged, and the camber rigidity of the target parts after degradation is obtained. The camber rigidity contribution value and contribution rate of the camber rigidity are calculated by comparing the difference value of the camber rigidity of the two working conditions and combining the occurrence frequency of the target component in the tire structure, and quantitative stripping of the camber rigidity influence of each component is achieved. According to the method, the component-level contribution spectrum can be quickly obtained on the premise of controllable errors, and an effective basis is provided for directional optimization design of the tire camber rigidity performance.

Provided is a method, etc., for estimating uneven tire wear. This tire state estimation method involves: obtaining an image which includes both ends of the tread of a target tire, and captures said tread from the front in a manner such that said tread is continuous in a prescribed direction; inputting the obtained image into a trained first machine learning model; and deriving an output from the trained first machine learning model. Therein, the output of the trained first machine learning model corresponds to the estimation results for the uneven wear of the target tire.

The invention relates to the technical field of tire detection, in particular to a method for identifying abnormal vibration of a tire through color difference of an automobile tire tread, which comprises the following steps: generating a point cloud picture; generating a first tire surface height point cloud picture at the first rotating speed; generating a first visual point cloud picture and determining an abnormal vibration level; dividing detection intervals, wherein n detection point sets are configured in each detection interval; generating a second tire surface height point cloud picture at a second rotating speed; reducing the rotating speed of the tire at a preset rate, calculating a stability score, and judging whether the stability of the detection device meets requirements or not; and in response to the satisfaction, rendering the tire surface to generate a second visual point cloud picture, and determining an abnormal vibration level. According to the method, the height difference of the tire surface height at each detection point position is calculated, and the tire surface is rendered according to the height difference and the preset color matching mechanism, so that the vibration condition caused by the tire surface height can be intuitively and visually displayed.

The invention relates to the technical field of rail transit monitoring, and discloses a multi-sensor fusion rail transit electric passenger car bogie dynamic performance monitoring method. The method comprises the steps that multi-source heterogeneous sensing data such as bogie vibration acceleration time sequence signals, wheel-rail contact force distribution data, bearing temperature gradient data and structural strain field data are collected; analyzing the vibration signal to extract a frequency band energy feature vector, performing spatial gridding mapping on the contact force data to generate a distribution matrix, and performing time-space alignment fusion on the two to form a primary fusion feature set; positioning a bearing temperature anomaly region through a deep convolutional network, and generating a secondary fusion feature set in combination with a structural strain concentration coefficient; and inputting the two-stage feature set into a dynamic performance evaluation model, outputting a performance degradation index set of scores of axle box bearing wear degree, framework fatigue cumulant, wheel set tread damage and the like, generating a maintenance priority sequence and triggering a preventive maintenance instruction according to the performance degradation index set, and realizing accurate monitoring and efficient operation and maintenance management and control of the dynamic performance of the bogie.

The utility model relates to the technical field of tires, and discloses a new energy tire which comprises a tire tread, a plurality of longitudinal grooves and transverse grooves are formed in the tire tread, and first water film breaking units, second water film breaking units and third water film breaking units are arranged in the longitudinal grooves. Through the design that the continuous pattern ribs of the pattern blocks in the center of the tread are connected with the steel sheets, the rigidity of patterns can be well balanced, and the grounding area is increased, so that the abrasion performance of the tire is improved, and the road holding force of the tire is improved; through the design of a plurality of first water film destroying units, a plurality of second water film destroying units, a plurality of third water film destroying units and self-flow-guiding patterns in the longitudinal grooves of the tire, the wet land safety of the tire can be obviously improved, and the rigidity of the shoulder pattern blocks can be guaranteed through a plurality of transverse steel sheets arranged in the shoulder pattern blocks of the tire; and the characteristic of low noise of the tire can be realized by coping with the instantaneous torque of the new energy automobile and improving the instantaneous road holding force and adopting a multi-layer variable-pitch arrangement mode.

The invention discloses a wheel rolling mill guide roller assembly, and belongs to the technical field of steel wheel manufacturing, the wheel rolling mill guide roller assembly comprises a guide sleeve, a guide shaft arranged in the guide sleeve in a penetrating manner, and guide plates fixedly arranged at the inner end of the guide shaft, the two guide plates are obliquely and symmetrically arranged, and sliding blocks are arranged on the inner side faces of the guide plates in the vertical direction in a sliding manner; the upper end faces of the sliding blocks are rotationally connected with guide rollers. When the wheel hot rolling device is used, the tread of a wheel is in contact with the sensing device when the wheel is subjected to hot rolling; the thickness of the wheel is reduced, so that the diameter of the wheel is increased, the diameter of the wheel is increased, the stepping face of the wheel presses the induction device downwards, the induction device moves downwards to drive the two sliding blocks to move downwards, the two sliding blocks slide downwards along the inclined face of the guide plate, and meanwhile the two sliding blocks move close to each other; and then the two guide rollers are driven to move towards the middle so as to compensate gaps between the guide rollers with the thinned wheel thickness and the side faces of the wheels, and clamping of the guide rollers to the side faces of the wheels is kept.

A flooring panel comprising a first end, a second end opposite the first end, and an axis extending between the first end and the second end. A tread portion extends between the first and second ends, the tread portion configured to be coupled to a tread of a stair. A curved cap is integrally formed with the tread portion and extends between the first end and the second end, the curved cap configured to be coupled to an edge of the stair. A plurality of grooves is formed in an inner surface of the curved cap, the plurality of grooves extending parallel to the axis of the tread portion, the plurality of grooves extending along a majority of inner surface of the curved cap. A cover member is adhesively coupled to the inner surface and covering the plurality of grooves.