Abstract: A position-limiting device includes a position-limiting element and a body. The position-limiting element has a position-limiting portion and a blocking portion. The body has a corresponding blocking portion and a fitting portion. The blocking portion of the position-limiting element and the corresponding blocking portion of the body block each other such that the position-limiting element and the body are fitted together. The fitting portion is fitted to an object. The position-limiting element penetrates a position-limited component before being rotated to block or position-limit the position-limited component. Therefore, the body is fitted to the object, and the position-limiting element is rotated to position-limit or move away from the position-limited component, so as to couple together and separate the object and the position-limited component, thereby allowing two objects to be coupled together and separated repeatedly and rapidly.

Abstract: A casing assembly adapted for a carrier and comprising a casing adapted to be stacked on the carrier and a latch mechanism comprising a first component, a second component, and a third component. The first component and the second component are movable by each other and are rotatably disposed on the casing, the third component is slidably disposed on the casing and movable by the second component, such that the third component is releasably engaged with a first engaging component of the carrier as the first component moves the second component.

Abstract: In general, orthopedic instrument adapters and methods of using orthopedic instrument adapters are provided. In an exemplary embodiment, an adapter is configured to releasably attach to an end effector configured to impact bone. The end effector can be a broach, chisel, or other surgical implement. The adapter includes a spring-loaded hook that is configured to releasably seat in a cut-out formed in the end effector. The adapter is also configured to releasably attach to a surgical impacting tool, such as an orthopedic impactor, configured to drive impacting of the end effector relative to bone.

Abstract: Fire control panel modular assemblies are described herein. In some examples, one or more embodiments include a fire control panel module (100) including a locking ridge (102), and a fire control panel module carrier (112) including a module carrier slot (114), a locking tab (130), and a release button (116), wherein the module carrier slot (114) is configured to accept the fire control panel module (100) therein, and the locking tab (130) is configured to engage the locking ridge (102) to releasably retain the fire control panel module (100) in the module carrier slot (114).

Abstract: A modular armor system configured to be readily attached and detached from a frame surrounding a window in a vehicle or other structure, such as a building. The modular armor system may be configured to provide any desired ballistics protection rating. In one embodiment, the modular armor system includes a ballistics-grade armor panel having an outer strike face and an inner surface opposite the outer strike face. The modular armor system also includes a fastener coupled to the ballistics-grade armor panel. The fastener is configured to detachably couple the ballistics-grade armor panel to the frame surrounding the window in the vehicle or other structure.

Abstract: A bracket device includes a bracket and a fastening member. The fastening member is pivoted to the bracket by a shaft member. The bracket includes a first structure and the fastening member includes a second structure. When the fastening member is located at a position, the first structure is in cooperation with the second structure, so as to prevent the fastening member from moving along an axis direction of the shaft member.

Abstract: A protective case for an electronic device includes an inner liner, a first aperture, a second aperture, and an outer shell. The inner liner receives the electronic device and the first aperture permits access to a touchscreen interface of the electronic device. The second aperture permits optical access to a camera of the installed electronic device. The outer shell includes an attachment mechanism for attaching an accessory. The attachment mechanism includes a receiver channel to slidably receive a rail member of the accessory to removably attach the accessory to the protective case. The receiver channel includes a lip for retaining the rail member in the receiver channel. The attachment mechanism further includes a snap feature having an interference fit with a corresponding snap feature of the rail member to removably lock the rail member into the receiver channel when the rail member is inserted into the receiver channel.

Abstract: A protective case system includes a mounting accessory and a protective case. The mounting accessory is attachable to an object and has a dovetail rail member, a snap feature, and an engagement feature. The protective case includes an inner liner and an outer shell. The outer shell is removably attachable to the mounting accessory to removably attach the protective case to the object through the mounting accessory. The outer shell includes a receiver channel in proximity to a first end of the outer shell. The receiver channel is adapted to slidably receive the dovetail rail member of the mounting accessory to removably attach the outer shell of the protective case to the mounting accessory. The outer shell further includes an engagement feature for engaging the engagement feature of the mounting accessory to further removably attach the outer shell to the mounting accessory.

Abstract: An axle alignment system for an axle assembly. The axle alignment system may include a bracket assembly and an alignment plate. The alignment plate may be moveably disposed on the bracket assembly with one or more fasteners that may move along one or more slots that may be provided with the bracket assembly and/or the alignment plate.

Abstract: Systems and devices using t-slot profiles and clamping devices to form a structure that may position an object in three-dimensional space. The clamping devices clamp two t-slot profiles together, either parallel or perpendicular to each other. The clamping device may be unlocked allowing t-slot profiles to move relative to each other, and then re-clamped, to lock the t-slot profiles in a new position. In some embodiments, the t-slot profiles and clamping devices form a structure that may position a camera in three-dimensional space over a table that supports at least one item to be photographed, and optionally digitized. The photographed items may comprise blueprints, artwork, architectural plans, and more.

Abstract: For use with a front-end loader etc, the coupler-assembly provides a rigid connection between the pivoting arm-end and the bucket. Included is a slider-block, guided in slide-guides and slider-slots in side-plates of the frame of the arm-end. Sliding the block using a hydraulic slider ram, wedges the bucket lugs tightly into the frame. The slider-ram is integrated into and moves with the block. A lock-spring urges a lock-bolt into position to lock the bucket-lug to the arm-end frame. A lock-ram releases the lock-bolt, to permit disengagement.

Abstract: A winch adapter including a unitary body having both a primary and a smaller secondary casing. A pair of levers, with handles, are pivotally attached to the secondary casing. A lug disposed on each lever opposite the handle is inserted through a hole in the primary casing and is maintained therein by tension from an associated elastic band against each lever, but the handle on each lever can be depressed to pull the lugs from their respective holes. The outer casing can then be inserted over a winch nipple with its own pair of holes, at which time, the handles would be released, causing the lugs to be inserted through holes on both the primary casing and the winch nipple. An air gun can then be used with the secondary casing and a drive on the secondary casing, allowing the air gun to rotate the winch adapter and the winch.

Abstract: An apparatus to retain an article includes a housing, a first jaw, a second opposed jaw, a pivoting ratchet arm, and a lever. The housing is adapted to receive a handle. The first jaw is adapted to pivot with respect to the housing. The pivoting ratchet arm is dimensioned to engage ratchet teeth of the first jaw when in an actuated position. The lever is connected to the ratchet arm and actuating the lever causes the ratchet arm to move into the actuated position to incrementally pivot the first jaw toward the second jaw.

Abstract: A connector assembly that includes a first connector, a lever, a second connector and a link. The lever is pivotally mounted to the first connector for movement about a pivot axis between a first lever position and a second lever position. The second connector has a lug. The link is pivotally coupled to the lever at a location that is spaced apart from the pivot axis. The link has a coupling member with a slotted interior aperture and an engagement tab. The lug is received into the slotted interior aperture when the lever is in the first lever position. The engagement tab engages the lug to inhibit relative movement of the second connector away from the coupling member when the lever is moved from the first lever position to the second lever position.

Abstract: A fastening device for furniture fittings on furniture parts which includes at least one dowel core that can be inserted into a hole of a furniture part. The dowel core can be arranged inside a dowel sleeve, and an actuating device moves the dowel sleeve relative to the dowel core. The dowel sleeve spreads on the dowel core and the dowel core is radially resilient.

Abstract: A locking device includes an operating lever, a base and a repulsion generating member, wherein the operating lever has a releasing position and a locking position relative to the base, and the repulsion generating member is arranged between the base and the operating lever and generates a repulsion force for application to the operating lever during movement from the releasing position to the locking position. When the operating lever does not completely reach the locking position due to abnormal operation, the repulsion generating member will cause the operating lever to return to the releasing position thereby provide an indication. The locking device can thus provide an indication when the locking operation does not reach the correct position, thereby avoiding user confusion and abnormal operation.

Abstract: A connector is provided, including a connector body, a fastener and an elastomer. The fastener is pivoted on the connector body with a hook end and a press end positioned on both sides thereof, respectively. The two ends of the elastomer contact the connector body and the press end of the fastener, respectively. The connector of the invention may accomplish plugging and unplugging of an electronic equipment in a single hand press way without bracer arrangement by a configuration of the press end, and may maintain an engagement state between the hook end and the electronic equipment with an arrangement of the elastomer.

Abstract: A pole system for holding a tool includes a manually activated mechanism, an extendable pole apparatus, and a clamp mechanism. The clamp mechanism includes a receiver with a locked configuration to retain a tool and a released configuration to release the tool. The pole apparatus operably couples the actuator mechanism to the clamp mechanism such that manual operation of the actuator mechanism causes operation of the tool.

Abstract: A locking mechanism includes a latch, a handle, a first link, and a second link. The latch to engage with a recess of a server rack chassis, and to lock an adaptor assembly within the server rack chassis. The handle is connected to the latch, and engages and disengages the latch with the recess. The first link includes a first stub. The first link puts the first stub in an up position in response to the handle being in a down position, and puts the first stab in a down position in response to the handle being in an up position. The second link includes a second stub, The second link puts the second stub in a down position in response to the handle being in the down position, and puts the second stub in an up position in response to the handle being in the up position.

Abstract: A device for quick splicing of a display screen is provided, the device comprises a left assembly (2) and a right assembly (3). The left assembly (2) comprises a rotation fixing seat (22), a rotation angle seat (20), a rotation locking mechanism, and a step angle-adjusting and clamping mechanism; the rotation angle seat (20) can lock with the right assembly (3), and is rotatably connected to the rotation fixing seat (22); the rotation locking mechanism is disposed between the rotation fixing seat (22) and the rotation angle seat (20); when the rotation locking mechanism is unlocked, the rotation angle seat (20) can rotate relative to the rotation fixing seat (22); and when the rotation locking mechanism is locked, the rotation angle seat (20) is fixedly connected to the rotation fixing seat (22); the step angle-adjusting and clamping mechanism is disposed between the rotation angle seat (20) and the rotation fixing seat (22).

Abstract: A loading work apparatus includes booms, attachment tools, an implement tool removably attached to the attachment tools, and implement tool cylinders. The implement tool includes an engaged member on a back surface thereof. The attachment tools include an attachment unit having an engaging member engaged with the engaged member, coupling members supporting the transverse shaft, and lock members locking/unlocking engagement between the engaging member and engaged member. Each coupling member includes brackets on lateral opposite sides of the lock member. The transverse shaft is supported at opposite ends thereof by lower portions of the right and left brackets. The support shaft is supported at opposite ends thereof by intermediate portions of the right and left brackets. The transverse shaft and the support shaft bridge across the lock member.

Abstract: A quick coupler for connecting an implement to a machine. The quick coupler including a frame, a first jaw pivotally connected to the frame and movable between an open position and a closed position, a second jaw pivotally connected to the frame and movable between an open position and a closed position, and a lock system connected to the first jaw and the second jaw. The lock system includes a first linkage pivotally connected to the frame and to the first jaw, a second linkage pivotally connected to the first linkage and to the second jaw, and a drive member connected to the first linkage and configured to selectively operate the lock system between an unlocked position and a locked position.

Abstract: A locking unit (10) for a vehicle seat (1) includes a pivotally mounted rotary latch (20) for locking to a bolt (12). The rotary latch (20) includes a rotary latch hole (24) for pivotably mounting on a bearing pin (51) which protrudes through the rotary latch hole (24). A detent (30) secures the locking unit (10) in the locked state in the event of a crash. The rotary latch (20) supports itself on a first contact point against the detent (30). The rotary latch (20) includes at least one recess area (25) which enables the rotary latch (20) to deform in the event of a crash. The recess area (25) is arranged at a distance from the rotary latch hole (24) in the radial direction.

Abstract: A device including: a load bearing structure for supporting a load on a surface; a surface engaging assembly operably connected to the load bearing structure; and, a biasing arrangement configured to be energized when the load is applied to the load bearing structure, the biasing arrangement urging the surface engaging assembly towards a disengaged condition to allow the movement of the device relative the surface.

Abstract: A fastening device for furniture fittings on furniture parts which includes at least one dowel core that can be inserted into a hole of a furniture part. The dowel core can be arranged inside a dowel sleeve, and an actuating device moves the dowel sleeve relative to the dowel core, so that the dowel sleeve spreads on the dowel core. The dowel core and the dowel sleeve have at least two, preferably more, corresponding inclined surfaces that are offset in the axial direction, so that if the dowel sleeve is moved relative to the dowel core, the dowel sleeve spreads substantially evenly at two, preferably more, axially offset locations.

Abstract: A quick release mechanism for at least partially muscle-powered two-wheeled vehicles such as bicycles having a through axle extending in the axial direction, a clamping device at a first end of the through axle and a fastener at the second end of the through axle and with a clamping mechanism for clamping the clamping device. The clamping device includes an engaging section for applying a clamping force from the clamping mechanism to the clamping device and a clamping section with an annular pressure area for clamping. The clamping device has a tubular mounting section extending from the clamping section in the direction of the second end of the through axle and to which the through axle is attached.

Abstract: A single mounting apparatus for securing a number of expansion cards includes a resisting member rotatably attached to the chassis and a clamping buckle. The clamping buckle includes a pressing piece, a supporting portion, an operating portion, and a catching member. A securing space is defined in the resisting member for latching the catching member. When the catching member is caught in the securing space, the securing member is clamped between a flange of the chassis and the resisting member to stop the rotation of the resisting member. The pressing piece presses down on and secures the expansion cards. Lifting the clamping buckle upwards unlatches the catching member from the securing space and causes re-rotation of the resisting member to allow dismounting of the expansion cards.

Abstract: The invention comprises systems and devices for securely clamping and easily unclamping a first t-slot profile to a second t-slot profile. The clamping devices may move along a first t-slot profile, allowing the invention to clamp at different places along the first profile. The clamping systems and devices may be used for positioning a side-fence, connected with the second profile, relative to a saw blade, or for construction of a trade show booths, display assemblies, or other structures that may be securely clamped together, and easily unclamped.

Abstract: A fitting lever (30) includes housing coupling substrates (31) which are coupled to the outside surfaces of a first connector housing (10), cam plates (32) which are coupled to the central parts of the housing coupling substrates (31), and a lever body 33 which is an operating part to pivot the cam plates (32). The cam plates (32) include cam grooves (322a, 322b) into which the connector housings (10, 20) are fitted with each other with pivoting, and engagement opening grooves (323) which make the cam plates (32) detachable from the connector housings when the cam plates (32) are moved to a pivoting final position N2.

Abstract: A latch mechanism is provided for latching a field-replaceable unit within an enclosure. The latch mechanism includes a rotatable latch coupled to the field-replaceable unit, via a pivot, at a first side of the field-replaceable unit, and a compliant spring member disposed to act on the pivot. The compliant spring member acts on the pivot and compresses with rotating of the latch from an open position to a latched position during latching of the field-replaceable unit within the enclosure. The compressing facilitates provision of a positive pressure on or across the field-replaceable unit directed towards a second side of the field-replaceable unit opposite to the first side. This positive pressure facilitates, for example, fixed coupling of a first connector at the second side of the field-replaceable unit to a second connector associated with the enclosure when the field-replaceable unit is latched within the enclosure.

Abstract: A fitting lever (30) includes a pair of lever bodies (31), shaft fitting holes (32) which are formed on opposed inner surface (31a) of a pair of lever bodies (31) and in which lever supporting shafts (11) of a firs connector housing (10) are pivotably fitted, cam grooves (34) which are formed to open at the end edges of the lever bodies (31) at the side of a second connector housing (20) and which act a moving force in a fitting direction on action receiving shafts (23) with the pivoting of the lever bodies (31) when the fitting lever (30) is pivoted while the connector housings are aligned at a fitting start position. When the connector housings have been fitted and connected with each other, by moving the pair of lever bodies (31) to a maximum separation position, the pair of lever bodies (31) are detached from the lever supporting shafts (11) and the action receiving shafts (23) and the fitting lever (30) is detached from the connector housings.

Abstract: An attachment element for mounting a vehicle seat on a vehicle structure includes a sleeve, at one end of which a lever element is arranged, and an element which can be a hollow cylinder and which has at least two wing-like extensions lying opposite one another, and which at least partially surrounds the sleeve. Also, a method is described for mounting a vehicle seat on a vehicle structure by using at least one fastening element.

Abstract: A connecting device for connecting glass panes of a door of a household appliance includes a first retainer configured to connect to an outer glass pane. The first retainer includes a first insertion structure configured to receive an inner glass pane. A second retainer is fixed to the first retainer and configured to pivot from a first position to a second position and from the second position to the first position. The second retainer includes a locking element configured to retain the inner glass pane in the first position of the second retainer. The second retainer further includes an actuating element including a handle. The handle is configured to pivot the second retainer from the first position to the second position and from the second position to the first position.

Abstract: A dump body latching system for application to a self dumping hopper comprises a battery, a linear actuator assembly having an actuator rod configured for reciprocal motion into and out of a housing, an actuator cable having a first end attached to the actuator rod and a second end attached to a biased trip lever and a controller configured to connect the battery with the linear actuator to withdraw the actuator rod into the housing and thereby pull the actuator cable and the biased trip lever to disengage the trip lever from a locking pin.

Abstract: Apparatus and methods for attaching and detaching a device to and from a DIN rail, the apparatus includes a housing carrier with a coupling assembly. The coupling assembly including one or more operator links, the one or more operator links rotatable relative to the housing carrier about a pivot, and the coupling assembly includes at least one DIN rail catch. The operator links have a first position in which the at least one DIN rail catch is in a first coupled position, and the operator links have a second position in which the at least one DIN rail catch is in a second uncoupled position. The operator links are operable to move the at least one DIN rail catch from the first coupled position to the second uncoupled position when the operator link is rotated about the pivot.

Abstract: lever bodies (31) include first shaft introducing grooves (34) which introduce lever supporting shafts (11) of a first connector housing (10) to first initial engaged positions P1, second shaft introducing grooves (35) which introduce action receiving shafts (23) of a second connector housing (20) to second initial engaged positions P2, first communicating grooves (37) which introduce the lever supporting shafts (11) to pivoting fulcrum parts (36), second communicating grooves (39) which introduce the action receiving shafts (23) to action receiving parts (38), and shaft detaching grooves (40, 41) which make the lever supporting shafts (11) and the action receiving shafts (23) escape to the outside of the lever bodies (31) along detachment moving traces which are different from those at the time of installing.

Abstract: A ejector assembly, comprising: an ejector (10) with a shape of “L”, being provided to rotate around an axis; a lock element (20), being provided to move along a direction substantially perpendicular to a plan of the rotation of the ejector (10); wherein the ejector (10) includes a cut-out portion (12), the lock element (12) includes an end portion (21), and the end portion (21) is provided to match with the cut-out portion (12) to prevent the ejector (10) from rotating.

Abstract: In a structure, which securely attaches a component to an opening portion in a plate-shaped member without stripping or turning over the plate-shaped member, each of a pair of mount members includes a first engagement portion engaged with a rear surface side of the plate-shaped member and a second engagement portion engaged with the component. The component includes projecting portions to be fitted between the mount members to enable fixing against coming off by engagement of the second engagement portion and the component. The projecting portions inhibit the mount members from moving so as not to come off the opening portion. Since the second engagement portion is formed from the multiple step portions engageable with the component, engagement with the component may be done even if plate thickness of the plate-shaped member varies, enabling fixing without backlash and improving versatility to the plate-shaped member having different plate thickness.

Abstract: A wrench quick release apparatus includes a sleeve, a positioning unit, a wrench unit and an elasticity unit. The sleeve includes a channel and an engaging section for engaging to a first plate. The positioning unit inserts in the channel of the sleeve, and includes one end inserted through the first plate and an opposite end protrudes out from the channel of the sleeve. The wrench unit is pivotally connected to the positioning unit and protrudes out from one end of the sleeve. The elasticity unit includes one end pushed against the positioning unit and an opposite end pushed against the sleeve. Accordingly, the wrench quick release apparatus is first engaged to the first plate through the sleeve and then engaged to or disengaged from a second plate to achieve a steady and quick assembly effect with minimal efforts in a convenient manner.

Abstract: A connection device for assembling together a receiver first section member presenting an inner cavity, and a fastener second section member presenting a groove having a constricted opening. The connection device includes a cage forming a pair of jaws for coming into engagement in the groove. The device also including a resilient drive mechanism for urging a spacer member between the jaws so as to space them apart in such a manner as to come into engagement with the groove through the constricted opening; and a pivotable lever that pivots about a pivot pin, the pivotable lever including a lever arm and a thrust head that engages the spacer member so as to move it against the force exerted by the resilient drive mechanism on the spacer member.

Abstract: A method and apparatus for retaining accessories to a vehicle.

Abstract: A locking device for a vehicle seat, includes a pawl for locking a mating element, which pawl is pivotally supported about a first axis, and a tensioning eccentric that is pivotally supported about a second axis, which is parallel to the first axis, between a locking position and an unlocking position and ensures a locked state of the pawl owing to the interaction with a first functional surface of the pawl, the tensioning eccentric acting upon the first functional surface by a tensioning surface when spring-loaded and locked, an unlocking element being pivotable about the first axis counter to a spring force from a locking position to an unlocking position by an actuation device and the tensioning eccentric being pivotally engaged by the unlocking element from its locking position towards its unlocking position.

Abstract: A sanitary clamp comprises a first member coupled to a projection with at least one external ratchet tooth, pivotally connected to a second member having at least one wall at least partially defining a well configured for receiving the projection. A rocker lock having a first portion and an opposed second portion including an engaging member is pivotally coupled to the at least one wall and configured such that the engaging member is resiliently positioned in the well to engage the at least one external ratchet tooth to latch the projection within the well, and such that the second portion travels outwardly when the first portion is inwardly depressed to retract the engaging member from the well and release the engaging member out of engagement with the at least one external ratchet tooth to unlatch the projection with respect to the well.

Abstract: The invention is directed to a module injection mechanism and a method of using the same for mounting a module to a chassis, the module injection mechanism comprising an injection assembly secured to the module, comprising a lever, a screw affixed to the chassis, a sliding bushing, disposed between the module and the screw, wherein the screw is fixed to the chassis via the sliding bushing, the lever comprising a lever grabbing portion and a lower lever portion capable of connecting to the sliding bushing, wherein the injection assembly is secured to the module so that the injection assembly is capable to transfer a mechanical force applied to the lever grabbing portion to the sliding bushing so that the module is mounted to the chassis.

Abstract: A system for forming a structure around a shipping container, the system includes a plurality of uprights positioned on the ground at a distance from the side of said shipping container. The system also includes a plurality of trusses. Each truss is having top and bottom members extending between proximate and distal ends. The proximate end of each of said top and bottom members having a bore therethrough engageable by a pin connection supported by said shipping container. The said distal ends of said top and bottom members is being engageable with and supported by one of said uprights.

Abstract: In a multi-function tool structure, a body and a work rod are pivotally connected together and can form a folded and retracted state. Moreover, an elastically movable press button is disposed on the body and can link up a positioning pin movably inserted into the work rod. Thus, pressing the press button can release a lock between the work rod and the positioning pin so that the work rod is swingable, while releasing the press button can lock the positioning pin and the work rod together again. Thus, the work rod and the body can be folded and retracted to facilitate the storage and carrying. After the work rod is developed, it can form multiple included angles with respect to the body so that the requirements of different operation angles can be satisfied.

Abstract: A releasably locking device, and clamping element for such a device, secures a bicycle component to a bicycle frame. The device has a traction rod associated with a rotation cam extending in a housing. The rotation of the cam is driven by a lever-operated manual actuation system between a clamping operating position and a release position. The rotation cam has two ends that can be commanded into synchronous rotation through said lever-operated manual actuation system.

Abstract: A quick release bicycle saddle mounting bracket has a mounting portion for a bicycle saddle and a seat post mounting portion including a quick release cam lock. The quick release bicycle saddle mounting bracket may be installed or removed from a bicycle seat post without the use of tools.

Abstract: A manually actuated robotic tool changer includes a first housing having a generally cylindrical piston with a central axis partially extending from the first housing, the piston rotatable about the axis. A plurality of tabs are disposed about the circumference of a portion of the piston extending from the first housing. A second housing has a bore to receive a portion of the piston. A plurality of locking lugs are disposed about the bore. The tool changer is manually actuated from an unlocked position wherein the piston assumes a position with respect to the first housing such that the extending portion of the piston may be moved within the bore with the tabs moving between the locking lugs, to a locked position wherein the piston is rotated with respect to the first housing such that the tabs move beneath the locking lugs to lock the first and second housings together.

Abstract: A fore connection member, comprising a fore connection member body and engaging-disengaging members. The engaging-disengaging members are pivoted to side surfaces of the fore connection member body respectively, and each comprise a recess, a grab, an operating end, an abutting end and a pivoting end. The engaging-disengaging members each have the pivoting end thereof pivoted to a corresponding one of the side surfaces and pivots about the fore connection member body. The operating end and the abutting end are disposed at two sides of the pivoting end respectively, the grab is provided with a hook portion facing the abutting end, and a circular arc abutting portion disposed at the abutting end comprises a circular arc abutting surface smoothly connected to the recess. A rear connection member for use with the fore connection member and a connection member comprising the fore connection member and the rear connection member are also provided.