GB206213A - Improvements in brakes - Google Patents

Abstract

206,213. Cole, T. H. July 29, 1922. Actuated by backward pressure of tractor or relaxation of pull; actuated by springs and weights; force-transmitting mechanism.-Brake mechanism for trailer vehicles, of the kind described in Specification 188,845 whereby the brakes are automatically applied when the tractive force is relaxed is adapted to give a braking pressure dependent upon the load as well, it may be, as upon the gradient. The lever a, Fig. 1, pivoted at a<1> on a pin carried by a pair of rods b is connected bv the rod e<1> to one end of the brake application spring e, the other end of which is held by an adjusting nut f<2> provided with a handle f<3> and abutting against a fixed bracket f<1>. The lever a is connected at a<3> to the balance bar g the ends of which are connected by rods g<2> to levers d<1> mounted upon the bearing springs d<2> and adapted to apply the brakes. The rod h by which the brakes are taken off when the tractive effort is applied to the draw-bar i<1> is also con.. nected to the lever a. This rod is coupled to the frame i by a nut and screw device h<4> which has the thread removed at the sides so that the nut may be slid on to the rod and the threads on these parts be then engaged by a quarter turn of the nut. Lugs h<5> on the nut are adapted to abut against bars h<2>, h<3> on the forward section of the rod h in such a manner as to permit freedom for longitudinal movement of the rod. The rod is jointed at h<6> and is supported when uncoupled by a depending rod h<8>. To render the braking pressure dependent upon the load, the sliding or shackled ends of the springs d<2> are disposed forward so that the axle moves forwardly in relation to the body as the load increases and thus increases the tension of the spring e when the brake is applied. Fig. 2 shows an arrangement in which the brakes are applied by a weight movable along a lever as described in the prior Specification modified to render the braking pressure dependent upon the load. The weight k<1> is suspended by rollers from the lever k which is fulcrummed at k<2> on brackets ! l secured to the axle and has a vertical arm which is slidably engaged with the balance bar n suspended from the body by links n<2> and connected by rods n<1> and levers o<1> to the brakes r. Vertical displacement of the body due to variation of the load thus effects a corresponding variation in the effective length of the vertical arm of the lever k. Bowden cable connections for the brakes may be employed and in one arrangement for operating rear wheel brakes the Bowden cable extends from the point a<2> of a lever such as a, Fig. 1, to a horizontal lever pivoted upon the draw-bar frame. This lever is connected also to the pawl frame i and to the forward end of the brake application spring, the rear end of this spring being connected to the front member of the fore carriage. The abutment for the rear end of the cable may be provided on the front cross-member of the body.