Abstract: A method for optically checking by interferometry the thickness of an object (2) being machined comprises a phase of direct checking wherein the spectrum of the result of interference between primary reflected radiations (R1) generated by reflection of incident radiations (I) on an external surface (16) and secondary reflected radiations (R2) generated by reflection on an internal surface of discontinuity (17) of the object is analysed, and a preliminary phase wherein information relative to the variation of a virtual thickness (D) delimited and defined by a reference surface (18) and the external surface of the object, indicative of thickness variations of the object being machined. In the preliminary phase, the processing is based on the analysis of the spectrum of the result of interference between primary reflected radiations and reference reflected radiations (Rref) generated by the reflection of the incident radiations on the reference surface, that defines the length of a reference optical path.

Abstract: An apparatus for checking dimensions and/or shape includes one or more feelers (7,8;9;67,68), three for preference, adapted to touch the surface of a mechanical part (2;61) to be checked, a transducer and/or display device (33;78) with a movable part (34;77), and a mechanical transmission assembly (20) to transmit to the movable part of the transducer and/or display device the displacements of the feeler/s. The mechanical transmission assembly includes a shaft (22) defining an axis (A) and a guiding element (30) adapted to house a guide portion (25) of the shaft. The shaft includes a resiliently deformable portion (26), that is preferably a reduced diameter portion having axial symmetry, in an intermediate position between the guide portion and an abutment portion (27).

Abstract: A modular system (1) for checking a valve seat and its associated valve guide in cylinder heads of internal combustion engines comprises a guide and support assembly (10), movable in three directions, which carries one or more electronic gauges (11) and a precentering pin (14) to guide the insertion of the gauge in the valve seat and its associated valve guide, and a tilting table (3) for loading and locating a cylinder head (4). Thanks to the particular structure of a support mechanism (12) connected to the guide and support assembly, the gauge is able to self-position on the valve seat to be checked and to disengage in a checking condition from the guide and support assembly at least in one of the three directions. The tilting table can be adjusted depending on the dimensions and layout of the cylinder head to be checked and includes a swing system (6) to set the tilt of the table as a function of the inclination of the valve seat and its associated valve guide to be checked.

Abstract: A system for checking size and/or position of an edge (5, R, T) of a workpiece (1, 1R, 1T) comprises two checking elements including matching elements (6, 7; 16, 17) which comprise respective surfaces having tapered matching zones (8, 9) adapted to cooperate with the edge (5, R, T) of the workpiece (1, 1R, 1T) along a longitudinal direction, and a transducer element (11) that provides electrical signals (M, M6, M7) indicative of the cooperation between the matching zones and the edge. The matching zones define slope angles (?, ?) with respect to the longitudinal direction that are different from each other. A method that uses such a system for checking includes bringing the matching elements in a checking condition in which the respective matching zone cooperates with the edge to be checked, detecting the electrical signals provided by the transducer element, and processing such signals with reference signals indicative of the cooperation between each matching zone and a reference edge.

Abstract: Method and apparatus (1) for measuring a manufacturing deviation in an external gear (2). The gear is arranged onto a stationary central pin (3), the external diameter of which is smaller than the internal diameter of the gear so that a relative movement between the gear and the pin is allowed; a coupling member (5), preferably including a head (17) that does not rotate and is adapted to fit into the teeth of the gear, is urged with a predetermined strength against the teeth of the gear in order to mesh with the teeth and concurrently bring an internal lateral surface of the gear into engagement with an external lateral surface of the pin. The position of the central axis (A) of the gear is determined and the manufacturing deviation of the gear is determined as a function of said position. The deviation so determined can be corrected as a function of a reference distance (D) indicative of the radial dimensions of the gear.

Abstract: Methods and apparatuses are used for optically measuring by interferometry the thickness (T) of an object (2) such as a slice of semiconductor material. Readings of the object thickness by optical interferometry are carried out, rough thickness values (RTW) are obtained and frequencies, indicating how often the rough thickness values occur, are evaluated. A limited set of adjacent rough thickness values whose frequency integration or summation represents an absolute maximum is identified, and the actual value of the thickness of the object is determined as a function of the rough thickness values belonging to said limited set of values. The rough thickness values can be divided up into classes (C) with corresponding frequencies (F), and in this case, a preponderant group (Gmax) of thickness classes is identified as the above-mentioned limited set of adjacent rough thickness.

Abstract: A touch probe (1; 1?; 1?; 1??) for applications in machine tools or measuring machines includes a support frame (2) with a protective casing (3), and a movable armset (5) with a feeler (11) to touch a part to be checked (13). The probe includes a detection device (23) with a laminar piezoelectric transducer (25) made of polymeric material, such as polyvinylidene fluoride, which is connected to the support frame and fixed at a bearing and locating area (7), on which the movable armset rests in a position defined by an isostatic rest system (17). Conditioning electronics (30) connected to the support frame include processing means for processing a force signal (M) provided by the detection device, comparing it with a threshold value (S) and generating a touch signal (T). The conditioning electronics include differential charge amplifiers (3) and a processing system (55) to dynamically vary the threshold value depending on the most recent values of the force signal detected.

Abstract: In a machine tool (1) comprising a rotating spindle (2) and a vision system (7) for acquiring images of a tool (3) mounted on the spindle, for each value (VC) of an interval (ICN) of preselected rotational speed values centred on a nominal rotational speed value (VN) of the spindle, an image acquisition period (TA) is determined, that is a multiple of the rotational period (TR) of the spindle calculated for that preselected speed value and compatible with the vision system, and, while the spindle is rotating at the nominal rotational speed, a representative couple of tool images that are temporally spaced apart from one another of the image acquisition period is obtained, in order to obtain an estimated speed value (VS), associated to the nominal speed value, by selecting that preselected speed value to which the representative couple of images that are the most similar to each other on the basis of a similarity rule corresponds.

Abstract: A method for positioning a tool (3) mounted on a spindle (2) of a numerical control machine tool in the visual field (20) of a visual system (7) for measuring the tool, includes a step of moving (35) the rotating spindle along an axis (Z) from a reference position (Z0) towards a target position (Zobj) defined in the visual field, and a step of acquiring images of the visual field. The stop of the spindle movement along the axis is controlled as soon as an acquired image (IM1) reveals (36) that a determined portion (13) of the tool, for instance a tip, has entered the visual field. When the stop is controlled (37), an instant position (Z1) of the spindle is acquired (38) and a distance (POS) between the tip of the tool and the target position is measured (39). On the basis of such instant position and distance, a final position (Z2) is calculated (40), and the spindle is brought (42) to such final position.

Abstract: Method and apparatus (1) for measuring a manufacturing deviation in an external gear (2). The gear is arranged onto a stationary central pin (3), the external diameter of which is smaller than the internal diameter of the gear so that a relative movement between the gear and the pin is allowed; a coupling member (5), preferably including a head (17) that does not rotate and is adapted to fit into the teeth of the gear, is urged with a predetermined strength against the teeth of the gear in order to mesh with the teeth and concurrently bring an internal lateral surface of the gear into engagement with an external lateral surface of the pin. The position of the central axis (A) of the gear is determined and the manufacturing deviation of the gear is determined as a function of said position. The deviation so determined can be corrected as a function of a reference distance (D) indicative of the radial dimensions of the gear.

Abstract: A method for checking the diameter of a cylindrical part, such as a crankpin of a crankshaft, in orbital motion in a numerical control grinding machine, by means of a checking apparatus with a Vee-shaped reference device for cooperating with the crankpin, a support device movably carrying the Vee-shaped reference device, and a measuring device movable with the Vee-shaped reference device. The Vee-shaped reference device is brought, from a rest position, into contact with the crankpin, and the contact, that defines a checking condition, is maintained by gravity during the orbital motion of the crankpin.

Abstract: A system for controlling a numerical control machine tool with movable component parts carrying tools (5) and/or mechanical component parts to be checked includes a control unit (7) and a sensor device (9) having an associated interface unit (15). A digital channel (20), through which there are transmitted measuring signals from the interface unit to the control unit, is used, at different moments and as an alternative to the measuring process, for transmitting confirmation pulse signals (ACK) consequent to request/instruction messages that the control unit sends to the interface unit. A method for controlling the machine tool includes the sending of request/instruction messages (M) from the control unit to the interface unit, for example for checking the efficiency and the operativeness of the measuring chain, and the reception of confirmation pulse signals through the transmission channel which is a component part of the measuring chain.

Abstract: A plug gauge (1) includes a support and protection frame with a handle (2) that defines a longitudinal axis and houses a position transducer (25) and electronic devices for wirelessly transmitting electrical signals indicative of a dimension to be checked. The gauge also comprises a probe (6) including a mechanical armset (7) provided with at least one movable feeler (10), and a transmission mechanism with a stem (17) transmitting movements of the feeler to the position transducer housed in the handle. The probe is connected to the handle by means of a quick coupling mechanism (5) with deformable locking portions (52), the radial arrangement of which is controlled by a clamping element (60).

Abstract: An apparatus for checking thickness dimensions in a semiconductor wafer (1) during grinding operations includes an optical probe (3) which transmits infrared radiations on the surface (2) being machined of the wafer (1), and detects beams that are reflected by said surface, by an opposite surface (2?) of the wafer and/or by surfaces (2?, 2??) separating different layers in the wafer. The beam of emitted and reflected radiations travels along a path (4) with known and constant discontinuities, in part through the air (15) and in part through a cushion (30) of low flow liquid, which flows with substantially laminar flow. A support and positioning element (7) for the optical probe includes hydraulic ducts (22,25) that generate the liquid cushion. A method for checking the thickness dimensions includes the generation of the liquid cushion at the path along which the beam of emitted and reflected radiations travels.

Abstract: A touch probe (1;1?;1?;1??) for applications in machine tools or measuring machines includes a support frame (2) with a protective casing (3), and a movable armset (5) with a feeler (11) to touch a part to be checked (13). The probe includes a detection device (23) with a laminar piezoelectric transducer (25) made of polymeric material, such as polyvinylidene fluoride, which is connected to the support frame and fixed at a bearing and locating area (7), on which the movable armset rests in a position defined by an isostatic rest system (17). Conditioning electronics (30) connected to the support frame include processing means for processing a force signal (M) provided by the detection device, comparing it with a threshold value (S) and generating a touch signal (T). The conditioning electronics include differential charge amplifiers (3) and a processing system (55) to dynamically vary the threshold value depending on the most recent values of the force signal detected.

Abstract: A touch probe (1;1?;1?;1??) for applications in machine tools or measuring machines includes a support frame (2) with a protective casing (3), and a movable armset (5) with a feeler (11) to touch a part to be checked (13). The probe includes a laminar piezoelectric transducer (25) made of polymeric material, such as polyvinylidene fluoride, which is connected to the support frame and fixed at a bearing and locating area (7) on which the movable armset rests in a position defined by an isostatic rest system (17). A thermal insulation system is placed between the protective casing and the piezoelectric transducer and preferably includes at least one element (28) made of thermal insulating material, such as fibreglass, between the piezoelectric transducer and the support frame.

Abstract: Methods and apparatuses are used for optically measuring by interferometry the thickness (T) of an object (2) such as a slice of semiconductor material. Readings of the object thickness by optical interferometry are carried out, rough thickness values (RTW) are obtained and frequencies, indicating how often the rough thickness values occur, are evaluated. A limited set of adjacent rough thickness values whose frequency integration or summation represents an absolute maximum is identified, and the actual value of the thickness of the object is determined as a function of the rough thickness values belonging to said limited set of values. The rough thickness values can be divided up into classes (C) with corresponding frequencies (F), and in this case, a preponderant group (Gmax) of thickness classes is identified as the above-mentioned limited set of adjacent rough thickness.

Abstract: In a method for measuring a distance from a base area (5) to a cross section, with a predefined diameter (A), of a tapering area (1.1) of a body (1), which tapering area forms an elevation or depression and has a circular cross-sectional form, a measuring body (3) with a diameter (A) is arranged on the base area (5). The arrangement is effected in such a manner that a distance in the form of a gap (6, X) is formed between the cross-sectional area, with the diameter (A), of the body (1) and the measuring body (3). A fluid medium is pressed through the gap (6, X) and the pressure and/or the flow rate of the fluid medium is/are measured. The distance value is determined in an evaluation device (9) on the basis of the measured pressure and/or the flow rate.

Abstract: An apparatus for checking the diameter of crankpins (18) of a crankshaft (34) in the course of the machining in a grinding machine comprises a first arm (9) rotating with respect to a support (5) arranged on the grinding-wheel slide (1) of the grinding machine, a second arm (12) rotating with respect to the first, a reference device (20) carried by the second arm and a measuring device (16, 17, 40-45) associated with a reference device. A guide device (21), fixed to the reference device (20), enables the apparatus to engage a crankpin, in the course of the orbital motion of the crankpin, and limit the displacements of the first arm and those of the second arm when a control device (28-30) displaces the apparatus to a rest position.

Abstract: An optoelectronic system for checking the relative attitude of component parts of an HSA (32) including a base (2); a reference system (40) connected to the base and having a stationary support (3) adapted to cooperate with positioning surfaces (34) of the HSA, and a floating device (10) which floats with respect to the stationary support and is adapted to cooperate with working surfaces (33) of the HSA; an optoelectronic detection device; and a processing unit for receiving and processing signals of the optoelectronic detection device. The floating device includes a floating element (11) adapted to cooperate with the optoelectronic detection device.