Eaton Corporation

Kish D Amlani

Paul W Morgan

Thomas J Ellwood

Sherif S Gindy

Martin W Hamilton

Craig Morgan

John B Hodges

Frederick J Zink

A compression type load cell (50) is provided for measuring a load (L) applied to an object (3). Cell (50) has a first end (7) adapted to receive load (L) thereupon and an opposite end (9) adapted to support cell (50) upon object (3) with end (7) adapted to direct load (L) axially along a central longitudinal axis (x) of cell (50). Cell (50) has a reduced section (8) having a first pair of bores (14,14') therethrough that are preferably oriented substantially transverse to axis (x) and are spaced-apart from each other substantially symmetrically on opposite sides of axis (x). Reduced section (8) has a second pair of bores (16,16') therethrough between bores (14,14') and end (9) that are preferably substantially transverse to axis (x) and respectively axially aligned with bores (14,14'). A pair of slots (19) and (19') extend from outside cell (50) and respectively preferably intersect bores (14,14') for their entire length and a channel (18) extends between and intersects bores (16) and (16') for their entire length providing section (8) with enhanced axial movement between bores (14,14') and (16,16') upon application of load (L) on cell (50) which is measured by strain sensing means mounted on load sensing surfaces (10,12) defined on opposite sides of section (8) between bores (14,14') and (16,16').

Load cell

A rotary transformer transducer system includes a rotatable shaft having a rotor and a transducer each mounted thereon, and a stationary member including a stator, with the rotor and stator coupling electrical energy therebetween without physical contact. A resistor mounted on the rotatable shaft is selectably switched to provide direct shunt calibration of the transducer without physical contact with the stationary member. A solid state switch, mounted on the shaft couples the resistor to the transducer. The switch is operated by a pulse coded signal coupled in the reverse direction through the rotary transformers normally provided to transmit the transducer signals.

Shunt calibration system for a transducer mounted on a rotating member

A system for calibrating a strain gage transducer mounted on a rotating member comprising a mechanical switch capable of making contact from a stator to selected terminals on the rotor to provide both positive and negative shunt calibration of the transducer. In a first embodiment, calibration is carried out while the rotor is stationary, providing a simple, cost effective calibration system for most applications. In a second embodiment, special terminals permit contact while the rotor is in motion. In a third embodiment, simultaneous calibration and gage measurements are possible while the rotor is in motion providing a means of continuous correction which is especially advantageous in applications where the rotor is subject to a rapidly changing environment.

Mechanical switching means for providing shunt calibration in a rotary

The performance and condition of a tool, workpiece or machine tool is sensed during machining operations by securing a single or plural strain gages to the tool holder. To increase the sensitivity of the strain gages on stationary tool holders, the tool holders are contoured to provide locations of higher strain in which the strain gages are attached. A single or plural strain gages are positioned to sense the combined effect of different strains such as axial thrust and torque and are electrically connected to provide a single Wheatstone bridge output 'signature' which may be monitored to detect a defective operation. In rotating tools, the single 'signature' output greatly reduces the coupling equipment such as rotary transformers and also reduces the monitoring equipment. A unique arrangement of a single strain gage or alternatively a plurality of gages enables monitoring of both torque and thrust simultaneously. The output from the plurality of strain gages can be made additive to increase sensitivity and yet requires only a single bridge circuit. The design is flexible in that the gages may be arranged for optimization of the single bridge output for either torque or thrust.

Combination loading transducer

Theload cell herein disclosed is designed for precise measurement of forces along or parallel to a single axis, while being substantially immune to forces applied along the other mutually perpendicular axes as well as moments applied about any of the three mutually perpendicular axes. Rigid force input and force output members are resiliently interconnected by a pair of parallel flexure beams which establish with such members a parallelogram type of linkage which is relatively yieldable to forces parallel to the selected measurement axis while being relatively stiff and unyieldable to forces parallel to the other two axes and to moments about any of the three axes. A strain gage-equipped sensing beam is mounted within the plane of the parallelogram linkage and between the two flexure beams. One end of the sensing beam is rigidly connected to the fixed force output member, while the other end is free to flex in cantilevered fashion responsive to displacement of the force input member. The sensing beam thereby provides part of the resilient interconnection between the force input and force output members, and is dimensioned so that its stiffness relative to that of the two flexure beams causes it to absorb 80 to 90% of the applied loads. Adjustable overload protection means are provided, which cause excessive forces to be safely by-passed around the resilient members and the strain gages.

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Troy, MI, United States of America

Kish D Amlani