Electric heating – Heating devices – Combined with diverse-type art device
Patent
1996-04-18
1998-09-08
Walberg, Teresa J.
Electric heating
Heating devices
Combined with diverse-type art device
104 2, H05B 100, E01B 708
Patent
active
058047930
DESCRIPTION:
BRIEF SUMMARY
This invention refers to an apparatus for heating railway rails during the laying down thereof.
When a long rail section is laid down in conditions of constrained thermal expansion, according to the presently preferred art, in order to prevent the troubles which, when the temperature of the rail changes, could be caused by an excessive expansion or contraction with respect to the conditions at the time of laying down, it is needed that the condition of absence of longitudinal strain (the so-called "null strain condition") in the rail is made to correspond to a prefixed temperature which, for example, for certain railway systems is prescribed to be 30.degree.C..+-.3.degree. C. It would be immediate to obtain this condition if one could effect the laying down of the rails and the tightening of the means for fixing the same to the ties when the rail temperature corresponds to this prefixed temperature but, in general, suitable environment conditions for doing so are not verified, and the actual temperature of laying down is lower than the prescribed temperature; therefore, conventionally the so-called "regulation" of the rail is effected, which comprises applying to the rail, by means of a mechanical traction, an expansion calculated in such a manner as to generate in the rail the same internal strain conditions which would be verified, in the same temperature conditions, in case the rail would have been laid down at the prescribed temperature.
According to a manner of operation, which can be deemed the most usual one, when replacing the rails, some rail sections of unitary length, usually in the length of 36 meters as they come from the hot-drawing, are laid down and fixed without welding them, thus forming a railway track which is temporarily used in these poor conditions. At a later time these rail sections are welded together to form sections separated from the one another by a free joint intended to form the regulation point, and the members for fixing the rails to the ties are loosened. Special tensioning clamps are installed in the regulation point, and by means of them the facing ends of the sections are drawn the one towards the other until the rail section receives an extension calculated as the product of the section length multiplied for the thermal expansion coefficient of the rail and for the difference between the actual temperature of the rail at the time of the regulation, and the prescribed temperature. At this point, the facing ends of the rail sections are welded together and all the members for fixing the rail to the ties are tightened.
The described operations require interrupting the traffic of the trains on the considered railway track; both the needed operations and the time during which the traffic is interrupted give rise to a heavy economical, technical and organization burden, as well as the period during which the traffic takes place on the poor railway track formed before the regulation, also involving a certain degree of danger; whereby the rail regulation still represents an open problem.
It would therefore be highly desirable that the regulation of the rails forming a railway track could be effected at the same time as their laying down, by heating the rails until a temperature higher than the environmental one, in order that the tightening of the members connecting the rails to the ties could take place at the very prescribed temperature. To this aim it has been proposed to heat the rails during their laying down by means of free flames, of heating apparatuses acting by irradiation or by electric induction means, but no one of these means allows obtaining a sufficient evenness in the rail heating along the whole length of the considered section; moreover, the needed installations are too expensive. It has also been proposed, in general, to heat the rails by means of the Joule effect, by having an electric current pass through the rails. However, even if this principle is very rational in theory, it has turned out that by proceeding, as it appears obvious, with alternating cu
REFERENCES:
patent: 3793544 (1974-02-01), Baumgartner et al.
patent: 3896734 (1975-07-01), Plasser et al.
patent: 3999276 (1976-12-01), Brown et al.
patent: 4339704 (1982-07-01), McSparran et al.
patent: 4429845 (1984-02-01), Stover et al.
patent: 4656333 (1987-04-01), Murphy
patent: 4815052 (1989-03-01), Walker
patent: 5004190 (1991-04-01), Montierth et al.
patent: 5181472 (1993-01-01), Scheuchzer
patent: 5299504 (1994-04-01), Abele
Paik Sam
Walberg Teresa J.
LandOfFree
Apparatus for heating rails during the laying down thereof does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for heating rails during the laying down thereof, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for heating rails during the laying down thereof will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1283788