The B. F. Goodrich Company

Other

The Uniroyal Goodrich Tire Company

John P Porter

James L Derudder

Kenneth M Schur

Ronald L Dellangelo

Emmitt R Harrell, Jr

A method of determining the fundamental viscoelastic properties of a viscoelastic material includes the steps of imparting a torsional stress in a viscoelastic material; measuring the relaxation of the torsional stress over time and converting the relaxation stress to a representative analog waveform; digitizing the representative analog waveform to produce a representative digital waveform; and, determining the frequency dependant fundamental viscoelastic properties of the material based on the shape of a portion of the representative digital waveform. To facilitate automating the method, the shape of the waveform may be analyzed to detect the start of a test, the end of the test, and whether the test is a valide test. Preferably, the fundamental viscoelastic properties of the test material are determined by converting the torque based amplitudes of the waveform to shear relaxation modulus values, such as by multiplying the torque amplitudes by the geometric form factor of the test material, and then by transforming the shear stress modulus values to frequency dependant fundamental viscoelastic properties through the known Yagii/Maekawa approximation. A related apparatus is also disclosed.

Method and apparatus for determining the fundamental viscoelastic

Determining the rate of change of fluid pressure in a tire comprises mounting the tire in an inflated condition. A tire pressure sensor senses fluid pressure in the tire and generates an electrical signal in proportion to the fluid pressure sensed in the tire. A temperature sensor senses the temperature adjacent the tire and generates an electrical signal in proportion to the temperature sensed adjacent the tire. A data acquisition system is in electrical communication with the sensors. The data acquisition system receives the electrical signals from the respective sensors at a substantially simulatneously time and converts the electrical signals into digital information. An electronic digital computer is an electrical communication with the data acquisition system for receiving the digital information and for calculating a value representative of a corrected pressure in the tire as a function of the digital information received. A plurality of the corrected pressure values are stored. The stored corrected pressure values are linearized to provide another value indicative of the rate of change of pressure in the tire.

Determining the air permeability of a tire

There is disclosed a technique for measuring the magnetic field of a sample, such as sheet material having one or more magnetic poles, including effecting relative movement between a magnetically responsive transducer and the sample to scan the magnetic field while controlling the distance between the transducer and sample. Apparatus is provided to practice such technique, including control of the relative scanning movement, and of the transducer/sample spacing. A breakaway support for the transducer prevents damage in case an obstruction is struck, and a circuit operates on the analog signal produced by the transducer to provide useful output information representative of the magnetic field.

Scanning apparatus and method for measuring a magnetic field produced by

Briefly, the invention comprehends an apparatus and method for measuring the surface characteristics of a specimen with improved accuracy and facility than was heretofore possible. Fundamentally, the apparatus includes a precision transducer positionable in direct engagement with a specimen for feeling the surface of the latter, a specimen support for supporting a specimen in proximity to such transducer, a motion mechanism for effecting relative movement between the specimen and transducer so that the latter effectively scans the surface of the former, and electric circuitry for analyzing information from the transducer and producing output information indicative of the surface characteristics of the specimen. According to the method of the invention, the surface characteristics of a specimen are measured by effecting relative movement, preferably of a scanning type, of a specimen with respect to a precision transducer and converting the information obtained from such transducer into output information directly respresentative of the surface characteristics of the specimen.

Surface irregularity analyzer

A fluidizing mixer works a mixture of materials, such as polyvinyl chloride (PVC) resin, together with plasticizers and liquid stabilizers and the batch is then discharged at the end of a work cycle of operation. The mixer employs an electrically energized driver which drives a working member, such as a high speed mixing blade, such that electrical energy is expended as work is being performed on the material. During each work cycle of operation the amount of expended electrical energy is sensed for purposes of providing a work signal having a value in accordance with the energy being expended. A work cycle is terminated when the amount of energy being expended to work the material decreases by a given amount.

Mixer control system

The data acquisition system disclosed herein serves to monitor and record various parameters of a mixer employed in an elastomer processing system. During each mixing operation, the elastomer compound identification and batch number are recorded. This information is then followed by periodic recordings of the concurrent values of real time, the temperature of the elastomer and the work performed, in terms of the amount of energy consumed to work the elastomer. The recording intervals take place in response to sensing such conditions as work chamber door closed, ram down, ram floating, and door open.

Data acquisition system

An apparatus for indicating the time integral of the electrical power consumed in elastomer mixing, working, warming or other processing and for controlling the processing in accordance therewith. An electrical signal, derived from the electrical power consumed by an electrical motor driven elastomer processing apparatus, is compensated for no-load operation of the apparatus and then continuously integrated with respect to time to provide an output which is employed to produce a digital read-out of the energy consumed in the processing with control of the processing being effected in accordance therewith.

Elastomer processing apparatus

A method for indicating the time integral of the electrical power consumed in elastomer mixing, working, warming or other processing and for controlling the processing in accordance therewith. An electrical signal, derived from the electrical power consumed by an electrical motor driven elastomer processing apparatus, is compensated for no-load operation of the apparatus and then continuously integrated with respect to time to provide an output which is employed to produce a digital readout of the energy consumed in the processing with control of the processing being effected in accordance therewith.

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Cuyahoga Falls, OH, United States of America

John P Porter