Illinois Tool Works Inc.

Eagle-picher Industries, Inc.

Micro-poise Measurement Systems LLC

James C Beebe

Barry D Cargould

Richard Matuszny

David W Lees, Sr

Thomas Williams

Barry Cargould

Steve Haydu

Neal Nehrenz

Ronald Jan Hall

Robert E Higbie

Steve Watson

Bill Shaffer

A machine and method for performing balancing measurements on a tire or tire/wheel assembly that includes a structure defining spaced apart tire centering and tire testing positions. A first conveyor moves a tire to a centering position where a shuttle assembly is operative to center the tire and, after it has been centered, engages the tire and effects the transfer of the tire from the centering station to a testing station. The shuttle assembly includes a pair of grippers that move towards and away from each other, in a lateral direction in order to engage the tire. The first conveyor permits movement of the tire in a lateral direction; whereas it substantially resists relative movement between the tire and conveyor in the longitudinal direction, i.e., the direction of movement of the conveyor. The shuttle assembly is mounted for movement in a longitudinal direction and includes a drive mechanism which allows the shuttle assembly to move relative to a tire in a longitudinal direction as the grippers engage the tire so that the shuttle assembly can align itself, in the longitudinal direction with respect to the tire. The frame structure of the machine includes three spaced apart support members providing a three point support arrangement for the machine. The machine also includes at least four legs which extend downwardly, but are spaced above a plane defined by the support members and inhibit tipping of the machine beyond predetermined limits. The testing station which includes a spindle assembly for rotating the tire also includes an elevator mechanism for lowering the tire on to the spindle and for raising the tire off the spindle. A lower marking mechanism forms part of the elevator and is operative to mark a predetermined location on the tire at the conclusion of a tire testing procedure. The spindle assembly includes a drive motor comprised of a drive motor housing and an armature. The armature is maintained in its operative position by a bearing arrangement associated with a shaft assembly forming part of the spindle assembly which eliminates the need for armature supporting bearings in the drive motor housing.

Tire balancing apparatus

A method and apparatus for testing tires in a repeatable manner. Testing steps are performed in a manner that minimizes impact on the tire characteristics being measured. In one aspect, tire rotation reversal is performed at a zero crossing of a first harmonic of radial load variation exerted on a load carriage by the tire. In another aspect, load carriage retraction is performed so that the tire is unloaded when the tire stops rotating.

Tire uniformity testing

An apparatus and method for improving the measurement of force variation in a tire ( ) being tested on a tire uniformity machine. The apparatus includes a loadwheel assembly ( ) including a rotatable loadwheel ( ) connected to load sensors ( ) for detecting forces imposed on the loadwheel ( ) by a tire ( ) being tested. Vibration sensors ( ) are associated with the loadwheel assembly ( ) for detecting vibrations in the loadwheel ( ) caused by forces other than the forces applied by the tire ( ). Means is provided for subtracting the vibration induced forces from the tire ( ) imposed forces in order to provide more precise tire uniformity data. The vibration sensors ( ) which comprise accelerometers are used to determine vibration induced forces in the lateral and radial direction with respect to the loadwheel ( ). The signals provided by the accelerometers ( ) are communicated to a differential amplifier which also receives signals from the load cells ( ). The net signal more closely represents the actual force variation generated by the tire ( ) being tested.

Vibration compensation system for tire testing systems

Methods and apparatus for determining an angular location on a round object during a current operation in order to facilitate positioning the object for subsequent operation. At a first station, an angular location identifying feature is sensed, and an angle at which a predetermined desired angular location is located with respect to the feature is determined. At a second station, the feature is sensed, the object is indexed from the feature in an amount equal to the angle, and the object is marked at the relocated predetermined desired angular location. Another method eliminates the marking step at the second station, and the subsequent operation is performed instead. Apparatus comprises a first station means and a second station means. The first station means includes means for sensing an angular location identifying feature on the object and measurement means for determining an angle at which a predetermined desired angular location on the object is located with respect to the feature. Second station means includes sensing means for sensing the feature, indexing means for indexing from the feature in an amount equal to the angle, and marking means for marking the object at the relocated desired location.

Apparatus and method for angle-dependent processing of objects

Tires are measured for a parameter correlated to a tendency to contribute to steering pull when used on a vehicle. A group of the measured tires is then ranked into a successive series by ordering the parameter measurements of the tires in the group non-decreasingly or non-increasingly. A set of at least two tires of substantially consecutive rank are then selected for mounting on the same vehicle in order to reduce steering pull.

Process and apparatus for selecting tires to reduce steering pull and

Steering pull to which a vehicle is subjected due to tire non-uniformity is measured accurately even in the presence of wind. An anemometer mounted in proximity of and in positionally fixed relation to the vehicle measures the speed and direction of wind apparent to the vehicle. Those measurements are used by a computer to determine a wind correction quantity which is subtracted from the steering pull measured at the steering wheel.

Apparatus and method for wind-corrected measurement of steering pull on

A tire uniformity inspection machine is calibrated by applying to at least one force measuring channel thereof a signal which simulates the application of a force of a magnitude greater than any force actually applied to the machine during calibration. That signal, which is preferably of a magnitude appropriate to simulate the largest forces encountered during actual tire testing, can be generated by connecting the channel, preferably at its input, to an energy source through an impedance. The response of the channel to the signal is measured and a calibration factor is determined based on that response. Such calibration factor accounts for the actual behavior of the channel more truely than prior art calibration techniques which relied solely upon the relatively small signal excitation conditions achievable by applying a relatively small actual force to the machine. Thus, the invention affords tire uniformity measurements of improved accuracy.

Calibration apparatus and method for improving the accuracy of tire

The mass of a tire/wheel assembly is altered to apply a static imbalance to the assembly in a manner which reduces the overall tendency of the assembly to cause vibration in the plane perpendicular to its axis of rotation when in use. The applied imbalance, combined with any static imbalance initially inherent in the tire/wheel assembly, results in a desired net static imbalance oriented so as to induce a centrifugal force which opposes, and therefore tends to cancel, at least one component, such as the first order harmonic, of radial force variation characterizing the assembly. The magnitude of the net static imbalance is limited and is preferably selected to substantially equal the lesser of either: (a) a predetermined maximum limit, or (b) the amount of static imbalance required to generate at a designated highway speed a centrifugal force whose magnitude substantially equals that of the aforementioned radial force variation component.

Method and apparatus utilizing static imbalance to reduce vibration

Tires are measured to determine the value of a parameter indicating a tendency of the tires to cause vibration in a given direction in tire/wheel assemblies. Each measured tire is assigned a tire rank designation in accordance with the order in which its measured value of the magnitude of that parameter falls in relation to the magnitudes of that parameter among a certain group of tires. Wheels are measured to determine the value of a second parameter indicating a tendency of the wheels to cause vibration in tire/wheel assemblies in that same given direction. Each wheel in a certain group of wheels is ranked in accordance with the order in which the magnitude of its second parameter falls in relation to the magnitudes of the second parameter among the other wheels in the group. Tires and wheels having corresponding respective rank designations are paired with one another to be combined into a tire/wheel assembly wherein the tire and wheel are mutually oriented such that the vibrational tendencies of the first and second parameters tend to cancel one another.

Process and apparatus for pairing tires and wheels

An object is positioned in fixed relation to a measuring axis without regard to centering the object on the axis and at least one series of data samples correlated to the distance between the measuring axis and a series of points located at angularly spaced intervals on at least one surface feature of the object are generated and stored. To determine the center of a first surface feature, the corresponding series of samples is analyzed to identify samples therein corresponding to points lying on a maximum inscribed circle whose center corresponds to that of the surface feature. To measure a second surface feature of an object with reference to the center of a first surface feature thereof, a first signal and a second signal correlated to the distance between the measuring axis and points on the first surface feature and second surface feature, respectively are generated. The center of the first surface feature is then determined to define a vector indicating the positional offset between the measuring axis and that center. The second signal is then adjusted in accordance with that vector to provide a coordinate-corrected signal to be used as a basis for a centered measurement.

Apparatus and method for determining a center and measuring with

A machine for measuring force variation or imbalance of tires particularly at high speeds. A rotating roadwheel is engaged by a tire mounted on a spindle. Force sensing means, such as load cells, are operably interposed between the tire spindle and a force sensor mount. To minimize the adverse effects of mechanical resonance of the machine on force measurement accuracy, the roadwheel and/or the force sensor mount are connected to ground through dampers which provide a damping ratio of at least about five percent and preferably higher. Where the force sensor mount is to be supported by such damping means, the invention further contemplates interposing a large mass between that damping means and the force sensor mount.

Damped high speed tire testing machine

A tire rim for a tire testing machine has a stepped contour providing multiple positions to accommodate tires of differing bead diameters. One or more filler rings are mountable on a bead seat to provide the proper contour for inflating a tire having the next smaller diameter bead seated on the adjacent bead seat.

Stepped rim for tire testing machine

A tire testing machine having a rotatably but actuatably fixed upper rim, a rotatable lower rim assembly and a hydraulic cylinder for raising and lowering the lower rim to a desired position. The lower rim assembly has a resiliently-biased center pilot in the form of a cone that is engageable with a recess in the upper rim to center the lower rim with respect to the upper rim and to transmit rotational forces from the upper rim to the lower rim. The centering action of the pilot is assisted by a pair of mating spherical washers associated with the lower rim assembly.

Tire testing machine having adjustable bead width

An apparatus and method for predicting fore-aft translations of tires. An inflated tire is rotated at a nominally constant angular velocity against a freely rotatable rigid loadwheel under a radial load. Changes in the instantaneous effective radius of the tire as it rolls give rise to fore/aft forces which tend to translate the tire alternately forward, toward the direction of travel and aft, toward the opposite direction. The tendency of the tire to so translate is predicted by measuring variations in effective radius or a parameter correlated thereto such as changes in the motion of the tread surface of the tire or the loadwheel relative to the angular speed of the tire.

Apparatus and method for predicting fore/aft forces generated by tires

Apparatus and methods for use in measuring the uniformity of a body such as a tire, wheel or the like wherein a waveform related to the uniformity of the body is digitally sampled to acquire a series of data samples, each of which is correlated with a respective physical location on the body. According to a first aspect of the invention, a non-repetitive error component of the waveform is corrected for by sampling the same location on the body at two different times and determining the difference between the corresponding data samples. A part of the total difference is allocated to each of the data samples in the series according to a predetermined methematical function which at least approximately describes the non-repetitive component of the waveform. The part of the difference allocated to each sample is then subtracted from it to obtain a corrected series of data sample. According to a second aspect of the invention, the maximum, minimum and/or peak-to-peak values of the waveform are more accurately determined by relating selected extreme data samples and one or more data samples adjacent thereto to a polynomial function of at least second order. The function is then evaluated at the location where its first derivative equals zero to determine a more accurate and repeatable approximation of a maximum, minimum or peak-to-peak value of the waveform. According to yet another aspect of the present invention the first and second aspects above are practiced in conjunction with one another.

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Kent, OH, United States of America

James C Beebe