Abstract: An improved height measuring instrument includes a hollow profile support member measuring a scale mounted to the support member, and a relatively flexible guide member which is adjustably mounted to the support member by means of a plurality of threaded fasteners which can be used to push or pull the guide member to correct measurement errors. A measurement carriage is guided along the guide member. This carriage bears an intermediate member onto which is mounted both a sensor and a reading unit arranged to scan the scale. A spring parallelogram including a pair of opposed, parallel plate springs connects the intermediate member to the carriage to provide a substantially constant measuring force. An apparatus is disclosed for altering the spring constant of the parallelogram to compensate for the proper weight of the intermediate member, the reading unit, and the sensor.

Abstract: An instrument for measuring the movement of a first object with respect to a second object is disclosed including a rotatable opaque disc mounted on the first object, which disc defines a plurality of translucent involute stripes proceeding from a base circle, a scale including a reflective grid pattern mounted on the second object, and an optical system for projecting an image of a portion of the grid pattern onto an image zone of the disc such that the stripes of the image of the grid are substantially perpendicular to a line drawn tangent to the base circle through the image zone.

Abstract: An instrument for measuring a dimension of an object is disclosed including a rotatable disc defining at least one translucent involute slit proceeding from a base circle centered at the center of rotation of the disc and a diaphragm mounted adjacent the disc and defining a linear slit arranged on a line tangent to the base circle. The intersection of the involute slit and the diaphragm slit forms a translucent overlap zone, and an image of the object is projected onto the disc or the diaphragm in the region of the diaphragm slit oriented such that the dimension to be measured is parallel to the diaphragm slit.

Abstract: In a measuring instrument for measuring or adjusting the relative position of two objects, including a measuring scale, a movably mounted sensor housing unit and an elongated hollow body which is resistant to bending and encloses the measuring scale and the movably mounted sensor housing unit to protect them from environmental influences, at least one ball joint for fastening the hollow body to one of the objects to be measured. According to one of the embodiments, two spheres are positioned at a fastening means at one end of the hollow body and a single, centrally-located ball joint is provided at a fastening means at the other end.

Abstract: A distance measuring instrument comprising a source of coherent light and a receiver is disclosed which may be used to measure the one dimensional position of an object surface. Coherent light is directed at a predetermined angle onto the object surface and the angle at which diffusely reflected light from this surface enters the receiver is measured. This entrance angle is measured with a photosensor and a movable aperture formed by the intersection of a fixedly mounted diaphragm and a movably mounted diaphragm. By measuring the position of the movably mounted diaphragm when the movable aperture is placed so as to allow reflected light to pass from the illuminated surface to the photosensor, the entrance angle of the reflected light and hence the position of the object is determined.

Abstract: An error correction apparatus adapted for use with a longitudinal measuring instrument is disclosed. In the preferred embodiment the correction apparatus is mounted on a measuring instrument having a longitudinal scale, a scanning unit movable along the scale, and a housing surrounding the scale and the scanning unit. In measuring the relative position of two objects, the first object is connected to the housing and the second object is connected to the scanning unit via the correction apparatus of this invention. The correction apparatus includes a segmented correction profile made up of a plurality of individual correction members joined end to end to form a track extending substantially in the direction of the scale. The correction members are pivotably interconnected by joints which permit a limited amount of longitudinal movement between adjacent correction members.

Abstract: A vibration resistant measuring device is disclosed of the type which includes a scale and a scanning unit which is guided along the scale. This device includes a compensating mass connected to the scanning unit to counteract and reduce the tendency of the scanning unit to lift off the scale during periods of high acceleration.

Abstract: A segmented longitudinal measuring device is disclosed which includes a plurality of hollow tubular housing segments. Inside each housing segment is mounted an intermediate support member which in turn serves as a mounting surface for a measuring scale segment. Thus, each segment forms a complete modular unit containing a length of measuring scale, intermediate support member, and housing. Generally the coefficient of thermal expansion of the support members is matched to that of the scale segments, and the support members are mounted on the housing segments in a longitudinally displaceable manner, as by a layer of resilient elastomeric material, for example. The measuring device also includes means for compressing the support members together, end to end, to form a continuous structure extending along the measuring direction. Adjustable contact members are provided between adjacent support members for precise adjustment of the separation between adjacent support members.

Abstract: A displacement measuring system for measuring relative displacements between two members. The second member is free to move relative to the first member along a main guide. The first member has a scale element which tracks the main guide. The second member is coupled to a scanner which moves along its own guide (which may be constituted by the scale element itself) scanning the scale element to provide a measure of the relative displacement. The coupling is flexible in directions at right angles to the direction of relative displacement in order to compensate for tracking errors between the main guide and the scale.An embodiment in which the scale is located off the neutral axis of the scale element the coupling is flexible in a first plane on the level of the neutral axis and in a second plane which includes the longitudinal central axis of the scale and is at right angles to the first plane.

Abstract: A longitudinal measuring instrument, preferably with digital path coverage, which is constructed according to the Abbe principle. The measuring instrument includes a stationary scale, a displaceably mounted scanning unit for scanning the scale, and a measuring spindle sleeve mounted on the scanning unit, said measuring spindle comprising at least two bars which surround the scale.

Abstract: A method and apparatus for the compensation of guiding errors in an incremental measuring instrument used in conjunction with machine tools or measuring machines is disclosed in which the measuring graduation is corrected in its mounting position in accordance with the error values of the machine. A preferred embodiment of this method is disclosed in which the error compensation is accomplished by the application of equal longitudinal compression or extension forces to the ends of the measuring graduation.

Abstract: A laser interferometer is disclosed in which the measuring path is enclosed in an elongated hollow body which has a flexible slot along one side through which extends the entrainment means for the movable reflector enclosed within the hollow body. This hollow body is maintained under a vacuum, with the area around the flexible slot being filled with a fluid to help maintain the vacuum. This fluid may be highly viscous oil or a magnetic fluid which is maintained by the magnetic field of permanent magnets.