Abstract: A coordinate positioning machine comprises a fixed structure including a table and a supporting frame, rigidly connected together. A movable arm is suspended from the frame by means of three powered telescopic struts, each of which is universally pivotally connected to both the arm and the frame. As a consequence, the movable arm is able to move with three rotational degrees of freedom. Movement of the arm with each of these degrees of freedom is constrained by a passive device, connected to the arm and the fixed structure, and which eliminates all rotational movement of the arm, while simultaneously permitting translation thereof.

Abstract: A coordinate positioning machine comprises a fixed structure including a table and a supporting frame (314), rigidly connected together. A moveable arm (310) is suspended from the frame by means of three powered telescopic struts (316), each of which is universally pivotally connected to both the arm and the frame. As a consequence the moveable arm is able to move with three rotational degrees of freedom. Movement of the arm with each of these degrees of freedom is constrained by a passive device (340), connected to the arm and the fixed structure, and which eliminates all rotational movement of the arm, while simultaneously permitting translation thereof.

Abstract: A coordinate positioning machine comprises a fixed structure including a table and a supporting frame (314), rigidly connected together. A moveable arm (310) is suspended from the frame by means of three powered telescopic struts (316), each of which is universally pivotally connected to both the arm and the frame. As a consequence the moveable arm is able to move with three rotational degrees of freedom. Movement of the arm with each of these degrees of freedom is constrained by a passive device (340), connected to the arm and the fixed structure, and which eliminates all rotational movement of the arm, while simultaneously permitting translation thereof.

Abstract: An automatic pallet handling system for a machine tool is described in which the pallets are formed as lightweight cassettes (10) which can be mounted by means of shaped locating features on the external periphery of a receiving device (4) mounted, for example, for rotation with a horizontal indexing spindle (2) in a vertical spindle CNC machine. A portable cassette-loading system (15) which consists of a chain conveyor (17) having links (18) pivotably connected side-by-side and formed from lightweight extrusions is positionable adjacent the machine or removable to a loading station. The extruded links form features for engaging the same cassette-locating features on the cassettes and a transfer mechanism (50) slides the cassettes from the loading conveyor to the periphery of the receiving device.

Abstract: A three-coordinate measuring machine has a probe (22) connected to an output member (11). A driving system (10) is made up of three carriages (15, 17, 19) on guide rails (14, 16, 18). In parallel with this, there is provided a driven system (20) made up of three carriages (25, 27, 29) on guide rails (24, 26, 28). The carriages 19, 29) are connected together via the output member (11). The other pairs of carriages (15, 25 and (17, 27) are linked via respective devices (55). The devices (55) each apply a force between the respective carriages in dependence on acceleration or deceleration of the carriages of the driving system (10). This compensates for dynamic deflections of the guide rails of the driven system (20) which would otherwise be caused by the accelerations. Measuring devices such as scales and readheads are provided on the driven system (20) to determine the position of the probe (22).

Abstract: A hydraulic variable-displacement axial piston pump comprising a swash means which tends to move to a de-swashed condition when the pump is working, and a torque limiting device, the torque limiting device comprising a piston and cylinder arrangement having a movable member which when extended acts via the swash means to increase the displacement of the pump, a spool, and a spring which has one end acting on the spool and its other end acting on the movable member thereby placing the spool under a spring load which varies with the extension of the movable member, the spool being coupled to pump delivery pressure at its end remote from the spring and the spool being arranged to control the flow of fluid to the movable member, whereby a limitation on the on-swash condition of the swash means is obtained which is inversely proportional to the pressure at which the hydraulic fluid is discharged from the pump.

Abstract: A hydraulic pumping arrangement for pumping a liquid to a hydraulic system, which comprises pumping means for pumping the liquid, swash means including a variable swash member which enables the liquid output of the pumping means to be infinitely varied between minimum and maximum, a first piston-and-cylinder arrangement for increasing the position of the swash member to increase the liquid output of the pumping means, a second piston-and-cylinder arrangement for decreasing the position of the swash member to decrease the liquid output of the pumping means, control means for controlling the flow of liquid for the second piston-and-cylinder arrangement, switching means operative to pass liquid from the system to the control means at a first condition in the system and operative to stop liquid from the system passing to the control means at a second condition in the system, and valve means for isolating the pumping arrangement from the system and from a main pump normally supplying liquid to the system, the cont