The invention relates to a device for selectively transmitting force, the device comprising a first element and a second element that is movably mounted on the first element, a friction member being arranged between the first element and the second element to exert a friction force between them, which force presents a maximum value that depends on prestress imparted by a presser member. The device includes control means for varying the prestress imparted by the presser member to the friction member and arranged, where appropriate, to substantially release the prestress imparted by the presser member so that the prestress becomes substantially zero.