The invention relates to an expansion joint for part of a railway track disposed on a foundation which has a stock rail with a stock rail head, web and foot and a tongue movable with respect to and along said stock rail, upon which tongue at least one fastening means acts to press it onto the head of the stock rail.
In known expansion joints, also designated as expansion devices and permitting a movement between the structure and the rail in the vicinity of bridges, for example, a positive connection is made to permit movement of the tongue relative to the stock rail. To this end, a tongue of solid rail profile can be fixed between the stock rail and a clamming jaw disposed stationarily on the opposite side. The foot of the tongue and that of the stock rail are disposed on a common foundation at the same level. As a result, the stock rail is supported substantially on the foundation only by the stock rail half facing away from the tongue. Instabilities are compensated for by the stock rail being attached with supports and angle pieces. This entails additional maintenance work.
A conventional rail joint is described in DE 30 16 492 A1, for example. There is a slight clearance between the clamping jaws and the facing web surface of the tongue, permitting the requisite movability of the tongue in relation to the stock rail. This too can led to tipping of the tongue or the rail.