Vehicle brake actuating systems

A power assisted pedal assembly comprising a lever pivotable about a fixed point, a brake pedal, a link having a first pivotal connection at one end with said lever and a second pivotal connection at the other end with said brake pedal, an actuating member adapted for connection to brake operating means and having a connection with said brake pedal intermediate the ends of said brake pedal whereby said brake pedal can apply a force to said actuating member along a predetermined line of action, and a power assisting means operable in response to movement of said brake pedal to apply an assisting force to said brake pedal said power assisting means having a force-transmitting member which is separate from said actuating member and which is in force-transmitting engagement with said lever and said link in the region of said line of action of the force applied to said actuating member by said brake pedal and so that said brake pedal, link and lever pivot about said fixed point when said power assisting means is operative, said pedal having a second pivot point intermediate said fixed point and said connection between said lever and said actuating member and means causing said pedal to pivot about said second point upon failure of said power assisting means.