Abstract: A contact sensing probe is disclosed for use with a measuring machine or machine tool for measuring the dimensions of a workpiece. The probe comprises a housing within which a stylus holder is mounted on a kinematic support. A spring urges the stylus holder into a rest position on the support and yieldingly resists tilting or lifting of the stylus holder from the support when the stylus engages a workpiece. A sensing device in the form of an accelerometer is supported within the housing on the stylus holder to sense one of the effects of stylus engagement with the workpiece, and to produce a signal which is used to stop the machine and read the signal and read the coordinates of the instantaneous stylus position. The effects sensed in different embodiments of the invention are, sudden lifting of the stylus holder due to physical displacement of the stylus, or the shockwave produced in the stylus on contact with the workpiece.

Abstract: A device for checking the accuracy of coordinate positioning apparatus which includes a support, a head and components for measuring the coordinate position of the head relative to the support. The device comprises a bar, a connecting member movably securable to the support, a first universal pivot for supporting the bar at one end on the connecting member, a second universal pivot adapted for establishing a universal pivotable connection between the other end of the bar and the head, and a switch for producing a signal responsive to the head attaining a predetermined location in a coordinate field of the apparatus.

Abstract: The method for measuring dimensions of a workpiece (15) in a coordinate measuring machine having an optical probe (14) arranged to output radiation in a direction (21A) at an angle to a surface (15A) to be measured. The probe has a housing (17) which is arranged to lie clear of a projection formed by the surface (15A) to be measured and another, adjacent, surface (15B) so that the housing can pass clear of the projection and the measurement can be made without halting the machine at the surface to be measured.The probe (14) is adapted for the radiation to be in the form of a cone (21) symmetric about an axis (Z1) transverse to the direction of movement of the probe so that the probe can sense all around the axis and therefore can sense any surface parallel or inclined to the axis regardless of the direction in which the surface faces.

Abstract: A machine tool having a table movable relative to a head for machining a workpiece mounted on the head by a tool mounted on the table. The table also supports a magazine for blank workpieces, and the table is movable between a first position in which the head and the tool are in machining proximity and a second position in which the head and the magazine are proximate. The head has a work holder adapted to grip a blank workpiece at said second position for transfer, by movement of the table, to said first position. After machining, the workpiece is correspondingly returnable to the magazine. The work holder is mounted on a spindle supported on the head and rotatable for machining purposes. In a modification the spindle supports a tool, and the head has a gripper which is separate from the spindle and is used for the transfer of workpieces between the magazine and a work holder mounted on the table.

Abstract: A contact sensing probe is disclosed for use with a measuring machine or machine tool for measuring the dimensions of a workpiece. The probe comprises a housing within which a stylus holder is mounted on a kinematic support. A spring urges the stylus holder into a rest position on the support and yieldingly resists tilting or lifting of the stylus holder from the support when the stylus engages a workpiece. A sensing device in the form of an accelerometer is supported within the housing on the stylus holder to sense one of the effects of stylus engagement with the workpiece, and to produce a signal which is used to stop the machine and read the signal and read the coordinates of the instantaneous stylus position. The effects sensed in different embodiments of the invention are, sudden lifting of the stylus holder due to physical displacement of the stylus, or the shock-wave produced in the stylus on contact with the workpiece.

Abstract: An apparatus for measuring displacement between two members subject to movement relative to one another. The apparatus includes a scale defined by spaced marks provided on one of the members. A light source is arranged to illuminate the marks, wherein light reflected from the marks constitutes light signals. A light-receiving device is provided on the other of the members for receiving at least two light signals reflected from the marks in predetermined phase relationship. A determining circuit is coupled for receiving the light signals and for determining the sense of direction of the relative movement of one of the members based upon the phase relationship of the two light signals. A single optical fiber is provided for transmitting the light signals between the light-receiving device and the determining circuit. Additionally, color-encoding means are located for color-encoding the respective light signals.

Abstract: In a machine tool having a spindle supporting a work holder, means are provided for automatically operating the work holder to grip or release a workpiece and for automatically securing the work holder to the spindle or release it therefrom. Within the spindle, a compression spring acts on a slide which has claws gripping a head provided at one end of a holder housing to draw the latter into engagement with a conical socket of the spindle thereby to secure the holder. Within the holder housing, a compression spring urges a set of jaws into a conical socket of the housing thereby to grip a workpiece. A hydraulic actuator mounted on fixed structure is adapted both for opening the jaws and for releasing the holder from the spindle. For opening the jaws, a piston of the actuator is moved through an initial distance X thereby to move the jaws in opposition to the spring in the opening sense. The piston acts through the intermediary of a rod supported in the slide for free movement relative thereto.

Abstract: A tool (12) is releasably supported on a head (10) by a kinematic support (35) having elements (36,37) provided respectively on the head (10) and the tool (12) and extending in a plane (A--A) transverse to an axis (10A) of the head (10) by a releasable coupling (17) which comprises a first element (21) provided on the head (10) and engaged with a second element (26) provided on the tool. To release the tool (12) from the head (10) the latter is moved to position the tool (12) at a magazine (16) and by such movement to connect the second element (26) with an operating member (41) provided on the magazine (16). Rotation of the second element (26) by the operating member (41) releases the second element (26) from the first element (21) and frees the head (10) for withdrawal in the direction of its axis (10A).

Abstract: A numerically controlled machine tool capable of milling and turning operations has a continuously rotatable first spindle (10) to which is releasably secured a work holder (50). A rotationally positionable second spindle (20) has releasably secured thereto a tool holder (60). For turning operations, the second spindle (20) is locked against rotation and has secured thereto a tool holder having a turning tool (61), the workpiece (51) being held by the work holder on the first spindle (10). For milling operations, the second spindle (20) is unlocked, the work holder (50) is secured to the second spindle (20), and a tool holder (60) with a milling tool therein is secured to the first spindle (10). The changeover of work and tool holders is done by a transfer mechanism which takes appropriate holders (60), as well as work blanks, from a magazine system.

Abstract: The machine tool is a machining center having an angularly positionable tool spindle 16, a work table 11 movable relative to the spindle, and a surface-sensing probe 25 mountable on the spindle for measuring dimensions or positions on a work piece situated on the table. The probe senses a surface when the latter lies a small distance ("the probe offset") away from the spindle axis.The method comprises providing on the workpiece a bore 24 defining opposite test surfaces -DX and +DX. The mid-point between the test surfaces has a known nominal position but an unknown actual position. The method further comprises operating the machine in a specified way to measure the test surfaces, the operation including rotating the spindle through 180.degree. between certain of the measuring operations. The measurements are then used for computing the probe offsets and the distance ("the work offset") between said nominal and actual positions.

Abstract: A numerically controlled machine tool has a rotatable spindle (10) to which is connected, in the place of the usual cutting tool, a probe (16) for measuring a work surface (25) to be, or having been, machined by a said tool. The probe (16) includes an electric circuit (30) adapted to respond to engagement between the probe (16) and the work surface (25), by disestablishing a signal (26) to a control system (12) and thereby effect measurement of the position of the work surface (25). The circuit (30) is energized by a battery (31) normally disconnected from the circuit (30) and connectable thereto by the control system (12) effecting a transient rotation of the spindle (10). The rotation acts on a centrifugally operated, normally open switch (FIG. 2) arranged within the probe (16). The circuit (30) is arranged to latch the switch in the "on" condition when the transient rotation ceases whereafter the probe (16) is ready for the probing operation.

Abstract: In a co-ordinate measuring machine a probe is connected to the head of the machine by a pivotal arm, and the orientation of the probe is changed by moving the head so that the arm engages a fixed structure and a moment is applied to the arm which is thereby caused to turn and present the probe in the required orientation.

Abstract: A numerically controlled machine tool having a tool secured to a support for machining a surface of a workpiece. The tool is also used for sensing the workpiece surface for measuring the distance between the workpiece surface and a datum surface. To this end, the tool is at first moved to a position clear of the workpiece surface and an electric circuit between the tool and the workpiece switched on. The tool is then moved toward the workpiece surface by a control system adapted to continually read the position of the tool by means of a counter. When the tool touches the workpiece the circuit is made and produces a signal used to read the instantaneous content of the counter into a computer. The computer determines the difference between the actual and demanded dimension of the workpiece surface and corrects the next machining position of the tool accordingly.

Abstract: The machine tool is a machining center having an angularly positionable tool spindle, a work table movable relative to the spindle, and a surface-sensing probe mountable on the spindle for measuring dimensions or positions on a work piece situated on the table. The probe senses a surface when the latter lies a small distance ("the probe offset") away from the spindle axis.The method comprises providing on the workpiece a bore 24 defining opposite test surfaces -DX and +DX. The mid-point between the test surfaces has a known nominal position but an unknown actual position. The method further comprises operating the machine in a specified way to measure the test surfaces, the operation including rotating the spindle through 180.degree. between certain of the measuring operations. The measurements are then used for computing the probe offsets and the distance ("the work offset") between said nominal and actual positions.

Abstract: A machine tool spindle (10), rotatable in a housing (11), is adapted to receive, as an alternative to a cutting tool, a probe (12) having a stylus (14) whereby to sense a workpiece (15) for the purpose of measuring it. On sensing the workpiece (15) the probe (12) generates a signal which is transmitted to a fixed location (X) on the housing (11). The probe (12) has a body (13) secured to the spindle (10) for rotation therewith, such rotation being required for certain measuring manouvres. To cope with the transmission of the signal (17) from the rotating probe (12) to the fixed location (X), the signal (17) is transmitted through the intermediary of a sleeve (19) supported on the probe body (13) such that the body (13) can rotate while the sleeve (19) is held still by an axially disengageable mechanical connector (21) connecting the sleeve (19) to the housing (11).

Abstract: A probe for sensing the position of a workpiece comprises a housing adapted to be secured to a coordinate measuring machine. A stylus projecting from the housing is engageable with the workpiece for sensing the position thereof. The stylus is secured to a moveable member supported within the housing by three bellows having mutually perpendicular axes and each secured to the moveable member and the housing in position therebetween. Since a bellows is inherently stiff in torsion about its axis but is flexible axially and transversely, the bellows cooperate to constrain the stylus for parallel motion. More particularly, any one first bellows can expand or contract to accommodate movement of the stylus in the direction of the axis of that the first bellows, a second one of the bellows prevents tilting of the stylus by virtue of its torsional stiffness. At the same time both the second and third bellows flex transversely to accommodate the expansion or contraction of the first bellows.

Abstract: A numerically controlled machine tool comprises a tool movable into engagement with a workpiece, means for generating a first signal being a measure of the distance between the tool and a datum surface provided on a relatively fixed part of the machine, a first closed loop system adapted to move the tool toward the workpiece and having the first signal as feedback, means for generating a second signal being a measure of the distance between the tool and the workpiece, a second closed loop system (33) having the second signal as feedback, and means responsive to the second-mentioned distance attaining a threshold value, while being moved under the control of the first system, for changing control of the tool movement from the first to the second system.

Abstract: A probe for use in measuring apparatus has a base member including a two-dimensional seat for an intermediate member which, in turn, includes a two-dimensional seat for a stylus holder. The two seats face in opposite directions so that the stylus holder can be displaced from the seated position in either of two opposite directions.

Abstract: A probe for measuring dimensions of a workpiece in coordinate positioning apparatus, comprises a base (20), a stylus holder (21) having an axis (21A), an intermediate member (22, 30) having a fixed region (22A) connected to said base and a free region (22B) connected to said holder, said intermediate member being resilient so as to be responsive to a displacing force (FW) acting on said holder in the sense tending to tilt or axially move said holder relative to said base, and sensing means (30) connected between said free region and said base for sensing the occurence of a said displacing force.The intermediate member is only sufficiently resilient to make possible said sensing.

Abstract: A probe for use in measuring apparatus has a base member including a two-dimensional seat for an intermediate member which, in turn, includes a two-dimensional seat for a stylus holder. The two seats face in opposite directions so that the stylus holder can be displaced from the seated position in either of two opposite directions.