Abstract: An image projection table including: a projector which projects an image; a housing in which the projector is housed; and a top plate on which the image projected from the projector is projected, wherein the top plate includes an operational part for operating the projector, and a top plate driving part which moves the top plate so that the operational part is located on the operator side.

Abstract: An electronic element testing apparatus for use with a number of probes. Each probe has a lower pole and an upper pole. The apparatus includes: a first plate having a first side and a second side, the first side having an array of lower pole regions disposed thereabout, each lower pole region configured to receive a lower pole of a probe; and a plurality of signal conductor regions disposed proximate the array of lower pole regions, each signal conductor region arranged to provide a non-cable electrical path between a lower pole region and a switching circuit. The switching circuits are operable to sequentially connect each electronic element to a testing circuit via the upper and lower poles.

Abstract: A method and apparatus for improving image quality in a reflector-type telescope are provided, through utilization of one or more nozzles disposed about the periphery of a reflecting mirror of the telescope, for directing a flow of air from a backside of the mirror across a concave reflecting surface of the mirror, to thereby sweep away and/or preclude formation of image distorting thermal boundary layers, or other impediments to image quality, resulting from the mirror not being in thermal equilibrium with ambient air surrounding the mirror. Supply nozzles are provided around a portion of the periphery of the mirror, and exhaust pick-up nozzles are provided around another portion of the periphery of the mirror, to thereby cause a flow of air to closely adhere to the concave surface of the mirror.

Abstract: A drape (101) for a surgical microscope (100) is attached to the surgical microscope (100) with a holding device (103) in the region of the surgical microscope main objective (104). The holding device (103) can accommodate a cover element (105). A tongue-shaped section is provided on the holding device (103) which applies a spring force to an outer peripheral surface of the surgical microscope main objective (104) when the holding device is arranged on the surgical microscope main objective (104) so that the holding device is held force-tight and friction-tight on the surgical microscope main objective. The cover element (105) can be inserted laterally into the holding device (103).

Abstract: The present invention relates to vibration detection devices. In one embodiment a corner reflective array is provided. The corner reflective array includes at least one corner cube. Each corner cube includes three mutually perpendicular reflective surfaces that intersect in a corner.

Abstract: The present invention includes conformable retroreflective structures. In some embodiments, the conformable retroreflective structures are also shrink resistant. The conformable retroreflective structures include a transparent plasticized polyvinyl chloride film having a first side and a second side; a first transparent polymer layer overlying the first side of the plasticized polyvinyl chloride film; a second transparent polymer layer overlying the second side of the plasticized polyvinyl chloride film; an array of retroreflective cube-corner elements underlying the second transparent polymer layer; and a plasticizer resistant adhesive underlying the array of retroreflective cube-corner elements. In some embodiments, the first and second transparent polymer layers are transparent, radiation-cured polymer layers.

Abstract: A laser beam dump dissipates laser energy. The laser dump includes a cradle for holding the laser and an open cavity lined with a laser energy absorbing material. Laser emissions are directed from the laser into the laser dump cavity where the laser energy is dissipated.

Abstract: A hinge actuator for a wing mirror unit includes a base plate, including base shaft with mirror support; output part; coupling ring; and gear wheel. The base plate and mirror support include cooperating stops. The coupling ring is arranged so as to be rotatable with limited travel about the base of the shaft between a first angle ?1, which corresponds to a folded-out position, and a second angle ?2. The coupling ring can cooperate with the mirror support via a first set of cooperating stops, and can cooperate with the base plate via a second set of cooperating stops, such that in the first angle ?1 of the coupling ring, the spring force is transmitted, through cooperation of the first set of stops, and that in the second angle ?2, the spring force, through cooperation of the second set of stops, is transmitted to the base plate.

Abstract: The invention provides a process for producing a high-precision reflector and its coating. A reflector is produced from a solid material using a material-removing process and is coated with a cold-light mirror layer.

Abstract: An improved device for reflecting, radiating, or receiving electromagnetic radiation, acoustic waves, or other energy forms through the use of a membrane stretched across a lightweight, round, frame structure. A near perfectly round and flat semi-rigid backplane surface (1) and a near perfectly round ring or stack of rings (2) are mutually reinforced, forming a raised circumferential planar surface, and a cavity within. A membrane (3) is attached to the top of the rings, forming one wall of a sealed chamber. A source of sub-ambient pressure (4) is applied to the chamber, causing a primary uniform deformation in the membrane for the purpose of manipulating electromagnetic radiation, acoustic waves, or other energy. The backplane surface also deforms uniformly, increasing the strength of the structure. A flat, rigid floating batten (5) prevents waves or wrinkles from forming in the membrane material.

Abstract: This invention relates to a hybrid deformable mirror. A deformable mirror is provided comprising a reflective surface provided on a substrate and a layer of deformable material attached to the substrate that is operable to deform the mirror and wherein the substrate is supported by an actuator that is operable to deform the mirror.

Abstract: The present abstract refers to a patent for utility model covering an actuating mechanism belonging to the field of the components of outer rear-view mirrors, which received the arrangement to provide a better usage and manufacturing conditions, an arrangement being of the type comprising: a pair of electric micro-engines (10) provided with endless axes (11); a pair of annular gears (20) coupled with the respective endless axes; two elastic grips (30) incorporated into the gears; two threaded actuating pins (40), which pass through and remain coupled with the grips; a casing (50)-(60), which houses the engine and gear assembly, and the ends of the actuating pins projecting outwards; a middle articulation assembly (70), whose first portion is incorporated into the body (50) of the casing; a plate (80) for supporting the mirror bracket (1) whose rear face features a pair of grooves (81), with which the ends of the actuating pins (40) are articulately coupled; said supporting plate (80) being further provided wi

Abstract: A display with a housing and an indicium that may be selectively back-illuminated. The housing includes a cavity having a first portion and a second portion. A first light source that provides light of one color and a first intensity is disposed in the first portion. A second light source that provides light of another color and a second, higher intensity is disposed in the second portion. The second portion is disposed in-line and encompasses an area that includes the indicium. Operation of only the first light source back-illuminates the indicium with a first color. Operation of the second light source back-illuminates the indicium with a second color regardless of whether the first light source is illuminated or not. A member may be disposed between the first and second portions to aid in controlling the brightness and uniformity with which the indicium is illuminated by the first light source.

Abstract: Light emitting assemblies include a light emitting panel member having at least one light source positioned, embedded, potted, bonded or otherwise mounted in a shaped slot, cavity, recess, opening or hole in the panel member. Deformities on at least one surface of the panel member may vary to cause light to be emitted from the panel member. At least one angled, faceted or curved reflective or refractive surface in close proximity to the light source redirects some of the light to fit a particular application.

Abstract: A device for fastening the lighting units in a backlight module is provided. A rigid board partially laps over the adjacent lighting unit or units. The rigid board and the backboard have holes respectively such that a bolt is passed through the holes and locked on a nut. Accordingly the rigid board exerts a compressing strength to fasten the adjacent lighting unit or units onto the backboard.

Abstract: A article of manufacture that includes a luminous medallion. A conductor having a coating of non-conductive material is formed into a loop having two discontinuities. A clasp that houses a removable battery is fixed within the first discontinuity and a bead having an internally embedded LED is located within the second discontinuity. Electrical connections are made to electrodes located within the clasp by interior electrical conductors exposed at the stripped ends of the coated conductors that define one discontinuity. The conductors are fixed in electrical contact with the LED at the other discontinuity at the stripped ends of the coated conductor in the region of the second discontinuity. A membrane with an interior surface and an exterior surface, with the exterior surface adapted to receive the medallion secured thereto, and the interior surface adapted to receive elements of the clasp.

Abstract: A combination linear spring clip and capturing guide retains a reflector to a ceiling lighting fixture, which has a mounting frame secured in a ceiling, wherein the mounting frame includes an opening to accommodate the reflector. One or more capturing guides are mounted on an upper surface of the mounting frame surrounding the opening. Each capturing guide extends radially from a center of the opening. Respective springs are linearly slidable within the respective capturing guides, with a portion of each spring extending out of each capturing guide. Each linear spring clip engages an outer surface of the light fixture reflector to secure it in place, allowing the mounting of reflectors of varying size.

Abstract: Waterproof miniature LED device including a cylinder having a first housing part with an internal thread and a second housing part with an external thread and rotatably coupled to the first housing part via engagement of the threads, an LED light assembly mounted to the cylinder and a dome connected to the cylinder and covering the LED light assembly. The cylinder defines a chamber for receiving batteries. Each housing part is conductive to enable formation of an electrical circuit including the batteries, LED light assembly and conductive portions of the housing parts. Illumination provided by the LED light assembly is controlled by rotating the housing parts relative to one another causing formation or interruption of the electrical circuit. An elastic ring covers a space between the housing parts alongside the threads to prevent water from entering between the threads into the interior of the cylinder and interrupting the electrical circuit.

Abstract: The present invention relates to a garage light assembly having a housing with a lamp mounting surface wherein a main high intensity discharge lamp and an auxiliary circular high output fluorescent lamp are mounted. The auxiliary lamp is mounted centrally within the assembly and above the light emitting portion of the high intensity discharge lamp so that the light pattern emitted from the auxiliary lamp is symmetrical and the auxiliary lamp does not shadow the light emitted from the high intensity discharge lamp.

Abstract: A system provides light of selectable spectral characteristic (e.g. a selectable color combination of light), for luminous applications such as signage and indicator lights. An optical integrating cavity combines energy of different wavelengths from different sources, typically different-color LEDs. The cavity has a diffusely reflective interior surface and an aperture for allowing emission of combined light. Control of the intensity of emission of the sources sets the amount of each wavelength of light in the combined output and thus determines a spectral characteristic of the light output through the aperture. A deflector shaped like a number, character, letter, or other symbol, may be coupled to a similarly shaped aperture. By combining several such fixtures, it is possible to spell out words and phrases, with selectable color lighting. Disclosed fixture examples use an extruded body member with appropriately located reflective surfaces, to form both the cavity and deflector.

Abstract: The present invention provides a bottom lighting backlight module comprising: a light reflecting plate, a plurality of light sources such as lamp and LED; and a diffusion sheet; wherein said diffusion sheet has an excavated structure of shape with cross-section of an inverted triangle having a specific apex angle ranging from 110 degrees to 130 degrees. Some of the light incident on the excavated structure inside the diffusion sheet can be totally reflected and redirected sideways, so that it is possible to reduce the local brightness for area around each light source but significantly improve the evenness of brightness for the whole module.

Abstract: A luminaire with improved lateral illuminance control comprising a light pipe with a longitudinal center is disclosed. A light-extraction means applied to a radial swath of the light pipe has a longitudinal portion having dimension along its length, centered about a slice on the light pipe longitudinally; said slice being orthogonal to the longitudinal center and located in a propagation plane through which light propagates to a virtual target area intersecting the propagation plane. The light pipe intervenes between the radial swath and the target area. A first average efficiency point of the light-extraction means corresponds to the minimum distance to the target area being at least approximately 20% less than a respective, second average efficiency point corresponding to a respective maximum distance to such area. The light-extraction means efficiency varies from the first average efficiency point to the second average efficiency point though more than one non-zero value.

Abstract: An external electrode fluorescent lamp includes an external electrode having an increased surface area. The external electrode fluorescent lamp includes a lamp tube, the lamp tube including a “W”-like shaped end portion, and a double-tube external electrode formed on an outer surface of the “W”-like shaped end portion, the double-tube external electrode including a first electrode on a concave outer surface of the “W”-like shaped end portion, and a second electrode formed on a non-concave outer surface of the “W”-like shaped end portion. Alternatively, the external electrode fluorescent lamp includes a lamp tube, the lamp tube having two end portions and an intermediate portion between the end portions and a diameter of the end portions being larger than a diameter of the intermediate portion, and external electrodes respectively formed on an outer surface of the end portions of the lamp tube.

Abstract: The present invention provides a lighting device that comprises at least one light emitting diode that is adapted for being electrically connected to a power source, and at least one sheet of fabric for covering the at least one light emitting diode. As such, light emitted from the at least one light emitting diode is able to shine through the at least one sheet of fabric.

Abstract: A backlight module comprises a baseboard, at least one light-emitting element and a heat-dispersing member. The baseboard has at least one through-hole. The light-emitting element is installed in one of the through-holes and is electrically connected to a surface of the baseboard. The heat-dispersing member adjacent to the baseboard can contact the light-emitting elements directly.

Abstract: An exterior light fixture includes a housing configured to be mounted to an exterior vertical wall. A luminaire is connected via a projecting arm to the housing and powered by electrical wires running therethrough. The housing includes a rotatable door which, when rotated from a closed position to an open position, exposes a ground fault interrupter circuit providing preferably three-pronged sockets to deliver grounded, protected AC current for consumer use.

Abstract: Lighted tubing includes an elongate wall and a light source. The elongate wall defines an interior channel. A conductor may be positioned adjacent to and extending from the light source to conduct light produced by the light source along the wall. A method of securing medical tubing includes the steps of providing medical tubing, providing a light source, attaching the light source to an elongate wall of the medical tubing, and the light source indicating the location of the wall in a dark environment.

Abstract: A lighted handle includes an elongate light transmitting member that has first and second end portions. First and second support surface engageable mounting brackets carry the first and second end portions of the light transmitting member. A narrow beam light emitter is located in the first mounting bracket and has a light beam emitting end. The light beam emitting end faces the adjacent first end portion of the light transmitting member and is aimed longitudinally along the light transmitting member to make the same more visible.

Abstract: A control unit of a vehicular headlamp apparatus can selectively perform steering angle control and navigation-cooperative control. The steering angle control operates a drive mechanism based on a steering angle and a speed of a vehicle to control a headlamp's swivel angle. The navigation-cooperative control operates the drive mechanism using a navigation unit to control the swivel angle. When a current position of the vehicle reaches an entry control start point, the control unit starts navigation-cooperative control at the entry into a curved road. The control unit finds a target swivel angle based on a curvature radius and curved road direction information about the curved road. While the vehicle moves from the entry control start point to a curved road start point, the control unit operates the drive mechanism to gradually change the headlamp's swivel angle to the target swivel angle.

Abstract: The invention relates to a device and method for displaying luminous radiation on a shell of an aircraft, comprising at least one light source for producing luminous radiation, and at least one projection device for converting the luminous radiation into projectable luminous radiation. The at least one projection device is mounted inside the shell in order to project the luminous radiation through the interior (15) and onto the shell (60). Said shell is translucent at least in portions thereof whereby making the projected luminous radiation visible from the outside. The invention also relates to a method for displaying luminous radiation on a shell of an aircraft.

Abstract: A center high mounted stop lamp (12) including a plurality of LEDs (34) mounted on a printed circuit board (30). TIR lenses (40) are employed to focus the light from the LEDs (34) to give an even lighting appearance. The TIR lenses (40) include a prism (44) for directing the light in a desired direction. The circuit board (30) and lenses (40) are mounted in a housing (18) so that each LED (34) includes a separate lens (40) configured relative thereto to provide the desired collection and reflectance of the light. The housing (18) includes a plurality of posts (70) that extend through openings (48, 50) in the circuit board (30) and the lenses (40) to align the LEDs (34) to the lenses (40) relative to the housing (18).

Abstract: The various embodiments of the present invention generally include a display device having a surface with indicia formed thereon. The indicia are indicative of at least one vehicle parameter. The display device includes a light guide connected to the surface and a light-reflecting portion formed in the light guide. The light-reflecting portion is disposed at least partially over one of the indicia. The light guide collects light, directs the light toward the light-reflecting portion and illuminates at least one of the indicia. The light guide and the light reflecting portion provide an enhanced or decorative effect for one or more of the indicia.

Abstract: A light guide for a transmission shifter assembly includes a light member having a top light transmitting surface, and a reflective bottom surface. The light member also includes first and second ends, as well as first and second sides. At least one light emitting diode is integrally formed with the light member. The light emitting diode produces light for backlighting the transmission shifter assembly.

Abstract: A backlight unit applied on a display device is disclosed. The backlight unit includes a base having a frame, an optical film, an adhesive and a shading tape. The frame has at least a recess, and the optical film has at least a flange for inserting in the recess of the frame. The shading tape locates on the frame, and the adhesive locates between the frame and the shading tape only. No adhesive exists between the optical film and the shading tape.

Abstract: An illumination module of light emitting elements is provided. The present illumination module includes a printed circuit board having a one-dimensional array of light emitting elements arranged thereon and a reflecting layer on the surface of the printed circuit board with the light emitting elements arranged thereon. The reflecting layer provides reflecting means for the light emitting elements, improving utilization of the light emitting from the light emitting elements, and thus increasing the luminance of the illumination module of light emitting elements.

Abstract: A flat planar light fixture formed of a translucent panel with for the transmission of light is illuminated by a plurality of high brightness LEDs disposed along the edges thereof. A layer of reflective material on a back surface of the panel facilitates reflection and dispersion of light that occurs within the panel through a front surface thereof. The LEDs are powered by low-voltage direct current and coupled with an emergency backup battery that is maintained in a charged condition by household current. The light fixture may be operatively connected with a signal receiver that controls the light intensity and turns the LEDs on and off responsive to signals transmitted from a remote signal transmitter. The LEDs may be provided in different colors to allow the user to vary the color of illumination. The light fixture may also be operatively connected with an alarm system.

Abstract: In an optical sheet which is used for light control illumination in a backlight unit for a display, in order from an incident side of an illuminating light, there are provided at least a light scattering layer which scatters the illuminating light toward an outgoing surface side, an adhesion layer or an adhesive layer, a light reflection layer which reflects light scattered by the light scattering layer toward the light scattering layer side, and a lens sheet whose flat rear face is fixed to the other side of the light reflection layer, and in which a plurality of unit lenses are disposed on the surface. Opening portions corresponding to the respective unit lenses one-to-one are provided to the light reflection layer, and thickness of the adhesion layer or the adhesive layer is thinner than that of the light reflection layer.

Abstract: A light guide device includes a main body having a first incident surface, a second incident surface, an emitting surface, a reflecting surface and a plurality of first microstructures. The first incident surface is opposite to the second incident surface. The emitting surface extends from the first incident surface to the second incident surface. The reflecting surface is opposite to the emitting surface, and the plurality of first microstructures are formed on the reflecting surface and extend parallel to the first and second incident surface. A distribution density and relative size of the first microstructures progressively decrease along directions from a center of the reflecting surface toward the first and second incident surface, respectively. The present light guide device does not employ additional optical correcting elements and thus has a simple structure. A backlight module using the same light guide device is also provided.

Abstract: A backlight module housing includes a frame forming a holding space, a light source being accommodated on a side of the holding space, and at least one lateral alignment structure connected to the side of the frame accommodating the light source and protruding to the holding space for laterally immobilizing a display panel when the display panel is accommodated inside the holding space of the frame.

Abstract: A method and apparatus for reducing the viscosity of a fluidic cementitious mixture, the apparatus including a high voltage source, first and second spaced electrode members electrically connected to the high voltage source and (when energized) define an electrostatic field therebetween. The positioning of particulate cementitious material within the electrostatic field imparts like charges to the cementitious particles. By establishing such an electric field and positioning cementitious particles within the field, the particles may be charged prior to mixing into a hydrated cementitious slurry. Such charging decreases the viscosity and/or enhances the flowability of the hydrated cementitious slurry.

Abstract: A method and a device are provided which can mix two liquids faster at a precise mixing ratio. The method for mixing at least two liquids transported in respective channels includes transporting, of the two liquids, a liquid having a low mixing rate intermittently in one of the channels, and transporting, of the two liquids, a liquid having a high mixing rate so as to join the liquid having a low mixing rate from both sides of the channel for the liquid having a low mixing rate.

Abstract: An agitator for use on an agitator shaft having an axis of rotation. The agitator has a blade mount configured and dimensioned to receive the agitator shaft and being further configured and dimensioned so as to hold a plurality of agitator blades radially with respect to the axis of rotation. Each agitator blade has a plurality of segments, including an upper segment relative to the axis of rotation and a lower segment relative to the axis of rotation. The segments are inclined at an acute angle relative to the axis of rotation in the direction of rotation, wherein the acute angle changes continuously or stepwise from about 25° at the upper segment to about 65° at the lower segment.

Abstract: A performance testing apparatus for a heat pipe includes an immovable portion having a cooling structure defined therein for cooling a heat pipe needing to be tested. A movable portion is capable of moving relative to the immovable portion. A receiving structure is located between the immovable portion and the movable portion for receiving the heat pipe therein. At least a temperature sensor is attached to at least one of the immovable portion and the movable portion for thermally contacting the heat pipe in the receiving structure for detecting temperature of the heat pipe. An enclosure encloses the immovable portion and the movable portions and has sidewalls thereof slidably contacting at least one of the immovable portion and the movable portion.

Abstract: A luminescent temperature sensor comprising (i) an object having a recess, (ii) a layer of luminescent material disposed in the recess, wherein the luminescent material emits electromagnetic radiation having a detectable optical characteristic that is functionally dependent on the temperature of the object, and (iii) a light waveguide in optical communication with the layer of luminescent material, is provided. A test device for measuring a temperature in a processing step comprising (i) an object having a surface and having a recess in the surface of the object, (ii) a layer of luminescent material disposed in the recess, wherein the luminescent material emits electromagnetic radiation having a detectable optical characteristic that is functionally dependent on the temperature of the object in response to a source of excitation radiation, and (iii) an optical window that seals said layer of luminescent material in the recess in the surface of the object, is provided.

Abstract: A contact thermometer for determining-temperature of an inner wall of a cavity, where accuracy and speed response is assured by use of a probe having a variable geometry where the first shape of the probe exists before and during placing the probe into a cavity and the second shape is formed during the measurement process. The temperature measuring tip of the probe makes an intimate thermal contact with an inner wall of a cavity after the second geometrical shape is assumed. The accuracy is assured by use of at least two temperature sensors while the speed response is improved by taking at least two readings, from one temperature sensor.

Abstract: Arrangement for taking a CT scan and a SPECT scan of a patient in a single-pass diagnostic procedure. A SPECT scanner and a CT scanner are included. The SPECT scanner is mounted on a SPECT gantry and the CT scanner is mounted on a CT gantry. The SPECT and CT gantries are moveable with respect to one another between a mated operating configuration and a separated maintenance configuration. A pair of receiving brackets is fixedly mounted on the SPECT gantry. A pair of self-locating brackets is fixedly mounted on the CT gantry. Each of the pair of self-locating brackets is configured for assuming a prescribed position relative to a respective one of the pair of receiving brackets when in snug abutment together. A floating connection interconnects the CT scanner with the pair of self-locating brackets, and in this manner float-mounts the CT scanner with the SPECT scanner and facilitates the taking of the CT scan and a SPECT scan of a patient in a single-pass diagnostic procedure.

Abstract: A gantry for a computed tomography apparatus has a rotary carriage that is rotatable around an axis and a support ring arranged around the rotary carriage with a circumferential cooling channel. The support ring has a number of openings distributed around its circumference and forming a non-uniform opening pattern. The rotary carriage likewise has inflow and outflow openings that, in operation, overlap the openings on the stationary part of the computed tomography apparatus such that a coolant flows through between the support ring and the rotary carriage. A steady pressure fluctuation that leads to a reduction of the noise stress in operation ensues thanks to the non-uniform opening pattern.

Abstract: A seal device fixed to an end portion of a slider of a guide device includes: a casing; a plurality of seal members; and elastic members, wherein each seal member has a recess portion in which a rail penetrates. An inner circumferential face of the recess portion comes into contact with an outer surface of the rail when the seal member is pushed onto one side of the rail by the elastic members. The plurality of seal members are arranged in the casing in such a manner that when a seal portion of one seal member is pushed by the elastic member and contacted with one side of the rail, a seal portion of the next seal member is pushed by the elastic member and contacted with the other side of the rail.

Abstract: A fluid dynamic-pressure bearing includes a thrust dynamic-pressure bearing between a bearing member and a rotor hub and a tapered sealing portion continuous with the thrust dynamic-pressure bearing and defining a radial gap whose width gradually increases in the axial direction. A neck is formed in a passageway between the thrust dynamic-pressure bearing and a lubricating fluid/air interface maintained in the tapered sealing portion for increasing flow resistance of the lubricating fluid.

Abstract: The invention relates to a hydrodynamic bearing arrangement for an electric motor, particularly for a spindle motor to drive the platters of a hard disk drive. The bearing arrangement comprises a shaft, a bearing bush and a thrust plate disposed fixedly on the shaft, the shaft and the thrust plate rotating with respect to the bearing bush, grooved patterns to generate fluid-dynamic pressure being provided on the thrust plate and/or the surfaces located opposite the thrust plate of the bearing sleeve and/or the cover plate. The grooved pattern comprises a number g of grooves distributed over the surface of the bearing sleeve, the thrust plate or the cover plate, wherein in the shaft and/or in the thrust plate, a number h of holes and/or recesses are provided at the inner edge of the thrust plate and/or at the outer edge of the shaft. According to the invention, the number g of grooves cannot be integrally divided by the number h of holes and likewise that h cannot be integrally divided by g.