Abstract: An endoscopic surgical instrument for aspiration and irrigation of a surgical site. The device includes at least one rotatable trumpet valve to provide for variable orientation of the device during use. Connection ports for irrigation fluid and a suction means are provided which communicate with a single lumen cannula which transports both the irrigation fluid and the suction pressure to the surgical site. The single lumen cannula is provided with a sleeve means to vary the pressure of the irrigation fluid to provide for high pressure application of the irrigation fluid to perform hydrodissection. A plurality of dissector tips and a novel means of securing the tips to the single lumen cannula are also disclosed.

Abstract: An endoscopic surgical instrument for aspiration and irrigation of a surgical site. The device inclues at least one rotatable trumpet valve to provide for variable oreintation of the device during use. Connection ports for connection to irrigation fluid and a suction source are provided which communicate with a single lumen cannula which transports both the irrigation fluid and the suction pressure to the surgical site. The single lumen cannula is provided with a sleeve to vary the pressure of the irrigation fluid to provide for high pressure application of the irrigation fluid to perform hydrodissection. A plurality of dissector tips and a novel mechanism for securing the tips to the single lumen cannula are also dislcosed. Also disclosed is a novel dispensing device for the tips and a kit which includes the tip dispenser and an endoscopic surgical instrument.

Abstract: In a coordinate measuring machine, apparatus for compensating the sensing means for determining the position of a probe for changes in temperature, where the machine base and the support column for the probe have differing coefficients of thermal expansion. In a preferred embodiment, the apparatus of this invention is used to prevent "zero shift" in the Z-direction for a Z-rail. The compensating apparatus is associated either with the support column or Z-rail. The apparatus offsets the greater expansion of the machine component having the greater coefficient of thermal expansion. Typically, the position sensing means for the Z-rail includes an encoder and a scale. In one embodiment, either the encoder or the scale is secured to a mount which is affixed to the column. One element of the mount which extends upwardly from the support column has a coefficient of thermal expansion which is substantially less than that of the aluminum of which the column is composed.

Abstract: A base assembly for a machine tool includes a support arrangement between a metal base and a granite worktable which eliminates distortion caused by differential thermal expansion and contraction and which isolates the base from deformation due to the weight of a workpiece. The support arrangement preferably includes three spaced-apart blocks, each with a V-groove track, attached to the bottom of the granite worktable. The axes of the V-groove tracks intersect at a common point. The metal base includes three spherical projections located for engagement in each of the V-groove tracks. The support arrangement permits the granite worktable and the base to expand, contract and distort separately, while providing vertical support and lateral and rotational restraint. Several configurations of tracks and projections are disclosed.