Abstract: Embodiments of golf club heads having a hydrophobic surface and methods to manufacture such golf club heads are generally described herein. The golf club heads are configured to comprise a ball-striking face and at least two channels formed therein. The channels are separated by a land portion of the ball-striking face extending therebetween. The land portion is associated with at least a first step portion extending at a first elevation and a second step portion extending at a second elevation, the second elevation being higher than the first elevation relative to a bottom of the channels. Each of the first and second step portions is so dimensioned as to be associated with a substantially hydrophobic contact angle.

Abstract: Some embodiments include a club head for adjusting vertical spin of a golf ball. Other embodiments of related systems and methods are also disclosed.

Abstract: A telescoping golf ball tee with an internal locking mechanism is provided. The internal locking mechanism permits the golf ball tee neck to adjust to a desired height while still supporting the weight of a golf ball. Upon impact, a bowl-like member at the base of the golf ball tee neck is forced into a cavity in the golf ball tee base which, in turn, applies force to the golf ball tee neck which prevents the neck from escaping the base.

Abstract: A golf tee dispenser is configured to provide a single tee for retrieval when the golf tee dispenser is agitated. A golf tee dispenser has a deflector to deflect a plurality of tees away from a tee-opening to increase the effectiveness of the tees being extended through the tee opening upon agitation. A golf tee dispenser also has a resilient retainer that is configured to retain a tee by a tee-head until the tee is pulled from the tee dispenser. A resilient retainer is configured to deform or deflect to allow the tee head to pass through the resilient retainer and then return substantially to a pre deformed state. A golf tee dispenser is configured to hold a plurality of tees in a container and a cap is configured to attach to a container opening.

Abstract: A system for fitting golf clubs to golfers that enables an overall club length to be varied without varying a length of a shaft. The system enables a greater number of combinations of club characteristics, such as shaft flex, brand, and length, to be contained within a club fitting cart and/or for a same number of combinations of club characteristics to be contained within a smaller cart.

Abstract: A catching game that is challenging even when played by one player. The catching game is a paddle-sized hand-held device that preferably incorporates an automatic launcher and an adjustable aperture catcher on the same hand-held device. The automatic launcher incorporates randomness into the launching mechanism, in order to increase the challenge to the player(s). The game also incorporates an electronic sensor to determine when a catch has been made.

Abstract: A lightweight sweet spot trainer includes a sleeve that is slipped over the barrel end of any bat. The sleeve covers the barrel over the primary contact area of the bat. The sleeve holds a force sensor placed inside it such that, when slid over the bat, the force sensor is coincident with the sweet spot of the bat. When a ball comes in contact with the sweet spot, the force sensor directly beneath it is triggered such that instantaneous feedback is given to the athlete thereby making him/her aware of accurate sweet spot contact. Moreover, an array of cylindrical contact/force sensors can be positioned such that the user gets feedback that would depend on how far from the sweet spot the user strikes/contacts the ball. The user may be notified by audio, visual, or sensory cues.

Abstract: A sporting device designed to help improve and teach a person as well as a trainer the correct wrist snap motion for playing many sports. This device is comprised of an adjustable wrist band that will adjust to the person's lower ulna and radius bones. with a resistance, adjustable strap around the finger/knuckle that connects from the finger/knuckle to the wrist strap. This device has an audible unit and can also have a vibration attachment as well as a counting attachment added to the wrist strap for different uses in sports or physical therapy. When the trainee is training they will make the same motion they would when they are playing said sport. This device can be set at a desired level of resistance and distance for desired wrist snapping motion. The trainee or trainer can set the desired wrist snapping motion for the device objective. When the objective is achieved the unit will respond with either a sound and or a vibration to indelicate that the desired motion was reached.

Abstract: A golf swing plane training aid device for use with a golf club is presented. The training aid device includes an ellipsoid shaped body having two reference endpoints and two forearm guides adapted to fit forearms of a golfer. The golf training aid device provides a visual reference and aids the forearms of the golfer in the proper swing position along the swing plane and a target line by guiding the forearms and using the reference endpoints as visual feedback aid to determine point of reference along the target line.

Abstract: A striking bag features a resiliently flexible foam tube, and a striking surface that is connected to an end of the flexible tube to hang therefrom in an exposed position strikeable from below. A threaded rod projects from an upper end of the flexible tube for coupling with a surface mount that is fastened to a ceiling or other suitable overhead surface. The surface mount features a rigid portion into which the threaded rod is threaded. The foam of the tube and the threaded rod solely define a resiliency by which the tube flexes and returns to a normal straight position relative to the ceiling mount. A fabric loop at a bottom of the striking surface allows selective connection of a stretchable tether between the striking surface and a ground based tether point to change a responsive character of the striking bag and enable two distinctive modes of use.

Abstract: A synthetic putting green includes a crown, skirt and trough. The putting green includes a support surface shaped to define a crown, a skirt circumferentially positioned about the crown and a trough circumferentially positioned about the skirt. Landscape edging is applied to the support surface about a perimeter of the crown so as to define an interior space functioning as a putting surface. A containment layer is applied upon the support surface within the interior space and an open cell foam material applied over the containment layer within the interior space. A layer of synthetic turf is then applied to cover the containment layer and the open cell foam material within the interior space. A method for making the synthetic putting green is also disclosed.

Abstract: A racket-free tennis training device includes a maneuverable platform on which an elevation mechanism is mounted. A ball receiving and shooting mechanism is mounted on the elevation mechanism. The ball receiving and shooting mechanism includes a ball receiving mechanism, a ball management mechanism, and a ball shooting mechanism. The ball receiving mechanism includes a ball receptacle. The ball management mechanism includes a ball collection barrel and an advancing mechanism. The above arrangement allows for correctly receiving a tennis ball from an opponent site and then serving a ball to the opponent site to simulate an actual tennis game.

Abstract: A free weight organization system is described that prevents misplacement of the free weight plates on the weight rack. The system includes weight plates with recesses and keyed weight rack posts with corresponding projections. The placement of the recesses varies from one size of weight plate to another, preventing a weight plate of the wrong sized being placed on a rack post of the weight rack. The weight plates may also include a loading rest recess, with the keyed rack posts having a loading rest rod to assist in the correct placement of the plates on the rack.

Abstract: An automated officiating and player development system for a game played on a court with a net. The system utilizes arrays of optical imaging devices that are positioned near the net and face outwardly toward the two halves of the court. Each of the arrays scan across the court in two scan fields, wherein a first scan field projects across the court in an area below the an elevated second scan field. The second scan field is positioned a few inches above the first scan field. In this manner, any object that contacts the court from above must pass through both the first scan field and the second scan field. Separate arrays of optical detecting devices are positioned along the net. All the arrays produce pixilated images of any object they scan. A processor analyzes the pixilated images to identify the pixilated images of the detected objects.

Abstract: The invention relates to a sporting device (1), in particular a touring ski assembly. The sporting device (1) comprises a sliding body (2) on which a bottom side (3) is designed as a sliding surface (4). Furthermore, the sporting device (1) comprises a binding apparatus (6) disposed on the top face (5) of the sliding body (2) for fastening to a sporting shoe (7) of a user (8) in such a way that the fastening can be released as and when necessary, a circulating belt (13) having a first segment (14) for establishing a relative motion between the sliding body (2) and the ground (12) and a second, returning segment (15), as well as a drive apparatus (17) and at least one first deflecting apparatus (18) for the belt (13). The first segment (14) is disposed next to the bottom side (3) of the sliding body (2) and the second, returning segment (15) is disposed next to the top face (5) of the sliding body (2).

Abstract: A running surface for a ski having a running surface profile that has slideback prevention elements with sliding surfaces which slope up counter to a sliding direction and merge into push-off flanks. The slideback prevention elements have at least one first ramp element having a longitudinally convexly curved sliding surface with a first radius of curvature (r1) and at least one second ramp element. The the second ramp element has a longitudinally convexly curved sliding surface with a second radius of curvature (r2) which is greater than that of the first ramp element.

Abstract: A binding strap assist mechanism. The binding strap assist mechanism can be retrofitted onto standard snowboard binding straps to bias the binding straps into the open configuration, thus guiding the straps way from the foot area of the binding. Binding straps pass through the binding strap assist mechanism so that tensile forces along the length of each of these binding straps during use is not significantly conveyed to the binding straps assist mechanism. The tensile forces are thus isolated to the binding straps which are intended to carry such forces. The present invention provides a safe and convenient feature to snowboard bindings and other bindings. If the binding strap assist mechanism breaks or fails to function, the binding straps will continue to function as normal, resulting in no safety concerns to user.

Abstract: A detachable chair lift leg rest is disclosed. The leg rest includes a lower attachment member and an upper attachment member which are removably secured to the shaft of a ski pole. The disclosure also includes a hanger that is either permanently or removably secured to a ski boot. In one embodiment, lightweight hooks, are spaced apart so that when a skier is on a chairlift, the lower hook is parallel to the ski boot and the upper hook is at the correct height to attach to the chairlift's restraint bar creating a ninety degree angle between the skier's knees and their torso. The lower engagement member is hooked to the hanger on the ski boot and the upper engagement member is engaged with the restraint bar of the chair lift. The ski pole with the upper and lower engagement members affixed allow the weight of the skier's legs, boots, and skis to hang from the restraint bar thereby reducing the strain on the skier's body, specifically the skier's knees.

Abstract: A wheel for a skateboard may include a bearing assembly, an annular rim coupled to and extending annularly around the bearing assembly, and a tapered tire portion coupled to and extending annularly around the annular rim. A dual wheel assembly may include a first wheel disposed on a longitudinal end portion of an axle, a spacer disposed on the longitudinal end portion of the axle adjacent to the first wheel and abutting against the first wheel, and a second wheel disposed on the longitudinal end portion of the axle adjacent to the spacer and abutting against the spacer. A method of making a dual wheel assembly may include disposing a first wheel on an axle, disposing a spacer on the axle adjacent to the first wheel, and disposing a second wheel on the axle adjacent to the spacer.

Abstract: A billiard rack is provided that includes a frame that extends around an interior space that is configured to receive a set of billiard balls resting on a bed of a billiard table. A bottom side of the frame includes a lower opening in which the upper portions of the set of billiard balls are able to extend therein. The frame also includes an inner wall having at least one cam surface that extends at least partially around the interior space and that tapers inwardly in directions from the lower opening to an upper opening. When the frame is placed on the set of billiard balls resting on the bed of the billiard table, the at least one cam surface is configured to contact all of the peripheral billiard balls of the set of billiard balls; and urge the set of billiard balls together without the rack contacting the billiard table.

Abstract: A ball delivery device, system, and method housing a plurality of balls for a game session is presented. The ball delivery device includes a mixing chamber, at least one instruction to start the game session, an identifier, at least one arm, a ball holder, a reader and a tube. The mixing chamber receives the balls for the game session. After receiving an instruction to begin the game session, balls are singly drawn from the mixing chamber. The identifier disposed on each ball uniquely identifies each ball. The arm mixes the balls in the mixing chamber. The ball holder disposed on the arm holds a single ball that is randomly selected from the mixing chamber. The reader reads the identifier of the ball selected by the ball holder. The tube receives each selected ball and holds the selected balls after the identifier reads the ball and until completion of the game session.

Abstract: A wheel assembly for a rotary shuffling device includes a fixed base portion with a central opening formed therein and a lower wheel assembly portion secured to the fixed base portion. The lower wheel assembly portion includes a flange portion and a sleeve portion extending from an underside of the flange portion. The sleeve portion is received within the central opening. The flange portion includes a central aperture formed therein. A bearing is disposed within the sleeve portion. An upper wheel assembly portion is in rotational communication with the lower wheel assembly portion. The upper wheel assembly portion has a top portion and a hub portion extending from an underside of the top portion. The hub portion includes an axle portion extending therefrom and through the central aperture for engagement with the bearing.

Abstract: The present invention includes a novel and modern numbering system design modernizing the design of gaming pieces, such as dice and dominos, while maintaining the qualities of utility for which these pieces were built. The novel design adds not only a pleasing and improved visual quality, but also a tactile quality that enhances the handling of the gaming piece.

Abstract: A system, a machine-readable storage medium storing instructions, and a computer-implemented method are directed to a Migration Engine that provides for installing a unified variant of an application. The Migration Engine determines presence a stock identifier for one of the first variant and the second variant. Upon determining presence of a respective stock identifier, the Migration Engine identifies a player identifier and transmits the respective stock identifier and the player identifier to a game networking system. The Migration Engine receives application state data. The application state data is representative of a current usage by the player of a variant identified by the respective stock identifier. The Migration Engine instantiates an instance of the unified variant to provide functionality of the variant identified by the respective stock identifier, where the instance of the unified variant of the application is initialized with the received application state data.

Abstract: A computerized system and method for measuring physical activity to advance play in a game. In example embodiments, a cell phone generates a screen display and the game is played through the mobile device. The measurement of physical activity progresses the player through the game by progressing the player through “game days,” by permitting the player to travel from a current location to another location on a map of the game, by earning rewards points for the player that may be utilized in game play, etc. A specified number of steps equates with a game day and a complete game is measured in game days. The device tracks physical activity, related game days, and completion of games. During a game day, a player advances in the game as well as encounters challenges and obstacles and may be prompted to make other decisions related to the game play.

Abstract: A system that incorporates teachings of the present disclosure may include, for example, a method for presenting in a graphical user interface a plurality of associable three-dimensional (3D) actions and a plurality of accessories having distinct operational functions, receiving a request to associate one of the plurality of 3D associable actions with an input function of a select one of the plurality of accessories, associating the 3D action with the input function of the selected accessory, monitoring the selected accessory for a stimulation of the input function, and transmitting the 3D action responsive to detecting the stimulation of the input function. Additional embodiments are disclosed.

Abstract: A wireless input device for playing an interactive motion-sensitive game using a wireless-compatible game console in which a virtual play environment is represented through one or more computer-animated visual, aural or tactile effects is provided wherein game play is conducted by moving, shaking, twisting, waving or pointing the input device in a particular manner. The input device can include motion-sensitive circuitry and/or command circuitry for generating control signals and/or an effects generator and associated control circuitry to enable the input device to selectively generate at least one visual, aural or tactile effect comprising sound, lighting or vibration. The input device can include a wireless transceiver for providing two-way wireless communication with the wireless-compatible game console. An optional display screen displays short text messages received through wireless communications with the wireless-compatible game console.

Abstract: A scanning game input mechanism that includes a light-emitting mechanism that defines multiple input regions for a game in which there are multiple players. Each of the input regions is a portion of the playing surface in which a corresponding player subset is to provide physical input (such as rolling dice, playing cards, or placing game pieces, and so forth) to affect game state. A scanning mechanism scans objects placed within the input regions, while a communication mechanism communicates information regarding the scanned object. The information might, for example, be communicated to affect an electronic game state maintained in another device or distributed across multiple devices.

Abstract: A gaming system is configured for dynamic and location-specific management of sound in a gaming environment. Various gaming stations, each including sound receivers and sound emitters, are disposed across multiple gaming zones. A server communicates with the gaming stations and is configured to sample ambient sounds with respect to the plurality of zones, and identify zone-specific exception sound signatures with respect to a dynamic noise threshold for at least a first of the plurality of zones, such as for example a jackpot or equivalent “hot spot” in the gaming environment. One or more gaming machines external to the first zone are directed to locally amplify sounds associated with the identified zone-specific exception sound signatures for the first zone. The server may further direct sound emitters external to the first zone to emit sound waves effective to locally suppress particular ambient sounds other than the identified zone-specific exception sound signatures.

Abstract: Embodiments of the present invention are generally directed towards software based controllers. Specifically, embodiments of the present invention are configured to provide a software based controller capable of utilization with games provided through a console, handheld device or other computing device.

Abstract: The present invention discloses a system and method for recognizing objects placed together using capacitance sensors in conjunction with the RFID technology. A structure that is made with a material of high dielectric constant and a RFID tag that comprises a unique identification code (UID) of an object is embedded with the object. With the objects recognized, the spatial structure or the spatial distribution formed by them is derived and corresponding sensory feedbacks are provided by the system.

Abstract: A method and system (10) is provided for playing an interactive mobile device based game system though a communication network. The communication network includes at least one system central server (13) and database (14) accessible to the internet or other communication networks. The system further includes any number of mobile devices (15), (16) and (17). Each mobile device includes software or a software application for communicating with the system server. In playing the game, users or players accrue points or otherwise advance in the game as they compete or obverse events which occur in real life situations in their geographic location. The events are entered into the central server and verified by communicating requests from the central server to the mobile devices of other players of the game.

Abstract: Systems and methods for interfacing video games and user communications are provided. Communications amongst users can affect a video game provided to the users. For example, communications can be monitored to determine when a video game event occurs and then a video game event can be generated. Moreover, one or more aspects of the video game can affect communications amongst the users. For example, the active user of a video game may be used to adjust the prominence of communications amongst the users.

Abstract: A server includes drawing means (121) for drawing an item by lottery from among an item group including a plurality of types of items with different scarcity values and providing the item to a user, and additional item providing means (122) for providing an additional item to the user in accordance with a provision count of the number of times an item is provided by the drawing means (121).

Abstract: A data processing method includes; determining, after receiving a casting instruction input by a user for a specified skill, first-type action data corresponding to the specified skill, the first-type action data being data that can be displayed before a server makes a response sending a data requesting message to the server, the data requesting message being used for requesting second-type action data corresponding to the specified skill, and displaying the first-type action data, the second-type action data being data that cannot be displayed until the server makes a response; and receiving the second-type action data sent by the server, and displaying the second-type action data.

Abstract: A method for determining the position of a controller device, comprises: receiving dimensions of the display input by a user of the computer-based system; capturing successive images of the display at the controller device; determining a position of the controller device relative to the display based on the dimensions of the display and a perspective distortion of the display in the captured successive images of the display; providing the determined position of the controller to the computer-based system to interface with the interactive program to cause an action by the interactive program.

Abstract: There is provided an information processing apparatus including an attribute management unit configured to manage a variable attribute value associated with each one or more characters existing in a real space, a detection unit configured to detect an interaction event between a first character and a real object by using an image captured by a camera that captures the real space, and a setting unit configured to set a rule for changing the attribute value of the first character depending on the interaction event. In a case where the detection unit has detected the interaction event, the attribute management unit changes the attribute value of the first character in accordance with the rule set by the setting unit.

Abstract: A computer system creates, stores, transmits, modifies, and enables users to exchange units of social currency, referred to as “social currency events” (SCEs). Each SCE represents social approval and/or disapproval of a behavior of one or more users by the same user or one or more other users. The users who send and receive an SCE may each assign their own distinct values to it. The computer system may generate various metrics based on one or more SCEs. For example, the computer system may generate a single SCE score for a user based on variables such as the number and value of SCEs the user has sent and received. SCEs may be used to recognize positive and/or negative social behaviors by users of the system, to encourage such users to engage in additional positive social behaviors, and to discourage such users from engaging in additional negative social behaviors.

Abstract: Methods for allowing a user to participate and change outcome of an asynchronous game includes receiving an indication of an attack initiated by a second player on a first player's game base during game play. In response, a first social post is generated to inform friends of the first player of the attack and request assistance to defend the first player's game base. An acceptance to defend the first player's game base is detected from a third player at the first social post. In response, game replay of the attack by the second player is initiated and the third player is enabled to participate in the game replay and defend the game base of the first player. A second social post is generated to inform the first player and the friends of the first player of the third player's contribution in defending the first player's game base.

Abstract: Techniques for simulating destruction in a simulated space, for example, terrain, are disclosed herein. In some cases, one or more textures may be associated with an area of a simulated space, which may include a three dimensional space. A destructibility value, which may indicate the area's resilience to destruction or strength, may be associated with the area of simulated space. One or more textures of the simulated space may be changed or updated based on the occurrence of a destruction causing event. The change in one or more textures of the simulated space may be determined based at least in part on an intensity associated with the destruction causing event and the destructibility value of the affected simulated area.

Abstract: A software agent interfaces with an interactive game program allowing for dynamic conveyance of objects during runtime for receiving data indicative of at least one parameter relating to a player of the interactive game program and/or to the player station on which the program is run. The data is used to set a dynamic policy that is customized on-the-fly according to the at least one parameter, and which is adapted to determine one or more objects to be conveyed to the player station for dynamically embedding in the program. The dynamic policy is also adapted to determine one or more characteristics of the object and is capable of subsequent re-customization and revision during game play. The objects are retrieved and periodically conveyed to the interactive game program based on the dynamic policy for dynamically embedding in the interactive game program to interface with the game player of the interactive game program.

Abstract: A method for training a semantic ability of a subject, the method being performed by a computer the method comprising: a. Displaying a linguistic task to the subject on a display of the computer, said linguistic task comprising providing one or more words, wherein said linguistic task is directed to training the subject in a specific semantic skill or skills; b. Providing a plurality of linguistic clues to the subject, through the display of the computer, said plurality of linguistic clues comprising content capable of activating concepts related to said one or more words but wherein said content does not include said one or more words or synonyms thereof, wherein said linguistic clues are selected such that the subject integrates said plurality of linguistic clues to solve said linguistic task, wherein said linguistic clue comprises an image, audio, video, text or a combination thereof; c. Receiving a solution to said linguistic task by the subject through the computer; and d.

Abstract: A real world image captured by a real camera such as an outside right imaging unit 23b is acquired, a synthesized image is generated by synthesizing the acquired real world image and a virtual image depicting a first virtual object such as an enemy object EO, in such a manner that the first virtual object such as an enemy object EO appears to be present behind the real world image, and the synthesized image thus generated is displayed on a display device.

Abstract: A system, a machine-readable storage medium storing instructions, and a computer-implemented method are described herein for a System Tuner for customizing a player's experience. The System Tuner creates an optimal game model based on game-related data of a plurality of players. The optimal game model corresponds to a player segment in the plurality of players. The System Tuner generates one or more rules for building a game variant based on the optimal game model. The System Tuner detects a first player accessing the game. The System Tuner determines a particular player segment to which the player belongs. The System Tuner generates a game variant based on an optimal game model for the particular player segment and sends the game variant to a client device.

Abstract: A ranking list display method in a game system, which can easily execute ranking confirmation of a user, who is a ranking confirmation target, such as the user himself/herself, a friend or a rival, is provided. The ranking list display method in a game system includes determining a position in a ranking list of a game of a user who is a ranking confirmation target in relation to a display range of the ranking list which is currently displayed on a terminal, and displaying a pointer, which corresponds to the determined position in the ranking list of the user who is the ranking confirmation target in relation to the display range of the ranking list which is currently displayed on the terminal, within the display range of the ranking list which is currently displayed on the terminal.

Abstract: An electronics module in a gaming device includes an inertial measurement unit (“IMU”) for detecting acceleration motion, angular movements, and an optics assembly to optimally calculate a moment of impact and to predict a virtual trajectory of a virtual golf ball or other hypothetical object. The virtual trajectory of the target object may be displayed on a display screen either on the gaming device itself, on a computer, or on a television display. A haptics member, such as a vibration or sound element is positioned in the shaft housing and actuated to simulate a ball impact when the shaft housing is indicative of a swing.

Abstract: A game system includes a generating unit that generates game data used in progression through a game, based on player's instruction information input to a first terminal of a plurality of terminals. The system also includes a progression unit that makes the game progression, using the game data generated by the generating unit. The system also includes a determining unit that makes a determination regarding prohibition of use of the game data by at least a terminal other than the first terminal of the plurality of terminals, based on at least one playing result for a player that plays the game that the progression unit progresses using the game data generated by the generating unit based on the player's instruction information. The system also includes a control unit that controls the prohibition of use of the game data, based on the result of the determination by the determining unit.

Abstract: One aspect of the disclosure relates to a multi-prize mystery box that dynamically changes probabilities to ensure payout value in an online game. The multi-prize mystery box which dynamically changes probabilities may provide the ability to arrange multiple items in a mystery box. The probability of acquiring an instance of the second item through Nth item may be dynamically weighted based on the value of the first item.

Abstract: A toy gyro has a gyro ring that can be assembled at both sides and includes an axis body, gyro ring, tip and cover that are disposed on the axis body. A direction of mounting the gyro ring on the axis body may be turned over vertically, so that by turning over vertical orientations of the gyro ring on the axis body, gyros having different shapes or different heights of center of gravity may be formed. In other words, the gyro ring may be mounted on the axis body with a front side facing upwards, or the gyro ring may be mounted on the axis body with a reverse side facing upwards, so that during playing of the present invention, gyros having different shapes or having different heights of center of gravity may be formed by assembling of the gyro ring on the axis body in different directions.

Abstract: A toy top includes a shaft unit and a body into which a slot to which a fork of a launcher is to be inserted is formed concentrically with a shaft axis. The body includes a lock receiver which is disposed in an end of a slot, and which is to be locked by a locking part of the fork to be inserted into the slot. A spinning force is applied by rotation of the fork of the launcher in a state in which the fork is slid inside the slot toward the end beforehand so that the lock receiver is locked by the locking part at a previously-set locking position. Locking positions are defined respectively at opposite ends of the slot. The lock receiver is movable to and from the locking positions.