Abstract: A bone foundation guide system has a bone foundation guide including a body that is contoured to reversibly affix to a bone segment of a dental implant surgical site. The body is further contoured to guide the cutting of a portion of the bone segment from a dental implant surgical site and alternatively support a dental implant surgical guide. The body is further contoured to support a bone foundation guide prosthesis as an alternative to the dental implant surgical guide. The bone foundation guide prosthesis combines with the body to accommodate the bone segment portion as placed through the body prior to the bone segment portion being removed from the dental implant site through the use of the body.

Abstract: An apparatus includes a dental model coupling portion and a base plate adapter coupling portion. The dental model coupling portion is configured to couple with a dental model. The base plate adapter coupling portion includes a body and a set of prongs extending from the body. The body is fixedly secured relative to the dental model coupling portion. The prongs are configured to removably secure the base plate adapter coupling portion to a base plate adapter of a dental model articulator. A base plate adapter includes a first side and a second side opposite the first side. The first side is configured to removably couple with the base plate adapter coupling portion. The second side is configured to removably couple with a dental model articulator.

Abstract: An articulator having a maxillary member and a mandibular member, which are connected to each other via condylar articulations, wherein a maxillary adaptor is attachable or attached at the maxillary member and a mandibular adaptor at the mandibular member, wherein a maxillary alignment member especially is form-fittingly connected to the maxillary adaptor and a mandibular alignment member is especially form-fittingly connected with the mandibular adaptor, and wherein the alignment members are automatically alignable to each other and comprising scanning members, by means of which the arrangement of alignment members and adaptors is scannable in a scanner and especially the relative position thereof moreover is detectable in relation to the articulator via the scanner.

Abstract: Improvements in a dental model tray and associated articulation system for use in forming a dental model includes providing: a flange integrally attached to the upper edge of an upstanding side wall of said tray; a pair of spaced apart ears that project outwardly from said flange; an alignment pin extending upwardly from and perpendicular to a planar base of said tray; a centric stop mechanism in which the cylindrical hollow post forming the centric stop is provided with a thin membrane covering over the otherwise open end of the post; and an articulation system which includes a ridged first leg and a second leg which is formed in the shape of a flat plate having sufficient thickness to be substantially rigid but which also allows limited torsional movement or bending about its longitudinal length as well as limited flexing about its longitudinal length.

Abstract: A head frame apparatus is secured to a human head during maxillofacial surgery and includes devices to easily position and secure an endotracheal (breathing) tube and an anesthesia delivery circuit for the patient that reduces the likelihood that the flow of oxygen through the tube is restricted thereby reducing the risk of severe injury or death. The head frame apparatus also includes a removable reference indicator, which may be easily attached and removed while identifying a reference point of the patient's face. Also the reference indicator includes a universal joint and pointer with an attached ruler. A transport apparatus positions multiple preset reference indicators and allows for preoperative transportation and removal, while protecting the preset reference indicators from inadvertent adjustment. A bendable reference indicator used in an articulator for preoperative modeling allows for easily identifying reference points in a cast model.

Abstract: An intraoral 3D scanner includes a probe light source configured to generate a probe light such that the probe light is transmitted towards the dental situation; a camera including an array of sensor elements, the camera being arranged such that the probe light from the dental situation is transmitted to the array of sensor elements, wherein the camera is configured to create images of the dental situation from which a point cloud is generated, and a guiding system configured to guide relative movement of the intraoral 3D scanner towards the dental situation, wherein the camera is part of the guiding system, the camera is configured to record images from which a relative position of the intraoral 3D scanner and the dental situation is determined, such that based on the relative position, the guiding system is configured to provide a positioning signal in the form of a positioning color code.

Abstract: The present invention relates to a probe device for analyzing physical properties of food, having a teeth form, and more specifically, to a probe device for analyzing physical properties of food, having a teeth form, capable of objectively analyzing various physical properties felt by a person when chewing food, selecting and using a probe corresponding to a molar, a front tooth or a canine tooth, allowing a vertical motion of a press to be interlocked with a motion of the jaw joint, and allowing chewing experiments similar to real chewing of the human body to be carried out by enabling smooth occlusion of the upper jaw and the lower jaw.

Abstract: An apparatus and system is disclosed for dental modeling. The apparatus includes a first tray positioned opposite a second tray and a dearticulating hinge coupling the first tray to the second tray. The dearticulating hinge includes a first hinging element coupled to one of the first tray and the second tray and a second hinging element coupled to the other of the first tray and the second tray. At least one of the first hinging element and the second hinging element includes a disengaging element configured to engage a spur to uncouple the first hinging element from the second hinging element upon extending the first tray and the second tray beyond a predefined angle relative to one another.

Abstract: The invention provides a method for creating a physical teeth model. The method comprises the following steps: providing a virtual three dimensional (3D) representation of a patient's dentition that comprises at least a region of the teeth that includes a tooth stump on which a crown is to be fitted or a region on to which a bridge is to be fitted; and preparing a physical model of the jaws of a subject from a blank, based on information from said virtual 3D image.

Abstract: Articulator—semiadjustable, arcon with lower and upper parts that could be detached from one another or interconnected, with two mechanical joints. An upper horizontal shoulder (5) is fixed to an elevator (4), said elevator (4) is connected to an upper vertical body (11) and can move vertically to adjust the vertical position. A lower vertical body (10) is fixed to the base (1) and holds an axis with two joint heads (14). The upper vertical body (11) is pivotably connected to the lower vertical body (10) through the two joint heads (14), the distance between the joint heads can vary due to an elastic element (18), thus reproducing the lateral shift. The articulation between the vertical bodies (11 and 10) can be locked and unlocked via an elbow shaped piece (13). The articulator lower part has an incisive platform (8) with a position angle that could be adapted.

Abstract: A system for fabricating a dental restoration to restore a tooth at a restoration site in a dentition of a patient is disclosed. The dentition includes a restoration dental arch and an opposing dental arch. The restoration dental arch include the restoration site and the opposing dental arch is opposite the restoration dental arch. The system includes an impression apparatus, a motion capture apparatus, an interface apparatus, and a restoration design system. The impression apparatus is configured to capture an impression of the dentition of the patient. The motion capture apparatus is configured to capture a plurality of location data points that represent the locations of the opposing dental arch relative to the restoration dental arch. The interference model generation system is configured to generate an interference model for the restoration site. The restoration design system is for designing a restoration using the interference model.

Abstract: A vertically adjustable rotational stabilizer (10) for a disposable articulator is provided. The articulator comprises a hinged pair of support arms, each support arm having a proximal end and a distal end, with the proximal ends of the support arms being hingedly fitted together. Each arm defines an opening or cavity between its distal and proximal ends. The vertically adjustable rotational stabilizer (10), in broad terms, comprises at least one body (30, 66) secured or securable to the support arms (14, 16) and positioned substantially within the opening defined by the support arm, and an elongate member (56) being adjustable relative to the at least one body so as to adjust and fix the distance between the distal ends of the support arms (14, 16).

Abstract: Dental systems and methods related to impressionless dental modeling. A dental modeling system includes a dental model base and a mounting plate. The dental model base includes a plate support surface and a plurality of pin receiving apertures formed in the support surface. The mounting plate includes a plate portion positioned on the plate support surface and a plurality of pins extending into the pin receiving apertures to provide removable attachment of the mounting plate to the dental model base. The plate portion includes a model support surface configured to support a model of a person's teeth. The model may be formed directly on the model support surface using an impressionless technique. The model may be formed separately using an impressionless technique and then bonded to the model support surface.

Abstract: For producing dentures, a new method and a device render it possible to evaluate and shape movements generated by the individual jaw joints of the patient such that work with appropriate articulators becomes possible, which employ the individual jaw joints as articulation joints and thus carry out the identical movements. The known articulators are equipped with joint-space duplicates such that they can be employed with optimal equipment for the respective patient. The support pin is moved back as fixing pin in the retral space of the articulator such that it does not constitute an impediment when working on and when inspecting the jaw models arranged on the frame upper part and the frame base part. Moreover, setting different biting positions is made significantly easier, because the frame upper part is fixed to a swivel arch of the frame base part by an adjustable position stabilizer but can also be detached.

Abstract: A device adapted for adjusting the inclination of an entire articulator in relation to a support plane includes a support element on the support plane, a fastening device attached to the articulator, and a mechanism configured to adjust the distance between the fastening device and the support element.

Abstract: A dental articulator apparatus and method of forming dental casts utilizing a dental articulator having pivotally connected upper and lower arms that each have a ball socket which receives a ball at the outer end of a respective model anchor, the opposed end of which is cast into a dental model. The model anchor ball is adjustably secured in the ball socket of the articulator arms by a set screw coupled with a rotatable magnetic extension rod that are installed, removed, advanced, and retracted as a unit and allow relative rotation between the set screw and the extension rod to facilitate fitting and positioning the ball in the socket when the set screw is loosened, and eliminate manually installing and positioning separate small shims and plungers that can be accidentally dropped and lost.

Abstract: Provided is a dental articulator, and more particularly, a dental articulator, in which a tray keeping a shape and dimensions of a dental model is fitted into an upper portion of a base member to which the dental model is coupled. Particularly, the tray coupled to a top surface of the base member is geometrically similar to the base member, and includes a boundary wall formed along an edge thereof at a predetermined thickness and height, a through-hole formed inside the boundary wall, and a pin cap structure that has a plurality of fitting holes into which pins of a pin structure of the base member are fitted and which are continuously formed along an inner central axis of the through-hole and that is connected to opposite inner ends of the boundary wall. Further, each of the arcuate and linear boundary walls of the tray has a plaster anti-overflow flange formed at an upper end thereof and bent in an outward direction to prevent plaster from overflowing down.

Abstract: The invention relates to a two-part model plate array for producing dentures. The model plate array comprises a model plate having a dental crown model and sliding elements, and a model base plate having guides. The sliding elements can be inserted into the guides of the model base plate.

Abstract: The invention relates to a device for mounting and temporarily clamping dental casts using multi-functional receiving formwork elements that secure the dental casts, allowing the ratio measurements to be repeated as many times as desired using telescopic cylinders having a memory unit, said cylinders being manual and/or mechanical with screws and/or pneumatic and/or hydraulic and being used to secure, support and universally calibrate the multi-functional receiving formwork element of the dental articulator, thereby allowing the dental record of the casts to be created.

Abstract: A plaster teeth model gripper and an articulator having the same that is capable of allowing a desired tooth to be attached to and detached from a plaster teeth model through only the cutting of a plaster teeth model, being simply manufactured, and being easily mounted on an articulator. The plaster teeth model gripper includes: a base plate disposed in a flat form on the underside of a gum of a teeth model; and a teeth model gum-supporting frame formed erectly on one surface of the base plate along the outer periphery of the gum of the teeth model in such a manner as to form a teeth model gum chamber open in a vertical direction from the base plate at the inside thereof.

Abstract: A model of at least a part of a dental structure, an articulator, and methods of manufacturing such devices are provided. The model and the articulator can be used to approximate the natural movements of a jaw of a patient to facilitate preparation of a dental restoration. The model can include the dental structure, an interface, and at least one void extending from a reference surface of the interface inwardly toward the void. The articulator can include upper and lower portions on which models of upper and lower dental structures can be held. The upper and lower portions of the articulator can be configured to generally maintain a vertical alignment while at least one gap formed between respective first and second alignment components thereof allows horizontal movability of the upper and lower portions relative to each other to test the interfit of the models therebetween.

Abstract: A dental cast stabilizer secures a dental cast to a dental cast articulator, and includes a fastening hole strap and a fastening post strap with a band body disposed therebetween. The fastening post strap includes a fastening post disposed thereon, and the fastening hole strap includes a fastening hole disposed thereon that is capable of receiving the fastening post or mounting plate thumb screw on an articulator.

Abstract: Provided is a dental articulator and a dental model fixing pin used for the same. The dental articulator has a base member for molding a dental model for a patient. The base member includes a protrusion bed that is formed on a top face of the base member along a central line in a lengthwise direction of the base member, comes into contact with a plaster dental model placed on the top face of the base member, and has a predetermined height, length, and width. The protrusion bed includes a plurality of pin fixing holes in a middle portion thereof, the plurality of pin fixing holes being spaced apart from one another at regular intervals and passing through an interior of the base member.

Abstract: A pinless dental articulator includes a work tray, a retention pocket, and a monorail formed by a plurality of upwardly tapering cylinders which allow jelly or stone to slide out of the retention pocket when the work tray is turned upside down. The work tray has a ledge which stabilizes a rotatable arm that retains the jelly or stone in the retention pocket. A method of using the articulator includes the steps of installing the locking arm onto the stabilizing ledge of the work tray, rotating the locking arm into a closed position on the stabilizing ledge, pouring jelly into the retention pocket, installing a height-adjusting post in the work tray, tightening a fastener against the post in order to keep the post in an upright position, and placing a small tray with at least one negative tooth impression on top of the jelly.

Abstract: A mechanical interfitting connector for repeatably connecting dental models of teeth to articulators without damaging the former. The connector may include a socket mountable to a model and a male member mountable to the articulator, wherein the male member enters and engages the socket. The socket may be adhered to the model or alternatively partially embedded therein. A screw may be passed through the socket and male member so as to leave a small marking on the dental model, thereby indexing the socket and model for subsequent mountings, and also to prevent disengagement of the male member from the socket. A supplementary plate may be provided to secure anchoring of the male member to the socket, and to shield plaster which has not fully hardened against damage during hardening.

Abstract: A device adapted for adjusting the inclination of an entire articulator in relation to a support plane includes a support element on the support plane, a fastening device attached to the articulator, and a mechanism configured to adjust the distance between the fastening device and the support element.

Abstract: Disclosed is a dental model articulator configured to combine maxillary and mandibular dental model casts with each other. The dental model articulator includes a frame, an arm member rotatably and reciprocatively supported to the frame, an elastic bias unit frontward elastically pressing the arm member with respect to the frame, a first connecting unit formed in the arm member to be connected with the maxillary dental model cast, and a second connecting unit connected to the frame to move reciprocatively through at least one penetration hole and combined with the mandibular dental model cast.

Abstract: An accessory for use with a dental articulator, the accessory including a dental model holder, adapted and configured to hold a dental model, and a mounting assembly for removably affixing said dental model holder to a conventional dental model articulator. In some embodiments, the dental model holder includes a model support, a rear stop member perpendicular to the model support, and a model engaging member mounted in the model support and arranged to engage a dental model and urge it towards the stop member.

Abstract: An apparatus for use in dentistry to obtain positional data related to movement of a mandible about a maxilla comprises a rigid support frame for supporting a maxilla support member, a positionable mandibular member and sensing assemblies. The support member fixedly attaches to the support frame. The mandibular member is positionable proximate the maxilla member. The sensing assemblies attach to the support frame and connect to the mandibular member to obtain positional data related to the movement of the mandibular member. The positional data is collected by a computing device and stored in a data storage medium as time history files. The files can then be transformed into usable information to replicate the mandibular movement in real time either virtually or mechanically.

Abstract: A dental cast stabilizer secures a dental cast to a dental cast articulator, and includes a fastening hole strap and a fastening post strap with a band body disposed therebetweeen. The fastening post strap includes a fastening post disposed thereon, and the fastening hole strap includes a fastening hole disposed thereon that is capable of receiving the fastening post or mounting plate thumb screw on an articulator.

Abstract: A Geller dental arch model includes openings to receive dies. An improvement to the Geller model uses slotted dies, along with complementary support members within the openings of the arch model, to provide proper x, y, and z orientation for the die within the dental model. By avoiding large planar surfaces within the die, this approach can achieve improved fabrication accuracy and better fit for dies and/or arches fabricated with computerized fabrication systems, particularly on surfaces where critical z-axis alignment of a die occurs.

Abstract: The systems and methods disclosed herein employ a combination of digital three-dimensional modeling and rapid fabrication technologies to provide pre-indexed, pre-registered, and/or precut components for articulated dental models. Dental articulators and components of dental models as described herein use a positioning key to encode positional information for components of the dental model, and/or a reference grid on mounting surfaces to enforce local accuracy of fabricated parts against a fixed reference array.

Abstract: The systems and methods disclosed herein employ a combination of digital three-dimensional modeling and rapid fabrication technologies to provide pre-indexed, pre-registered, and/or precut components for articulated dental models. Dental articulators and components of dental models as described herein use a positioning key to encode positional information for components of the dental model, and/or a reference grid on mounting surfaces to enforce local accuracy of fabricated parts against a fixed reference array.

Abstract: A dental model tray (12) for use in forming a dental model has a rigid bottom wall (16) and a relatively thin side wall (17) extending upwardly from the perimeter of the bottom wall (16) to form an open-topped cavity which is adapted to receive the dental casting material. The bottom wall (16) and the side wall (17) are formed integrally of polymeric material, with the side wall (17) being joined to or attached to the bottom wall (16) by a thin membrane-like connector member (19) that is formed integrally with the perimeter of the bottom wall (16) and a lower side edge of the side wall (17). The connector member (19) is frangible and easily broken so that the side wall (17) can be torn away from the base and discarded after dental casting material has hardened in the cavity formed by the side wall (17). The dental model tray (12) further includes an ell-shaped articulator member (13,14) that extends from a back side of the bottom wall (16).

Abstract: A method for preparing a surgical guide for positioning of a dental implementation. The method includes positioning a positioning device relative to a model jawbone, translating the positioning device in a BL direction, adjusting a BL angle of the positioning device about a BL pivot axis corresponding to a desired position of a top of the dental implementation, and fixing the BL position, BL angle, and z-height of the positioning device. A mounting assembly mounts to the positioning device and includes a removable rotation block with a guide hole. The mounting assembly is movable in the MD direction while the BL position is fixed. A template fixes the mounting assembly for transferring the positioning information to a patient's mouth. Various aspects of the design process can be performed on a computer. The guide and a method of using the guide to perform an implant procedure are also disclosed.

Abstract: A mechanical interfitting connector for repeatably connecting dental models of teeth to articulators without damaging the former. The connector may comprise a socket mountable to a model and a male member mountable to the articulator, wherein the male member enters and engages the socket. The socket may be adhered to the model or alternatively partially embedded therein. A screw may be passed through the socket and male member so as to leave a small marking on the dental model, thereby indexing the socket and model for subsequent mountings, and also to prevent disengagement of the male member from the socket. A supplementary plate may be provided to secure anchoring of the male member to the socket, and to shield plaster which has not fully hardened against damage during hardening.

Abstract: A model of at least a part of a dental structure, an articulator, and methods of manufacturing such devices are provided. The model and the articulator can be used to approximate the natural movements of a jaw of a patient to facilitate preparation of a dental restoration. The model can comprise the dental structure, an interface, and at least one void extending from a reference surface of the interface inwardly toward the void. The articulator can comprise upper and lower portions on which models of upper and lower dental structures can be held. The upper and lower portions of the articulator can be configured to generally maintain a vertical alignment while at least one gap formed between respective first and second alignment components thereof allows horizontal movability of the upper and lower portions relative to each other to test the interfit of the models therebetween.

Abstract: A dental modeling system for forming a dental model from a mold of at least a portion of a person's opposed upper and lower teeth. The modeling system includes dental articulator features that are integrated with opposing bases and dental model bases configured to receive removable tapered pins. The system also includes pin locators for improved alignment of teeth of the dental mold when creating the dental model. The pin locator can also include removable tapered pins for use in aligning with specific teeth of the dental mold.

Abstract: An accessory for use with a dental articulator, the accessory including a dental model holder, adapted and configured to hold a dental model, and a mounting assembly for removably affixing said dental model holder to a conventional dental model articulator. In some embodiments, the dental model holder includes a model support, a rear stop member perpendicular to the model support, and a model engaging member mounted in the model support and arranged to engage a dental model and urge it towards the stop member.

Abstract: A dental articulator has upper and lower cast models of a patient's upper and lower teeth in shells (13a, 13b) linked by an articulation joint (14). The models are formed in the shells (13a, 13b) by locating a bite tray (1, 25) having impressions on opposite sides between the shells (13a, 13b) in fixed positional relationship thereto. The lowermost shell (13a) is filled with casting material in contact with the lowermost impression and this is allowed to set to form one model. The bite tray (1, 25) and shells (13a, 13b) are then turned over to enable the other model to be formed in the other shell (13b). The bite tray (1, 25) has a projecting handle (6, 28) which is clamped with a clamping device (19) which can be detachably mounted on a base (10) both ways up. The shells (13a, 13b) can also be detachably mounted on the base (10) both ways up. Locating devices (11, 12) are provided so that the clamping devices (19) and the shells (13a, 13b) retain their positional interrelationship both ways up.

Abstract: A holding device that can be braced in a surveying machining together with an individual preparation model produced by dental laboratory techniques. The holding device has a mechanically stable frame with bores disposed at a distance (a) to one another, in which at least two holding pins are locked that can be displaced at least in the axial direction (A).

Abstract: A dental articulator (1) having an upper tray (2) and a lower tray (3) connected together with an articulator arm (7) having an upper arm (27) and a lower arm (28) wherein an upper access cover (4) is removably secured to the upper tray (2) and a lower access cover (5) is removably secured to the lower tray (3). Flanges (24, 25, 31) and/or apertures (20 and 21) are provided to removably secure the access covers (4 and 5) to the trays (2 and 3). In this manner, a user may work on casts (8, 9, 29 and 30) without disassembling the articulator (1) and removing the casts (8, 9, 29 and 30). An alternate embodiment includes triangular trays (2 and 3) having at least one cast holder (35) extending from each tray (2 and 3).

Abstract: A removable centric stop mechanism 10 for use in a system for making dental restorations. The stop mechanism 10 includes an elongate stop member 11 that can be firmly attached or connected to the dental model and can further be removed from the dental model when so desired. The elongate stop member 11 further incorporates a threaded elongate member 36 that can be threaded to and fro in a bore 34 in the elongate stop member 11 to thereby adjust the effective length of the elongate stop member 11.

Abstract: A dental articulating system and method configured to duplicate at least a portion of a patient's mouth for use in producing a dental prosthesis securing an impression tray to a flexible and resilient material on a stabilizing plate of an alignment fixture. The position of the impression tray is adjusted on the flexible and resilient material. A tray base is detachably secured to a bottom of the alignment fixture. The tray base with the alignment fixture thereon is placed on a drilling fixture. A drill bit is aligned with a location of an impression corresponding to a prepped tooth of the impression tray. A hole is drilled in the tray base corresponding to the prepped tooth.

Abstract: The present invention broadly comprises a sleeve for a dental articulator having upper and lower jaws operatively arranged to simulate a human mouth, the sleeve including an enclosure having a mounting surface and at least one open end, the enclosure arranged to substantially cover and releasably engage the upper or lower jaw of the dental articulator. The sleeve may further include a releasable locking means operatively arranged to releasably secure the sleeve to the upper or lower jaw of the dental articulator. The present invention also broadly comprises a method of mounting a dental model on a dental articulator having upper and lower jaws arranged to simulate a human mouth, the method including the steps of releasably securing a sleeve on the upper or lower jaw of the dental articulator and fixedly securing the dental model to the sleeve. The method may further include the step of removing the sleeve from the upper or lower jaw of the dental articulator.

Abstract: A visible coding of components of an articulator apparatus that mount maxillary and mandible casts indicates the relative correspondence between post-treatment goals and the present locations of a person's teeth and jaws. From another aspect, the visible coding indicates at least a direction, and preferably, a direction and a distance, which a person's teeth and/or jaws must be moved to achieve the goals.

Abstract: A dental prostheses modeling system includes a molding tray for molding the base of a quadrant or full-arch dental model cast which has a longitudinally disposed partition panel disposed generally between upper and lower surfaces of the tray that forms therewithin an upper well for receiving liquid die stone to mold the base of a dental impression model, and a lower well shaped symmetrically to the upper well for providing clearance for optional manipulating pins installable in the bases of selected die segments modeling individual dental prostheses severed from the hardened die stone base of the model. The partition panel includes peripheral flanges for supporting the base of the dental model, and an openable central portion for enabling a hardened dental model to be ejected from the tray, and for providing access for manipulating pins depending downwardly from die segments.

Abstract: A dental articulator system including a device and method of forming dental casts. The dental articulator has adjustable ball and socket joints, which are secured in place with a hand tightenable screw. Tightening the screw applies force through a plunger to the ball, impinging the ball against the inner wall of the socket of the ball and socket joint. The device does not require any glue; thus the dental articulator is easily adjusted and reusable.

Abstract: An articulator system employing magnetic and supporting means enabling dental casts to be mounted in or removed from an articulator and replaced as desired.

Abstract: A dental articulator capable of finely adjusting a three-dimensional articulation posture and exerting a secure fastening force by a lever is provided. The dental articulator includes a lower grip plate, a column, an arm, and an upper grip plate, wherein a first ball and a second ball are disposed between the arm and the upper grip plate, and wherein the dental articulator further comprises: a first clamp block having spherical recesses contacting with the first and second balls; a second clamp block having spherical recesses contacting with the first and second balls; a lever disposed on an outer surface of the second clamp block; an engaging bolt passing through the lever and the second clamp block into the first clamp block; and fastening bolts engaged into the lever to shorten a distance between the first and second clamp blocks.