Abstract: A method for indoor wear testing tires includes the steps of characterizing a vehicle and a wear test course and combining the characterized data to create input data for an indoor wear test machine. The input data allows the indoor wear test machine to accurately simulate an outdoor wear test course for the characterized vehicle. The method allows multiple wear test courses to be used with a single characterized vehicle and allows a single wear test course to be used with multiple characterized vehicles. The method allows tires to be wear tested in relatively short time periods in the controlled environment of the indoor laboratory. In addition, the method is relatively easy to set up and perform.

Abstract: An improved estimator is provided for road/tire friction. The friction estimator provides near-real-time friction estimation, even while the car is accelerating, braking or turning. It is desirable to have an instantaneous and continuous estimate of the road/tire friction, but an estimate that occurs over several wheel rotations is more realistic. The estimate relies on easily measured signals such as yaw rate, lateral acceleration, wheel speed, etc. The estimate can be used to give the driver or a closed-loop controller an advanced warning when the tire force limit is being approached.

Abstract: A method for influencing traction of motor vehicle tires made from polymer materials which are mounted and in the operating/driving state, in particular, pneumatic tires for motor vehicles, wherein an ionized gas (plasma) is generated in the vicinity of the surface of the rolling tire that is in the operating state, and wherein the ionized gas is conveyed onto a region of the surface in such a way that the ionized gas acts upon the respective surface region before said surface region rolls into the road contact surface region of the tire.

Abstract: A method of testing at least one tire of a test vehicle provided with a sensor for measuring the forces and moments of at least one test tire, the method including coupling the test vehicle to an anchor vehicle wherein the coupling restricts the lateral and longitudinal and yaw movement of the test vehicle relative to the anchor vehicle such that the anchor vehicle maintains the course and velocity of the test vehicle; and performing testing of the test vehicle while the test vehicle is coupled to the anchor vehicle.

Abstract: Provided is a road surface friction coefficient measuring method and device for measuring the friction coefficient of road surfaces such as roads and runways, and which can be used by being mounted on a general car. This device has a spindle 5 detachably connected to the wheel of a travelling wheel 3 of a car, a support arm 6 oscillatably connected to the spindle, and a measuring wheel supported rotatably by the support arm.

Abstract: Vibrations generated by the wheel units of a vehicle are reduced by a low pulsating operation that optimally simulates actual vehicle operating conditions. For this purpose the mass moment of inertia of the wheel unit and of rotating components such as the hub and the brake disc are taken into account. The wheel unit is rotatably mounted on a balancing spindle (2) in a measuring apparatus to determine the mass and angular location of balancing weights (31). The vibrations are measured at a speed that corresponds to a typical travel speed of a vehicle. A loading mechanism including a roller shoe (20) applies a force to the tire tread surface through a spring damping (14, 15) to optimally simulate the conditions of a roadway. The roller shoe (20) has rollers (13) with sections of larger and smaller diameters so that neighboring rollers intermesh. The combined masses of the rollers, as reduced to the roller radius dw, corresponds to the rotational mass of the vehicle wheel as reduced to the tread radius (dR).

Abstract: To provide a method capable of easily analyzing frictional energy of a rolling tire, in-plane pressure Pxy(L) and vertical pressure Pz(L) at one point of a tread produced by rolling the tire are measured, static frictional force R(L) is calculated and the frictional energy is calculated by determining a portion corresponding to the static frictional force R(L) equal to or larger than a primary maximum value as a slipping region LR.

Abstract: A friction test apparatus provided with a rotating friction means having an endless belt set around one pair of rotating drums, a belt supporting means disposed near an inner face of the belt, a sample holder to which a sample is detachably attached, and a sample holder driving means which holds the sample holder as to be rotatable and by which the sample attached to the sample holder is pressed to and part from an outer face of the belt. Further, the friction test apparatus is also provided with a meandering prevention mechanism which prevents the belt rotated by the pair of rotating drums from meandering.

Abstract: In a tire uniformity machine in which a tire is mounted between upper and lower spindles via upper and lower rims, a rim holding apparatus 10 is composed of a parallel spindle 1 which is in parallel with the axis of tire uniformity machine, a taper collet 2 formed with an inner hole engaging concentrically with the parallel spindle 1 at the center portion thereof and a taper surface at the outer peripheral portion thereof, a rim formed with a taper surface engaging with the taper surface of the taper collet 2 at the inner peripheral portion thereof, a rim clamping device 4 which holds the rim 3 and is mounted so that the parallel spindle 1 is capable of being moved in the axial direction, and a fixing device 5 for determining the axial position of the rim clamping device 4. Thereby, there is provided a highly accurate tire uniformity machine in which (1) the change of rim width and the fitting/removal of rim can be performed easily, and (2) the runout of rim can be decreased to 0.025 mm (standard) or less.

Abstract: A wear resistance index G1 of a tire whose wear life is to be estimated is measured by the Lambourn abrasion tester. Then, friction energies in free rolling, when the tire is fitted with a toe angle, under application of a side force, under application of a braking force and under application of a driving force of the tire are measured. An expected value of the wear life T1 is calculated using the wear resistance index G1 and the friction energies thus obtained and the wear life of the tire is estimated on the basis of the expected value of the wear life T1. The wear life of a tire can be estimated accurately in a short time in accordance with the method for estimating a tire wear life of the present invention.

Abstract: A method for minimizing the radial runout of a tire and rim assembly 10 having the steps of locating the position of maximum radial runout and measuring the amount of maximum radial runout; loosening the threaded fasteners 24 attaching the rim 20 and disk 22; and moving the disk 22 radially toward the location of the maximum radial runout a distance one-half the measured runout amount and then retightening the threaded fasteners is disclosed. The method minimizes first harmonic vibrations caused by the normal assembly of these components.

Abstract: Apparatus for measuring two parallel spaced surface profiles is disclosed. The apparatus disclosed has dual laterally spaced beams linked to a transport device shown as a trailer that is towable by a motor vehicle. Each beam has a profiling wheel that measures road surface deviations and transmits the resulting measurements to a recording device. The beams are foldable and stowable on the trailer for transport of the apparatus between measuring sites.

Abstract: A method of testing a tire for rain groove wander is provided which allows a tire to be objectively tested in a laboratory wherein the objective test results closely correlate with subjective field analysis type data, thereby allowing for the subjective tire performance to be predicted while precluding the need for subjective field analysis of the particular tire. The method also allows objective testing of a single tire size by varying the radial loading in the laboratory test set, thereby precluding the construction of multiple tire sizes each having the same tread design. The method simulates rain groove road conditions and correlates objective analysis data obtained via the laboratory test methodology with subjective field analysis data of rain groove wander tire performance of other tires, thereby providing a substantially accurate technique for identifying the subjective performance of the tire without having to conduct the field testing to obtain such subjective field analysis data.

Abstract: The present invention provides and apparatus and method for analyzing the rutting and stripping characteristics of hot mix asphalt concrete samples. The apparatus of the invention measures the vertical penetration of a wheel rolling in a reciprocating motion across the surface of a compacted asphalt mix specimen. The apparatus incorporates precise environmental control and includes features for testing two or more samples simultaneously under wet or dry conditions or a combination of wet and dry conditions.

Abstract: A portable test apparatus (and associated method) for measuring nonuniformity of a tire/wheel assembly in situ on a wheel bearing hub of a vehicle are characterized by a lightweight assembly of components including, in particular, a probe for monitoring deflections of a surface of the tire/wheel assembly during rotation of the tire/wheel assembly and producing an electrical output indicative of the surface deflections, and an indexing device for producing an electrical output indicative of the rotational position of the tire/wheel assembly during rotation thereof, the indexing device having an attachment mechanism for removable coupling to the tire/wheel assembly.

Abstract: An apparatus for determining a coefficient of friction on a surface of objects such as rails. In one embodiment, the apparatus comprises a vertical sensor assembly for determining the coefficient of friction of a top surface of a rail. A different embodiment comprises a lateral sensor assembly for determining a coefficient of friction of a gage face of a rail. The sensor assemblies may include a shoe. The sensor assemblies may include a load cell. Other embodiments include various combinations of lateral sensor assemblies and vertical sensor assemblies. Structure for mounting the assemblies to a vehicle may also be provided.

Abstract: A method of estimating irregular wear of pneumatic tires, in which a deformable paint is coated on the tire tread surface in a regular manner. The wearing degree of the paint is recorded as a plurality of image information at regular time intervals, while running the tire under a loaded condition. A predetermined portion of the respective image information is divided into a number of pixels. Weights are applied to the respective pixels corresponding to painted potions, respectively, such that each weight is inversely proportional to the duration of time during which the paint has been worn. Wear information for the painted portion is converted into a wide range wear information which also covers the respective pixels for the non-painted portion, by calculating the wear level values of the respective pixels including the non-painted portion in view of the weight of the pixels and weights of the periphery pixels.

Abstract: A device for a braking and traction test of a wheel integral with a hub that is free to rotate, comprises a road-wheel, a crank integral with the hub and a connecting rod that causes the reciprocating movement of a piston sealingly sliding in a chamber of a cylinder containing air. The piston exerts on the wheel and on the tire a sinusoidal torque consisting in a braking torque during its compression stroke and in a traction torque during its expansion stroke. The device also comprises a first deformation transducer associated with the hub and a second and a third speed transducer associated with the hub and with the road-wheel, respectively.

Abstract: The invention provides a process for the advance recognition of the hydroplaning of a vehicle tire on a wet road, in which the rotational speed of the wheel carrying the tire is sensed by a rotational speed sensor and the frequency spectrum of the rotational wheel speed is evaluated. According to the invention, in the frequency range above 20 Hz, the natural resonance behavior of the rotational tire vibrations is evaluated continuously, and a conclusion on hydroplaning of the tire is drawn from detuning of the rotatory natural frequencies.

Abstract: In a method of determining the traction of motor vehicle wheels on wet pavements, a surge force generated by a water film on the pavement in front of at least one of the vehicle wheels is measured and from the measured surge force value and the instantaneous vehicle speed a critical speed at which the vehicle wheel will aqua-plane is determined and this critical speed is displayed to the driver or it is used to control a vehicle drive unit to keep the vehicle speed below the critical speed.

Abstract: The disclosed machine is comprised of a chassis, process control box and load wheel assembly. The chassis is designed to attach to commercially available controlled temperature heating baths. The primary functions of the process control box are to distribute electrical power, monitor sensor responses to electrical inputs, and to control the overall operation of the load wheel assembly. The load wheel assembly applies multiple load applications while not rolling off the surface of a standard asphalt concrete specimen.

Abstract: The distribution of a specific pressure in the ground-contacting area of a tire (4) under examination is detected by means of a plurality of sensing cells (7) distributed on a plate-like support (8) applied to a rest surface (2) acted upon by the tire through its rolling surface (5). Each sensing cell (7) sends an electric signal correlated with the specific pressure applied thereto to a processing unit (10) through which the processed signals are sent to a display device (12) graphically representing the distribution of the specific pressure in the ground-contacting area. By causing the tire (4) to roll on the rest surface (2) and therefore the sensing cells (7), the dynamic variation of the specific pressures in the ground-contacting area can be detected. A protection sheet (11) interposed between the rolling surface of the tire (4) and the sensing cells (7) protects the latter against risks of damages due to tangential shearing stresses produced at the ground-contacting area.

Abstract: A device and method for monitoring conditions associated with pavement deterioration are disclosed. Conditions such as voids or loss of support under a rigid pavement, moisture infiltration in asphalt concrete pavement, fine cracking in pavements, delamination of overlays, and aging of asphalt may be measured according to the present invention. These pavement conditions are detected by estimating Young's and shear moduli in the pavement, base, and subgrade from the following wave propagation measurements: Impact Echo; Impulse Response; Spectral Analysis of Surface Waves; Ultrasonic Surface Wave; and Ultrasonic Body Wave Velocity. The pavement response produced by high- and low-frequency pneumatic hammers on five accelerometers and three geophones is recorded. A computer controls data acquisition, instrument control, and interpretation; measurements and interpretations are reported in both screen and database formats.

Abstract: An adjustable testing system for supporting a rotating tire against a roadway simulator includes a frame, wherein the tire is mounted on a side of the frame, and a moveable frame. A first linkage joins the moveable frame to the frame allowing the moveable frame to be displaced relative to the frame. A support member is used to mount a wheel of the tire, the support member being mounted to the moveable frame with a second linkage to allow movement of the support member relative to the moveable frame. The assembly is of a compact design for both the first linkage and the second linkage are characterized by two representative planes that intersect with each other on the same side of the frame.

Abstract: A portable machine for testing on site the uniformity of a tire or other components of a tire/wheel assembly. A compact rigid frame has a base formed by a plurality of longitudinal and transverse frame members for supporting the machine on a planar surface. A box-like subframe is mounted on the base and supports a mounting plate for the tire/wheel assembly. The mounting plate is slidably mounted on a pair of slide rods extending upwardly from the subframe. A road wheel and drive motor are mounted on the base, with the motor being mounted within the subframe and the load wheel being located beneath the tire/wheel assembly mounting plate. An air spring raises and lowers the mounting plate for placement and removal of a tire/wheel assembly thereon. A loading mechanism applies a force on the tire/wheel assembly mounting plate to forceably move a tire into contact with the road wheel, and is measurable by a first load cell.

Abstract: In a tire uniformity machine of the type wherein a loadwheel is received on a carriage slidably mounted on the machine frame for movement toward and away from the tire, the frame and the carriage are interconnected by mounting plates, one attached to the frame and one attached to the carriage, and interconnected by precision anti-friction flatway linear motion bearings of the type characterized by cross rollers or balls mounted in anti-friction gibs or ways so as to facilitate movement of the carriage and stability thereof in two axes to insure precise positioning of the loadwheel relatively of the tire. In a modified form of the invention, the carriage is T-shaped so that the top extended legs serve to support the bearing ways, engage the top of the bearings, and a gib or way is attached directly to the underside of the frame, thus eliminating the mounting plates while still insuring the facilitated movement of the carriage relatively of the frame.

Abstract: An apparatus and technique for determining the abrasion potential for tire treads is presented. A tire is rotatably and forcefully brought into contacting engagement with a reflective surface received upon an illuminated glass plate. A charge coupled device monitors the internal reflection light which evidences a grey level corresponding to the force of engagement between the associated portion of the tire and the glass support plate. A marker is placed upon the tire centrally within a region of interest. The video image of the marker and region of interest is analyzed as to slip and force at that area. The product of the slip and force functions is an indication of frictional work at the interface between the tire and support surface and is correspondingly an indication of the propensity of the tire to wear.

Abstract: In a tire uniformity machine of the type wherein a loadwheel is received on a carriage slidably mounted on the machine frame for movement toward and away from the tire, the frame and the carriage are interconnected by mounting plates, one attached to the frame and one attached to the carriage, and interconnected by precision anti-friction flatway linear motion bearings of the type characterized by cross rollers or balls mounted in anti-friction ways so as to facilitate movement of the carriage and stability thereof in two axes to insure precise positioning of the loadwheel relatively of the tire.

Abstract: A system for changing the chucks of a tire uniformity machine includes a control which inactivates the main machine hydraulic and electrical system. The control also activates the chuck changing system which includes a small hydraulic power unit and a low set pressure relief valve for raising and lowering the lower chuck assembly and a small gearmotor for rotating the upper chuck assembly to facilitate removal of the upper chuck. The small hydraulic power unit and gearmotor, while mounted on the tire uniformity machine, operate entirely independently thereof for safety purposes.

Abstract: 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.

Abstract: An apparatus for measuring a force produced by a tire assembly over an irregular surface is disclosed comprising a test block having a plurality of removable blanks which define a first and second surface over which the tire assembly is rolled during the test. The first surface is stepped relative to the second surface. The apparatus further includes a pair of transducers disposed across the first and second surface for generating an electrical signal indicative of the force produced by the tire assembly.

Abstract: A method and apparatus for rail seat abrasion measurement and analysis is shown wherein a rail seat measurement device is mounted with reference to non-wear portions of a concrete railroad tie and includes linear potentiometer devices adapted to determine a spacial relationship between the body of the measurement device and wearing portions of the rail seat. In this manner, the measurement device may be consistently mounted upon the non-wear portions of the concrete railroad tie in order that a series of accurate abrasion measurements may be taken. Other information collected includes static information such as track curvature, bank, and grade and dynamic information such as loading conditions and environmental conditions to which the rail seat is exposed between abrasion measurements.

Abstract: A rim gap setting device in a tire uniformity inspecting machine include upper and lower rims for mounting a tire, which are vertically movably fitted on opposed ends of upper and lower spindles, respectively. Upper and lower hydraulically locking devices are provided for locking the upper and lower rims from the inner circumferences thereof, and are mounted around the upper and lower spindles, respectively. Upper and lower hydraulically engaging devices are mounted on the upper and lower spindles and can be radially retreated by being hydraulically interlocked with the upper and lower hydraulically locking devices to be thereby engaged with the upper and lower rims on the locking operation of the upper and lower hydraulically locking devices, respectively.

Abstract: A method and apparatus for predicting tire traction characteristics of tread compounds are provided. The method makes possible the determination of such characteristics without building tires. Also, the compounds can be easily characterized for a large number of different road surfaces and many different weather conditions. In the method, about 2 to 10 gms of tread compound is molded into a sample which can be tested for traction on the apparatus. Peak traction, slide traction and other traction characteristics of the compound can be correlated with traction properties of known compounds, thereby establishing the expected traction properties of the test compound in a tire.

Abstract: A rim mounting mechanism for a tire uniformity machine has on the side of upper and lower spindles thereof an upper rim and a lower rim to be fitted in bead portions of a tire, respectively, and arranged to lift up the tire by a tire transfer means, grip the tire from the upper and lower sides thereof by means of the upper and lower rims and rotate the tire T about its axis by rotation of the upper spindle about the axis thereof. The rim mounting mechanism includes a rim assembly transfer device delivering a rim assembly R, formed by assembling together an upper rim, a lower rim and a lower spindle at a place outside the machine, to a position above the tire transfer device and in vertical alignment with the axis of the upper spindle and to dismantle a tested tire from the machine at a position immediately beneath the upper spindle.

Abstract: An apparatus for automatically adjusting the rim width between upper and lower rims on a tire uniformity machine of the type includes an upper spindle rotatable about the axis thereof, a lower spindle located opposingly in vertical alignment with the upper spindle, the lower spindle being rotatable about the axis thereof and movable in the axial direction, and upper and lower rims detachably mounted coaxially on opposing end portions of the upper and lower spindles, respectively, to release grip therebetween a testing tire to be rotated and held in contact with a load wheel for inspection of uniformity. The rim width adjusting apparatus includes a ring-like adapter threaded on a lower end portion of the upper spindle and vertically movably supporting the upper rim on the upper spindle; and a rotation blocking device mounted on a bearing housing over the adapter for blocking rotation of the adapter relative to the upper spindle.

Abstract: A method of setting a distance between upper and lower rims mounted on upper and lower spindles in a tire uniformity machine. The upper and lower rims under a superposed condition are first laid on an arm. Then, the arm is lifted or lowered until the upper rim reaches a desired upper position on the upper spindle. Then, the upper rim is fixed from an inner circumference thereof to the upper spindle at the desired upper position by an upper locking device. Then, the arm is lowered until the lower rim reaches a desired lower position on the lower spindle. Then, the lower rim is fixed from an inner circumference thereof to the lower spindle at the desired lower position by a lower locking device. Accordingly, a distance between the upper and lower rims can be set easily and quickly in a simple operation without using a spacer or the like.

Abstract: A wheel measuring machine includes juxtaposed first and second spindles relatively movable toward and away from one another for mounting a wheel to be measured therebetween. A first centering device is mounted on the first spindle to selectively center a first surface feature of the wheel on an axis. The second spindle includes a second centering device engageable with both the wheel and with the first spindle to selectively center a second surface feature on the axis when the first centering device disengages the wheel. A distance transducer sensingly engageable with a third surface feature of the wheel measures the distance between points along the surface feature and the spindle axis once when the first surface feature is centered on the axis and again when the second surface feature is so centered. From those measurements, parameter values describing dimensional relationships between the surface features are calculated.

Abstract: A dynamic load simulator is provided to simulate the suspension system of a vehicle. A spindle, connected to a suspension system, receives a tire in engagement with a rotating drum. A force gauge and velocity gauge are maintained at the spindle to monitor axle forces and movement. Road force is monitored by gauges maintained within the rotating drum. Adjustable springs, dampers, resonators, and weights allow the characteristics of the suspension system to be tailored to simulate those of an actual or conceptual.

Abstract: A method of abrading a tire tread compound to measure its irregular wear characteristics, includes the steps of abrading each of a plurality of sample wheels in rotating engagement with a respective abrasive member. An outer layer of each sample wheel is made of a tire tread compound to be abraded. The velocity of the sample wheels relative to the velocity of the abrasive members defines a first slip value. Each sample wheel is abraded in rotating engagement with a plurality of abrasive members at the first slip value. The loss of the tire tread compound of each sample wheel at the first slip value is then measured. Each sample wheel is then abraded in rotating engagement with a plurality of respective abrasive members at a second slip value. The loss of the tire tread compound of each sample member at the second slip value is then measured. Each sample wheel is then abraded in rotating engagement with a plurality of respective abrasive members at a third slip value.

Abstract: A testing device for vehicle tires, especially anti-skid features situated in the vehicle tire, in which the tire to be tested is pressed against an outer circle or surface of another tire, while these two tires are rotated in opposite directions. The other tire acting as a counterpart or pair for the tire being tested is a pneumatic tire, while the tire to be tested and the other tire are disposed to be pressed against one another so that a contact surface between the two tires is substantially straight. The other tire acting as the pair or counterpart for the tire to be tested is provided with a wear surface having good wear resistance properties.

Abstract: The present invention relates to an abrasion tester, and in particular to an abrasion tester capable of testing abrasion or breakage of a road generated by the travel of cars in the winter or summer under actual road conditions. The tester includes a turntable rotatably supported in the apparatus for receiving test pieces, a cooling or high temperature chamber confronting the turntable so as to subject the test pieces to high or low temperatures, and a rotatable grinding member movable into and out of contact with the test pieces. Thus, when the grinding member is brought into contact with a test piece and is rotated, the turntable rotates to simulate travel of the grinding member on the test piece. Further, rotation of the turntable moves the test pieces through the chamber where they are subjected to appointed temperature conditions.

Abstract: A diagnostic testing device for diagnosing and testing chassis, mechanical, tire and tire tread problems in vehicles which simulates normal operating angles and normal vehicle weight conditions with the wheels of the vehicle being cycled and steered at a full range of vehicle speeds. The diagnostic testing device includes a support having a horizontal upper surface, a platform movably coupled to the upper surface of the support so as to allow the platform to glide horizontally in any direction, and a pair of support rollers rotatably connected to the platform so as to provide rolling surfaces to contact the tire tread and which allow a tire to cycle and be steered when placed upon said rollers.

Abstract: According to the present invention, an apparatus for measuring a resistance against slippage on the road surface is so constructed that two measuring wheels adapted to be rotated by imparting a tractive force to the apparatus are connected to one another via a torsion bar extending therebetween, a difference in rotation is forcibly produced by changing a rotational speed of one of the measuring wheels and a slippage resistance on the road surface is measured by detecting a torque generated on the torsion bar due to the slippage resistance on the road surface.

Abstract: An apparatus for testing amd evaluating traffic bearing formation and pavements includes one or more arms extending radially from a center pivot, each arm being adapted to connect to a bogey comprising one or more wheels and to constrain its respective bogey to movement in a generally circular path on the pavement about a pivot during operation of the apparatus; a plurality of bogies, each adapted to be coupled to an arm and comprising differing combinations of one or more multiple wheels so as to each represent an actual wheel or wheel set of a vehicle; a wheel suspension system for each bogey constraining the wheel or wheels thereof to move such that the dynamic responses of the wheel or wheels to pavement irregularities substantially replicate the dynamic response of actual vehicle wheels to actual roadway irregularities; a driving system for the wheels adapted to apply tractive and braking efforts thereto for the vehicle type which any wheel set represents, the road speed of the wheel on the pavement bein

Abstract: 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.

Abstract: 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.

Abstract: A compact air sampling impactor assembly has an inlet nozzle overlying an impaction plate that is mounted on a flat housing that defines an interior chamber covered by a filter. An air flow outlet tube leading from the chamber is connected to an air pump and a flow is established through the nozzle so the air impinges on the impaction plate to leave particles thereon and the flow then passes through the filter to the chamber and then out the air outlet. The size is kept small for personal use. Cascade impactors can be made using additional flow paths defining covers in association with the basic impactor plate and filter-carrying housing.

Abstract: A test apparatus for measuring side-slip and gravity slip of a vehicle moving along a curved road or travelling across downhill. The test apparatus is adapted to be towed by a vehicle. The test apparatus is connected to a vehicle by a bar which has the other end connected to a vertically extending bushing which houses a pivot member extending perpendicularly to a riding surface. The lower end of the pivot member is connected pivotably to a wheel fork horizontally extending and supporting a test wheel in contact with a riding surface, while the other end of the pivot member extends out of the upper portion of the bushing and is connected by a horizontally extending level member which has the other end connected to a counterweight. An angle-measuring sensor is disposed over the upper end of the pivot member and is supported on a bracket secured to the upper end of the bushing.

Abstract: A flat belt type testing apparatus for measuring the cornering characteristics of a tire has a pair of rotatable drums around which an endless steel belt is stretched. A tire is supported on the endless steel belt by water jets ejected from a water bearing equipped below the endless steel belt. Waterdrops attached to the reverse side of the endless steel belt are removed by a rear wiper pressed against the endless steel belt downstream of the water bearing. An air blower mechanism placed between the water bearing and the rear wiper includes at least one air pipe having air jet holes for ejecting air under high pressure against the reverse side of the endless steel belt to remove waterdrops from the endless steel belt. Since water can completely be removed from the endless steel belt by the air blower mechanism and the wiper, the drums are free from rust, and a centering sensor equipped close to the endless steel belt is not subjected to a detection failure due to getting wet with water.