Hofmann Werkstatt-technik Gmbh

Gebr.hofmann Gmbh & Co Kg Maschinenfabrik

Snap-on Technologies, Inc.

Gebr. Hofmann, G.m.b.h. & Co., Maschinenfabrik

Snap-on Deutschand Holding Gmbh

Eickhart Goebel

Karl Rothamel

Josef Drechsler

Horst Kogler

Ulrich Diez

Lorenz Lenhardt

Gottfried Kuhn

Bernhard Hoffmann

Jorg Wowes

Ludwig Held

Walter Hollube

Klaus Ruehl

In a method and an apparatus for balancing a motor vehicle wheel comprising a pneumatic tire and a disk wheel, the wheel is clamped on a measuring spindle and geometrical data of the wheel are sensed and stored. Wheel unbalance is ascertained in at least one measuring run and at least one balancing vector for balancing mass and balancing position is calculated in accordance with a balancing program selected in dependence on the disk wheel type and material, in at least one balancing plane. At least one balancing weight is fixed to the wheel in dependence on the balancing vector. When sensing a rim region of the wheel a sensor detects whether a rim portion extending substantially perpendicularly to the measuring spindle is or is not present in the rim region being sensed and the balancing program is selected in dependence on the signal obtained in the sensing operation with the sensor. A sensing apparatus includes a sensing member for sensing geometrical data of the wheel and a sensor for sensing a suitable rim configuration for applying a balancing weight thereto and/or the wheel material.

Method and apparatus for balancing a vehicle wheel

An apparatus for the measurement of centrifugal forces generated by a rotary member such as a vehicle wheel which is out of balance, comprises a rotary member mounting for supporting the rotary member with respect to an apparatus frame structure. The rotary member and the rotary member mounting form a sub-critical oscillating system in measurement of the rotary member which rotates for a measuring procedure. The apparatus further includes a measurement sensor which is in the form of a force pick-up and whose direction of application of force extends approximately tangentially to a circle through the location of the application of force at the measurement sensor, around a virtual mounting location.

Apparatus for measuring forces produced by unbalance of a rotary member

A device for measuring forces generated by unbalance of a rotor, in particular a motor vehicle wheel, includes a stationary frame, an intermediate frame positioned radially within the stationary frame, and first levers supporting the intermediate frame on the stationary frame. The first levers are arranged along imaginary lines that are either parallel to each other or intersect at a first virtual mounting position. A pivot bearing is supported on the intermediate frame by second levers, which are arranged along imaginary lines that intersect at a second virtual mounting position. Mounted coaxially in the pivot bearing is a measuring shaft, which is rotatable about a common axis of the measuring shaft and the pivot bearing. An outer force sensor measures displacement between the intermediate frame and the stationary frame. An inner force sensor measures displacement between the pivot bearing and the intermediate frame.

Device for measuring the forces generated by a rotor Imbalance

An arrangement for driving a measuring spindle of a balancing machine has a friction wheel which is drivable by an electric motor and which can be brought into and out of a condition of driving relationship with the measuring spindle. The electric motor and the friction wheel form a motion unit supported movably about a mounting assembly which is disposed on the machine frame structure and which is arranged in displaced relationship with the axis of the rotor of the electric motor. A torque which is produced about the mounting assembly when the rotor of the electric motor is accelerated causes movement of the motion unit thereby to produce the driving connection between the friction wheel and the measuring spindle.

Arrangement for driving a measuring spindle of a balancing machine

An unbalance measuring machine has an arrangement for clamping and release a motor vehicle wheel or other rotary member on a motor-driven shaft. The machine has a bar which is guided movably in the shaft in its axial direction. The bar is engaged at one end with the rotary member and at the other end with a belt pulley via interengaged screw threads. When the belt pulley is driven by the drive motor in one direction of rotation, the bar axially clamps the rotary member on the shaft to hold it fast. When the belt pulley is driven by the drive motor in the other direction, the bar moves in the opposite direction to release the rotary member.

Method and assembly for clamping and releasing a rotary member on a

A method and apparatus for measuring unbalance of a vehicle wheel that is freely rotatable and mounted on a motor vehicle. The wheel is rotated during the measuring operation at a measurement speed and a mark on the wheel is sensed to provide accurate information concerning the angular wheel position of the rotating wheel. An incremental generator is operatively associated with the wheel for supplying a predetermined number of increments between each two sensings of the mark on the wheel, which is associated with a rotational angle of 360.degree.. The respective counter condition is used for detecting the rotational angle of the wheel.

Method and apparatus for measuring unbalance of a motor vehicle wheel on

A method and apparatus for driving a motor vehicle wheel mounted on a motor vehicle. The wheel is freely rotatable for unbalance measurement thereof a friction wheel driven by an electric motor that is pressed against the tire with varying pressure force. The respective peripheral speeds of the friction wheel and the vehicle wheel in relation to the contact periphery at which the friction wheel bears against the vehicle wheel are ascertained and the electric motor is regulated in a continuous or discontinuous mode in dependence on a difference between the two measured peripheral speeds.

Method and apparatus for driving a motor vehicle wheel on a motor

A method of correcting unbalance on a motor vehicle wheel by means of at least one balancing weight which can be fixed to the wheel at appropriate positions ascertained by an electronic measuring apparatus during an unbalance measuring procedure involves the use of a sensing device which is coupled to the electronic measuring apparatus and which senses relevant dimensions of the wheel for storage thereof in the electronic measurement apparatus, for evaluation of the measurement values obtained in the unbalance measuring procedure.

Method of correcting unbalance on a motor vehicle wheel

An apparatus for driving a motor vehicle wheel while it is fitted to the motor vehicle for detecting unbalance thereof comprises a friction wheel which is driven by a drive motor and which is pressed against the motor vehicle wheel for driving same at a speed required for measuring its unbalance. The drive motor is switched on or off in dependence on the pressure force with which the friction wheel is pressed against the motor vehicle wheel, in such a way that no slip occurs between the friction wheel and the motor vehicle wheel.

Apparatus for driving a motor vehicle wheel for determining unbalance

A tire demounting apparatus for a tire secured to a wheel rim, having a actuating lever, pivotably supported on the wheel about a first pivot axis, and a tire bead holder pivotably supported on the actuating lever about a second axis. The tire bead holder has an engagement portion engaging the tire bead. Upon pivoting of the actuating lever in the intended demounting pivot direction, the tire bead holder engaging the tire bead pivots in the opposite direction on the actuating lever, thereby engaging a tire bead portion to be released. The portion engaged by the tire bead holder is initially moved radially inward out of range of the wheel flange, and then in the axial direction away from the wheel. The tire demounting apparatus also includes a stop which limits the pivoting motion of the tire bead holder on the actuating lever oriented opposite the demounting pivoting direction of the actuating lever.

Tire demounting tool

Optimization of running conditions of an automobile wheel is achieved by matching (readjustment of tire relative to rim) after two measuring runs of the tire/rim assembly and in which the static and dynamic unbalance vectors of the tire and rim include coefficients of influence on said running conditions.

Method and apparatus for optimization of running conditions of an

A tire-mounting apparatus for mounting a tire having two beads on a rim in a tire/rim assembly where the rim has two opposed flanges that are bent radially inwards to define a drop center, and where the beads of the tire extend over the rim and are located behind the rim flanges in the drop center. The apparatus includes a base on which a rim-mounting adaptor is rotatably mounted. A clamp is used to retain the beads of the tire on the rim. A mounting tool forces one of the tire beads over one of the rim flanges. The mounting tool is rotatably driven to move the tire and the rim so that the one tire bead is rolled over the one rim flange into the drop center of the rim.

Tire-mounting apparatus

A method and apparatus is described for determining the unbalance of wheels mounted on the drive axle of an automobile by transducers detecting the forces and/or vibrations produced by the unbalance present in an automobile wheel which is jacked up for this purpose. Other equipment, in addition to the engine of the automobile, drives or brakes either of the two wheels in order to obtain a speed difference between the wheels. A measuring unit determines the magnitude and direction of unbalance. A device also determines the speeds of the driven wheels.

Method and apparatus for determining the unbalance of wheels mounted on

A method and apparatus for determining and indexing the angular location of unbalance of a rotatable body. Such unbalance is determined by mounting the body on a balancing machine and rotating the body to obtain an unbalance measurement. The method and apparatus provide for the subsequent rotation of the body to a correction position over the shortest possible distance.

Method and apparatus for determining and indexing the angular location

A clamping device for clamping a vehicle wheel on a threaded clamping shaft of a test machine, such as, a balancing machine. The clamping device includes a basic body positionable on the clamping shaft and a pair of swivelling levers pivotally mounted on the basic body. Each of the levers has an extremity forming a threaded section movable into and out of engagement with the threaded clamping shaft and an actuating lever for controlling engagement of the threaded segment with the clamping shaft. The levers have portions thereof cooperating with each other in such manner that movement of one of the levers results in conjoint movement of the other of the levers. The basic body has handles formed integrally therewith or attached thereto that protrude away from the axis of the threaded shaft. The handles have recessed portions for receiving the actuating ends of the swivelling levers. The swivelling levers have stop portions engageable with portions of the basic body to limit engagement of the threaded segments with the clamping shaft. The distance between the pivotal connections of the swivelling levels to the basic body is less than the distance between the threaded segments, when in a clamping position. Springs are provided for biasing the threaded segments into engagement with the clamping shaft.

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Pfungstadt, Germany

Eickhart Goebel