Abstract: A vehicle is received in a stationary controlled area of a controlled testing environment. Simulation inputs corresponding to a simulated scene are generated and transmitted to the vehicle. The vehicle applies torque in response. A vehicle control mechanism of the controlled testing environment, such as a chassis dynamometer, a motorized treadmill, or a lift, keeps the vehicle within the stationary controlled area during the test despite the torque applied by the vehicle. A path of the vehicle within the simulated scene is determined based on the applied torque, based upon which the vehicle's navigation system is calibrated.

Abstract: The disclosure provides a vehicle excitation advice. The vehicle excitation device that excites a vehicle having a plurality of wheels includes a plurality of excitation machine bodies on which the wheels are placed, respectively. The excitation machine body includes a front shaft and a rear shaft on which the wheels are placed at intervals in the in the front-rear direction of the vehicle, and an actuator (hydraulic actuator) that excites vibration to the wheels by moving at least one of the front shaft and the rear shaft in the front-rear direction. The front shaft is inclined such that the inner end portion of the front shaft in the left-right direction of the vehicle is located closer to the front of the vehicle than the outer end portion of the front shaft in the left-right direction of the vehicle.

Abstract: A vibrating device is provided that can appropriately reproduce a vibrating state during travel of a vehicle. A vibrating actuator (12) of a vibrating device (1) vibrates a driving wheel W by driving a second roller (16) in a front-rear direction in a state where a lower side portion of the driving wheel W is held between a first roller (17) and the second roller (16). In a case where the wheel W is in a creep state, the second roller (16) is driven so as to rotate in a reverse direction to the driving wheel W by a rotating actuator (170).

Abstract: A power tool, such as a rotary hammer, includes a housing, an output shaft for mounting a tool accessary and a motor having a motor shaft that generates a rotational output for rotating and linearly hammering the output shaft. The rotational output of the motor shaft is coupled to the output shaft via a driving mechanism that includes a hammer mechanism. An intervening member is axially movable relative to the motor shaft and is operably coupled between the motor shaft and the hammer mechanism. The hammer mechanism and the output shaft are supported by a movable support that is axially movable relative to the housing. Because the output shaft and the driving mechanism are movable relative to the motor and the housing, which preferably includes handle, via the intervening member and the movable support during hammering operations, vibration generated during hammering operations can be dampened before reaching the housing.

Abstract: A method for emulating a three-phase electric motor using a load emulator, wherein the load emulator is connected in a three-phase manner via its load terminals to the supply terminals of a motor controller. The load emulator has emulator power electronics and an emulator controller for controlling the emulator power electronics. The emulator controller determines the supply terminals that are driven by the motor controller and the supply terminals that are not driven. The emulator power electronics are driven by the emulator controller in such a manner that phase currents calculated by the emulator controller on the basis of a motor model flow in the supply terminals that are driven by the motor controller. A phase voltage calculated by the emulator controller on the basis of a motor model is applied to the supply terminal that is not driven by the motor controller.

Abstract: A brake test stand for testing vehicle brakes and for determining the brake forces acting on the respective vehicle wheel. The brake test stand comprises first and second pairs of rollers for positioning the two wheels mounted on a common axis of a vehicle thereon, wherein the rollers of each pair of rollers are arranged opposite to each other and the pairs of rollers are provided side by side. A control unit controls the test stand. First sensing devices are positioned respectively below and between the rollers of each pair of rollers for sensing the pattern of the running surface of each of the tires of the wheels mounted on the common axis. A processing and calculation unit processes the data obtained by the first sensing devices for calculating tire conditions based on a correlation of the data of the coaxially mounted tires.

Abstract: A chassis dynamometer for a vehicle has a base seat, a fixed shaft having one end thereof attached to the base seat, a rotary proximal portion rotatably supported to the fixed shaft, a roller connected to the rotary proximal portion, for loading a wheel of a vehicle, and a motor connected to the roller so that power can be transmitted therebetween. The roller has a single flange portion connected to the rotary proximal portion and extending obliquely to the axis, and an outer peripheral portion extending both axial directions from an outer periphery of the flange portion and disposed outward in the radial direction of the motor.

Abstract: The invention concerns a roller for a motor vehicle brake test bench comprising a roller body (11), wherein the peripheral wall (17) of the roller body (11) is formed at least partially from plastic. The invention further concerns a brake test bench (12) for motor vehicles having such a roller (10).

Abstract: A compact, modular and versatile vehicle testing assembly for testing at least the brakes of an assembled vehicle comprises a pair of rollers adapted to support a tire of a tire and wheel assembly of a vehicle positioned on the testing assembly, with the pair of rollers being moveable relative to one another to alter the spacing there between. A drive system is connected to one of the rollers to operate as a drive roller for selectively imparting rotational motion to a tire of a vehicle tire and wheel assembly, with the other roller comprising a freewheeling roller to which rotational motion is imparted by a vehicle tire. A brake member is engageable with the freewheeling roller to selectively inhibit rotation of the freewheeling roller.

Abstract: A chassis dynamometer is disclosed having a dynamometer drum member, a housing member to house a stator, a shoe member to form a gap with the dynamometer drum member, an extension shaft member to radially vary the gap dimension. The extension shaft member may extend radially from the housing member, and the extension shaft member may include external threads. The extension shaft member may include a smooth portion, and the extension shaft member may cooperate with a collar member. The extension shaft member may include a hole member, and the extension shaft member may include a fastening member. The collar member may include a shoulder member, and the extension shaft member may include a flange member.

Abstract: The present invention relates to a roller brake testing dynamometer (P) for vehicles whose braking forces are to be ascertained, wherein there is provided at least one roller (L) which is driven by way of a drive (A) in order in turn to drive a vehicle tire (R) bearing against the roller (L), and wherein the dynamometer (P) has at least one contact-less sensor unit (S) for detecting the position of the tire (R) relative to the at least one roller (L).

Abstract: A method for automatic vehicle testing, inspection and valuation for a manual front wheel drive vehicle. The method includes connecting a probe for the emission test to the exhaust pipe and connecting the rpm cable to the cigarette lighter before starting the test. The testing begins by driving in so that the front wheels of the vehicle enter the VCT rollers, running the vehicle to 60 km/h and then shifting to 3rd gear. The method also includes accelerating to maximum rpm before shifting to neutral and waiting until the vehicle speed drops back to 60 km/h and after 3 seconds applying the brakes to stop. Then the vehicle is advanced until the rear wheels engage the VCT rollers and after 3 seconds the rollers start rolling up to 90 km/h. The foot brake is pumped systematically until the speed drops to 20 km/h, and then the parking brake is operated to stop. The overall vehicle is evaluated relative to the model and year of the vehicle.

Abstract: A compact, modular and versatile vehicle testing assembly for testing at least the brakes of an assembled vehicle comprises a pair of rollers adapted to support a tire of a tire and wheel assembly of a vehicle positioned on the testing assembly, with the pair of rollers being moveable relative to one another to alter the spacing there between. A drive system is connected to one of the rollers to operate as a drive roller for selectively imparting rotational motion to a tire of a vehicle tire and wheel assembly, with the other roller comprising a freewheeling roller to which rotational motion is imparted by a vehicle tire. A brake member is engageable with the freewheeling roller to selectively inhibit rotation of the freewheeling roller.

Abstract: The present invention relates to a roller brake testing dynamometer (P) for vehicles whose braking forces are to be ascertained, wherein there is provided at least one roller (L) which is driven by way of a drive (A) in order in turn to drive a vehicle tire (R) bearing against the roller (L), wherein there is provided at least one braking force sensor (S) for ascertaining a braking force exerted on the roller (L) by the tire (R), and wherein there is provided an evaluation and control unit (E) to which the signals of the braking force sensor (S) can be fed. Furthermore, it is provided that the evaluation and control unit (E) is adapted on the basis of the signals from the braking force sensor (S) to ascertain the transition from static friction to sliding friction between the tire (R) and the roller (L) independently of the speed of rotation of the roller.

Abstract: An apparatus for testing the brakes, wheel alignment, suspension, transmission, and engine of motorized wheeled vehicles, includes a dynamometer for self-calibration. A platform supports a road vehicle to be tested. Two or four pairs of short high-inertia rollers are revolvably supported adjacent to the platform, and positioned to individually support either the front wheels or the back wheels of the vehicle. The rollers are drivable by a stationary vehicle resting thereon, each pair of high-inertia rollers supporting one vehicle wheel. A floating roller contacts the wheel to detect side forces. Sensors are connected to the rollers and a computer for data processing, display and recording is connected to the sensors. Speed of the rollers is monitored by an encoder having a resolution of at least 1000 pulses/sec. A preferred embodiment of the apparatus includes electric motors which can be connected to drive the rollers.

Abstract: An apparatus and a method for inspecting a brake system of a two-wheeled vehicle are provided, which not only can reduce the time required for each inspection of the two-wheeled vehicle to efficiently perform inspection of the two-wheeled vehicle, but also remarkably improve the inspection accuracy. Each wheel of the two-wheeled vehicle is supported by respective corresponding support rollers and an anti-lock brake system and a front and rear wheel interlocking brake system acts on the wheels. Data for rotational speeds of the rollers supporting the wheel acted upon by the anti-lock brake system are measured by measuring encoders 20, 31. Data for temperature of a brake actuating part 45 of the wheel acted upon by the front and rear wheel interlocking brake system is measured by a measuring sensor 46.

Abstract: A test stand for motor vehicles with a roller assembly (1) having a contact surface (3) for rolling the wheels (2), with the contact surface (3) being rotatably driven and adapted to be blocked, and/or braked, and/or released. The roller assembly (1) is mounted for at least a slight movement with at least two degrees of freedom, and to determine the force which is generated by the motor vehicle during driving and/or braking movements of the vehicle, it is possible to measure the force that is operative between the roller assembly (1) and a predeterminable fixed point (10), and/or the displacement occurring during driving and braking movements of the motor vehicle, and/or the angle of rotation between the roller assembly (1) and a predeterminable fixed point (10).

Abstract: A roller support assembly for a dynamometer system includes a plurality of bearing support structures wherein each bearing support structure includes at least one roller bearing, at least one vertical support assembly for supporting the at least one roller bearing in a vertical plane, at least one horizontal support assembly for supporting the at least one roller bearing in a horizontal plane, and an installation site structure supporting each of the plurality of bearing support structures. Each of the at least two bearing support structures further includes at least one vertical support assembly for supporting the at least one roller bearing in a vertical plane and each of the at least two bearing support structures further includes a pair of vertical support assembly for supporting the at least one roller bearing in a vertical plane.

Abstract: A vehicle positioning apparatus capable of avoiding the elastic deformation of the tires or the development of histeresis in and around the legs allows a vehicle to be positioned with high accuracy. The apparatus includes two front wheel guide units 10 and two rear wheel guide units 20, each including a pair of guide members g1 and g2 with a predetermined length that extend in parallel while an interval is maintained between the guide members in accordance with the tire widths W1 and W2 of front wheels 51 and the rear wheels 52, respectively, of a vehicle 50 to be positioned. A correct position of the vehicle can be ensured as the vehicle travels along the wheel guide units with each of the tires restrained by each pair of guide members g1 and g2 on either side of the tire. The apparatus also includes a mechanism for adjusting each of the wheel guide units in accordance with the wheel tracks T1 and T2 of the vehicle 50, whereby various types of vehicles can be handled with a single apparatus.

Abstract: A chassis dynamometer for use with a test vehicle such as a snowmobile is provided. First and second spaced apart rolls support the test vehicle. A belt is arranged around the first and second rolls and rotationally couples the rolls to one another. The belt includes an outer surface on a test side of the belt for supporting the test vehicle. The belt reduces slipping of the track on the dynamometer. The belt receives inputs from the test vehicle. A processor quantifies the inputs from the test vehicle. A platform is arranged between the first and second rolls beneath the belt to maintain engagement of the track with the belt. The platform includes a load cell for detecting a longitudinal load imparted to the platform by the belt.

Abstract: A method and an apparatus for operating a test bench, e.g. a roller test bench, for carrying out simulation drives of a vehicle placed on the test bench. At least one vehicle wheel contacts at least one roller of the roller test bench. To determine the roller setpoint speed, a reaction torque of the roller in relation to the vehicle wheel is measured on the roller of the roller test bench.

Abstract: A device for simulating slip on vehicle test benches wherein a vehicle wheel which rolls on a movable testing surface of a test device such as a test roller or flat belt and performs the object of changing the frictional force between the wheel and the testing surface without necessarily having to change the coefficient of friction A lifting/lowering device changes the contact force FA of the wheel in a predeterminable way from the tire to an apparatus as the wheel rotates.

Abstract: A motorized chassis dynamometer machine. In one embodiment, the dynamometer machine includes a fixed frame assembly. At least one roller assembly is mounted on the fixed frame assembly. At least one independent motor assembly is connected to each roller assembly. The independent motor assembly is used for driving the roller assembly. At least one independent loading dynamometer assembly capable of measuring the vehicle input power at each roller assembly is coupled to each roller assembly. In a preferred embodiment, the dynamometer assembly is only operable for loading each independent roller assembly, while the motor assembly is operable for driving each independent roller assembly. The machine has at least one motor controller capable of controlling each independent motor assembly and at least one dynamometer controller capable of controlling each independent dynamometer assembly.

Abstract: A motorized chassis dynamometer machine. In one embodiment, the dynamometer machine includes a fixed frame assembly. At least one roller assembly is mounted on the fixed frame assembly. At least one independent motor assembly is connected to each roller assembly. The independent motor assembly is used for driving the roller assembly. At least one independent loading dynamometer assembly capable of measuring the vehicle input power at each roller assembly is coupled to each roller assembly. In a preferred embodiment, the dynamometer assembly is only operable for loading each independent roller assembly, while the motor assembly is operable for driving each independent roller assembly. The machine has at least one motor controller capable of controlling each independent motor assembly and at least one dynamometer controller capable of controlling each independent dynamometer assembly.

Abstract: A device for simulating slip on vehicle test benches wherein a vehicle wheel which rolls on a movable testing surface of a test device such as a test roller or flat belt and performs the object of changing the frictional force between the wheel and the testing surface without necessarily having to change the coefficient of friction, A lifting/lowering device changes the contact force FA of the wheel in a predeterminable way from the tire to an apparatus as the wheel rotates.

Abstract: A test device and method for verifying the proper operation of a dynamometer is described. The inventive test device is portable and simple to operate, allowing dynamometer accuracy to be readily tested in the field.

Abstract: A roller type test stand for motor vehicles and/or wheel/tire combinations including at least one running roller for supporting the wheels, a supporting frame and a drive arranged between the running rollers. The drive is a motor/transmission combination including a shaft for supporting the running rollers, a transmission and at least one motor. The motor is arranged next to the shaft and is connected to the shaft via a transmission. The motor/transmission combination is arranged on a frame that is swing mounted on the supporting frame. At least one measuring apparatus is arranged on the frame between the running rollers. Alternatively, the frame may be replaced by a housing.

Abstract: A roller dynamometer is provided, having at least one supporting carriage having a rotatable roller and a dynamometer linked to the roller for measuring torque output of a vehicle. The carriages are rollable on a substrate for positioning under a vehicle. In one aspect, multiple dynamometer and roller units are provided, for engagement with multiple vehicle wheels, with the units being linked electronically for common control by a control unit that simulates either straight line or curved driving conditions. In a further aspect, the dynamometer is supported on the carriage by a rotary mount. In a further aspect, the rollers have a generally hourglass shape to permit vehicle wheel self-centering.

Abstract: In the tire examination method before and after an alteration in the tire pressure a respective interferogram is produced of the tire surface using coherent radiation and the interferogram is converted into a modulo 2 .pi. image, which for its part is processed to obtain a gray value image and in the case of which from a comparison of the gray value images information concerning any defects present in the tire is obtained. For testing a tire the wheel, which bears such tire to be tested, is arranged on a driven roller set by driving the vehicle with the wheel, a test head is moved toward the tire to be at a predetermined test distance therefrom for producing such interferograms, at a first test segment of the tire examination for defects is performed, the wheel is incrementally rotated by the roller set by an amount equal to the size of a test segment and so many test segments are examined that the complete tire is tested.

Abstract: The invention is in the field of dynamometer testing of aircraft wheel and brake assemblies and, more particularly, relates to the simulation of brake and landing gear vibration dynamics on a dynamometer. The test apparatus and method according to the invention employ a pitch beam that simulates bogie pitch motion, and a walk beam that simulates landing gear walk.

Abstract: A device for restraining the driving tires of a vehicle on a chassis dynamometer which includes sidewall rollers that position themselves automatically as the vehicle approaches the dynamometer and which lock in place before the dynamometer test begins. The restraining rollers are rotatably mounted on one or more carriers that are initially free to move right or left to accommodate the position of the vehicle's tires. When the latter are satisfactorily aligned with respect to the dynamometer rollers, the movable carriers are locked in place, restricting the lateral movement of the driving tires during the test on the dynamometer. The invention is intended particularly for dynamometers in exhaust emission testing facilities, including garages and service stations, where a low-cost, yet robust, vehicle restraint system is desired.

Abstract: A method checks a vehicle brake system rapidly and reproducibly to measure the correlation between the brake pedal travel and the retardation produced. A test-bed routine is called up in the control unit. During the operation of the test-bed routine, the functioning of the brake system is checked. For this purpose, a pressure difference is produced in the vacuum brake booster. The brake booster pressure difference produces a brake pressure in the brake master cylinder, and a pedal travel corresponding to this brake pressure simultaneously arises. The retardation can either be measured at the rollers of the test bed or is derived from continuously measured wheel speed values. A retardation value can be determined for each wheel as can a correlation between the pedal travel and the retardation from the measured values in the presence of different brake booster pressure difference. The process can average the values measured at the individual wheels.

Abstract: A mobile speedometer tester comprising at least two main wheels rotatably attached to a trailer frame, and a trailer frame. A target disk, pickup and totalizer measure the rate of roller rotation, and bellcranks rotatably mounted to the trailer frame allow the main wheels to be extended and retracted. A brake is provided to stop the rollers from rotating, and the front wheel is retractable by means of an electric motor. The main wheels are quickly and easily removable from the bellcranks. Ramps attached to the trailer frame allow test vehicles to drive up onto the mobile speedometer tester in order to test their speedometers. A motorcycle version allows motorcycle speedometers to be tested.

Abstract: A simulator for testing an Anti-lock braking system modulator capable of easily setting the yawing of a vehicle and disproportionate concentration of a vehicle weight according to the various vehicle weights and diverse road surface conditions has wheels rotated by compressively contacting flywheel pairs, a flywheel driving portion for transmitting and managing a driving force to the flywheels, rotation-speed sensors for monitoring the rotational speed of the wheels and flywheels, pneumatic cylinders installed to respective wheels for regulating a frictional force between the wheels and flywheels, a braking system for inciting a braking force to the wheels to which a modulator to be tested is mounted, a pneumatic pressure generating circuit for supplying a predetermined pressure to the braking system and pneumatic cylinder, and a controller electrically connected to the flywheel driving portion, rotation-speed sensors and pneumatic pressure generating circuit, in which the controller controls the flywheel dri

Abstract: A suspended large, single roll dynamometer for use in a compact pit. The dynamometer includes a power absorption unit operably coupled to a pair of rolls. The rolls support the driven wheels of a vehicle thereon for rotational movement. A cradle is used to support the power absorption unit, and thus the rolls, within the pit in a manner which does not require significant clearance between the perimeter of the cradle or the rolls and the interior walls of the pit. The components associated with the dynamometer which require periodic access and/or maintenance are further disposed on the power absorption unit so as to be readily physically accessible by an individual without physically entering the pit.

Abstract: An apparatus for testing an anti-lock brake system has rolls and device for detecting rotational changes of the rolls. The test is performed by running a vehicle having mounted thereon the anti-lock brake system while wheels of the vehicle are placed on the rolls, actuating the anti-lock brake system when a predetermined speed has been attained, and judging operating conditions of the anti-lock brake system from rotational changes of the rolls at the time of braking. In the apparatus, the friction coefficient of each of the rolls is set to such a value that a frictional force to act between each of the rolls and each of the wheels at the time of braking exceeds an inertia force of each of the rolls.

Abstract: Process and device for controlling the braking of a brake bench of a wheeled vehicle having plural interconnected drive shafts, each shaft having a differential. One wheel on a shaft is driven in the forward direction and the other wheel on the same shaft is driven in the rearward direction. The speed (V.sub.A) of the drive motor (7a) of the one wheel (3a) and the speed (V.sub.B) of the drive motor (7b) of the other wheel (3b) differ from each other such that the difference of the two speeds (V.sub.A, V.sub.B) is maintained less than a value such as will move another shaft of the vehicle which is external to the brake bench. The difference in the two speeds (V.sub.A, V.sub.B) is maintained less than 5% of the speed (V.sub.A) of the drive motor (7a) in the forward direction (A).

Abstract: A roller brake dynamometer includes shuttle wheels which engage the dynamometer rollers and are movable between raised and lowered ground engaging positions. The shuttle wheels may be rotated in the same or opposite directions to move the dynamometer forwardly, rearwardly or turn it about its own axis. A dynamometer transport trailer includes an endless conveyor chain running the length of the center of the tiltable trailer bed which includes a tongue engagable with the dynamometer frame for pulling the dynamometer on to and off of the trailer bed.

Abstract: A simple, compact and inexpensive chassis dynamometer capable of performing a multiplicity of tests and of simulating a variety of conditions, including wind resistance, weight of the vehicle and grade or slope of a road, includes first and second pairs of rolls for supporting the tires of a vehicle to be tested. An electric drive motor is connected with the rolls to drive them, and a single flywheel and associated eddy current motor are connected with the rolls to impart various levels of apparent inertia to the rotational movement of the rolls for thereby simulating the various conditions encountered by a vehicle travelling on a road. The frame is of open construction and the drive motor, eddy current motor, flywheel, rolls and associated components are confined within the periphery of the frame. The open construction of the frame simplifies the apparatus and enables maintenance and repair to be performed in situ.

Abstract: An apparatus for testing an anti-lock brake system has rolls and device for detecting rotational changes of the rolls. The test is performed by running a vehicle having mounted thereon the anti-lock brake system while wheels of the vehicle are placed on the rolls, actuating the anti-lock brake system when a predetermined speed has been attained, and judging operating conditions of the anti-lock brake system from rotational changes of the rolls at the time of braking. In the apparatus, the friction coefficient of each of the rolls is set to such a value that a frictional force to act between each of the rolls and each of the wheels at the time of braking exceeds an inertia force of each of the rolls.

Abstract: The brakes of a two-axle vehicle are tested by weighing the vehicle and measuring the braking forces for both axles to determine the actual ratio of front axle braking force to total braking force. The deceleration applied to the vehicle is determined from the weight of the vehicle and the applied braking forces. A nominal preferred value of the ratio of front axle braking force to total braking force is calculated from the determined deceleration and the measured weight of the vehicle. The nominal preferred value varies from test to test with both the actual deceleration and the vehicle weight. For each test, upper and lower limits for the acceptability of the actual ratio of front axle braking force to total braking force are set based upon the computed nominal preferred value. These limits move from test to test with the computed nominal preferred value. The nominal preferred value, the movable limits, and the actual ratio are displayed to the user on a CRT screen.

Abstract: A vehicle inspection facility comprises a horizontal base frame supporting a pair of brake testing sub-assemblies. Each sub-assembly comprises a driven roller and a companion roller, and includes means for rotating the driver roller for rotating the wheels of a vehicle being tested and means for measuring the braking force applied by the vehicle brakes against the driven roller. Also included is a vehicle suspension and steering testing assembly comprising a pair of horizontal supporting surfaces for supporting the vehicle front wheels and including means for producing reciprocal motion of the supporting surfaces along perpendicular directions to determine the degree of "play" of the wheels.

Abstract: A method of testing the performance of an anti-lock brake control system of the type wherein an electronic control circuit signals each modulator to increase, decrease, or hold the hydraulic fluid pressure on the corresponding wheel brake as required by the varying wheel speed. The method dictates the sequential delivery of quasi brake control signals from the control circuit to the respective modulators, each signal being capable of causing an increase, a decrease and a holding of the fluid pressure on one brake. The resulting braking forces being exerted on the respective vehicle wheels are measured as by a dynamometer connected to motored rollers under the vehicle wheels.

Abstract: Method and device for testing an anti-skid braking system (ABS) of a motor vehicle, using a roller test bench with at least four rollers or pairs of rollers. These rollers are put into rotation by the roller bench and braked by the brakes of the vehicle. A difference in speed of rotation between at least one of the (pairs of) rollers and the other(s) is brought about by the roller bench. During the braking, the response of the anti-skid system to this difference in speed is observed.

Abstract: A hammer drill has a housing provided with a tool chuck in which a tool is to be mounted. A drive is provided which is capable of rotating and/or axially impacting the tool chuck. This drive includes a piston reciprocable in axial direction of the tool chuck, a drum rotating on a shaft extending parallel to the direction of reciprocation of the piston and provided with a circumferentially extending cam track, and a transmitting arrangement which travels in part in engagement with the cam track and which has another part connected with the piston to reciprocate the same.

Abstract: A roller is disclosed which is intended to have frictional engagement with a vehicle wheel during a testing operation and which is constructed by welding together: a central supporting shaft, a plurality of outwardly-extending axially-spaced supporting discs, and a plurality of axially-extending members supported in slots on the peripheries of the discs and arranged to provide wheel-engaging ribs extending at right angles to the direction of motion of the wheel periphery.

Abstract: The disclosure describes an improved apparatus for testing a wheeled vehicle utilizing wheel-supporting rollers. All the wheel-supporting rollers are constrained to rotate at the same peripheral speed. Means are provided for measuring the angular acceleration or deceleration of the rollers.