Abstract: The invention relates to a coupling body that can convert a linear input movement into a linear output movement transversal to the input movement. The coupling body includes two parallel flexional arms of the same length, the ends of the flexional arms being connected by means of transversal connection arms. The connection arms carry driving bodies which represent load bodies arranged at the same distance from the neutral lines of the connection arms, in the same direction.

Abstract: A medical or dental handpiece comprises a grip sleeve, a handpiece head, an engagement element and a retaining member. The handpiece head comprises a head housing and a hollow connecting sleeve extending from the head housing for connecting the handpiece head to the grip sleeve. The engagement element has a first end positionable to extend through the grip sleeve and a second end engageable within an opening in the handpiece head. The retaining member is spaced proximally from the handpiece head. The first end of the engagement element is connectable with the retaining member to secure the second end of the engagement element against the handpiece head and to retain the grip sleeve around the engagement element and against the handpiece head.

Abstract: The invention relates to an electric-motor arrangement for a medical, in particular dental, hand piece which has a motor housing (2) and a rotor (4) which is arranged in the motor housing (2) so that it can be rotated about an axis (L) via a first bearing (6) and a second bearing (8). A stator (14) is arranged around the rotor (4) in relation to the axis (L). The first bearing (6) is received in a first bearing flange (10), and the second bearing (8) is received in a second bearing flange (12). Both bearing flanges (10, 12) are composed of metal and adjoin the motor housing (2) directly by way of their circumferential faces (101, 121). As a result, running noise and vibrations can be reduced. Moreover, premature wear and/or failure can be prevented.

Abstract: A dental drill is intended for performing flapless implant surgery by being mounted on a drill device. The dental drill comprises a drill body and a mounting portion for mounting the drill body to a drill device. The drill body comprises: a cutting part for providing a side blade having a certain length from the cutting edge, and a body portion with limited cutting ability. Tooth bone can be easily removed because of the cutting part at the end portion of the drill body. Also, gums can be protected because the body portion is not only formed with the cutting part integrally, but the side blade either does not exist or is removed.

Abstract: An extender for a dental apparatus comprises a distal connecting portion, a proximal connecting portion, and an elongated portion disposed between the distal connecting portion and the proximal connecting portion, wherein the distal connecting portion is configured to connect to a dental drill bit or the proximal connecting portion and wherein the proximal connecting portion is configured to connect to a dental hand piece or the distal connecting portion.

Abstract: A dental handpiece having a grip with a head in which a treatment tool may be detachably attached. A front casing portion of the grip is continuous to a rear casing portion at an obtuse angle. A first rotary shaft is rotatably supported in the rear casing portion. A cylindrical jacket extends from the head and is arranged in the front casing portion toward the first rotary shaft. A second rotary shaft is rotatably supported in the jacket, and is operatively connected to the treatment tool at one end and to the first rotary shaft at the other end via a gear. The rotary shafts transmit driving force to the head section to drive the treatment tool. The jacket is provided with an engagement groove on its circumferential surface. An engaging device disposed in the rear casing portion detachably engages the groove, thereby fixing the jacket in the front casing portion.

Abstract: A dental prophylaxis angle and handpiece assembly for cleaning and polishing teeth is provided. The dental prophylaxis angle is removably attached to the dental handpiece by an interlocking mechanism that includes extension locking tabs, a locking annular member, and an interlocking drive member in the handpiece. The prophy angle is securely snap-fitted onto the handpiece and locked in place so that it has minimal lateral movement. After the prophy angle has been used to treat a patient, it can be removed easily from the handpiece and disposed thereof.

Abstract: A cordless dental handpiece, a system including a cordless dental handpiece, and a method of connecting a cordless dental handpiece are disclosed. The cordless dental handpiece includes a first module and a second module. The second module is configured to detachably engage the first module. The second module includes a battery compartment.

Abstract: A dental power instrument, in particular, an endodontic instrument, has an operative part (2) at one end and a handle (3) at the opposite end. The handle (3) of the dental instrument is provided with a rotary drive (4) which, when mounted in the head (5) of a handpiece, can directly engage with a rotary drive (4?) upstream of the head. The rotary drive (4) can be inserted and withdrawn independently of the rotary drive (4?) associated with the head of the handpiece, and rotates in the same direction as the rotary drive (4?) associated with the handpiece. Also provided is a handpiece head (5) and a dispenser (30) for such dental power instruments.

Abstract: A medical, in particular dental-medical, handpiece, having a shaft, having a forward shaft section and a rearward shaft section, which defines an obtuse angle with regard to each other, having a working head at a forward end of the forward shaft section, which is tapered towards the working head, and having a drive shaft in the shaft, which drive shaft has a forward drive shaft section and a rearward drive shaft section, which stand in drive connection with one another, the forward end of the forward drive shaft section standing in drive connection with a tool holder moveably mounted in the working head, and the forward drive shaft section being mounted in a receiving sleeve. The receiving sleeve can be screwed in, from the rear, into the forward shaft section.

Abstract: Apparatus for dental treatment includes a base, a treatment unit, and a connecting piece. The treatment unit has one or more treatment instruments and one or more lines for the supply of water, air and electricity. The connecting piece is placed in between the base and the treatment unit. The treatment unit can be disconnected from and connected to the base by using the connecting piece.

Abstract: There is provided a coupling device for electrically coupling a dental instrument to an electrical connector, including a tubular clasp made of an electrically conductive material having a first portion attachable to the connector and a second portion attachable to the dental instrument, the second portion having a slot facilitating insertion and holding of the dental instrument while performing a dental procedure.

Abstract: A dental handpiece having a distal end including an attachment for assembly of a removable workpiece and a handpiece body intermediate a proximal end and the distal end. The handpiece extends in a substantially axial direction. A coupler is included having a cylinder portion and a supply-end portion, the cylinder portion being assembled into the handpiece extending in the axial direction toward the distal end. The cylinder portion includes at least one seal that interfaces with an interior of the body so as to isolate a portion of the body interior into at least one distinct chamber. The supply-end portion of the coupler extends from the proximal end of the handpiece body at an angle from the axis. The supply-end portion also includes a plurality of outlets, the at least one distinct chamber in fluid communication with one of the outlets of the plurality of outlets.

Abstract: A disposable dental angle with a housing consisting of two sections is provided. The vertical aperture of the head section of the housing allows insertion of a driven rotor such that the driven rotor is properly positioned. The horizontal aperture of the tail section of the housing allows insertion of a driving shaft such that the driving shaft is properly positioned. The front stepped end of the tail section engages the horizontal aperture of the head section firmly such that the two sections form a right angle. This ensures that the gear of the driven rotor is properly coupled to the matching gear of the driving shaft. Hence the driving shaft transfers the rotation from a dental tool to the driven rotor for the purpose of tooth cleaning using a cleaning cup.

Abstract: The invention relates to an improved dental tool drive arrangement for a hand-piece with a drive head, the tool drive arrangement permitting length adjustment of the tool in the drive head by concentrically supporting the tool in the drive head at any position from a fully inserted position to a maximum retracted position. The tool drive arrangement preferably includes a tool and a rotatable tool supporting element for concentrically supporting the tool from the fully inserted to the maximum retracted position, the tool preferably including a maximum retraction indicator for indicating to a user when the tool has been retracted to the maximum retraction position. This provides a significant advantage over the prior art by allowing a user to adjust the exposed length of a rotatable tool, preferably a dental bur, without exceeding safe operating limits.

Abstract: The invention concerns a handpiece for a surgical or dental tool (3), which can be inserted in the head of the handpiece (1) through an insertion hole (14) into a tool holder (2) and is rotationally supported by means of two axially separated bearings (12, 13), with positive torque transmission (8) to the tool (3) by the drive (9) installed in the handpiece, such that the tool possibly has a longitudinal bore (6) for supplying cooling liquid to the work site, and the handpiece (1) possibly has a short, fixed feed tube (7), which extends into the longitudinal bore and is sealed from the tool (3). To increase the torque that can be transmitted, the invention is characterized by the fact that the torque transmission (8) occurs in the region of the bearing (13) that is adjacent to the insertion hole (14). The invention also concerns the development of suitable tools.

Abstract: The invention relates to a method for establishing a releasable connection between a tool connection or coupling piece, which is formed on a dental handpiece, and the tool shank of a dental hand instrument. In order to connect a journal-like fastening section, which tapers toward a free end, on one of the elements to be connected, is inserted into an opening while matching the same, which is adapted to this section, on the other of the elements to be connected.

Abstract: A dental handpiece for root canal treatment comprises an outer sleeve, a connecting device for connecting the handpiece to a control and analyzing unit, a measurement circuit having a power source and to a drive unit, an electrically conducting tool receptacle and an electrically conducting driving device, wherein the tool receptacle and the driving device are mechanically and electrically connected together so that a driving motion generated by the drive unit can be transmitted via the driving device to the tool receptacle and electrical measurement signals can be transmitted between the driving device and the tool receptacle. A first connection is provided for transmitting the driving motion. A second electrically conducting connection, which may comprise sliding contacts, is provided for transmitting the electrical measurement signals.

Abstract: A two-part, modular dental handpiece cable connector system that provides a convenient method for fast field replacement of worn or defective handpiece cables without disassembling the dental device. The two parts include a female connector element that mounts within the device housing and a male connector element to attach the cable. The female connector is further defined into two categories: snap-in mounting for enclosed, confined space cabinets and threaded panel mounting for universal attachment.

Abstract: In a dental, dental-medical or dental-technical handpiece, having an elongate grip sleeve there are provided at the rearward end of the grip sleeve coupling elements for the connection of the handpiece to a supply hose to be connected with a dental supply arrangement, and there are provided at the forward end of the grip sleeve a head section with a tool receiver for mounting a tool to be put into rotation. The handpiece further has an electric motor for driving a tool held by the tool receiver, which motor is completely integrated into the grip sleeve such that grip sleeve and motor form a unit.

Abstract: The invention concerns a device for locking a dental instrument having a rotating spindle, formed by a hollow spindle and adapted to receive the head of an instrument, and a locking spring formed by a lower ring extending on a common side by two branches or a plurality of elastic branches. Each branch is provided with a pin engaged in an annular groove provided in the head of the instrument. There is a push-button having, in its underside, a central conical pressure head adapted to space apart radially the branches of the locking spring to release the pins from the annular groove of the instrument. The locking branches are housed in the slots provided in the rotary spindle to lock in rotation the spring relative to the rotary spindle, the spring being moreover maintained axially between the push-button and a shoulder of the rotary spindle.

Abstract: There is disclosed a medical or dental hand-piece element comprising a coupling mechanism for a detachable connection of the hand-piece element to a drive unit, a tool receptacle that is or can be connected to the hand-piece element, and a drive element for transmitting a driving movement from the drive unit to the tool receptacle so that the tool receptacle can be set into a working movement, wherein the drive element comprises at least one rotatable shaft, and a generator for converting mechanical energy into electric energy, wherein the generator can be driven by the at least one rotatable shaft of the drive element.

Abstract: Functional handpiece 1 having an elongate handpiece body which has at its rearward end a connection element for connection with a flexible supply line, and has at its forward end a light emission element of a light permeable material for the illumination of the treatment site, and has in the light emission element an outlet opening for a medium such as water or air or spray, the light emission element forming a forward region of the functional handpiece and being releasably connected with the remaining region of the functional handpiece, and the light emission element having a plug-in fitting for the light emission element.

Abstract: The invention relates to a medical or dental-medical treatment which at its rearward end has a coupling element for coupling on to a matching coupling element of a flexible supply line, and in its forward region has a holder device for a tool, the handpiece being of a rearward and a forward handpiece section which are connected with one another by means of a plug-in connection and are fixed on one another by means of a latching device which has a latching arm extending approximately axis-parallel and which is transversely elastically bendable, which latching arm is arranged on the one plug-in connection part and is latched in its free end region with a latching element arranged on the other plug-in connection part . For the purpose of improving the connection between the rearward and the forward handpiece section the latching device at the same time axially fixes an insert part of the handpiece, which insert part sits in a plug-in recess of the one and/or of the other plug-in connection part.

Abstract: A rotation locking device located in the area of two separate, independent shafts or shaft sections for preventing the undesired rotation of a shaft or shaft section. The rotation locking device includes a locking pin which, in its idle position (during operation of the appliance), rests on a displacement surface of a shaft or shaft section. In the event of the undesired rotation of a shaft (caused, for example, when a tool is being unscrewed from a coupling which is connected to the shafts), the shaft underneath the locking pin turns until the pin is forced out of the displacement surface, is displaced outwards radially and pressed against a component which is fixed to the body of the appliance (e.g. the bearing sleeve of the gearbox in which the rotation locking device is fitted). Any further rotation of the shafts is prevented in this manner.

Abstract: The invention relates to a medical or dental-medical instrument (2) having a memory element (10p) for identification and/or operational parameter data. IN order to extend the range of possible applications of the instrument, the memory element (10p) is constituted for the overwriting of the data by other data.

Abstract: An adapter for a handpiece system , especially for use in conjunction with medical and dental light emitting apparatus for the transmission of light to cure photo-polymerisable materials. A device, preferably in the form of an adapter, enables the user to correctly match the polarity of the contacts in the supply hose or conduit with those of the light emitting apparatus.

Abstract: In a medicinal or dental hand instrument (1) comprising a hand piece (2) and a handle (6) arranged on the hand piece (2), an outlet opening (5), arranged on the front side of the handle (6), for the outlet of an abrasive therapeutic agent and a transport fluid, and a coupling terminal (4) for coupling the hand instrument (1) to a supply line for at least one transport fluid, in particular water and/or air, wherein the coupling terminal (4) is a coupling component (14b) of a coupling (13), the coupling component (14b) is arranged on an insert piece (20) which can be plugged into a plug-in socket or plug-in recess (19) and in its end zone, facing away from the flow, has one or more coaxially or paraxially disposed, sealed pipe socket couplings (10), which each connect a feed line (9, 11) for the transport fluid to an ongoing feed line (21, 22).

Abstract: The light curing devices of the invention are configured with a light applicator and one or more detachable power supply units. The light applicator is configured to emit radiant energy that is suitable to cure photo-sensitive compounds. The light applicator is also configured to be detached from the detachable power supply and to be autoclaved. The detachable power supply units are configured to provide power to the light applicator and may comprise a power cord or a battery pack that is configured in size and shape to be held within the holding slot of a holding tray, an example of which is a standard dental hand piece holding tray.

Abstract: Dental instrument, with a handpiece (15) housing a driven tool (5), which handpiece is rotatably connected to a supply device (28) by a tube (14) containing lines.

Abstract: In a medicinal or dental hand instrument (1) comprising a hand piece (2) and a handle (6) arranged on the hand piece (2), an outlet opening (5), arranged on the front side of the handle (6), for the outlet of an abrasive therapeutic agent and a transport fluid, and a coupling terminal (4) for coupling the hand instrument (1) to a supply line for at least one transport fluid, in particular water and/or air, wherein the coupling terminal (4) is a coupling component (14b) of a coupling (13), the coupling component (14b) is arranged on an insert piece (20) which can be plugged into a plug-in socket or plug-in recess (19) and in its end zone, facing away from the flow, has one or more coaxially or paraxially disposed, sealed pipe socket couplings (10), which each connect a feed line (9, 11) for the transport fluid to an ongoing feed line (21, 22).

Abstract: A rotation locking device located in the area of two separate, independent shafts or shaft sections for preventing the undesired rotation of a shaft or shaft section. The rotation locking device includes a locking pin which, in its idle position (during operation of the appliance), rests on a displacement surface of a shaft or shaft section. In the event of the undesired rotation of a shaft (caused, for example, when a tool is being unscrewed from a coupling which is connected to the shafts), the shaft underneath the locking pin turns until the pin is forced out of the displacement surface, is displaced outwards radially and pressed against a component which is fixed to the body of the appliance (e.g. the bearing sleeve of the gearbox in which the rotation locking device is fitted). Any further rotation of the shafts is prevented in this manner.

Abstract: The invention relates to a medical or dental-medical treatment (3) which at its rearward end has a coupling element (7) for coupling on to a matching coupling element (8) of a flexible supply line (2a), and in its forward region has a holder device (5) for a tool, the handpiece (3) being of a rearward and a forward handpiece section (3a, 3b) which are connected with one another by means of a plug-in connection (17) and are fixed on one another by means of a latching device (72) which has a latching arm (75) extending approximately axis-parallel and which is transversely elastically bendable, which latching arm is arranged on the one plug-in connection part (77) and is latched in its free end region with a latching element (76) arranged on the other plug-in connection part (80).

Abstract: A dental handpiece for the polymerization of photosetting resins or compounds comprising as its polymerizing light source, at least one LED incorporated in the handpiece, the electrical supply signal for the LED light source being drawn from connectors of other types of hand pieces and being processed by means of an appropriate electronic circuit in order to make the electrical supply signal suitable for bias of said LED light source.

Abstract: The invention is an improved endodontic adapter for a sonic scaler consisting of a talon having a threaded end for insertion into the handle of the sonic scaler. A pair of downwardly pointed barbs protrudes radially from the side of the adapter for receiving an elastic ligature, which firmly holds the dental instrument such as file to the talon. The opposite end of the talon has a tapered shaft that receives an aperture drilled into the side of the dental instrument. The ligature is simply wrapped around the dental instrument on opposite sides of the talon and then the ends are wrapped around the downwardly pointing barbs.

Abstract: A dental facility includes a latch disposed in a coupler and having a tongue extendible outward of the coupler, a dental tool member having a barrel engageable onto the coupler, and a spring for biasing the tongue of the latch to engage with the barrel and to detachably secure the dental tool member to the coupler. The dental tool member may be detached from the coupler for being discarded or changed with the other one after use, and for preventing both the patients and the dentists from being contaminated or infected by the dental tool member.

Abstract: A high-speed medical/dental handpiece includes a handle, which carries air, water, and light to a disposable cartridge which is received on the sleeve. The cartridge includes a head portion and a sleeve portion. The cartridge head defines a chamber having an upper and lower portions each of which receives a bobbin shaped sleeve bearing, and a central portion which receives a turbine. The bearings each form annular channels with their respective chambers. The cartridge includes water and air passages which direct water to the turbine so that the turbine is driven by an air/water mixture. Water is also directed to the upper bearing and grooves in the lower bearing chamber allow water to enter the annular channel around the lower bearing. Axial passages in the bearings enable water to pass from the annular chamber to the bit to contact the bit shaft. The air and water in the chamber are exhausted through the bit opening in the bottom of the head as well as through a plurality of exhaust ports in the head.

Abstract: A two-part, modular dental handpiece cable connector system that provides a convenient method for fast field replacement of worn or defective handpiece cables without disassembling the dental device. The two parts include a female connector element that mounts within the device housing and a male connector element to attach the cable. The female connector is further defined into two categories: snap-in mounting for enclosed, confined space cabinets and threaded panel mounting for universal attachment.

Abstract: A portable tooth or nail polisher has a motor connected to a coupler formed in a body. A head member is mounted on the coupler during use. An accommodating space is formed in the body for holding the head when not in use. A head holder for fixing the head member in the accommodating space presses in a direction perpendicular to a longitudinal direction and is constructed of a pair of protrusions extending from the body defining the accommodating space. The distance between the protrusions is smaller than the width of the head member.

Abstract: A socket for removably receiving an end of a dental saliva ejector tube includes a central body having a first end forming a port for being coupled to a vacuum hose. The central body includes a passage extending therethrough from the first end toward a second opposing and that includes an enlarged bore forming a socket for receiving the end of the dental saliva ejector tube. A lever, slide member, or other movable retaining member is movably secured to the central body for selectively engaging, or moving away from, the sidewall of the ejector tube. The movable retaining member includes a sharpened tip for lightly digging into the sidewall of the ejector tube. A biasing spring may be provided for urging the retaining member into engagement with the sidewall of the ejector tube. A user may depress or otherwise actuate the retaining member to move it away from the ejector tube to insert or remove the ejector tube from the socket.

Abstract: In a medicinal or dental hand instrument (1) comprising a hand piece (2) and a handle (6) arranged on the hand piece (2), an outlet opening (5), arranged on the front side of the handle (6), for the outlet of an abrasive therapeutic agent and a transport fluid, and a coupling terminal (4) for coupling the hand instrument (1) to a supply line for at least one transport fluid, in particular water and/or air, wherein the coupling terminal (4) is a coupling component (14b) of a coupling (13), the coupling component (14b) is arranged on an insert piece (20) which can be plugged into a plug-in socket or plug-in recess (19) and in its end zone, facing away from the flow, has one or more coaxially or paraxially disposed, sealed pipe socket couplings (10), which each connect a feed line (9, 11) for the transport fluid to an ongoing feed line (21, 22).

Abstract: An adapter for use with a piezoelectric and/or magnetostrictive ultrasonic unit can be coupled between the handpiece and the cable. The adapter includes a symmetrically oriented flow path with offset ends to mate with the handpiece and the cable respectively. The adapter also includes a rotary electrical connection facilitating the transfer of energy from the cable to the handpiece while the handpiece is being rotated. The rotary connection of the adapter can be integrated into either of the handpiece or the cable termination.

Abstract: A high-speed medical/dental handpiece includes a handle, which carries air, water, and light to a disposable cartridge which is received on the sleeve. The cartridge includes a head portion and a sleeve portion. The cartridge head defines a chamber having an upper and lower portions each of which receives a bobbin shaped sleeve bearing, and a central portion which receives a turbine. The bearings each form annular channels with their respective chambers. The cartridge includes water and air passages which direct water to the turbine so that the turbine is driven by an air/water mixture. Water is also directed to the upper bearing and grooves in the lower bearing chamber allow water to enter the annular channel around the lower bearing. Axial passages in the bearings enable water to pass from the annular chamber to the bit to contact the bit shaft. The air and water in the chamber are exhausted through the bit opening in the bottom of the head as well as through a plurality of exhaust ports in the head.

Abstract: The invention relates to a medical or dental-medical treatment instrument (1) having a media line, in particular for water or spray, extending from its rearward end to its forward end region, in which line an exchangeable filter element (21) is arranged. In order to reduce the flow resistance of the filter element (21), while providing a small cross-sectional size, the filter element (21) has the form of a sleeve and the direction of passage of the medium is directed transversely to the sleeve wall (21a).

Abstract: In a medicinal or dental hand instrument (1) comprising a hand piece (2) and a handle (6) arranged on the hand piece (2), an outlet opening (5), arranged on the front side of the handle (6), for the outlet of an abrasive therapeutic agent and a transport fluid, and a coupling terminal (4) for coupling the hand instrument (1) to a supply line for at least one transport fluid, in particular water and/or air, wherein the coupling terminal (4) is a coupling component (14b) of a coupling (13), the coupling component (14b) is arranged on an insert piece (20) which can be plugged into a plug-in socket or plug-in recess (19) and in its end zone, facing away from the flow, has one or more coaxially or paraxially disposed, sealed pipe socket couplings (10), which each connect a feed line (9, 11) for the transport fluid to an ongoing feed line (21, 22).

Abstract: A collapsible angle piece for dental or surgical use has a head part, an elbow part detachably connected to the head part, and a handle detachably connected to the elbow part remote from the head part and having an actuating surface. The elbow part has a cage that is axially moveable between a locking position and a release position. At least one locking element is radially moveably supported in the cage, wherein the at least one locking element can be in a radially inner position or a radially outer position depending on whether the cage is in the locking position or in the release position. At least one elongate actuating member is arranged in the elbow part so as to be substantially axially moveable, wherein the at least one elongate actuating member has a first end cooperating with the cage and a second end cooperating with the actuating surface of the handle.

Abstract: The present invention provides a dental handpiece filter unit containing a filter that minimizes the exposure of patients to pathogens found in the dental water supply lines while promoting frequent replacement of DUWL filters by providing a disposable microfiltration filter that is easily replaced at low cost. A disk or membrane type filter is placed in a disconnectable autoclavable filter unit in the handle of an existing design dental instrument such that the form and function of the dental instrument are not adversely affected. The handpiece filter unit, which fits in-line between the dental unit and the water line fitting, includes a waterline connector, a filter-housing unit, and a handpiece connector. Each of these components is connected to each other via plastic tubing. Specifically, the air and exhaust lines run from the waterline connector to the handpiece connector, circumventing the filter unit.

Abstract: The invention relates to a medical or dental-medical treatment instrument (1) having a grip sleeve (11), an oscillatory rod (13) which extends longitudinally in the grip sleeve (11) and is mounted therein in a radially or also axially elastically yielding manner, and an oscillation generator (31) for transmitting oscillations to the oscillatory rod (13). In order to attain a compact construction, the oscillatory rod (13) is of a base part and an attachment part which is fixed on the base part.

Abstract: In order to allow a dental instrument such as an air turbine or an electric motor hand piece to be quickly connected or disconnected to a supply unit, a revolving connecting unit is provided with a fixed portion (4), provided with channels (13 to 16) for fluids and electric contact rings (26) at the front, a coupling sleeve (32) freely rotating on the fixed portion, an a stop ring inserted between said sleeve and the fixed portion and rotating freely thereon. The coupling sleeve (32) is secured to the back of the instrument by a bayonet device (38). This sleeve extends far enough forwards to prevent accidental contact between the electric contact rings (26) and an external object when the connecting unit is not connected to an instrument.

Abstract: A high-speed dental drill is comprised of a hand piece having a drill head at an end thereof. A turbine assembly is supported in a turbine chamber inside the drill head. The turbine assembly has a chuck which is rotatably secured between bearings. An impeller is secured about the chuck and aligned with an air inlet port in a sidewall of the turbine chamber. An exhaust port is provided in the sidewall to exhaust air. An air conduit is provided in the handpiece to direct air pressure to the air inlet port to drive the turbine and rotate the chuck. The chuck has a work bit engaging free end which is exteriorly accessible. An insert is secured to the drill head and provides access to the turbine chamber. The insert has a smooth conical tapered circumferential external sidewall for frictional engagement by a mating conical bore of a key for the removal and connection of the insert. The exhaust port has a non-circular cross-section in which the aspect ratio of the exhaust port is not equal to one.