Patent Publication Number: US-2021164854-A1

Title: Smart bicycle wheel sensor system

Description:
1. PRIORITY CLAIM 
     This application claims priority to and the benefit of U.S. patent application Ser. No. 16/534,642 filed on Aug. 7, 2019, which claims priority to U.S. Provisional Application No. 62/715,291, which was filed on Aug. 7, 2018, the contents of which are hereby incorporated by reference. 
    
    
     2. BACKGROUND 
     The disclosed embodiments relate to vehicle sensor systems. More specifically, the disclosed embodiments relate to bicycle sensors and particularly to wheel bicycle sensors. 
     Cycling is an enjoyable pastime for both the casual and professional rider. Riders of almost all skill levels have more and more access to data to help them become better riders. For example, smartphones or other GPS devices may be used when cycling to track speed, distance, elevation change, split times, and the like. Heart rate monitors may also be used to monitor the user&#39;s conditioning during one or more rides. 
     However, some information that riders may be interested in is not currently available to them. These conditions include data that may only be obtained from the inside of a bicycle tire on a bicycle wheel. For example, while air pressure may be detected at a valve stem, this requires opening the valve. Thus, while a reading may be obtained, pressure may also be lost while the valve is opened to obtain the reading. Furthermore, any pressure changes during a ride cannot be obtained. Other environmental factors within the tire or wheel data may also be of interest to enhance the riders training or to add to the safety of the rider. 
     Accordingly, a system or device to obtain data from the inside of a bicycle tire during a ride is desired. 
     SUMMARY 
     A bicycle wheel sensor is provided and includes a housing configured to be disposed at least partially within a tire of a bicycle wheel. In some instances, it is beneficial to mount the bicycle wheel sensor opposite a valve stem location to help balance the bicycle wheel. The bicycle wheel sensor has one or more sensors that is exposed to the inside of the tire and is configured to provide data obtained from within the tire. The bicycle wheel sensor includes an electronic control unit that receives the data from the sensors and transmits the data to a user device via a transceiver. 
     In some embodiments, the housing is configured to be mounted at a spoke hole. The housing may be shaped to extend along the wheel from the spoke hole to at least a point on the bicycle wheel opposite the valve stem location. The housing may further comprise one or more balancing weight mounts configured to receive balancing weights. The housing may also have an elongated hole to facilitate adjustable positioning of the housing to the bicycle wheel at the spoke hole opposite the valve stem location. 
     In some embodiments, the one or more sensors comprise a pressure sensor and an accelerometer. Other sensors may also be used such as a gyroscope, humidity sensor, and thermometer. The transceiver may be configured to communicate according to one or more known wireless standards such as Bluetooth Low Energy and ANT+ protocols. 
     In some embodiments, the housing of the bicycle wheel sensor comprises a flanged portion on a front end thereof. A rear end of the housing may extend through an opening in the rim between spoke holes which are on the rim. The opening may be disposed opposite a valve stem of the bicycle wheel so that the bicycle wheel sensor may aid in balancing the wheel. 
     The flanged portion may include an aperture exposed to the enclosed area. A pressure sensor and/or other sensors may be disposed within the aperture. The flanged portion may be hermetically sealed to an outer rim wall of the bicycle wheel rim. 
     In some embodiments, the bicycle wheel sensor comprises a charge port disposed on an inner rim wall of the bicycle wheel rim. This allows access to the sensor to charge the sensor without disassembling the bicycle wheel. The housing may be comprised of a top housing and a bottom housing, the top housing and the bottom housing being hermetically sealed to one another. The flanged portion may include through holes to receive fasteners to attach the flanged portion to the bicycle wheel rim. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. In the figures, like reference numerals designate corresponding parts throughout the different views. 
         FIG. 1  shows an example of a bicycle wheel and tire. 
         FIG. 2A  shows an enlarged portion of a bicycle wheel without a tire and showing a bicycle wheel sensor device, according to one exemplary embodiment;  FIG. 2B  shows a cross-section view of a bicycle tire and a bicycle wheel sensor device, including an attachment device for the bicycle wheel sensor; and  FIG. 2C  shows a perspective cross section of the bicycle wheel with the bicycle wheel sensor. 
         FIG. 3A  shows a perspective view of the bicycle wheel sensor, according to one exemplary embodiment;  FIG. 3B  shows a top view of the bicycle wheel sensor in  FIG. 3A ; and  FIG. 3C  shows a side view of the bicycle wheel sensor of  FIG. 3A . 
         FIG. 4  shows an attachment bolt for a bicycle wheel sensor, according to one exemplary embodiment. 
         FIG. 5  shows a gasket for installing a bicycle wheel sensor, according to one exemplary embodiment. 
         FIG. 6  shows a schematic of a bicycle wheel sensor, according to one exemplary embodiment. 
         FIG. 7A  shows a front view of a bicycle wheel sensor, according to one exemplary embodiment;  FIG. 7B  shows a rear perspective view of the bicycle wheel sensor of  FIG. 7A ; and  FIG. 7C  shows a top view of the bicycle wheel sensor of  FIG. 7A . 
         FIG. 8A  shows an enlarged view of a bicycle wheel,  FIG. 8B  shows an exemplary embodiment of a bicycle wheel sensor installed on a bicycle wheel, and  FIG. 8C  shows a cross-section of a bicycle wheel with the bicycle wheel sensor installed. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       FIG. 1  shows an example of a bicycle wheel and tire. A typical bicycle wheel and tire  10  includes a rim  12  formed in an annular shape that provides structure to the overall wheel. Spokes  14  extend from a hub  16  to provide rigidity to the wheel. The hub  16  includes an axle which is mounted to a bicycle frame. A tire  18  is fitted over the rim  12  and provides the riding interface with the ground for the bicycle. Tires  18  are typically formed from a rubber or synthetic rubber material. The rim  12  and tire  18  may be part of a tubeless system, or a tube may be inserted into the tire  18 . 
     The wheel  10  in a tubeless system or the tube in a tubed system includes a valve stem  20 . The valve stem  20  allows air or another fluid to be inserted into the tire  18  (or tube within the tire). 
       FIG. 2A  shows an enlarged portion of a bicycle wheel without a tire and showing a bicycle wheel sensor device, according to one exemplary embodiment. As shown in  FIG. 2A , the spokes  14  are connected to the rim  12  via the spoke nipples  202 . The spoke nipples  202  may also be used to true the rim  12  to ensure the roundness and runout of the rim  12 . 
     A bicycle wheel sensor  300  is positioned on an outer surface of the rim  12 . Preferably, the bicycle wheel sensor is positioned such that it serves to balance the wheel  10 . Thus, the bicycle wheel sensor  300  is configured so that its position may be adjustable along the rim  12 . The weight of the bicycle wheel sensor  300  may also be adjusted as will be explained in more detail below. 
     In order balance the wheel  10 , the bicycle wheel sensor  300  may be placed opposite the valve stem  20  to counterbalance the added weight of the valve stem  20 . However, typically the valve stem  20  is located between two spokes, and thus the area opposite valve stem  20  on the rim where the counterbalance is needed is also between two spokes. In this embodiment, to mount the bicycle wheel sensor  300  to the rim, it is preferable to access the rim from a spoke hole. Thus, as shown in  FIG. 2A , the bicycle wheel sensor  300  has a mount on one side of the bicycle wheel sensor so that the bicycle wheel sensor extends from the mount that corresponds to a spoke over the area that is opposite the valve stem. Thus, the bicycle wheel sensor  300  can provide balance to the wheel while being mounted at a spoke hole in the rim  12 . 
       FIG. 2B  shows a cross-section view of a bicycle tire and a bicycle wheel sensor device, including an attachment device for the bicycle wheel sensor; and  FIG. 2C  shows a perspective cross section of the bicycle wheel with the bicycle wheel sensor. As shown in  FIGS. 2B and 2C , some rims  12  include an inner rim wall  206  and an outer rim wall  208 . A spoke hole  204  is disposed within the inner rim wall  206 . A nipple of a spoke  14  seats at the spoke hole  204  so the spoke  14  does not need to be removed to access the outer rim wall  208  or a spoke access hole  210 . 
     The bicycle wheel sensor  300  may be mounted to the outer rim wall  208  so that it is disposed in the enclosed area between the rim  12  and the tire  18 . Here, the bicycle wheel sensor  300  may measure conditions in the space enclosed by the rim  12  and the tire  18 . The bicycle wheel sensor  300  is mounted to the rim  12  via a bolt  400 . The bolt  400  may secure the bicycle wheel sensor  300  via a nut  220 . The bolt  400  extends through a spoke access hole  210  which serves as a mounting aperture within the outer rim wall  208 . A gasket  500  is provided to seal the spoke access hole  210  when the bicycle wheel sensor  300  is tightened against the rim  12  by the bolt  400  and nut  220 . 
     Of course, other methods may also be used to mount the bicycle wheel sensor  300  such that the bicycle wheel sensor may be positioned within the enclosed area between the rim  12  and the tire  18 . For example, other types of fasteners other than the bolt  400  and nut  220  may be used such as screw, rivets, etc. The fasteners may be attached at any position along the rim  12  in addition to being placed at a spoke access hole  210  as described above. 
     In one embodiment, an adhesive may be used to adhere the bicycle wheel sensor  300  to the outer wall  208  of the rim or to an inner surface of the tire  18 . In another embodiment, the bicycle wheel sensor  300  may be built into or encased in a rim strap that is placed around the outer wall  208  of the rim  12 . As another alternative, the bicycle wheel sensor  300  may be encased in expandable foam that is secured between the rim  12  and the tire  18 . The bicycle wheel sensor  300  may be built into or encased on a tire tube&#39;s interior or exterior. The bicycle wheel sensor  300  may also be attached to the valve stem internally or externally. 
       FIG. 3A  shows a perspective view of the bicycle wheel sensor, according to one exemplary embodiment;  FIG. 3B  shows a top view of the bicycle wheel sensor in  FIG. 3A ; and  FIG. 3C  shows a side view of the bicycle wheel sensor of  FIG. 3A . The bicycle wheel sensor  300  comprises a housing  301 . The housing  301  includes a top side  302 , a bottom side  304 , a first end  306 , a second end  308 , a first side  310 , and a second side  312 . The housing  301  is formed with a curvature to match the frame  12  of a bicycle wheel  10  as shown in  FIG. 2A . That is, as best seen in  FIG. 3C , the top surface  302  and the bottom surface  304  have a radius of curvature to match a wheel on which the bicycle wheel sensor  300  is mounted. For example, the radius of curvature of the bottom surface  304  may match a  700 C wheel, or any other wheel as desired. 
     An elongated through-hole  314  runs partially along the length of the housing  301  from the top surface  302  to the bottom surface  304 . The elongated hole  314  is positioned on one side of the housing  301 . As shown, the positioning of the elongated hole  314  is closer to the second end  308  than the first end  306 , although the elongated hole  314  could be positioned at either end. The elongated hole  314  allows the position of the mounting of the bicycle wheel sensor  300  to be adjusted so that the wheel  10  can be balanced. As explained above, the bicycle wheel sensor  300  is disposed on the wheel  10  opposite the valve stem  20  to balance the wheel  10 . The elongated hole  314  is aligned with a spoke hole  204  almost opposite the valve stem  10 . The placement of the elongated hole  314  near the end  308  of the housing  302  allows the housing  301  to extend along the wheel so that at least a portion of the housing  301  is opposite the valve stem  20 . The balance of the wheel  10  may be achieved at least in part by fine tuning the positioning of the housing  301  on the wheel  10  via the elongated hole  314 . 
     The housing  301  further comprises one or more holes  316  in the top surface  302  of the housing  301 . The holes  316  serve as balancing weight mounts and may receive balancing weights (not shown) to further help precisely balance the wheel. In the figures, there are three holes  316  disposed on an opposite end of the housing  301  from the elongated hole  314 . However, any number and arrangement of holes may be used. Preferably, the holes  316  are positioned such that when the housing is mounted on a wheel, at least one of the holes  316  will be directly opposite the stem valve  20  on the wheel  10 . 
       FIG. 4  shows an attachment bolt for a bicycle wheel sensor, according to one exemplary embodiment. A bolt  400  is used to mount the bicycle wheel sensor  300  to the wheel  10  as shown in  FIG. 2A-2C . The bolt  400  may include a head  402  having wings  404  to provide tension on the rim when the nut  220  is tightened to hold the sensor  300  in place on the rim  12 . There are three wings  404  shown in  FIG. 4 , but any number of suitable wings  404  may be used. The bolt  400  also comprises a threaded portion  410  extending to a distal end  412 . 
     To ensure that the wheel  10  and tire  18  remain air tight, a grommet or gasket  500  is provided.  FIG. 5  shows a gasket for installing a bicycle wheel sensor, according to one exemplary embodiment. The gasket  500  comprises a first end  503  and a second end  504 . The gasket  500  is formed in a flat conical shape where an area of the bottom end  504  is less than an area of the top end  503 . An annular sidewall  506  extends from the first end  503  to the second end  504 . A through hole  508  is provided that runs from the first end  503  to the second end  504  to accommodate the bolt  400  ( FIG. 2B-2C ). The gasket  500  is formed from a resilient material that deforms to seal against surrounding surfaces when placed under compression. For example, the gasket  500  may be formed from a natural or synthetic rubber material. 
       FIG. 6  shows a schematic of a bicycle wheel sensor, according to one exemplary embodiment. In  FIG. 6 , a bicycle wheel sensor  600  may be similar to the bicycle wheel sensor  300  shown in  FIGS. 3A-3C . In order to provide relevant information to a bicycle rider, the bicycle wheel sensor  600  comprises a plurality of components. The components are controlled by an electronic control unit (“ECU”)  602 . The ECU comprises a wireless module  604  that controls wireless communication to and from the bicycle wheel sensor  600 . The wireless module  604  may be configured to process communications in any desired communication protocol. For example, the wireless module  604  may be configured according Bluetooth Low Energy and/or ANT+ wireless protocols. 
     The ECU  602  further comprises a processor that communicates with the other components of the bicycle wheel sensor  600 . The processor  604  may comprise any type of processor or controller capable of performing as described herein. The processor  604  may comprise a general-purpose microprocessor or microcontroller, ASIC, DSP, or any other type of processing device. 
     The ECU  602  may also include one or more memories  608 . The one or more memories  608  are part of the bicycle wheel sensor  600  for storage of machine readable code for execution on the processor  606  and for storage of data, such as sensor data, user data, accelerometer data, or any other type of data. The memory  608  may comprise RAM, ROM, flash memory, optical memory, or micro-drive memory. The machine-readable code as described herein is non-transitory. 
     The ECU  602  and other elements of the bicycle wheel sensor  600  receive power from a battery  620  or other similar power source. A charge controller  622  controls power delivery to the battery and may provide one or more electrical ports to electrically interface with the bicycle wheel sensor  600 , such as with a second electronic device, computer, or a power supply/charging device. In some embodiments, the charge controller  622  may facilitate wireless charging, such as through inductive charging. 
     As part of this embodiment, the ECU  602  connects to a user interface  614 . The user interface  614  may comprise any system or device configured to accept user input to control the bicycle wheel sensor  600 . For example, the user interface  614  may comprise one or more buttons  616  to control the functionality of the bicycle wheel sensor  600 , such as to pair the bicycle wheel sensor  600  with a mobile device via one or more communication protocols, such as Bluetooth Low Energy or ANT+. The user interface  614  may also comprise one or more LEDs  618  or other indicator to provide status feedback to the user, such as a connection status or low battery indicator. 
     Also connected to the ECU  602  is a wireless transceiver  610  which connects to a respective antenna  612 . The transceiver  610  is configured to receive incoming signals from a remote transmitter and perform analog front-end processing on the signals to generate analog baseband signals. The incoming signal may be further processed by conversion to a digital format, such as by an analog to digital converter, for subsequent processing by the ECU  602 . Likewise, the transceiver  610  is configured to receive outgoing signals from the ECU  602 , or another component of the bicycle wheel sensor  600 , and up convert these signals from baseband to RF frequency for transmission over the antenna  612 . Although shown with one transceiver  610 , it is contemplated that the bicycle wheel sensor  600  may have two or more transceivers. For example, some devices are tri-band or quad-band capable. 
     It is contemplated that the bicycle wheel sensor  600 , and hence the wireless transceiver  610 , may be configured to operate according to any presently existing or future developed wireless standard including, but not limited to, Bluetooth Low Energy, ANT+, ISM, Wi-Fi such as IEEE 802.11 a,b,g,n, wireless LAN, WMAN, broadband fixed access, WiMAX, any cellular technology including CDMA, GSM, EDGE, 3G, 4G, 5G, TDMA, AMPS, FRS, GMRS, citizen band radio, VHF, AM, FM, UHF, and wireless USB. 
     Also, part of the bicycle wheel sensor  600  is one or more systems which are connected to and interface with the ECU  602 . A pressure sensor  630  is provided to measure the internal air pressure of the bicycle wheel. The pressure sensor  630  is configured to be durable to withstand tire sealants or the like which may be introduced inside the tire or tube of the bicycle wheel. 
     A thermometer  632  may also be provided to connect to the ECU  602  and track an internal temperature of the wheel. The outputted temperature may help to identify overheating due to braking or other abnormalities occurring on the wheel. An accelerometer  634  connects to the ECU  602  to provide information or data regarding shocks or forces experienced by the bicycle wheel. In some embodiments, the accelerometer  634  may measure centrifugal forces (inertial forces) and tangential forces which may indicate a rotational speed of the bicycle wheel. A magnetometer  638  is provided to provide directional information for the bicycle wheel sensor  600 . A gyroscope  640  connects to the ECU  602  to generate and provide orientation data regarding the orientation of the bicycle wheel sensor  600 . In one configuration, the accelerometer  634 , magnetometer  638 , and gyroscope  640  generate and provide data to the ECU  602  to indicate speed data for the bicycle wheel. Voltage and/or current sensors  642  are also provided to monitor a power level of the battery  620 . 
     Once the bicycle wheel sensor  600  is installed onto a bicycle wheel as described above, the bicycle wheel sensor  600  may be used to monitor the inside of a bicycle tire and provide relevant data to the user. The user may connect or “pair” a mobile device to the bicycle wheel sensor  600  before or after installation on the bicycle wheel. The connection is a wireless connection via known communication protocols such as Bluetooth Low Energy or ANT+. 
     During operation of the bicycle, the bicycle wheel sensor  600  may collect data from one or more of the systems installed on the bicycle wheel sensor  600  at predetermined time intervals. The data is collected by the ECU  602  and is transmitted to the user&#39;s mobile device via the transceiver  610 . Such data may include internal pressure and humidity information indicating a condition/health of the tire, speed data based on the rotation of the wheel, and other relevant information. 
       FIG. 7A  shows a front view of a bicycle wheel sensor, according to one exemplary embodiment;  FIG. 7B  shows a rear perspective view of the bicycle wheel sensor of  FIG. 7A ; and  FIG. 7C  shows a top view of the bicycle wheel sensor of  FIG. 7A . A bicycle wheel sensor  700  may be similar to the bicycle wheel  600  and may include some or all of the same features and components as described above with reference to  FIG. 6 . 
     The bicycle wheel sensor  700  may be formed as a two-part construction with a top housing  720  and a bottom housing  730 . The top housing  720  may be fastened to the bottom housing  730  via any suitable manner such as via adhesives, a snap-fit, fasteners, or the like. In some embodiments, the interface between the top housing  720  and the bottom housing  730  is hermetically sealed. The top and bottom housing  720 ,  730  may be configured to house the various internal components of the bicycle wheel sensor, such as ECU  602 , battery  620 , and the other components shown in  FIG. 6 . 
     While the two-part construction in shown in the embodiment and allows for ease of assembly during manufacturing, other constructions are also possible. For example, the bicycle wheel sensor  700  may be formed as a single housing with a hinged door to provide access to the interior of the housing. 
     On a front side  702  of the bicycle wheel sensor  700 , the top housing  720  and the bottom housing  730  form a mounting flange  740 . The mounting flange  740  includes two apertures  722 ,  732  formed toward a first side  706  of the bicycle wheel sensor  700  and another two apertures  722 ,  732  formed on the second side  708  of the bicycle week sensor  700 . The apertures  722 ,  732  are formed in overhangs  742 ,  746  of the mounting flange  740 . The mounting flange  740  has a radius of curvature equal to that of the outer rim wall  208  of the bicycle wheel rim  12  (see  FIG. 2C ). The apertures  722 ,  732  and the radius of curvature facilitate the installation of the bicycle wheel sensor  700  to the rim  12 , as will be described in more detail below. 
     As shown in  FIG. 7A , the front  702  of the bicycle wheel sensor  700  comprises an opening  750 . The opening exposes at least a portion of the interior of the bicycle wheel sensor  700  to the environment surrounding the opening  750 . For example, within the opening  750  is a pressure sensor  752 . The pressure sensor  752  may be similar to pressure sensor  630  described above. 
     In one embodiment, as shown in  FIGS. 7B and 7C , the bicycle wheel sensor  700  may include external wiring  760  extending from a rear side  704  of the bicycle wheel sensor. The wiring  760  may facilitate the charging of a battery such as battery  620 . 
       FIG. 8A  shows an enlarged view of a bicycle wheel,  FIG. 8B  shows an exemplary embodiment of a bicycle wheel sensor installed on a bicycle wheel, and  FIG. 8C  shows a cross-section of a bicycle wheel with the bicycle wheel sensor installed. In this embodiment, to install the bicycle wheel sensor  700 , an opening  802  may be formed in the outer rim wall  208  of the rim  12  of the bicycle wheel  10 . The opening  802  may be advantageously placed at a position directly opposite the valve stem  20  (see  FIG. 1 ) of the wheel  10  between two spoke holes  210 . To facilitate the fit of the bicycle wheel sensor  700 , a flat shoulder  804  may be machined in the outer rim wall  208 . In some embodiments, instead of the opening  802  and shoulder  804  being machined from a rim  12 , the rim may be formed with the opening  802  and shoulder  804 . 
     As shown in  FIGS. 8B and 8C , the bicycle wheel sensor  700  may be disposed within the opening  802 . Specifically, the rear end  704  of the bicycle wheel sensor  700  is inserted into the opening  802  and back surfaces  744 ,  748  of the flange  740  is configured to rest on the shoulder  804 . Fasteners (not shown) may be used to secure the flange  740  to the outer rim wall  208 . Further, a sealing material  810  may be provided on the back surfaces  744 ,  748  to create a hermetic seal between the back surfaces  744 ,  748  and the outer rim wall  208 . For example, a resilient sealing material  810  such as rubber may be adhered to the back surface  744 ,  748  that seals against the outer rim wall  208  upon the tightening of the fasteners to force the flange  740  against the outer rim wall  208 . Other sealing methods and materials may also be used as are now known or may be later developed. 
     Similar to the sensor  300 , the bicycle wheel sensor  600  allows for direct sensor exposure and measurement of conditions within a tire  18  of a bicycle wheel  10 . With the sensor  700  installed as shown in  FIGS. 8B and 8C , the opening  750  faces the space between the outer rim wall  208  and the inside of the tire  18 . Thus, the sensors in the bicycle wheel sensor  700 , such as a pressure sensor  752  may directly and in real time measure the conditions within the tire. 
     In some embodiments, the wiring  760  may attach to a port  820  installed on an inner wall  206  of the rim  12  to facilitate charging of the sensor  700  without the need to disassemble the wheel  10 , as shown in  FIG. 8C . For example, a USB charge port  820  may be disposed on the inner wall  206  to which the wiring  760  connects. Thus, when the wheel  10  is not in use, the user may attach a power source to the USB charge port  820  to charge a battery within the sensor  700 . Of course, the USB charge port  820  is merely exemplary and other charge ports according to various specifications may also be used. 
     In some embodiments, the distance between the outer rim wall  208  and inner wall  206  may not be sufficient to fully house the sensor  700 . In such cases, a second opening may be formed in the inner wall  206  to accommodate the sensor  700 . When the rear  704  of the sensor extends through the inner wall  206 , the charge port  810  may be disposed in one of the top and bottom housings  720 ,  730  in place of the wiring  760 . 
     The bicycle wheel sensor as disclosed herein allows the user to obtain real time information from the inside of a bicycle wheel. Furthermore, the bicycle wheel sensor does not add significant weight to the bicycle, and further serves to balance the wheel. Thus, the bicycle wheel sensor provides a better ride while simultaneously providing useful information to the user concerning the condition of the bicycle wheels. 
     While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of this invention. In addition, the various features, elements, and embodiments described herein may be claimed or combined in any combination or arrangement.