Brown & Sharpe Manufacturing Co.

Other

Vitaly I Pesikov

William J McCabe

Andrew Anthony Szczepanowski

Neville E Andrews

Walter L Beckwith, Jr

Yuzhong Dai

Raymond J Guertin

Thomas Charlton, Jr

Jim Salemme

William Dowst

A writing instrument is provided having an elongated shell having a longitudinal axis and an elongated assembly having a writing tip disposed at a first end of the elongated assembly. The elongated assembly is disposed at least partially in the elongated shell. The elongated assembly moves relative to the elongated shell between first and second positions along the longitudinal axis, a surface of the elongated assembly abutting a surface of the elongated shell with the elongated assembly in the first position and the surface of the elongated assembly spaced from the surface of the elongated shell with the elongated assembly in the second position. The writing instrument also includes a flexible bushing having a first end and a second end. The first end of the flexible bushing is secured to the elongated shell and the second end of the flexible bushing secured to the elongated assembly. The flexible bushing biases the elongated assembly toward the second position.

Writing instrument with biased rotatable assembly

A coordinate measuring machine includes a support structure, an articulated arm having a first end pivotally connected to the support structure and a second end that is movable in a horizontal plane. A Z-ram assembly is mounted to the second end of the articulated arm. The Z-ram assembly includes a Z-ram housing and a probe that is vertically movable with respect to the Z-ram housing. The probe is movable within a measurement volume defined by the articulated arm and the Z-ram assembly. The coordinate measuring machine further includes a measuring assembly for determining coordinates of the probe in the measurement volume. The articulated arm preferably includes first and second arm assemblies that have a parallelogram configuration to prevent substantial rotation of the Z-ram assembly as the articulated arm is moved in the horizontal plane. The angles of the articulated arm are preferably measured using a sensor which includes a pattern of parallel, straight grating lines.

Coordinate measuring machine having articulated arm

Apparatus for counterbalancing a vertically movable element of a machine includes an air cylinder attached to the movable element on the axis of movement and having a small axial opening at its upper end. A piston located in the air cylinder is attached to a fixed machine element by a nonelastic, flexible member such as a thin, nylon-jacketed wire passing through the axial opening in the cylinder. Air under pressure sufficient to counterbalance the weight of the movable element is supplied to the space between the piston and the axial opening in the cylinder. The flexible member makes the counterbalancing assembly relatively insensitive to misalignment and vibration. Air is permitted to leak around the piston to reduce friction and to relieve pressure buildup during downward movement. In another embodiment, the air cylinder is attached to the fixed machine element.

Counterweight for coordinate measuring machine

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. In another embodiment of this invention, the encoder the scale is secured to a lower end of a rod depending downwardly from the support column. In this alternative embodiment, the rod is composed of a material having a coefficient of thermal expansion substantially greater than that of the component of the support column, which is especially aluminum. In a third embodiment, two supports can be used, one having a coefficient of thermal expansion substantially greater than aluminum and another having a coefficient of thermal expansion substantially less than aluminum. Similar apparatus also is used to prevent 'zero shift' in the X and Y directions.

Apparatus for temperature compensation of sensing means of a machine

In a precision machine, such as a coordinate measuring machine or a machine tool in which a carriage rides along a rail, a gas bearing for applying a constant preload force to a bearing shoe over a range of relative movement between said bearing shoe and the carriage to accommodate imperfections and non-parallelism in the rail. The constant preload force is provided by a disc spring, which may be a Belleville spring. A preferred spring has a free height to thickness ratio in the range of from about 1.35:1 to about 1.6:1. The gas bearing of this invention is used in opposed relation with another gas bearing.

Gas bearing for guiding relative movement of precision machine parts

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.

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Providence, RI, United States of America

Vitaly I Pesikov