Abstract: The arrangement of this invention for measuring the dimensions of a workpiece (14) includes a circuit in which a fluid circulates. Such circuit comprises a first branch (15) provided with an inlet nozzle (16) and at least one measuring nozzle (17) directed towards the workpiece the dimensions of which are to be measured, and a second branch (19) provided with an inlet nozzle (20) and opening into an output reference nozzle (21). A pressure transducer (22) furnishes an electrical signal representing the pressure difference in the two branches. The arrangement is original inasmuch as the fluid employed is a liquid and that the inlet nozzles are arranged to deliver a liquid flow at their output producing a minimum of noise on the electrical signal issuing from the pressure transducer. Utilization is for in-process measurement of cylindrical bores or outer diameters of cylindrical workpieces or indeed of planar surfaces.

Abstract: This measuring arrangement (1) enables the self-calibration of cylindrical parts (2) in the course of machining and interrupts such machining when a predetermined dimension has been attained. It comprises a head (5) exhibiting a V opening bearing on the part to be measured (2) and a pneumatic sensor (10) associated therewith. The system includes coupling means (25, 26, 27, 29, 31, 32), urging means (33, 34) and sustaining means (39) for the head in order to assure a permanent contact between the part to be measured and contact pieces (8, 9) carried on the V opening. The arrangement offers a very small thickness so that it may attain narrow and deep zones as for example those of cylindrical crankshaft bearings.

Abstract: Measuring method and equipment for automatic control of forward and backward movements of a grinding wheel of a surface grinder. The upper surfaces of the workpieces are felt by means of a length measuring head mounted on the frame of the grinder during different successive passes of these pieces under the grinding wheel to obtain each time a measuring signal which substantially represents their actual size. A reference block of given thickness composed of one or several pieces is placed on the grinder table, in addition to the pieces to be machined and out of reach of the grinding wheel. The upper surface of this block is periodically felt with the measuring head to obtain a reference signal and the value of this signal is stored each time.

Abstract: Automatic calibration equipment for planar grinding machines comprises a measuring head (12) fixed to a table (4) of the associated grinding machine for measuring the distance between this table and the grinding wheel (6), and an electronic measuring and control apparatus (14) for receiving the output signal of the measuring head and producing signals controlling the forward and rearward movement of the grinding wheel. The measuring head comprises a pneumatic circuit with a first branch of very low internal volume provided with an inlet nozzle and a measurement outlet nozzle (48) oriented to blow towards the edge of the grinding wheel, a second branch provided with an inlet nozzle and a reference nozzle, means for connecting the inlet nozzles of these branches to an installation (18) delivering compressed air at regulated pressure, and a pressure-differential transducer with a semi-conducting element for detecting the difference between the pressures in the two branches.

Abstract: A contact sensor for very precise calipering of workpieces. The sensor has a force generating mechanism with two oppositely acting elastic members (64, 66) connected to one part (34) of the suspension device of a feeler (42) and deformable in the direction of movement of the feeler. An assembly carried by another part (36) of the suspension device includes an abutment (82), two mobile elements (72, 74) acting reciprocally on the two elastic members, and a spring (78) permanently biasing the mobile elements against the abutment from opposite directions. When the feeler is in a rest position, the two elastic members are pre-stressed by the mobile elements so that both elastic members remain under tension as long as movement of the feeler is confined to a calipering zone.

Abstract: A ring gauge includes an entry zone followed by a measuring zone defined by a guide cylinder in which is installed an air jet measuring system. The entry zone includes a first region exhibiting an opening substantially larger than the opening of the guide cylinder then a second region including a spring support guide structure which defines a circle the diameter of which is equal to the diameter of the guide cylinder opening, and finally a third tapered region having an entry diameter substantially greater than that of the guide cylinder opening and an exit diameter equal to that of the guide cylinder opening. The gauge is employed for checking the outer diameter of cylindrical parts which may penetrate therein without jamming.

Abstract: A vibration sensor, located on a chuck member for a workpiece and rotating therewith, detects the signal emitted at the instant a tool member contacts the workpiece. The vibration sensor produces an output signal to modulate a transmitter and a receiver fastened to the machine tool frame receives the information broadcast by the transmitter. The information is processed to produce a signal which reduces the speed of a motor controlling the advance of the tool member. The speed of the tool member is thus reduced as soon as the tool member contacts the workpiece. The arrangement is particularly suited to machines for grinding interior diameters and prevents damage following accidental collision of the workpiece and tool member.

Abstract: The arrangement enables controlling the speed of advance of the tool part of a machine tool during its approach phase toward a workpiece and reducing such speed as soon as the tool contacts the workpiece.It includes an acoustic sensor adapted to detect the signal emitted at the instant of contact, an electronic circuit for processing such signal and a motor responding to the circuit to regulate the speed of advance of the tool part. The sensor is fastened to a feeler mounted on the machine framework by means of shock absorbers, said feeler being arranged to be in contact with the workpiece or its carrier.

Abstract: The measuring head intended for measuring diameters of cylindrical parts, e.g. parts being ground to diameter, comprises two measuring projections which are easily adjustable when a change is made from one diameter to another diameter, while maintaining excellent precision whatever the diameter concerned and the distance which separates the measuring head from the part to be machined. For this purpose, each of the measuring projections is a crank comprising a pivoted arm and a cylindrical rod projecting from the arm and forming a measuring contact element. The cranks are secured to an upper block and a lower block, respectively. A pick-up measures the distance existing between the blocks. The cranks are implemented in such manner that the axes of the rods always remain parallel to each other whatever the angle of rotation or adjustment of each of the arms.

Abstract: A device for handling a cylindrical piece (2), equipped with means to measure its diameter comprises two arms (3, 4) provided to grip the piece. In at least one of the arms a dihedron is formed, in which the piece (2) is held, and a length measuring sensor (8) is mounted on the edge of the dihedron, in order to determine the distance from the surface of the piece to the edge, the said distance representing the diameter of the piece.

Abstract: A pneumatic measuring device is disclosed which comprises a pneumatic circuit containing a first branch (15) equipped with an inlet nozzle (16), oppositely disposed measuring nozzles (17) and a second branch (19) equipped with an inlet nozzle (20) and a reference nozzle (21). A differential pressure transducer (22) having a semiconductor element enables the difference in pressure between the branches (15) and (19) to be measured and to supply through a terminal (23) a signal representing the dimensions measured opposite the nozzles (17). The pneumatic circuit system, with the pressure transducer, is included in the measuring spindle (12).

Abstract: A measuring device is disclosed which contains a sensor fastened to sensor holding elements (4, 5, 6, 7, 8) and suspended so as to be displaceable in relation to a frame (1) in three orthogonal directions (x, y, z).For each direction of displacement, two parallel moving bridges (11 and 12, 20 and 21, 28 and 24) are provided which are hinged on rigid connecting elements (13, 14, 22, 25). The device permits the return of the sensor to its reference position in the first two directions of displacement (x, y) by gravity or by centering elements provided for that purpose.

Abstract: A contact sensing head, for example for a measuring device, comprises a sensor having a free end which is vibrated at low amplitude by a motor at the resonant frequency of the sensor. A transducer senses the vibrations and feeds a signal to an electronic detection system. When the sensor contacts an object, the frequency and amplitude of its oscillation changes. This is picked up by the electronic detection system, which signals that contact has been made.