Abstract: A latch for each of a pair of cushioning arms, respectively, of a stair-climbing wheelchiar. The latch for each arm includes a first member coupled to the arm and a second member coupled to a fixed support of the wheelchair, with the second member being coupled to the armature of a solenoid which is energized to unlatch the arm from latched relationship with the support when it is desired to use the arm for cushioning purposes. An ultrasonic transducer coupled to the wheelchair adjacent to each latch, respectively, provides signals to energize the respecting latch solenoid when the arm is to be unlatched. To latch each arm, the adjacent edge margins of the two members are bevelled so that, during upward movement of the arm, such as by movement of the wheelchair from an inclined position to a horizontal position, the members are spread apart and a first spring biases the two members back together in coupled relationship to each other.