Systems Research Laboratories

The Bendix Corporation

James S Nevitt

James D Hoeffel

Richard E Elliott

Wally C Hoppe

Daniel P Mazzone

A detachable, articulated rotating eddy current inspection tool includes a body member having a connector at one end for mechanically and electrically attaching the body member to a rotating drive member while at the other an eddy current probe is supported for radial movement with respect to the axis of rotation of the body member. A motor located within the body moves a slide on which the probe is mounted while at the same time a counterbalancing slide is moved radially in the opposite direction to maintain said tool in dynamic balance. An encoder housed within said body member senses the location of said eddy current probe with respect to the axis of rotation of said body member. A rotary transformer is used to transfer signals which control the position of the probe and to receive information from the eddy current probe and the encoder. The encoder output signals are modulated by the eddy current probe exciter signal to enable probe positions information to be sent through a rotary transformer.

Eddy current proble with adjustable position rotating head

An apparatus for maintaining the end of a probe carrying a sensor, such as an eddy current probe, a predetermined distance from a workpiece includes a housing in which a piston is permitted to move. Air under pressure, introduced into a first chamber formed within the housing, acts on a first surface of the piston to urge it toward the workpiece. An air bearing is used to permit the almost friction free axial movement of the piston within the housing. Some of the air passes from the first chamber through a restricted opening in the piston into a second chamber and is vented toward the workpiece. The pressure in the second chamber will vary as a function of the distance of the end of the probe to the workpiece surface. The piston is provided with a second, larger, surface area exposed to the variable pressure in the second chamber, and as a result, the piston is urged away from the workpiece. The pressures acting in the two surfaces work together to maintain the piston, and the sensor, a constant distance from the workpiece.

Pneumatic surface-following control system

A back pressure fluid gaging circuit for measuring dimensions of a workpiece. The gaging circuit (100) includes gage tooling (190) including at least one fluid jet (192) disposed to be directed at a surface (210) of the workpiece (200), with variations in the distance between the surface (210) and the tooling (190) providing a varying back pressure of the fluid which is measured by a gage (150) located intermediate the length of a conduit (170) connecting a source (110) of fluid under pressure with the tooling (190). First and second adjustable (variable) fluid passage restrictions (130, 140) in the conduit (170, are adjusted to provide an output within a range that can be displayed by the gage (150) for the particular tooling selected. One of the adjustable restrictions (130) is located along the conduit between the source (110) of pressurized fluid and the gage (150) and the other restrictions (140) between the gage (150) and the tooling (190). The use of two adjustable passage restrictions allows the use of a constant (non-varying) fluid pressure source, supplied by a fixed fluid pressure regulator (120).

Growing community of inventors

Bellbrook, OH, United States of America

James S Nevitt