Patents Assigned to Gebr. Hofmann GmbH & Co. KG, Maschinenfabrik
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Patent number: 5676025Abstract: An apparatus for balancing a rotary member such as a grinding wheel has at least one balancing weight which is guided movably for varying its position with respect to the axis of rotation of the rotary member. The balancing position of the balancing weight is adjusted by means of at least one displacement device including an electric motor. The motor is arranged with its axis of rotary oriented radially with respect to the axis of rotation of the rotary member. The rotor of the motor can be supported by way of a thrust bearing against a main body portion.Type: GrantFiled: December 15, 1995Date of Patent: October 14, 1997Assignee: Gebr. Hofmann GmbH & Co. KG MaschinenfabrikInventor: Eugen Lulay
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Patent number: 5243788Abstract: In a method and an apparatus for balancing a grinding wheel, balancing weights on the grinding wheel remain secured to the grinding wheel in an unbalance measuring operation, and the positions at which the balancing weights are secured to the grinding wheel are stored. In a repositioning operation for compensating for measured unbalance of the grinding wheel, the influences of the forces of the balancing weights during the unbalance measuring operation are derived from the stored positions of the weights and compensated for so as to balance the ginding wheel.Type: GrantFiled: August 15, 1990Date of Patent: September 14, 1993Assignee: Gebr. Hofmann GmbH & Co., KG MaschinenfabrikInventors: Gunther Rossmann, Jesus Varona, Andreas Hofmann
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Patent number: 5178011Abstract: In a method and an apparatus for balancing successive rotary members, an unbalance measuring operation is carried out in one or more planes on each rotary member which is rotated at a measuring speed in a measuring run within an overall unbalance measuring time for ascertaining the required number of items of measuring information in a plurality of repetitive measuring cycles. After the elapse of a fraction of the overall unbalance measuring time the unbalance measuring operation is interrupted for an interruption time for the purposes of permitting the performance of working operations which due to vibration caused thereby could result in falsification of the unbalance measurement results, then unbalance measurement is resumed, and further interrupted, and so on in a repetitive procedure to make up the overall measurement time.Type: GrantFiled: August 15, 1990Date of Patent: January 12, 1993Assignee: Gebr. Hofmann GmbH & Co. KG MaschinenfabrikInventors: Klaus-Peter Ohms, Jesus Varona
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Patent number: 5138882Abstract: In a method and apparatus for measuring static unbalance of a rotary member, involving determining the axial moment of inertia of the rotary member which is mounted pivotably in a horizontal position in a balancing system, about an axis of the balancing system, a deviation of the rotary member from its horizontal position is detected and a return force for returning the rotary member to the horizontal position is produced in response to a control parameter from a regulating circuit in dependence on the detected deviation, with regulation of the return force also being effected in dependence on the weight of the rotary member. The value of the static unbalance of the rotary member is formed from the measured return force.Type: GrantFiled: May 15, 1990Date of Patent: August 18, 1992Assignee: Gebr. Hofmann GmbH & Co. KG MaschinenfabrikInventors: Kurt Humber, Gunther Rossmann
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Patent number: 5067348Abstract: A measuring apparatus in which a rotary member is mounted and rotated for measurement or testing thereof, with measuring devices including measurement value pick-up structures for periodically detecting varying forces and/or moments caused by the rotating rotary member. The measuring apparatus includes a machine bed which serves as a component for carrying the measuring devices and for mounting the rotary member. The machine bed is in the form of a casting comprising polymer concrete.Type: GrantFiled: April 19, 1990Date of Patent: November 26, 1991Assignee: Gebr. Hofmann GmbH & Co. KG MaschinenfabrikInventors: Gunther Himmler, Uwe Moench
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Patent number: 5067347Abstract: In a method and an apparatus for testing a pneumatic tire such as for testing the uniformity thereof, a tire to be tested is inflated to a given pressure and rolled against a test surface at a tire contact patch, and forces and/or moments acting at the contact patch are measured. To at least reduce the period of time required for the tire to warm up for a testing operation, the compressed air used to inflate the tire is heated to a given temperature before being passed into the interior of the tire. The compressed air may be heated as it flows through a supply conduit, under the control of a sensor for sensing the temperature in the tire.Type: GrantFiled: July 19, 1990Date of Patent: November 26, 1991Assignee: Gebr. Hofmann GmbH & Co. KG MaschinenfabrikInventor: Uwe Monch
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Patent number: 5033302Abstract: A mounting stand in a balancing machine mounting assembly includes a stationary mounting block and a mount for a rotary member to be balanced. The mount is supported on the mounting block by two parallel springs capable of oscillating movement in a mounting plane in the measurement direction. The mounting stand further has at least one measurement value pick-up sensor operatively disposed between the mounting block and the oscillatable mount for detecting oscillation of the mount produced by an out-of-balance rotary member and to supply corresponding measurement signals. A rotatable adjusting unbalance weight of a known magnitude is mounted to the oscillatable mount and can be selectively brought into operation to cause oscillatory movement of the oscillatable system, to perform a calibration.Type: GrantFiled: January 3, 1990Date of Patent: July 23, 1991Assignee: Gebr. Hofmann GmbH & Co. KG MaschinenfabrikInventor: Uwe Monch
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Patent number: 5019017Abstract: In a monitoring arrangement for a belt drive in which a torque produced by a drive motor is transmitted by way of an endless drive belt to a rotary member to be rotated, the drive belt is provided in its longitudinal direction with markings which are adapted to be sensed and which are disposed at equal spacings from each other. First and second sensing members are arranged at a given spacing from each other in succession in the direction of travel of the belt and are operable to sense the markings on the drive belt as they move past the sensing members. The sensing members output corresponding sensing signals in response to the markings. A signal evaluation member is connected to the first and second sensing members, for interrelating the sensing signals in respect of time in dependence on the spacing between the first and second sensing members and the speed of movement of the drive belt.Type: GrantFiled: February 5, 1990Date of Patent: May 28, 1991Assignee: Gebr. Hofmann GmbH & Co. KG MaschinenfabrikInventor: Uwe Monch
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Patent number: 5016470Abstract: In an apparatus for testing a motor vehicle tire and in particular for ascertaining characteristic parameters of a bead thereof, the bead of the tire is subjected to stretching by radially outwardly displaceable clamping jaws and the compression force applied to the tire by the respective clamping jaws are measured by force measuring means. Each of the force measuring means includes a respective measuring body in which a force transmission portion carries the actuating force applied to the respective clamping jaw and experiences deformation in consequence of the force. The force transmission portion bears strain gauges to measure the force, and it is supported by resiliently bendable support portions in such as way that the measuring body is substantially insensitive to moments and transverse forces which could result from radial guidance for the clamping jaws.Type: GrantFiled: July 27, 1990Date of Patent: May 21, 1991Assignee: Gebr. Hofmann GmbH & Co. KG MaschinenfabrikInventor: Gunther Himmler
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Patent number: 4989449Abstract: In a method and an apparatus for determining the restoring moment produced by tangential forces in a tire testing operation, a tire to be tested is rolled against a test surface under identical rolling conditions in first and second measuring runs, the second of which is performed with the tire being turned round through 180.degree. from its position in the first measuring run. The restoring moment which is related to the center of the contact surface at which the tire is in contact with the test surface is formed from the restoring moment values which are obtained in the first and second measuring runs.Type: GrantFiled: January 18, 1990Date of Patent: February 5, 1991Assignee: Gebr. Hofmann GmbH & Co. KG MaschinenfabrikInventor: Uwe Monch
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Patent number: 4955229Abstract: A method and apparatus is proposed for determining the uniformity of pneumatic tires. The apparatus has two measuring rim halves between which a tire to be tested can be mounted and rolled along a test drum. The apparatus has a measuring system for measuring force fluctuations resulting from nonuniformities of the tire and for emitting a corresponding signal, and an evaluation system which evaluates tire uniformity by subtracting a correction signal obtained from eccentricities of the measuring rim halves from a measurement signal. In this way, a compensation of the error component in the measurement signal resulting from eccentricity of the rim halves is obtained.Type: GrantFiled: October 20, 1989Date of Patent: September 11, 1990Assignee: Gebr. Hofmann GmbH & Co. KG MaschinenfabrikInventor: Gunther Himmler
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Patent number: 4941352Abstract: In a method and apparatus for mass centering of a rotor, the unbalance of the rotor is measured and the result of the unbalance measuring operation and the weight of the rotor are used to determine the position of the axis of inertia which extends through the center of mass of the rotor, with respect to the axis of rotation thereof. The position of the axis of inertia is marked on an end face of the rotor by a marking tool. For that purpose, to bring the position of the axis of inertia and the marking tool into the appropriate relationship, relative displacement is produced by an actuating means as between the rotor and the marking tool in the radial direction with respect to the axis of rotation of the rotor, with the rotor or the marking tool being guided in the direction of displacement by a guide means disposed at an angle with respect to the axis of rotation of the rotor.Type: GrantFiled: May 5, 1989Date of Patent: July 17, 1990Assignee: Gebr. Hofmann GmbH & Co. KG MaschinenfabrikInventor: Gunter Fietzke
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Patent number: 4918983Abstract: In an apparatus for checking a motor vehicle tire the bead of a tire is subjected to a stretching effect by radially outwardly displaceable clamping jaws, and the compression force applied to the bead by the respective clamping jaws is measured by force measuring means. Each force measuring means comprises a radially movable frame structure in which a central force transmitting portion connected to the respective clamping jaw is supported movably in relation to outer portions of the frame structure by resiliently bendable support portions bearing strain gauges, in such a way that when a tire is clamped by the clamping jaws, the force transmitting portion is displaced, causing deformation of the support portions, such deformation being measured by means of the strain gauges. The force transmtting portion is supported in the frame structure in such a way that it is substantially insensitive to movements and transverse forces which can result from radial guidance for the clamping jaws.Type: GrantFiled: April 28, 1989Date of Patent: April 24, 1990Assignee: Gebr. Hofmann GmbH & Co. KG MaschinenfabrikInventor: Gunther Himmler
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Patent number: 4916943Abstract: An apparatus for monitoring and controlling the tire inflation pressure in a tire testing machine comprises first and second measuring rim portions for mounting a tire therebetween, and a pressure sensor operable to detect the inflation pressure of the tire. The pressure sensor has a pressure-receiving surface which is arranged to directly detect the pressure in the interior of the tire. The pressure sensor rotates with the tire in a tire testing run. A spindle connected to the measuring rim portions and rotatable therewith has conduit means for supplying compressed air to inflate the tire. A control means is operable to close off the conduit means, thereby constituting a closed volume of air defined by the space within the tire, the space between the measuring rim portions holding the tire, and the conduit means in the spindle, that volume of air rotating as a unit with the components defining same, during a tire testing operation.Type: GrantFiled: July 13, 1989Date of Patent: April 17, 1990Assignee: Gebr. Hofmann GmbH & Co. KG MaschinenfabrikInventors: Gunther Himmler, Werner Lehr
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Patent number: 4905515Abstract: A device for measuring rotor imbalance of a rotor is disclosed. The rotor shaft housing support for the shaft for a rotor to be balanced in a machine includes two pairs of springs disposed in two parallel planes. Each pair of springs consists of two parallel bar or rod springs that support the rotor shaft housing support in a plane of oscillation coincident with the shaft of the rotor on the machine stand in such a way that it oscillates. Each of the two bar or rod springs of each pair of springs forms part of a single-piece frame. Mounting strips are attached to the machine stand and to the rotor shaft housing.Type: GrantFiled: May 13, 1988Date of Patent: March 6, 1990Assignee: Gebr. Hofmann GmbH & Co. KG MaschinenfabrikInventor: Gunther Himmler
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Patent number: 4817421Abstract: In order to improve running characteristics of an automobile wheel comprised of rim and respective tire fitted thereon and presenting spring qualities, a matching procedure is used to readjust the tire and rim in clearly defined positions relative to each other. Radial run-out effects both of rim and tire are so arranged in opposite directions as to reduce the resulting radial run-out of the wheel. The matching consists in detail of opposing resultant tire radial force variations mathematically calculated on the basis of non-uniform mass distribution in the contact area of the tire under load with differences in tire spring rate on the one hand and radial run-out of the rim on the other hand.Type: GrantFiled: April 28, 1987Date of Patent: April 4, 1989Assignee: Gebr. Hofmann GmbH & Co. KG, MaschinenfabrikInventor: Gunther Himmler
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Patent number: 4694875Abstract: 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.Type: GrantFiled: January 18, 1985Date of Patent: September 22, 1987Assignee: Gebr. Hofmann GmbH & Co. Kg MaschinenfabrikInventor: Eickhart Goebel
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Patent number: 4691567Abstract: A unitary adaptor plate for determining static unbalance in a body. The plate includes an outer body, a middle body, and an inner body, and each of the inner and outer bodies is connected to the middle body by means of opposed torsion elements to provide a structure that defines a gimbal system capable of rotation about two mutually perpendicular axes of rotation defining two degrees of freedom of the adaptor plate. Deflection sensors sense the inclination of the adaptor plate caused by unbalance in a body placed on the adaptor plate, and force transducers operate to restore the plate to a horizontal position and provide an output indicative of the unbalance of the body.Type: GrantFiled: September 2, 1986Date of Patent: September 8, 1987Assignee: Gebr. Hofmann GmbH & Co. KG. MaschinenfabrikInventors: Gunther Himmler, Gunter Knoll
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Patent number: 4676648Abstract: A method and an apparatus for determination of run-out of a rotating body, especially an automobile tire, without the need for mechanically contacting the rotating body. The apparatus includes a device for rotating the body, a scanning system with a transmitter for transmitting parallel rays directed toward the rotating body, a receiver to receive the residual rays not blocked by the rotating body, and an analyzer circuit for determination of variations in blockage on the basis of which run-out of the rotating body is determined.Type: GrantFiled: September 26, 1984Date of Patent: June 30, 1987Assignees: Gebr.Hofmann GmbH & Co KG Maschinenfabrik, Dr.-Ing.Wolfgang Schulz MesstechnikInventors: Wolfgang Schulz, Gunther Himmler, Gunter Knoll, Friedrich Wenz
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Apparatus for automatic insertion of balance weights for use in automobile-wheel balancing equipment
Patent number: 4554734Abstract: Delivery apparatus for carrying a plurality of balance weights for automobile wheels and delivering a suitable weight to an insertion device to fit the weight on the rim of a wheel in a predetermined circumferential position. The balance weights have parallel through bores and the insertion device includes a pair of spaced mandrels receivable in the through bores of the weights to carry the weights from a storage compartment to an automobile wheel and install the weight on the rim at the predetermined position. The apparatus includes a clip applying apparatus to force a retaining clip over the balance weight and the wheel rim to secure the weight to the rim.Type: GrantFiled: May 9, 1984Date of Patent: November 26, 1985Assignee: Gebr. Hofmann GmbH & Co. KG MaschinenfabrikInventor: Rembrandt Sander