S. Himmelstein and Company

Sydney Himmelstein

Richard S Tveter

James P Beck

Method and apparatus for calibrating a transducer having real and reactive impedance, which is excited from an excitation source and which provides an output signal connected by an electrical conductor to a remote load. A preamplifier is provided having a high impedance input and a low impedance output connected to the electrical conductor, and calibration structure is provided for alternatively connecting the transducer output to the preamplifier input for preamplifying the transducer output signal and providing to the remote load a low impedance preamplified output signal or providing a substantially purely resistive calibration signal to the preamplifier input for use in calibrating the transducer. In one embodiment, a remote auxiliary calibration circuit is provided including circuitry for selectively calibrating the auxiliary calibration circuit. In one embodiment, a power supply is provided for powering the preamplifier to provide further improved accuracy and convenience.

Method and apparatus for calibrating a transducer having real and

A nonintrusive torquemeter for measuring torque in a shaft having variable reluctance as a result of torque stresses developed in the shaft. The torquemeter includes an annular first coil, a second coil wound about the first coil coaxially of the annular axis of the first coil to be in space quadrature therewith, structure for mounting the coil assembly coaxially about the shaft to include the shaft in the magnetic flux coupling path between the coils, and structure for providing a signal corresponding to the voltage developed in the pickup winding as a result of changes in the magnetic reluctance of the shaft resulting from torque developed therein. One of the coils is electrically excited to define an excitation winding, and the other of the coils serves as a pickup winding, with the coils being effectively uncoupled in the absence of torque in the shaft and being variably coupled as an incident of torque being developed in the shaft causing a corresponding change in the reluctance thereof. A shield is provided for substantially eliminating inherent coupling between the coils under zero torque conditions, and in the illustrated embodiment, the shield is defined by an annular magnetic core structure extending about the inner coil. A shielding core structure may be provided extending about the assembled coils shielding them from external magnetic fields and providing mechanical protection to the torquemeter. In one illustrated embodiment, a shield is provided for shielding the secondary portion of the outer coil from torque-induced voltages in the inner coil. The outer coil may be differentially wound with a first turn portion wound in a first helical direction and a second turn portion wound in an opposite helical direction.

Shaft torquemeter

A nonintrusive, or noncontact, shaft torquemeter for use in measuring torque transmission through a rotatable shaft. The torquemeter includes an annular torque-sensing coil structure having an annular excitation coil and a pickup coil magnetically coupled to the excitation coil through an improved magnetostrictive coupling structure carried by the shaft. In the illustrated embodiment, the magnetostrictive coupling portion is provided on a tube coaxially fixed at its ends to the shaft. The invention comprehends the provision of structure for preventing a continuous annular conductive path through the coupling portion or tube. Other structure for improving torque measuring accuracy may be provided, including the use of an outer magnetic stator core, and the provision of annular corrugations in the tube for preventing transmission of nontorque forces, such as bending forces, to the coupling portion. In one embodiment, the coupling portion is defined by a portion of the mounting tube, and in another embodiment, the coupling portion is defined by a layer of magnetostrictive material on the tube.

Torquemeter

A nonintrusive torquemeter for measuring torque in a shaft having variable reluctance as a result of torque stresses developed in the shaft. The torquemeter includes an annular first coil disposed axially about the shaft, a second coil wound about the first coil coaxially of the annular axis of the first coil to be in space quadrature therewith, structure for mounting the coil assembly coaxially about the shaft to include the shaft in the magnetic flux coupling path between the coils, and structure for providing a signal corresponding to the voltage developed in the pickup winding as a result of changes in the magnetic reluctance of the shaft resulting from torque developed therein. One of the coils is electrically excited to define an excitation winding, and the other of the coils serves as a pickup winding, with the coils being effectively uncoupled in the absence of torque in the shaft and being variably coupled as an incident of torque being developed in the shaft causing a corresponding change in the reluctance thereof.

A method for testing leakage from an element, such as a container. The element to be tested is sealed within an enclosure so as to define a reduced volume space in the enclosure around the container. An increase in the pressure in the surrounding space is detected as a function of the amount of leakage of high pressure fluid from the container to that space. Reduced temperature sensitivity is effected by reducing the pressure in the space. However, the device functions to improve sensitivity where the space is provided at ambient pressure at the start of the test cycle, as well. The apparatus may include a control for effecting the leakage testing automatically and indicating to the user the result of the testing as desired.

Fluid leak testing method

An energy efficient drive system having apparatus for determining the load power, load speed, and necessary adjustment of the drive system to obtain a minimum brake specific energy consumption. The drive system includes structure for adjusting the drive in accordance with the determined adjustment. In one form, the drive system includes a variable speed transmission and the adjustment of the drive system is effected by adjusting the transmission in accordance with a determination of the necessary adjusted speed ratio for causing the motive device speed to be a minimum. In one form, the motive device is an internal combustion engine. The adjustment of the drive system to obtain maximum efficiency may alternatively be effected by adjusting the number of active cylinders of the engine. The determination may be made by reference to input information concerning the characteristics of the motive drive. In a modified form, the adjustment is effected by a constant monitoring of the brake specific energy consumption and a resultant adjustment of the drive system to constantly seek the lowest brake specific energy consumption.

Energy efficient drive system

A production control system wherein statistical determinations are continuously made on the basis of current manufacturing process data corresponding to preselected parameters of the product being manufactured. The control method includes a determination of the mean .+-.3 standard deviations of statistical samples. The method further includes the step of determining whether the mean .+-.3 standard deviation is within preselected permissible limits. Parameter determinations which are outside the permissible limits may be signalled for suitable action. In one form, the method includes the feedback of control signals to the manufacturing apparatus for effecting automatic corrective adjustment thereof when necessary. The determinations may be made by a statistical computer with information as to the product parameters being provided to the computer from conventional sensing devices.

Production control system

An apparatus for applying torque between one or more pairs of threaded members to effect a desired set condition. The set condition is determined by a control which terminates the application of torque when a preselected yielded tensioning of the threaded members is determined. The control is responsive to signals received from a torquemeter and an angle sensing device for determining seriatim the incremental increase in torque provided by the torque apparatus corresponding to a preselected incremental angle of rotational change. The control discontinues application of torque between the threaded members as an incident of a preselected decrease in the determined incremental torque increase. The threaded members may be first seated as by use of a low torque, high speed threading operation. The setting of the seated members may then be effected by a high torque, low speed threading operation. A plurality of pairs of threaded members may be concurrently set by the apparatus. The high torque, low speed threading operation may be controlled so as to permit application thereof only after all of the plurality of pairs of threaded members are seated by the low torque, high speed threading apparatus. The control utilizes a peak memory for retaining the highest value of torque applied between the threaded members and compares the sensed torque seriatim with the peak torque value of the peak memory in effecting the desired control of the threading operation.

Torque-yield control system

A rotary torquemeter utilizing a rotary transformer means in conjunction with a strain gauge for indicating torque being transmitted through a drive means. The use of the rotary transformer permits the detection of the torque without mechanical coupling to the drive means. An improved strain responsive means utilizing a foil strain gauge is incorporated in the torquemeter for improved torque reading.

Growing community of inventors

Barrington Hills, IL, United States of America

Sydney Himmelstein