Field of the Invention
The present disclosure is directed to couplers for railway cars, and more particularly, to a device for automatic horizontal positioning of a railway car coupler.
Description of Related Art
Railway cars include couplers for connecting adjacent cars to each other to form a train composition. Each coupler is adapted to swing within a predetermined angular range in a horizontal direction to facilitate car coupling and movement on a curved track. Adjoining car couplers are generally aligned to be on-center with the longitudinal axis of the railway car during a car coupling procedure. Due to variations in sizes of the cars and the type of coupler installed on each car, there may exist significant horizontal offsets between adjacent couplers in the lateral directions of the railway car. Such horizontal offsets are further compounded when attempting to couple adjacent railway cars on a curved section of a railway track. For instances in which coupling on a curved track is necessary, manual swing is typically required.
Existing couplers utilize pneumatically or hydraulically assisted coupler positioning devices capable of moving the car coupler within a predetermined angular range in a horizontal direction. Coupler alignment is achieved by a manual control input from an operator. Prior to the advent of hydraulic and pneumatic coupler positioning devices, coupler positioning was accomplished by spring centering elements having attachment points on the coupler head and the car body. The spring arrangement aligns the coupler with a longitudinal axis of the car to allow coupling on straight track sections. In order to connect adjacent cars on a curved track section, the springs are disconnected to allow the coupler on the first railway car to be manually moved into alignment with the coupler on an adjacent second railway car.
Several existing coupler positioning devices are known in the art. Each prior art coupler positioning device requires manual assistance while coupling on a curved section of the track. Some of the existing coupler positioning devices require a mechanical connection to the bogie, which is undesirable because it requires interfacing with the bogie and potentially induces large forces on the bogie during a collision that occurs when coupling cars. One such coupler positioning device is a pneumatic centering device that uses cylinders to ensure that the coupler is kept centered relative to a bogie and car body of a railway vehicle. The cylinders push against plates operatively connected to a coupler. By pushing on the plates, the coupler is kept in a centered position. If the coupler is moved in a horizontal plane towards one of the cylinders, that cylinder will push on one of the plates and push the coupler back into an on-center position. This coupler positioning device is not used to position the coupler in an off-center position. Likewise, another coupler positioning device keeps the coupler at a centered position at all times. This coupler positioning device includes cylinders are operatively connected to a rack and pinion system that moves laterally with regards to the coupler. Upon the coupler moving in one direction, an opposite cylinder pushes the rack and pinion system towards itself in order to place the coupler back in a centered position. Lastly, another coupler positioning device uses a traditional mechanical arrangement to keep the coupler centered relative to the body of the railway vehicle. In this coupler positioning device, springs are connected to the railway vehicle at one end and connected to the coupler at an opposing end. Upon the coupler moving to an off-center direction, a first spring is pulled in the off-center direction. Once the coupler stops moving, an opposing spring pulls the coupler back into a centered position. All of these coupler positioning devices are used to keep the coupler in a centered position to allow the coupler to couple to an adjacent coupler along a straight section of track. None of them contemplate moving and maintaining a coupler in an off-center position.