DE1922602A1 - Disc brake for vehicles - Google Patents

Description

relating to disc brakes for vehicles

The invention relates to a disc brake for vehicles, in particular agricultural tractors and machines to earthmoving.

The invention comprises a brake in which at least one disc rotatable within a stationary housing means a hydraulically actuated, annular piston which is seated in an annular recess in an end wall of the housing is arranged, is axially movable in frictional engagement with a stationary surface, and in which the disc or one of the Discs, if several discs are provided, has a cylindrical circumferential surface with which a band, which contract lets, is engageable.

The hydraulic actuation of the brake with the aid of the annular piston serves as a service brake, while the Band brake can be used as a parking brake.

The annular piston preferably does not wank over one rotatable, axially movable pressure plate on the rotatable disk or one of the disks. The pressure plate has a

009835/1129

automatic readjusting device, by means of which the rest position of the pressure plate is automatically readjusted, when the friction surfaces wear out, so that the pressure medium volume required to actuate the brake is essentially remains constant.

A ring of heat insulating material can be placed between the annular piston and the pressure plate, about the heat transfer when the brake is actuated from the braking surfaces to the piston and thus to the pressure medium to a minimum.

The invention and advantageous details of the invention are described below with reference to schematic drawings two embodiments explained in more detail.

Fig. 1 shows a section through a brake with a single rotatable disk, the section in one plane which extends at right angles to the axis of the brake;

Fig. 2 shows a section along the line 2-2 in Fig. 1;

Fig. 3 shows a section similar to FIG. 1, but represents. a modified brake with two rotatable discs;

Fig. 4 shows a section along the line 4-4 in Fig. 3

In the brake shown in Figures 1 and 2, a disc Io, which carries a ring 11 of friction material on each side, is axially on one by means of keyways 12 through a stationary housing 13 extending, rotatable Movable shaft attached. On one side of the disc, a non-rotatable pressure plate 14 is provided, which means an annular piston 15, which in an annular Recess 16 in an end wall 17 of the housing works, can be pressed against the disc. If the recess 16 behind the A pressure medium is supplied to the piston through an inlet 18,

009835/1129

the piston presses the pressure plate 14 against the adjacent surface of the disc, and the disc is axially brought into engagement with a radial braking surface 19 on the inside of the opposite end wall 21 of the housing, whereby the disc comes into frictional engagement between the pressure plate 14 and surface 19. A ring 22 made of heat insulating Material is arranged between the piston and the pressure plate in order to transfer heat to the pressure medium to a minimum.

The pressure plate is held against one rotation by pins which are fastened in the housing and with slots in Lugs 24 are engaged on the periphery of the pressure plate so that the plate can slide axially on the pin.

Adjusting screws 25 are provided for automatic readjustment of the brake to compensate for the wear and tear on the friction surfaces axially screwed through diametrically opposed lugs 26 on the pressure plate. These screws have heads 27, which are aligned with stops 28 on the end wall 17 of the housing while their other ends are adapted to against the end wall 21 of the housing.

The screws have multiple threads with a large pitch, and when the brake is actuated after the friction surfaces have worn down, the screws are engaged with the end wall 2'1 of the housing pushed as far through the pressure plate as it corresponds to the distance corresponding to the wear. After releasing the brake, the pressure plate returns to a new position, which is created by the engagement of the heads 27 the stops 2S is determined, with a rotation of the screws in the opposite sense by any known Kind of a spring clip or locking device is prevented.

The brake disc is extended radially beyond the braking surfaces and widened axially there by a cylindrical one

009835/1 1 29

Urafangsbremsflache 29 su bilfen. This braking surface is surrounded by a brake band 31, which by an angular movement a triangular plate 32 with which the ends of the belt are connected to the braking surface is attracted around. The triangular plate is mounted on a rotatable shaft 33, which can be operated by a hand lever.

In the modified embodiment of the brake shown in FIGS. 3 and 4, two rotatable, axially movable disks 3 ^ - and 35 are provided. A second, non-rotatable pressure plate J> 6 is arranged between the discs.

axial

The disc 34 offers only radial friction surfaces for engagement with the pressure plates, but the disc 35 »which is stronger in the axial direction than the disc 34 ·» is radially elongated and expanded to a cylindrical peripheral surface 37, which is used for Engagement with a brake band 38 is used.

Claims

009835/1129

Claims (5)

Patent to sayings IJ disc brake, characterized in that at least one disc (Io; 34, 35) within a stationary housing (13) is rotatable by means of a hydraulically operated, annular piston (15) »which works in an annular recess (16) in an end wall (17) of the housing, is axially movable in frictional engagement with a stationary surface (19), and that the disc (Io) or one of the Disks (35i if several disks are provided, one cylindrical Has circumferential surface (29; 37) with which a band brake (31 j 38) can be brought into engagement. 2. Disc brake, characterized by a disc (Io) which is slidably mounted on a rotatable shaft which extends through a stationary housing (13) having a first and second end wall (17, 21) in the right Has angle to the axis of the shaft, through an annular recess (16) in one end wall (17) of the housing (13), through an annular piston (15) »which works in the recess (16), through a non-rotatable pressure plate (14), which is axially slidably movably guided in the housing and is arranged between the piston and the disc (Io), a dem Pressure medium supplied to the piston moves the pressure plate and the disc in the axial direction and the disc is in frictional engagement with the other end wall (21) of the housing presses, through a cylindrical peripheral surface (29) on the disc, and through a band brake (31) suitable for engagement with this surface. 3. Disc brake, characterized by a first and a second, spaced apart Disc (34, 35) movable on a rotatable shaft are attached, which extends through a stationary housing (13) which has a first and a second end wall (17, 21) 009835/1129 upwards at right angles to the axis of the shaft, through an annular recess (16) in one end wall of the housing, through a hydraulically actuated, annular piston (15) which works in the recess, through a non-rotatable first pressure plate (14) which axially movably guided in the housing and arranged between the piston and the first disk {JA-) , by a second non-rotatable pressure plate (36), which is axially movably guided and is arranged between the disks (34, 35), with a piston supplied Pressure means presses the assembly consisting of the disks and pressure plates towards the other end wall of the housing, through a cylindrical peripheral surface (37) on the second disk (35) and through a band brake (38) suitable for engagement with this surface. 4. Disc brake according to one of the preceding claims, characterized in that a ring (22) of heat insulating material between the annular piston (15) and the pressure plate (14), on which the piston acts, is arranged. 5. Disc brake according to one of the preceding claims, characterized in that a device (21, 25-28) are provided for automatically adjusting the rest position of the pressure plate (14) on which the piston (15) acts that compensates for the wear and tear on the friction surfaces. 009835/1129 Blank page