Patent ID: 7850195
Filing Date: 2010-12-14
Classification: B60G,Y10T

Abstract:
1. A tandem suspension for connecting a chassis of a vehicle to front and rear axles, the front and rear axles being steerable, the tandem suspension comprising, on each side of the vehicle: a front leaf spring linking the chassis and the front axle, the front leaf spring having first and second extremities and the front axle being mounted therebetween, the first extremity of the front leaf spring engaging the chassis; a rear leaf spring linking the chassis and the rear axle, the rear leaf spring having first and second extremities and the rear axle being mounted therebetween, the first extremity of the rear leaf spring engaging the chassis; an equalizer assembly mounted to the chassis for equalizing the front and rear axles, the equalizer assembly linking the respective second extremities of the front and rear leaf springs; a front air spring disposed between the chassis and the front axle; a rear air spring disposed between the chassis and the rear axle; a pneumatic control system pneumatically linked to the front and rear air springs for supplying pressurized gas thereto and operable to selectively unload one of the front and rear air springs such that the one of the front and rear air springs does not take the load of the vehicle, the pneumatic control system comprising: a switch for sending a control signal to the pneumatic control system in response to an action by an operator, the pneumatic control system being responsive to the sending of the control signal by selecting the second mode of operation of the three-way valve and thereby selectively unloading the one of the front and rear air springs.