Patent GB-464130-A (GB)
Title: Improvements in friction brakes
IPC: F16D51/02
Filed: 1935-08-06
Abstract: 464,130. Brakes; friction clutches. KOWALSKI, L. Aug. 6, 1935, No. 22184. [A Specification was laid open to inspection under Sect. 91 of the Acts, Feb. 7, 1936.] [Class 103 (i)] [Also in Group XXIV] A drum 1 is braked by a split friction ring 2 which is movable freely in the peripheral direction, while being located endwise by cheeks or flanges, and which is pressed against the drum 1 by a divided pressure ring 3 whose diameter is varied by mechanical or hydraulic means acting thereon at points removed from the split part or parts thereof. The ends of the ring 3 are chamfered and overlapped, and the ends of the ring 2 are rounded. As shown in Fig. 1, the mid-point of the split ring 3 is secured with radial play to a fixed part by a pin-and-slot connection 7, 8, the ring 3 being normally contracted against adjustable eccentric stops 10 by a spring 9 and being expanded by introducing pressure fluid into a cylinder 5 between a pair of pistons 6 acting on lugs 4 of the ring 3. Alternatively, the ring 3 may be expanded by a cam acting on the lugs 4. As shown in Fig. 3, the ring 3 is in the form of a number of segments, each connected by an arm 3a to a common rotatable actuating ring 3b. In other constructions, automatic adjustment for wear is provided. Thus, as shown in Fig. 7, one end of the split ring 3 has internal ratchet teeth 16 engaged by a spring-loaded pawl 18, the pivot pin 20 of which engages in a slot 21 in the other end of the ring 3, whereby the contraction of the latter is limited by the length of the slot 21. Each end carries an eccentric 23 which is urged by a spring to rotate in one direction and which is prevented from rotation in the other direction by a pawl 25. The actuating shaft 28 carries two eccentrically-disposed rollers 26 of different diameter co-operating with the eccentrics 23, the larger roller coming into operation before the smaller. The ring 3 has circumferential play at its mid-point connection 13, 14. In another form, the actuating shaft 28, Fig. 9, has an arm 36 to which is pivoted one end of a rod 37 guided in a forked member 39 pivoted to the left-hand end of the ring 3, the rod passing through a spring-loaded plate 41 tiltably arranged between the forks so as to act as a one-way clamp. A rod 46, having a slot 47 engaging a pivot pin 45 in the left-hand end of the ring 3, is guided in a forked member 48 pivoted to the right-hand end of the ring 3 and passes through a spring-loaded plate 51 tiltably arranged between the forks to act as a one-way clamp acting in the opposite direction, whereby the contraction of the ring 3 is limited by the length of the slot 47. Alternatively, the rod 37 may be actuated by a fluid-operated piston. The form shown in Fig. 12 is similar to that shown in Fig. 9, but the arm 36 is linked to a pair of toggle links 55, 55<1>, the link 55 being pivoted to the left-hand end of the ring 3 while the link 55<1> is connected to the rod 37, the co-operating clamping member 39 of which is pivoted to the right-hand end of the ring 3, and is also connected by link 57 to the right hand end of the ring. Thus, expanding force is transmitted to both ends of the ring 3. In another construction, the rings 2 and 3 are external to the drum 1, the ring 3 being contracted by a lever mounted on one end thereof, one end of the lever being connected to an operating rod while the other end is linked to the other end of the ring. The Specification as open to inspection under Sect. 91, states that the device may be used as a clutch, and comprises also a construction similar to that shown in Fig. 1, but in which the pistons 6 act directly on the ends of the ring 3, the curved outer side of the cylinder 5 bearing against the ring 2. This subject-matter does not appear in the Specification as accepted.