Abstract: A surface friction tester in the form of a friction sled which may be pulled over a surface to determine the coefficient of friction of that surface. The sled has a friction surface characterizing a vehicle tire tread attached to the bottom of a base plate. The base plate is a part of a sled frame which also has a tongue portion. A straight spring scale attached to the tongue is used to measure the force required to pull the sled over the surface. The friction sled is especially adapted for accident investigations in order to allow the investigator to determine the coefficient of friction of the surfaces upon which skid marks exist and, thus, calculate the vehicle velocity at the time of brake locking on the basis of the skid marks left by the sliding vehicle.

Abstract: The present invention relates to a standard surface assembly that may be used in conjunction with a pendulum type variable speed friction skid tester for calibrating the same. The standard surface assembly includes a standard surface specimen, such as aluminum oxide, and, in use, is positioned below a pendulum swing arm with a rubber tire secured about the lower remote end thereof. The standard surface assembly is positioned with respect to the pendulum such that the rubber tire passes generally tangential to the upper surface thereof, and because the rubber tire is locked it will skid across the upper surface of the standard surface. For any particular swing of the pendulum arm, the energy lost in friction by the skidding wheel against the standard surface is known and consequently the variable speed friction tester can be calibrated to reflect this energy loss.

Abstract: A device for testing the contact-action effects between rotating and stationary structural elements of flow-related engines, such as turbine power plants, is formed of a motor driven rotary supporting arrangement for a rotational test element and a support frame for mounting a stationary test element so that the contact-action effects between the rotational test element and the stationary test element can be evaluated. The support frame for mounting the stationary test element includes positioning devices for adjusting the position of the stationary test element which is mounted on the support frame by way of a mounting block that is suspended by spring rods which are fastened to a yoke-forming portion of the support frame.

Abstract: The present invention relates to measuring techniques intended to determine the operational characteristics of a road pavement by assessing the braking conditions of transport vehicles. The device comprises a single-axle trailer whose frame is coupled by a tow pole to a towing vehicle. The trailer has only two wheels adapted for rotating on the moving trailer with longitudinal slipping in opposite directions. The device also comprises a recording instrument with a sensitive element which is located between the trailer frame and the free end of the pole and is kinematically linked therewith in such a manner that on the moving trailer the sensitive element is acted upon by a force which is proportional in magnitude to the sum of absolute values of the longitudinal traction forces acting on the wheels and is directed essentially parallel to the forces.

Abstract: To determine the characteristics of resistance to movement of an automobile vehicle several test runs are made with the internal combustion engine and transmission replaced by a working electric motor and drive to the wheels, and dummy engine and drive components to simulate the airflow resistance of these parts. Two separate tests at the same speed are made with and without a tare weight and from the power absorbed by the electric motor, in each case measured in terms of the electric power fed to the motor, and taking into account the efficiency of the motor and of the drive transmission connecting it to the drive wheels, the delivered power is determined. Subtraction of the delivered power values gives an indication of the power loss due to the effect of the tare weight on the rolling resistance, and hence the rolling resistance coefficient.

Abstract: A device for measuring the coefficient of friction between a test material and a surface comprises a frame upon which is slidably mounted a test pad holder. The test pad holder has a pad of test material mounted on it so that the test material is in contact with the surface whose coefficient of friction is to be measured when the test pad holder is mounted on the frame. A fillable container fits into the test pad holder, which container is filled with particulate material to thereby provide a force on the test pad in a direction normal to the surface whose coefficient of friction is to be measured. The test pad holder abuts an actuator shaft connected to a piston, which piston abuts a flexible diaphragm that forms one wall of a fluid filled chamber. When the frame is pulled, the test pad holder slides relative to the frame and pushes against the actuator shaft. The actuator shaft in turn urges the piston against the flexible diaphragm, resulting in an increase in pressure within the fluid filled chamber.

Abstract: A testing method and apparatus for measuring the frictional force between abrasive surfaces and a fibrous mat are disclosed. The measure of the frictional force gives an indication of the looseness of the bonding of the fibers on the surface of the mat.

Abstract: A method and apparatus for measuring and indicating limiting values for driving and braking vehicles in which a measuring wheel can be raised and lowered from a conventional wheeled vehicle to engage and disengage a substructure. The wheel is driven with a predetermined slip in relation to vehicle speed and the resulting loads detected by suitably mounted transducers. The signals produced by the transducers are combined in an electronic unit and displayed to indicate the braking force number, the coefficient of friction and resistance to rolling.

Abstract: A device for measuring the stress of tangential friction of a shoe on a surfacing for the ground comprises a guiding device, a carriage displaceable over the length of said guiding device, a shoe on said carriage and being subjected to a vertical load dynamometric pick-up means suitable for measuring the tangential friction of the shoe on the surfacing in the course of the displacement of said carriage, a driving assembly for moving the carriage in translation and recorder means connected to the dynamometric pick-up means to record the variation of tangential friction of the shoe on the surfacing.

Abstract: A device for demonstrating the coefficient of friction of a V-belt. Two dissimilar V-belt segments are secured together with a tension spring to form a continuous loop, the segments engaging aligned pulleys. Manual rotation of the pulleys applies frictional force to the side faces of the belt segments to indicate comparative slippage of each segment.

Abstract: An apparatus has a rotatable shaft driven within a vacuum chamber through a magnetic clutch. A mounting block is carried on a test bearing adjacent one end of the shaft and is restricted from rotating with the shaft by a friction torque measuring device engaged therewith. The block is subjected to axial and radial loads which are adjustably variable during testing by control devices located outside the vacuum chamber and connected to the mounting block by traction linkages passing through seals in the chamber walls. The test bearing is heated inductively; cooling discs and a reservoir are provided on and adjacent the shaft. Vibration measuring and visual observation devices are also disclosed.

Abstract: A method and apparatus for providing data related to the ice breaking efficiency of a hull of a vessel as the vessel passes through ice, and particularly for providing data related to the frictional forces experienced on the hull of the vessel as the vessel passes through ice. Movable means is carried on the hull of the vessel generally flush with the hull for displacement in response to forces applied thereto as the vessel passes through ice. The displacement of said movable means relative to the hull of the vessel is determined as a manifestation of frictional forces between the hull of the vessel and the ice. The movable means preferably comprises a generally coplanar relation therewith and flush with the outer hull skin. The plate is mounted on a plate suspending means which permits omnidirectional movement of the plate at least in the plane of the hull.

Abstract: A method and apparatus for measuring or testing static and dynamic coefficients of friction. The frame of the apparatus is held fixed with respect to the test surface, and a friction pad, mounted on the frame and capable of moving relative to the frame, also rests on the test surface. A torque is developed in the friction pad, through the means of a fluid bed, and the resulting relative movement between the test surface and the friction pad is sensed. Also disclosed are mechanisms for setting the normal force which the friction pad exerts on the test surface, for adjusting to misalignments and small surface irregularities without deleterious effects, and for regulating the torque developed in the friction pad.

Abstract: The present invention relates to a device for measuring friction between wheels and the wheel support. The device of the present invention is such that the friction, upon movement of the wheels, results in a measurable turning moment about a line, perpendicular to the direction of movement and substantially parallel or coinciding with a line through the centers of the wheels. The moment arises and is measured on suspension means of the wheels and/or a member interconnecting them.

Abstract: A machine for testing and comparing bearings of the plain or sliding type and bearing materials comprising one or a pair of bearing test stations each having a test bearing housing for fixedly retaining a selected test bearing. A rotatably driven shaft is journalled in the test bearing. Means are provided for applying a predetermined load radially on the test bearing in the housing and means are also provided for measuring the friction force generated by rotation of the shaft in the test bearing, whereby the coefficient of friction of the test bearing can be determined. Means are also provided for damping oscillations occurring in the test bearing housing and for limiting rotation of the test bearing and housing under excess generated friction force.

Abstract: Apparatus and method for indicating whether friction forces within a position modulating valve are approaching a predetermined friction value. The invention includes pressure detectors which monitor the pressure forces required by the valve actuator to move the valve plug predetermined distances toward open and seated positions. Means are provided which generate signal proportional to the difference between opening and seating actuating pressures and which is functionally related to the friction force within the valve. Means for comparing the generated signal to a predetermined reference signal, and for indicating if the generated signal exceeds the reference, are also provided.

Abstract: A method of and apparatus for testing a moving elongate strip of material to determine the coefficient of friction with respect to a control sample having known surface characteristics with a predetermined correlation to the surface characteristics normally encountered by the strip of material in use or processing, and/or the proportion of increased tension caused by movement of the strip in contact with the control sample to the original tension in the strip are provided by this invention. This determination is made by moving the elongate strip of material under tension of any magnitude in sliding frictional engagement with the control sample which moves in response to unbalanced forces generated by the incoming tension and the sliding frictional engagement along a predetermined path of travel, preferably arcuate, until the forces exerted on the control sample become balanced at a given position along the path of travel.

Abstract: A portable unit comprising a tiltable accelerometer is mounted on a vehicle which is allowed to coast on a plane and a reading is taken to provide an indication of vehicle rolling resistance without regard to terrain, slope, vehicle weight or speed. By proper precalibration of the accelerometer, it is possible to obtain the coefficient of friction directly from the accelerometer reading. Other values which may be directly obtained from the output of the accelerometer when it is properly recalibrated include accelerating rate and braking rate of a vehicle and grade of terrain.

Abstract: A portable frictometer employing the principle of passing a standard yarn sample across a cylindrical surface under test at a fixed wrap angle and detecting the ratio of the yarn tensions at the output and input ends of the wrap. This ratio is related to the coefficient of friction of the surface under test. The apparatus includes a yarn guiding system of two guide pulleys at the extremities of two rigid arms so as to achieve a predetermined fixed yarn wrap on the cylindrical surface under test when the arms are placed to contact and straddle the surface and a tension ratio monitor consisting of a disc rotatably mounted about its center with two small concentric central yarn guide pulleys and two separated peripheral guide pulleys thereon.

Abstract: This invention relates to a method and apparatus for determining whether or not a freight car in a classification yard can be adequately retarded, prior to it being moved to make up a freight train, by measuring whether the wheels of the freight car are too slippery for the car to be properly retarded to a safe speed while being moved toward the freight train.

Abstract: This disclosure relates to a predictor for determining the coefficient of friction existing between the rotating wheels of moving railway vehicles and the brake shoes of a pair of brake elements prior to the humping operation in a classification. One of the brake elements is slidably mounted to move longitudinally relative to the track rail when engaged by the rotating wheels of the railway vehicle. The kinetic energy or force imparted to the slidable brake element is transposed in fluid pressure by a pressurized responsive transducer. The fluid pressure is sensed by a measuring device which activates an alarm when the wheels of the railway vehicle are dirty or contaminated by unctuous material to permit the vehicle to be diverted to a sidetrack for special handling.

Abstract: A mucus sample from a bodily cavity is introduced between inner and outer bearing members, one of which is fixed, one of which is biased, and both of which have bearing surfaces of predetermined surface finish. Relative mechanical movement of the members indicates menstrual cycle phase.

Abstract: A device for determining the rheological properties of a liquid comprises an inner bearing member having a horizontally disposed outer cylindrical surface and an outer bearing member having a horizontally disposed inner cylindrical surface, each cylindrical surface constituting a bearing surface of predetermined grit. A liquid sample is introduced between the inner and outer cylindrical surfaces, which are disposed eccentrically relative to one another. Relative mechanical movement of the members, which is related to both shear and displacement of the liquid disposed between them, provides an indication of the rheological properties of the liquid.

Abstract: The static coefficient of friction between contacting surfaces of a plurality of bodies is determined by applying a load to the bodies in a direction normal to the contacting surfaces. Opposite ends of a flexible filament are fixedly connected to a load cell and a first of the bodies. A motor continuously moves a second of the bodies away from the load cell at constant velocity to pull the first body at right angles to the force of the normal load so that the first body moves intermittently relative to the second body across a contact surface between them. The load on the surfaces, the nature of the surfaces, and the speed of the first body relative to the load cell are such that the filament is alternately and cyclically tensioned and relaxed as the movement occurs. The maximum tension occurs at the incipient stages of movement of the first body relative to the second body.

Abstract: A portable testing device for determining the static coefficient of frict between a floor surface and a shoe sole or heel material includes an upper, weighted strut movable within a vertical plane and a lower strut pivotably secured to the bottom portion of the upper strut. The upper strut is mounted within a bearing block which is translatably movable within a horizontal plane, and the lower strut has secured to the bottom portion thereof a yoke within which a metal shoe carrying a representative shoe sole or heel material to be tested is pivotably secured. The yoke and shoe project through the base of the device framework so as to rest upon the flooring material being tested, and a trigger is disposed near the shoe so as to be actuated thereby upon the occurrence of slip between the shoe and flooring materials.

Abstract: A device for testing an endless chain-link mechanism comprises a disc, mounted to a DC-servomotor, which is resiliently urged against the rollers which serve to support the chain-link. The current of the motor is recorded in function of time and the significant part which is a measure of the resistance to rotation is determined. When this value exceeds a predetermined one, the roller is considered to be defective. Auxiliary circuits for signal processing may be provided, if desired.

Abstract: An apparatus is disclosed for testing the traction properties of pneumatic tires. A frame is provided having a plurality of structural members. A suspension system having upper and lower arms each having first and second ends is rotatably attached to the frame at the first ends of the upper and lower arms. A hub assembly having a triaxial force transducer mounted therein is attached to the second ends of the suspension system by means of a pair of spherical bearings. An aperture extending through a rear wall of the hub assembly, through the triaxial force transducer and through a front wall of the hub assembly supports a driven axle for applying driving or restraining torque to a pneumatic tire mounted on the front surface of the hub assembly.

Abstract: A wheel speed sensor including a rotor and a stator with the stator being coaxially disposed within an elastomeric member for incremental axial movement upon engagement with the rotor. The stator includes a pole member, a bobbin and coil assembly, and a magnet which are axially aligned to provide an elongated stator structure which is coaxially disposed in a tubular member which guides the incremental axial movement of the stator. A method for prestressing the elastomeric member for setting the required applied force for axially moving the stator.

Abstract: A device for performing friction and wear tests inside a closed high-pressure autoclave under additional surrounding high pressure adjustable from the outside, wherein a test element arranged inside the autoclave is rotated by means of a driving shaft passed in a pressure-tight manner through the wall of the autoclave into the latter, a contact pressure in the form of an additional unidirectional load is exerted on the test element by means of a unit arranged inside the autoclave, and both the contact pressure and the torsional moment acting on the test element are determined and indicated outside the autoclave.