BRAKE

Technical Field

The present invention relates to a parking brake arrangement for a rail vehicle bogie brake, comprising at least one rotatable means at or in the bogie for receiving a manually provided parking brake force, a cardan shaft for transmitting a rotational movement from the rotatable means to a gear box mounted on a brake beam, having at least one brake actuator, and transmitting means for transmitting the parking brake force to the actuator.

Background of the Invention

Typical examples of parking brake arrangements for bogie brakes are shown in DE 42 17 231 A, EP 1 097 075 B, US 6 186 284 B, and EP 1 457 401 B. In the first- mentioned and the last-mentioned of these, use is made of a hand wheel at the side of the bogie for the application and release, respectively, of the parking brake arrangement.

In EP 1 457 401 there are shown two different embodiments of a parking brake arrangement of the kind defined above. In the first embodiment of Fig 1 the bogie brake is generally conventional, whereas in the second embodiment of Fig 10 in combination with Fig 7 one of the brake beams is unconventional and contains two brake actuators. In both embodiments, however, the parking brake arrangements apply their application force to the piston or the pistons, respectively, of the brake actuators. This means that relatively complex means have to be provided in conjunction with the pistons for transforming a rotational movement from the hand wheel to a translational movement affecting the piston.

The main object of the invention is to maintain the general advantages of the arrangement disclosed in EP 1 457 401 while improving the transmittal of the parking brake force from the gear box into and past the brake actuator and providing a simplified design.

The Invention

This is according to the invention attained in that the transmitting means is an operating shaft having a spindle-and-nut arrangement for transforming the rotational movement from the gear box to a translational movement to a parking brake lever of the brake actuator, the lever being connected to the outgoing push rod of the actuator.

The rotatable means may be a hand wheel at the side of the bogie. Preferably, a hand wheel is preferably provided at each side of the bogie, and the brake beam is preferably provided with two brake actuators.

Brief Description of the Drawings

The invention will be described in further detail below under reference to the accompanying drawings, in which

Fig 1 is an isometric view of a rail vehicle bogie with a parking brake arrangement according to the invention,

Fig 2 is an isometric view of the bogie brake included in the bogie of Fig 1, Fig 3 is a detail view of a portion of the bogie brake of Fig 2 (with the housing of a gear box partly broken away), and

Fig 4 is a partly sectioned side view of a push shaft of the bogie brake of Fig 2. Detailed Description of Embodiments

Fig 1 shows a conventional rail vehicle bogie 1 comprising as its main constituents a bolster 2, two side frames 3 and - journalled in the side frames - two wheel sets 4.

The bogie 1 is provided with a bogie brake, further shown in Fig 2 and for example of the general type disclosed in EP-B-1 097 075. As is well known for any person skilled in the art, such a bogie brake comprises two brake beams 5 A and 5B. These beams are provided with brake blocks at their ends for braking engagement with the treads of the wheels and in the shown case suspended from the bolster 2.

Means are provided for service braking by pressing the two brake beams apart for accomplishing the braking engagement of the brake blocks with the wheel treads. In the present case these means are two normally pneumatically operated brake actuators or brake units 6 mounted in the fore brake beam 5 A and connected to the other brake beam 5B by means of push rods 6 ^' .

The present invention relates to a parking brake arrangement for the so far described bogie brake.

A rotatable means for receiving a parking brake force in the form of a hand wheel 7 is journalled for rotation at each side of the bogie 1. By means of a cardan shaft 8 the hand wheel 7 is connected to a gear box 9.

As appears most clearly in Fig 3, the gear box 9 is mounted on the fore brake beam 5 A, preferably centrally thereon. In Fig 3 the housing of the gear box 9 is partly broken away, and it appears that it contains gears for obtaining a suitable gear ratio between a rotational input shaft 10 from each of the preferably two cardan shafts 8 and a rotational output shaft 11 directed towards each of the two brake actuators 6. For the mounting of the gear box 9, the brake beam 5A is preferably provided with longitudinal, axial holes, which together with a mounting arrangement of the gear box 9 with a minor play on the brake beam 5 A allows a certain relative movement between gear box and beam. In this way a certain variation in brake block play at either side of the beam may be compensated for

The brake actuator 6 is provided with a rotationally arranged parking brake lever 12 in operational connection with its outgoing push rod 6', which thus is pushed out for parking brake actuation at counter-clockwise rotation of the lever 12.

The brake actuator 6 is for example of the type disclosed in US 3 995 537 B, where there is no operational contact between the parking brake lever 12 and the service brake piston in the actuator and the former acts on the outgoing push rod 6'.

The rotational output shaft 11 is connected to the lever 12 by means of a parking brake force transmitting means in the form of an operating shaft 13. As shown in Fig 4, the operating shaft 13 is a spindle-and-nut-arrangement for transforming a rotational movement from the output shaft 11 into a translational movement to the parking brake lever 12. In the shown arrangement the operating shaft 13 is a push shaft, but it may alternatively be a pull shaft.

The above-mentioned "floating" mounting of the gear box 9 has the effect that no unfavorable forces will be introduced in the gear box at the possible occurrence of different strokes for the two parking brake levers 12, but that rather the gear box 9 will move slightly laterally on the brake beam 5. Also, the forces in the operating shaft 13 will be the same, resulting in the same brake forces on the two brake actuators 6.

By means of the shown and described parking brake arrangement, a manual rotation of the hand wheel 7 (preferably in the clockwise direction) will result in a translation movement to the parking brake lever 12 on the brake actuator 6, so that the brake blocks are manually applied to the wheel treads for parking braking. A release of the parking brake is performed by turning the hand wheel 7 in the opposite direction.

In the shown and described embodiment there are hand wheels 7 at either side of the bogie 1, and the brake beam 5 A is provided with two actuators. Other

embodiments with regard to the number and positioning of these means are possible.

In a second embodiment, not shown in the drawings, a hand wheel for applying the parking brake force is provided outside the bogie, for example on an end platform of the rail vehicle on which the bogie is mounted. In such a case the bogie may be provided with a rotatable means for receiving the parking brake force from the hand wheel and applying it on the cardan shaft. Further modifications are possible within the scope of the appended claims.