Ingersoll-rand Company

Sps Technologies, LLC

Angelo L Tambini

John J Linehan

John T Boys

Ian E Kibblewhite

A test apparatus includes a torque sensor that outputs an indication of torque when rotated by a tool to be tested, and an angle potentiometer that outputs an indication of the rotation angle. A rotatable arm is connected to the torque sensor. A stop prevents the arm from rotating past a rest position. At least one of the group consisting of the arm and the stop includes a magnet. The magnet causes a magnetic force that attracts the arm toward the rest position when the arm is at or near the rest position, simulating static friction. At least one elastic member, which may be a spring, urges the arm toward the rest position.

Test apparatus for a wrench used to test previously tightened fasteners

A system for monitoring and/or controlling the torque applied by a fluid driven tool for driving threaded fasteners, such as tools driven by either air or oil. The system includes a fluid flow meter to measure a parameter which is a function of the rate of fluid flow into the tool during operation of the tool, a transducer for converting the measured parameter into an electrical signal, and a data processing unit for processing that electrical signal into a signal representative of the torque applied by said tool. A system for digitally processing the measured parameter and comparing it to predetermined expected parameters to infer the condition of the fluid driven tool and for reporting that inferred condition is also included. The system is applicable to both nutrunner type fluid tools and impact wrenches.

Monitoring and control of fluid driven tools

A method of utilizing a non-contact velocity sensor is disclosed which involves a subpoint set delay and reset feature as a means for minimizing problems with zero drift that would cause inaccuracies in tightening procedures.

Method for torque wrench non-contact angle measurement

The torque and angular displacement transducers in a controlled wrench apparatus are relocated to reduce the problems encountered therewith from the harsh physical environment experienced by such transducers in conventional designs. In one preferred embodiment, both the torque and angular displacement transducers are located at remote locations from the movable elements of the wrench mechanism and are each housed in a conventional hydraulic fitting to be more readily replaceable for maintenance purposes, as compared to the transducers of conventional designs.

Torque and angular displacement sensing in controlled wrenches

The torque and angular displacement transducers in a yield threshold controlled wrench apparatus are relocated to reduce the problems encountered therewith from the harsh physical environment experienced by such transducers in conventional designs. In one preferred embodiment, both the torque and angular displacement transducers are located at completely remote locations from the movable elements of the wrench mechanism and are each housed in a conventional hydraulic fitting to be more readily replaceable for maintenance purposes, as compared to the transducers of conventional designs.

Torque and angular displacement sensing in yield threshold controlled

A self-contained impact wrench having an adaptive control system for determining the yield point or some similarly significant tightened condition of a fastener assembly by detecting a signal representative of the forward rotation angle of the fastener assembly is disclosed. One embodiment utilizes a computed signal of time over a fixed interval of forward rotation angle, as an estimate of the torque applied by the impact wrench, and the torque estimate vs. rotation angle curve is differentiated to obtain the gradient thereof. Successive gradient values are stored and compared, and when the present gradient value has attained a predetermined relationship relative to a stored value of a gradient in a tightening region of the curve, further tightening of the fastener assembly is discontinued. This ensures that the yield point or other similarly significant tightened condition of the assembly has been reached.

Impact wrench

The preferred embodiment of the invention disclosed in this application includes a wrench, for example an operator powered wrench, for tightening a fastener assembly by the incremental application of tightening force. Also included is a control circuit for detecting a phenomena indicating that the joint assembly in which the fastener assembly is installed has been tightened to its yield point. The control circuit further includes checking means for determining that the fastener assembly is being tightened to assure that when the phenomena is detected, the joint assembly has been tightened to the yield point.

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Manor Kilbride, Ireland

Angelo L Tambini