This invention relates to securing devices for securing a railway-type rail, typically but not exclusively a bullhead type rail, in a rail chair.
Many sections of railway track still use bullhead type rails which are secured in position by means of what are known as chairs in which the rails sit and held against lateral movement by securing devices commonly known as rail keys. A known type of securing device or rail key is described in GB-A-2102478 and comprises an elongate piece of sheet metal which has been bent to provide a central portion having first and second locking portions at its opposite extremities and first and second end portions which are joined together by the central portion and the locking portions. The clip is arranged so that when the bullhead rail is standing in a standard bullhead rail chair the clip can be driven in a direction substantially parallel to the length of the railway rail so that it moves into the space between the web of the rail and the facing surface of a wall upstanding from the base of the chair.
When in position one of the locking portions engages around one edge of the wall of the chair and the other engages around the other edge of the wall of the chair, and the end portions of the clip engage one side of the web of the rail and urge the rail away from the surface of the chair so that the side of the web is maintained in contact with a joint in order to prevent lateral movement of the rail in use.
Such clips have been in use for a considerable period of time, but have been found to be subject to failure particularly under conditions of high lateral loading on the rails. The present invention is concerned with an improved type of securing device which is not prone to such failure.