Line bore gauge

A line bore gauge to measure variations in the radius of a selected bearing seat with respect to a defined reference axis comprising:

• first and second reference bearing seats, defining the reference axis by their centers of curvature;
• an elongated shaft of circular cross-section disposed concentrically within said reference bearing seats;
• a positionable collar disposed on the shaft;
• first and second bearing means disposed along the shaft, concentrically within the first and second reference bearing seats respectively;
• at least two pair of grooves disposed on the shaft, one groove being disposed on each side of the first and second bearing means;
• a circular clip removably seated in each groove to prevent axial movement of the bearing means with respect to the shaft;
• a threaded hole extending radially from the center of the collar to its periphery;
• a set screw disposed in the threaded hole to lock the collar to the shaft;
• a hole extending axially through the collar between its minor and major radii, and aligned with the longitudinal axis of the shaft;
• a pin disposed within the hole and extending outwardly, parallel to the axis of the elongated shaft;
• a ball disposed at the distal end of the pin;
• a radially displaceable probe;
• a visual readout means to measure variations in the radial displacement of the probe;
• a hinge pivotally affixing the probe to the visual readout means, such that pivoting of the probe on the hinge varies the distance from a point defined by the distal end of the probe to the geometric foot of the point in the reference axis;
• means coupling the proximal end of the probe to the visual readout means, such that variations in the distance from the point defined by the distal end of the probe to the geometric foot of that point in the reference axis are registered in calibrated units on the visual readout means;
• a socket disposed at the proximal end of the visual readout means;
• the ball being disposed within the socket;
• a threaded sleeve which may be selectively tightened onto the socket to maintain the ball in fixed orientation in the socket;
• and
• a spring additionally coupling the proximal end of the probe to the visual readout means biasing the probe away from alignment with the reference axis, into contact with selected bearing seats.

A line bore gauge for measuring in an engine or the like having a series of at least three arcuate bearing seats with substantially common centers of curvature, a selected property of a selected bearing seat of the series at differing angular positions about a reference axis defined by the centers of curvature of a given pair of the remaining bearing seats of the series chosen for purposes of defining the reference axis for seats of interest, the line bore gauge comprising:

• an elongate shaft;
• a pair of axially positionable toroid-shaped adaptors on the shaft, the adaptors having outer surfaces corresponding to the chosen bearing seats for alignment of the shaft when in use with the centers of curvature of such respective chosen seats, the adaptors when in use being positioned relative to each other to correspond to the axial separation of the chosen referencing bearing seats;
• a collar disposed upon the shaft which is axially positionable relative to the adaptors;
• a radial distance indicator mechanism;
• coupling means for coupling the radial distance indicator mechanism between the collar and the surface of the selected bearing seat, thereby to provide measurement of such bearing surface relative to the reference axis;
• and
• positional means for changing the angular position of the radial distance indicator mechanism about the reference axis thereby to vary the angular relation of the mechanism to the adjacent bearing surface to obtain measurements at different locations on the bearing surface.

A line bore gauge to measure variations in the radius of a selected bearing seat with respect to a reference axis defined by the centers of curvature of a pair of different reference bearing seats, the line bore gauge comprising:

• an elongated shaft for concentric disposition within said reference seats;
• a positionable collar disposed upon the shaft;
• a radial distance indicator mechanism;
• means for coupling the radial distance indicator mechanism to the collar and for contacting the radial distance indicator mechanism to the selected bearing seat comprising:
• a hole extending axially through the collar and aligned with the longitudinal axis of the shaft;
• a pin disposed within the hole and extending outwardly, parallel to the axis of the elongated shaft;
• a ball disposed at the distal end of the pin;
• a socket disposed at the proximal end of the radial distance indicator mechanism, the ball being disposed within the socket;
• and
• means for selectively clamping the ball within the socket to position the radial distance indicator mechanism relative to the reference axis;
• and
• means for rotating the radial distance indicator mechanism about the reference axis.