Abstract: A robot arm for industrial robots comprises one or several jointed arms (1,1c) that are mutually connected to each other by means of rotary joints (1a, 1b), and a jointed arm (1) connected to a base (3), in which an angle transducer is arranged in the rotary joints (1a,1b) in order to measure exactly the angular relationship between the jointed arms (1,1c) or between the jointed arm (1) and the base (3), in order to make possible adjustment of the robot arm into the desired angular position.

Abstract: An angle transducer comprising a first disk, the rotor, with circularly arranged and radially directed receiver electrodes and a second disk, the stator, equipped with circularly arranged and radially directed transmitter electrodes arranged at the same radius as the receiver electrodes and with a fixed separation between the receiver and transmitter electrodes, whereby the disks are arranged coaxially and rotatable relative to each other, and the disks are further separated by a thin air-gap. The transmitter electrodes are each supplied with an alternating voltage with different phases for neighboring electrodes, whereby the number of supply phases, ?, is greater than two, and the separation of the transmitter electrodes=the separation of receiver electrodes/?. The transmitter electrodes of the stator are geometrically arranged such that errors in their geometry relative to the geometry of the receiver electrodes produce equal but opposite error signal in the receiver electrodes of the rotor.

Abstract: The present invention relates to an arrangement for determining dimensions in a three-dimensional object. According to the invention, the arrangement includes a pillar (2), an arm (3) which is mounted fro linear movement in a rotatable guide member (4) that is carried by the pillar and rotatable about the longitudinal axis (Z—Z) of the pillar and also about an axis (X—X) perpendicular to the longitudinal axis (Z—Z). The arrangement further includes a measuring probe attached to one end of the arm, and angle indicators (8, 9) for measuring rotation of the rotatable guide member about its rotational axes, and a scale (10) for measuring linear movement of the arm.

Abstract: A measuring machine produces an essentially linear movement in a moving part by transforming rotary movement to linear movement through a transmission element having a high modulus of elasticity in a longitudinal direction, and which is flexible in a transverse direction. The transmission element has two ends which are each fastened to the same mechanical element, and the transmission element is given a pre-stress which is greater than a maximum force encountered during acceleration while the machine is in use.

Abstract: The present invention relates to a machine frame, and particularly but not exclusively, to a machine frame for so-called coordinate measuring machines of the kind which include at least one first portal that includes two parallel, vertical first and second legs (7, 8) which are rotationally and flexurally rigid in relation to a base member (10). The legs support a horizontal beam (11) on which there is movably supported a rod, bar or the like for supporting a measuring head, tool or corresponding device. The horizontal beam (11) is connected to the first leg (8) by a pivot joint (13) which permits the beam (11) to rotate in the vertical plane of the legs (7, 8), and is connected to the second leg (7) by a connection (14) which permits the beam (11) to rotate in this vertical plane and also to move in the direction of its longitudinal axis in relation to the second leg. The invention also relates to a method of determining the geometry of the portal occasioned by deformation of such machine frames.

Abstract: A scale system for absolute measurement includes at least one scale (1') which extends along a measuring length, and at least one measuring slide which is movable in relation to the scale. The system includes a fine sensor which functions to measure the absolute values within each of the intervals lying along the scale (1'), and further includes a rough sensor which functions to measure the absolute values with regard to the interval in which the fine sensor is located at that time. The scale system further includes at least one rough scale (2', 3') whose scale electrodes (2a, b, 3a, b) define a predetermined angle to the direction in which a measuring slide is moved along the scale, wherein the measuring electrodes of the measuring slide also define a preferably corresponding angle (.alpha.

Abstract: A machine stand and a method of constructing it particularly a machine stand for so-called coordinate measuring machines. The machine includes one or more vertical legs, one or more horizontal beams, and a rod or bar which is mounted on a horizontal beam and intended to carry a measuring head tool or the like. At least one vertical leg is supported by a base element. The vertical leg supports at least one beam, and the rod can be moved to any selected point within the space volume defined by the stand by moving the leg, the beam and the rod relative to the base element. At least one vertical leg is mounted relative to the base element so as to be flexurally rigid and non-rotatable about its longitudinal axis; the beam or beams are not non-rotatably and flexurally rigidly connected, so that a yielding structure is obtained. Deformation of the first vertical leg is measured by measuring means, so as to be able to determine deformation of the structure.

Abstract: A method for determining and, when appropriate, compensating for the linear (heat) expansion of elongated bodies (1), such as physical length scales (1) or of elongated bodies which are intended to support physical length scales on, e.g., instruments or measuring machines equipped with physical length scales, in which measurement errors occur because of length deviations of the scale (1) as a result of deviations from a reference temperature at which the scale was calibrated.The method is mainly characterized by measuring the linear expansion of the body (1) in relation to at least one reference (6) made of a material whose coefficient of linear (heat) expansion (.alpha.) deviates from the coefficient of linear (heat) expansion of the body material, and thereafter determining, when appropriate, a compensation factor for correcting the body length.The invention also relates to an arrangement for carrying out the method.

Abstract: An absolute measuring scale system comprising a scale which extends along a measuring length, and a measuring head which is movable relative to the scale. The system further includes a fine-measurement sensor which is intended to measure the absolute values within each of a multiple of intervals lying sequentially along the scale, and a coarse-measurement sensor intended to measure the absolute values with regard to the interval within which the fine-measurement sensor is located at that moment. The invention is characterized in that the scale (2) comprises a carrier made of a transparent and form-stable material, preferably glass, which has provided on its surface an outer coating or layer which forms an opaque pattern (3, 4). The pattern formed along the length of the scale (2) forms transparent, mutually parallel binary code tracks (12), preferably in accordance with the so-called Grey-code.

Abstract: A method for determining and correcting positional errors or deviations which occur when measuring the position of a point in space, or when positioning to a point which has a specific position in space, where the position refers to a specific coordinate system, such as a rectangular coordinate system. The method comprises making a comparison between a multiple of measured values and at least one reference, and determining a correction on the basis of this comparison, wherewith a positionable member, such as a contact probe, a tool holder or corresponding device (1, 13) is moved to a given position in space during the measuring or positioning process. The method is particularly characterized in that the reference consists of a geometry of known kind, and in that the measured values are correlated to a geometry of known kind, this correlation being used to calculate corrections for the coordinate axes of the system. There is also an apparatus for carrying out the method.