Apparatus for use in balancing motor vehicle and other wheels

Claim 2

Apparatus for detecting unbalance in motor vehicle and other wheels, comprising a rotatable shaft, means for resiliently supporting said shaft in two reaction zones which are spaced lengthwise of the shaft so that a free end portion of the shaft projects beyond one of said reaction zones, means for mounting an unbalance wheel to be tested on the free end portion of said shaft, transducer means located in each said zone for sensing motion of said support means, electrical circuitry means associated with said transducer means for producing an electrical analogue by vibrations to which the shaft is subjected during rotation of the unbalanced wheel and for using said electrical analogue to determine the magnitude and operative positions of balance weights that may require to be fitted in inner and outer balancing planes coinciding substantially with the inner and outer rim portions of the wheel being tested, means for effecting relative movement between said wheel mounting means and said shaft and said reaction zones so that the inner balancing plane of the wheel may be located in substantially the same plane extending transversely of the shaft axis as that of the adjacent reaction zone, means for rotating the shaft at a predetermined speed which is lower than the natural oscillating frequency of the shaft and its supporting means so that the system is high tuned, and operative connections including said transducer means extending between the shaft supporting means in each said zone and said electrical circuitry means, whereby during rotation of the shaft and the wheel carried thereby, the resultant signals produced by the dynamic components of the reaction in the shaft support means in each said zone are evaluated by said electrical circuitry means and utilized to determine during a single wheel testing operation, the respective magnitude of at least two balance weiGhts that may require to be fitted respectively to the inner and outer rim portions of said wheel to balance the same.

Claim 3

Apparatus according to claim 1, wherein said shaft supporting means includes a main body member and opposite end portions which are partially separated from and flexibly connected to said main body member, a rigid base structure on which each of said opposite end portions is mounted, said main body member being provided with bearings for said shaft.

Claim 4

Apparatus according to claim 1, wherein said shaft is mounted in a housing having a main body member and opposite end portions which are partially separated from and flexibly connected to said main body member, a rigid base structure on which each of said opposite end portions is mounted, said main body member being provided with bearings for said shaft, one of said transducer means being connected to each of the opposite end portions of said housing.

Claim 5

Apparatus according to claim 1, wherein said electrical circuitry means also includes means adapted to be influenced by said signals for visually indicating the operative positions of the balance weights that may be required to be fitted on the inner and outer balancing planes of said wheel.

Claim 6

Apparatus according to claim 1, wherein said shaft is of telescopic construction including a sleeve in which a main shaft carrying the wheel mounting means is slidable lengthwise, means for retaining said main shaft in the desired operative position after adjustment within its sleeve and means for releasing said retaining means in accordance with requirements.

Claim 7

Apparatus for detecting unbalance in motor vehicle and other wheels, comprising a rotatable shaft, means for resiliently supporting said shaft in two reaction zones which are spaced lengthwise of the shaft so that a free end portion of the shaft projects beyond one of said reaction zones, means for mounting an unbalanced wheel to be tested on the free end portion of said shaft, transducer means located in each said zone for sensing motion of said support means, electrical circuitry means associated with said transducer means for producing an electrical analogue by vibrations to which the shaft is subjected during rotation of the unbalanced wheel and for using said electrical analogue to determine the weight and operative positions of balance weights that may require to be fitted in inner and outer balancing planes coinciding substantially with the inner and outer rim portions of the wheel being tested, means for effecting relative movement between said wheel mounting means and said shaft and said reaction zones so that the inner balancing plane of the wheel may be located in substantially the same plane extending transversely of the shaft axis as that of the adjacent reaction zone, means for rotating the shaft at a predetermined speed which is lower than the natural oscillating frequency of the shaft and its supporting means so that the system is high tuned, and operative connections including said transducer means extending between the supporting means in each said zone and said electrical circuitry means, said transducer means and the associated electrical circuitry means being adapted to convert the dynamic components of the forces acting on said shaft supporting means while said wheel is rotating into two electrical signals of amplitude and phase representative of the magnitude and direction of such forces, said electrical circuitry means including processing means for the evaluation of said signals, said processing means including voltage divider means for evaluating the imbalance in the outer balancing plane, said voltage divider means being electrically connected to the transducer means associated with the shaft supporting means in the reaction zone remote from said wheel and being adjustable to such a setting as is representative of the ratio of the distance between the two reaction zones and the distance between the inner and outer balancing planes of said wheel, said processing means also being adapted to enable evaluation of the imbalance in the wheel as referred to its inner balancing plane to be determined by electrical summing means, whereby a proportion of the signal derived from the shaft supporting means in the adjacent reaction zone is summed with a signal derived from the shaft supporting means in the remote reaction zone and which is processed in an electrical network including said voltage divider means, while still adjusted at said setting, said resultant signal being representative of the imbalance related to the inner balancing plane of said wheel.

Claim 8

Apparatus for detecting unbalance in motor vehicle and other wheels, comprising a rotatable shaft, means for resiliently supporting said shaft in two reaction zones which are spaced lengthwise of the shaft so that a free end portion of the shaft projects beyond one of said reaction zones, means for mounting an unbalanced wheel to be tested on the free end portion of said shaft, transducer means located in each said zone for sensing motion of said support means, electrical circuitry means associated with said transducer means for producing an electrical analogue by vibrations to which the shaft is subjected during rotation of the unbalanced wheel and for using said electrical analogue to determine the weight and operative positions of balance weights that may require to be fitted in inner and outer balancing planes coinciding substantially with the inner and outer rim portions of the wheel being tested, means for effecting relative movement between said wheel mounting means and said shaft and said reaction zones so that the inner balancing plane of the wheel may be located in substantially the same plane extending transversely of the shaft axis as that of the adjacent reaction zone, means for rotating the shaft at a predetermined speed which is lower than the natural oscillating frequency of the shaft and its supporting means so that the system is high tuned, and operative connections including said transducer means extending between the supporting means in each said zone and said electrical circuitry means, said transducer means and the associated electrical circuitry means being adapted to convert the dynamic components of the forces acting on said shaft supporting means while said wheel is rotating into two electrical signals of amplitude and phase representative of the magnitude and direction of such forces, said electrical circuitry means including processing means for the evaluation of said signals, said processing means including voltage divider means for evaluating the imbalance in the outer balancing plane, said voltage divider means being electrically connected to the transducer means associated with the shaft supporting means in the reaction zone remote from said wheel and being adjustable to such a setting as is representative of the ratio of the distance between the two reaction zones and the distance between the inner and outer balancing planes of said wheel, said processing means also being adapted to enable evaluation of the imbalance in the wheel as referred to its inner balancing plane to be determined by electrical summing means, whereby a proportion of the signal derived from the shaft supporting means in the adjacent reaction zone is summed with a signal derived from the shaft supporting means in the remote reaction zone and which is processed in an electrical network including said voltage divider means, while still adjusted at said setting, said resultant signal being representative of the imbalance related to the inner balancing plane of said wheel.