Abstract: A sensor for measuring linear or angular dimension. The sensor can be moved with respect to a magnetized scale with a period &lgr;. It is equipped with magnetoresistive electrodes provided with barber-pole structures and connected so as to form n measuring bridges, each measuring bridge formed by four sets of magnetoresistive electrodes. The magnetoresistive electrodes making up each set are connected in series, the magnetoresistive electrodes being distributed spatially so as to constitute x groups. Each group being formed by more than eight consecutive magnetoresistive electrodes coming from two sets of a same measuring bridge.

Abstract: Double-emitting and multiple-receiving capacitive measuring device: it comprises a scale equipped with an array of electrodes and a transducer, which moves parallel to and opposite the scale and is equipped with two emitting electrodes and an array of receiving electrodes distributed into N groups. The capacitive coupling between the different electrodes allows the position of the transducer to be determined. A generator emits two emission signals (E0, E1) in phase opposition on the two emitting electrodes of the transducer. The frequency of generated emission signals (E0, E1) depends upon the speed of displacement of the transducer. Processing means determine a dimension with the aid of N signals (R0, R7) received on the receiving electrodes. The more significant bits of the result are provided by a primary counting system using a first algorithm. The less significant bits are provided by a secondary precision system using a second algorithm.

Abstract: A capacitive measuring device has a scale and a transducer, both provided with an array of electrodes. The position of the transducer with respect to the scale is determined in a processing circuit by evaluating the capacitances formed between the two arrays. These capacitances vary periodically as a function of the relative position of the transducer. The scale electrodes are spaced by a pitch (.lambda.). In order to increase the resolution, the transducer electrodes occupy possible initial positions spaced by an elementary interval (P) which is a submultiple of the pitch (.lambda.). The transducer electrodes are thus divided into N groups according to the initial position which they occupy. In order to compensate for manufacturing imprecisions of periodic type, the succession of transducer electrodes is highly non-periodic. To this end, the set intervals (I.sub.

Abstract: A capacitive measuring device or apparatus; in particular, a length-measuring apparatus, which incorporates a scale portion and a scanning unit which is movable relative to the former and which supports transmitting electrodes and at least one receiving electrode. Herein, a transmission circuit applies transmitting signals at a basic frequency to the transmitting electrodes, and with the receiving electrode being connected to a reception circuit, to the output side of which there is connected an evaluating circuit for the receiving signals. The transmitting signals are applied to the transmitting electrodes through a pulse width modulator and a synchronous modulator and the receiving signal is conducted through a demodulator.

Abstract: The apparatus comprises a bearing plate (1), a slideway (2) and a girder (3) which are perpendicular to the bearing plane of the bearing plate, a slide (4) with tracer head (5) movable along the slideway and a drive plate (7) located in front of the slide and stabilized by guides (8, 9) independent of the slide. The plate (7) and the slide (4) are connected by balancing (10) and damping (11) springs. A drive device by cable (13) and return pulleys (15-18) which is moved by a movement generator (19) is connected to the plate (7) and is entirely supported by the girder (3) and the bearing plate (1). A counterweight (14) inserted in the circuit of the cable (13) balances the weight itself of the movable elements (4, 7). A body (63) for protection against impacts is fastened to the girder (3) and to the bearing plate (1).

Abstract: The sensor has at least one sensor unit arranged opposite an incremental measurement scale (1) with reflecting graduation (2). The sensor unit comprises a photoemitter (3) and an adjacent photoreceiver (4), located in a printed circuit (6), with optical axes (xx') parallel to each other and perpendicular to the plane of the scale (1), and an optical group (9) with two focusing lenses (10, 12) and two deflection faces (11, 13) integrated by molding in a support of transparent synthetic material. In the optical group, one of the two lenses and one of the two deflection faces are aligned on each of the two said optical axes (x, x') in order to direct and deviate the light rays coming from the photoemitter (3) and to recover them on the photoreceiver (4) after their passage through a graduated sensing graticule (14).

Abstract: The detector comprises an optoelectronic sensing unit (3) and a transparent rule (2) having two parallel graduation tracks (4, 5). One track (5) has incremental graduation of constant step and the other track (4) has pseudo-random graduation forming binary coding bits constituting a continuous sequence of words which are different from each other, the width of a bit being a function of the step of the incremental graduation. The incremental track (5) is read through a sensing graticule (9) by photodetectors (8) which are 90 electrical degrees out of phase in order to permit an interpolation in the step of said track. The track (4) with pseudo-random graduation is read by a CCD detector (11) through an image-enlarging lens (13). The signals generated are processed by circuits (15a, 15b) which assure the combining of the information taken from the two tracks of the rule.

Abstract: The device, shown associated with a bore measuring machine, comprises two elements in engagement in the form of a bolt (20) and a nut (21) of reversible relative axial rotation and displacement. The bolt (20) is a threaded cylindrical sleeve mounted coaxial to the measurement rod (4) of the machine and with free rotation between two stops (9, 23) thereof, and the nut (21) is formed by an inner thread on the cylindrical body (1) of the machine. The force of friction developed by the relative bolt-nut rotation is adapted to yield to at least the pressure of the return spring (7) of the measurement rod and to constitute a brake for modulating the speed of the displacements in both directions of the measurement rod (4) in the body of the machine.

Abstract: The sensor is of the type having a cylindrical body within which a measurement rod equipped with an outer measurement feeler bears a ferrite core which by its displacements influences the impedance of a system of coils to produce an electrical measurement signal. In the body, a fixed stop and an interposed movable stop make it possible to adjust the positioning of the measurement feeler in one or the other of two positions with respect to the electrical zero of the feeler and they have for this purpose interpenetration means with two stages spaced at an angle from each other and selected by manual push and rotation of the rod driving the movable stop in opposition to a spring and then release, in the manner of the so called "bayonet" connections.

Abstract: The feeler comprises a stationary support (1) and a movable support (4) provided with a tip (5), which are pressed against each other by a spring (21). The immobilizing of the movable support with respect to the stationary support is obtained by a system of connections with zero degree of freedom formed of four spherical positioning pieces (7 to 10) applied, by six contact points, to six inclined resting surfaces (15 to 20) with flat contact surface, two first pairs (15-16, 17-18) of which are convergent and arranged respectively under two first opposing positioning pieces (7, 8) and the last two of which (19, 20) are parallel and each arranged under one of the two other opposing positioning pieces (9-10). An electrical circuit is provided to detect any interruption of contact between at least one positioning piece and one resting piece signifying an encounter of the tip (5) with the object.

Abstract: The device comprises a sensor (2) which is connected to a movable housing (1) by an elastically deformable mechanism (4).The sensor and the housing are connected to an electric circuit (5) comprising:a capacitive amplifier producing a measurement pulse constituting a datum for a computer and an order for the stopping of the displacement of the sensor when the latter comes into contact with a part to be measured which is mounted in insulated fashion on a measurement table,a short-circuiting device (17-18) producing a safety pulse which constitute an order for the stopping of this displacement in the event of deformation of the mechanism (4) as a result of the non-issuance of the measurement pulse.A measurement is thus taken with full safety without deformation of the linking mechanism and without the part to be measured having to be connected to the electric circuit.

Abstract: The sensor comprises a reference body (1) in which there is displaceably mounted a movable body (3) bearing a measurement finger (6) and a pick-up (9) which translates the displacements of the movable body into electrical signals.The movable body (3) has a stop (18) subjected to the opposing pressures of two springs (19, 26), one of which (26) lies in the extension of the rod of the piston (24) of a single-acting pneumatic cylinder-piston unit (23).When the cylinder-piston unit is at rest, the measurement finger is disengaged by pressure of the spring (19) opposite said cylinder-piston unit.When the cylinder-piston unit is extended, the measurement finger is pressed against the part to be measured by the action of the spring (26) borne by the rod of the piston.The finger of this sensor is thus disengaged in the position of rest of the cylinder-piston unit and can easily be brought towards the finger of another sensor of the same type in the direction of the taking of the measurement.

Abstract: The instrument is a slide caliper with inner and outer feelers borne by a slideblock (3) and by a slider (6) which is mounted for sliding on the slideblock via a play take-up device (7).That device comprises a base plate (10) having two symmetric end inclined planes (14) on which two shoes (11) are arranged. The base plate bears a central shoulder (16) pierced by a hole (17) in which there is engaged the stud (25) of a drive and locking screw. Two compression springs (12) are interposed between this shoulder and the two shoes in order to cause the latter to rise on the inclined planes.This device automatically takes up the play formed by the sliding system. It is irreversible.The shoes (11) are narrower than the base plate and means (22) are provided to avoid their rubbing against the walls of the slider.

Abstract: The device comprises a scale (1) and a slide (2) which are provided with electrodes arranged to form two pairs of capacitances for the measurement of the displacement of the slide on the scale (CA.sub.1 -CA.sub.2, CB.sub.1 -CB.sub.2). These measurement capacitances are connected to an electronic feed and processing circuit (3) in which they are connected in a bridge (4A, 4B) with switched reference capacitances of MOS type. In this circuit, the outputs of these bridges are connected via comparators (5A, 5B) to a processor (6) of CMOS type adapted to produce a terminal digital measurement signal by counting the periods of the signal of the measurement capacitances and by numerical interpolation within each of these periods. This interpolation is effected by balancing the capacitive bridges by means of a digital algorithm.

Abstract: The apparatus comprises a body (1) provided with three point-contact feelers (12, 13) which open under the action of a spring (19) and close under the action of a lever (20) via a rod (14) and a spacer stop (15). A displacement pick-up (22) and an electronic circuit (25) convert the displacement of the feelers into a measurement signal which is representative of the diameter of the circle which they define. The electronic circuit comprises a minimum memory (31) to memorize the minimum value of the measurement signal, a member (39) for displaying this value (39) and a measurement-initialization switch (32). After the feelers, folded together, have been introduced into the bore, the lever is released, the switch is actuated, and the apparatus is moved in all directions by the operator in order to cause the plane of the feelers to pass in a diametral plane of the bore, this passage generating the minimum value displayed which is representative of the actual diameter of the bore.

Abstract: A comparator is provided including a body in which there is fastened a plate comprising a lever for transmission of movements of a pivoting feeler, and an amplification device, with gearing, actuated by said lever and driving a needle of a reading dial. The stroke of the transmission lever is limited by a rigid end-of-stroke stop. On the path of the transmission lever, a coil spring is arranged between its position of rest and its end-of-stroke position to protect the mechanism from accidental impact. In case of impact on the feeler, the energy developed by the amplification device is partly absorbed before the impact of transmission lever on the rigid end-of-stroke stop.

Abstract: An instrument composed of a measurement head (1) and a fixed stop (2) which are connected by a body (3) formed of interchangeable extension pieces (4, 5), the instrument being intended to check the dimensions of bulky parts.The two contact stops (12) of this instrument are offset at the end of two parallel measurement feelers (10, 11).With each of these two contact members there is associated an instrument for measuring their inclination, which consists of an electronic clinometer (25, 26).The two clinometers are connected to an apparatus (30) for reading the inclination of the two measurement feelers.The inclination of one of the two measurement feelers (11) is adjustable by means of an operating screw (17).In this way it is possible to reestablish parallelism of the measurement feelers when the instrument bends, upon measurements of large dimensions.

Abstract: An instrument for the measurement and verification of linear dimensions includes a body equipped with external and internal feelers, a perch mounted in a slideway in the body and equipped with external and internal feelers cooperating with those of the body, and independent depth gauge mounted in a second slideway of the body, and a feeler rod mounted in a third slideway of the body, and cooperating with a contact piece fastened with an inner face of the external feeler of the perch. A movable member of a measurement transducer is selectively connected to the perch, to the gauge and to the feeler rod by a selective coupling device. In turn, a display device with zeroing control is connected to the measurement transducer.