Patent GB-698726-A (GB)
Title: Improvements in or relating to disc brakes
IPC: F16D55/14
Filed: 1952-04-02
Abstract: 698,726. Disc-brakes. LAMBERT BRAKE CORPORATION. April 2, 1952 [July 24, 1951], No. 8447/52. Class 103 (i). A brake mechanism comprises a rotary member to be braked, a braking unit composed of a pair of relativelyrotatable back-to-back discs frictionally engageable with and disengageable from the rotary member, each disc having at least one seat for an actuating plunger, the seats being arranged in opposed relationship, a fixedly-mounted actuator cylinder arranged between the seats and having opposed pistons each adapted to act on one of the said plungers for rotating one disc relatively to the other, and means between the discs for increasing their spacing or spreading the same in response to such relative movement to frictionally engage the rotary member. In one form of the invention shown in Fig. 1, the double disc assembly 12 is concentrically located by two diametrically opposed actuator cylinders 7 and 8 of the double-acting type having rocker pin plungers 18 and 20 which are actuated by pistons 9 and 10 respectively and act on lugs 17 and 19 respectively which are provided on the double disc unit 12. The cylinders form anchoring abutments at 22 and 23 for the respective discs, one at a time, according to the direction of rotation of the rotary housing 1 to be braked. Thus, one disc is held against rotation while permitting the other disc to have a limited rotary movement relative to the relatively stationary disc for the purpose of producing axial separation of the discs, against the action of the springs 14, responsive to the camming action of the balls 13 that are disposed between the discs and are seated in opposed ramped ball seats 15 in the opposed faces of the discs. Springs 25 and 26 are provided to assist springs 14 in restoring the two discs of the double disc unit 12 to their normal brake-released position and automatic adjusters 24 are provided to take up any wear between the friction surfaces of the brake. A strip of heat-resistant insulation 21 is attached to each of the cylinders 7, 8 so as to prevent transfer of heat from the discs to the hydraulic fluid in the cylinders. The forgoing construction is known as a " semifloating " mounting. In a preferred embodiment shown in Fig. 2, the arrangement of the double disc assembly unit and the cylinders is similar to that described in the foregoing, but is characterised by a completely free and " fullfloating " mounting of the double disc assembly 12<SP>1</SP> about improved actuator cylinders 7<SP>1</SP>, 8<SP>1</SP> throughout the braking action. According to this preferred embodiment, the double-disc unit is only generally located about the cylinders 71, 8<SP>1</SP> which may be displaced 90 degrees from the position shown in Fig. 1, without any direct frictional contact therewith, the discs being supported upon universally movable rocker plungers 18<SP>1</SP>, 20<SP>1</SP> which in turn are rockably seated on pistons 9<SP>1</SP>, 10<SP>1</SP> respectively in the cylinders. Alternate anchoring of the respective discs according to the direction of rotation of the rotary part to be braked is accomplished by alternate abutment of the pistons against the cylinders as the pistons reach the limit of their inward travel. An improved lay-out of the hydraulic lines which supply fluid to the actuator cylinders 7<SP>1</SP>, 8<SP>1</SP> is incorporated in the preferred embodiment. Reference is made to U.S.A. Specifications 2,526,149 and 2,555,651 to enable the reader to gain a fuller understanding of the advantages of double disc brakes.