Device for lowering the pantograph arms of an overhead bus current collector

Abstract

Device for lowering the pantograph arms (2) of an overhead bus pantograph, wherein each pantograph arm (2) is joined to an independent turntable (1) by means of a joint, wherein a lifting spring (4) is installed between the turntable (1) and each of the pantograph arms (2), and wherein the pantograph arms (2) are provided with a locking shoe (21), characterized in that a stop (64) is directed against the locking shoe (21), through which a linkage (6) is closed, which is joined to the turntable (1) by means of a joint, wherein a compressed air bellows (3) is arranged between the turntable (1) and the linkage (6), wherein the pantograph arms (2) are not connected to the linkage (6).

Description

[0001] The invention relates to a device for lowering the pantograph arms of an overhead bus pantograph according to the preamble of claim 1.

[0002] Originally, the pantograph arms were lowered manually. This was done by pulling a cord attached to the end of each arm, overcoming the resistance of springs. The manual movement engaged the arms with upward-pointing hooks. The loosened cord was then wound onto a winch mounted on the rear of the vehicle body. This operation required the operator to leave the vehicle, which first had to be secured, regardless of the weather conditions.

[0003] In older trolleybus pantographs, a pneumatic cylinder is inserted between the rotating disc (which forms part of the frame) and the free end of the pantograph arm. This is a simple solution. However, at higher trolleybus speeds, the catenary curve of the overhead line sag causes the pantograph arm to oscillate. The mass of the pantograph arm is increased by the mass of the piston moving within the pneumatic cylinder. Therefore, the dynamic action of the piston and piston rod masses can easily lead to the pantograph shoe separating from the overhead line.

[0004] The device described in CZ 299 211 B6 for lowering the pantograph arms of the trolleybus is known, in which the pantograph arms are connected to a turntable, which is part of the frame, by means of a hinge. Between the frame and each pantograph arm, a lifting spring is located on one side and a tiltable pneumatic cylinder on the other. The piston rod of this cylinder is connected by a hinge to an arm on the pantograph arm. The arm is connected by a hinge to the pantograph arm, on which a locking shoe is located for the end of the respective arm, with its contact area against the piston rod of the pneumatic cylinder. The arm is provided with a metal-rubber element for contact with the locking shoe.During the pantograph's operation, when the pantograph shoe is in contact with the overhead line, the piston rod of the pneumatic cylinder is retracted, thus lifting the arm from the pantograph's locking shoe. The dynamic effect of the pneumatic cylinder's mass on the pantograph's rod is minimized, as the pneumatic cylinder and the pantograph's rod only move in a pendulum motion, while the piston and its rod remain in a stable position relative to the pneumatic cylinder. Despite the demonstrable benefit to the interaction between the shoe and the overhead line, the pneumatic cylinder also introduces disadvantages due to its mass. This is because the design utilizes the relative displacement of the piston and its rod mass compared to the mass of the pneumatic cylinder. Finally, the design also takes advantage of the pneumatic cylinder's own mass resulting from its attachment to the pantograph's rod.

[0005] WO 00 / 41 908 A1 discloses a device for lowering the pantograph arms of a trolleybus current collector. Each pantograph arm is connected to an independent turntable by means of a joint. A compressed air bellows is arranged between the turntable and each pantograph arm, which raises the pantograph arm when compressed air is applied.

[0006] JP S55 - 46 805 A discloses a device for lowering an overhead line locomotive pantograph, consisting of four lower arms articulated to a base, four upper arms articulated to these lower arms about pivot axes, and a pallet with two contact strips articulated to each other about a pivot axis. The lower arms are arranged as opposing pairs of lower arms opposite the base, allowing them to be lowered about their own parallel pivot axes. The base is designed for non-rotatable mounting on the locomotive roof relative to a longitudinal axis of the locomotive. All pivot axes of the pantograph run horizontally and parallel to each other, perpendicular to the longitudinal axis of the locomotive. In the raised position, the contact strips of the pantograph rest against a live overhead line. A lifting spring is installed between the base and one of the lower arms. A locking shoe is arranged on another lower arm.A stop is directed against the locking shoe by a compressed air cylinder, which can be pressurized with compressed air via a compressed air line and is joined to the base. The object of the invention is to create a device for lowering the pantograph arms of an overhead line pantograph in which the movable masses of the linkage have a negative influence on the pantograph arms and therefore cannot negatively affect their movement.

[0007] The invention relates to a device for lowering the pantograph arms of an overhead line current collector, in which each pantograph arm is connected to an independent turntable by means of a joint. A lifting spring is located between the turntable and each pantograph arm, the pantograph arms being equipped with a locking shoe. According to the invention, a stop, generally a rubber-metal element, is directed against the locking shoe. A linkage, connected to the turntable by means of a joint, terminates at the stop. A compressed air bellows is arranged between the turntable and the linkage. Compared to a pneumatic cylinder, the compressed air bellows reduces the mass as well as the acquisition and maintenance costs. The moving masses of the linkage are in no way connected to the pantograph arm, as they do not have any negative influence on its movement.

[0008] The shorter stroke of the pneumatic bellows compared to the pneumatic cylinder is compensated for by a linkage consisting of a pivot lever connected to the rotary table via a joint, against which the pneumatic bellows rests, and a rocker arm with a stop, which is connected to the piston rod via a joint. The relative positions of the pivot lever and rocker arm allow for optimal force transmission from the stop to the locking shoe, thus utilizing the advantageous properties of the pneumatic bellows.

[0009] If the compressed air bellows is arranged vertically between the turntable and the linkage, it does not increase the overall height of the turntable and ensures sufficient access for overhauls and maintenance of this part of the trolleybus pantograph.

[0010] The invention will be explained in more detail with reference to the drawings and an exemplary embodiment. The drawings show... Fig. 1 and Fig. 2 the perspective view of the trolleybus pantograph, Fig. 3 the top view of the relevant part of the trolleybus pantograph, Fig. 4 the side view, and Fig. 5 the front view from the side of the compressed air bellows.

[0011] Each pickup rod 2 is connected by means of a joint to an independent turntable 1 mounted on a frame 5. A lifting spring 4 is located between the turntable 1 and each pickup rod 2. The pickup rods 2 are provided with a locking shoe 21 on top. A stop 64 is directed against the locking shoe 21, through which a linkage 6, connected to the turntable 1 by means of a joint, is terminated. A compressed air bellows 3, arranged vertically, is located between the turntable 1 and the linkage 6. The linkage 6 consists of a pivot lever 61, connected to the turntable 1 by means of a joint, and a rocker arm 62, which is provided with a stop 64 and to which the pivot lever 61 is connected by means of a connecting rod 63. The pivot lever 61 rests against the compressed air bellows 3 and is articulated to the rocker arm 62 by means of the connecting rod 63.

[0012] When the pickup rods 2 are lowered, the pneumatic bellows 3 is pressurized with compressed air. The pneumatic bellows 3 then begins to act on the pivot lever 61, which is part of the linkage 6. As the pivot lever 61 pivots around a pin, which connects it to the turntable 1 via a hinge, the rocker arm 62 is pushed away by the connecting rod 63. The rocker arm 62 is also connected to the turntable 1 via a hinge. This movement causes the stop 64, which typically consists of a rubber-metal element, to move closer to the locking shoe 21, which is fitted to the pickup rod 2 from above. This overcomes the tensile force exerted by the lifting springs 4. The pickup rods 2 are lowered and clamped into brackets at the rear of the trolleybus. The air is then released from the compressed air bellows 3.

Claims

[1] Device for lowering pickup rods (2) of a trolleybus current collector, each pickup rod (2) being joined to an independent turntable (1) by means of a joint, a lifting spring (4) being installed between the turntable (1) and each of the pickup rods (2), and the pickup rods (2) being provided with a locking shoe (21), characterized by that a stop (64) is directed against the locking shoe (21), by means of which a rod assembly (6) is closed off, which rod assembly is joined to the turntable (1) by means of a joint, a compressed air bellows (3) being arranged between the turntable (1) and the rod assembly (6), the pickup rods (2) not being connected to the rod assembly (6). [2] Device according to claim 1, characterized bythat the rod (6) consists of a pivoting lever (61) which is joined to the turntable (1) by means of a joint and leaning against the pneumatic bellows (3), and of a rocker lever (62) provided with a stop (64) which is joined to the pivoting lever (61) in an articulated manner by means of a connecting rod (63). [3] Device according to claim 1 or 2, characterized by that the compressed air bellows (3) is arranged vertically between the turntable (1) and the rod (6). [4] Device according to claim 1, 2 or 3, characterized by that the pickup rods (2) are provided with the locking shoe (21) from above.

Images