US2087731A - Rail for heat treating furnaces - Google Patents

Description

y 1937- H. KLOUMAN 2,087,731

RAIL FOR HEAT TREATING FURNACES Filed June 15, 1956 O wocDgQ o oQ wowgg 20 Patented July 20, 1937 UNITED STATES PATENT OFFICE RAIL FOR HEAT TREATING FURNACES Application June 13, 1936, Serial No. 85,089

4Claims.

Iron pipe made by centrifugal casting and such like are usually heat treated to relieve any strains in and to anneal the metal before they are put in service. In a familiar furnace used for that treatment the pipes are rolled through the furnace chamber on several rails, sometimes required to align on top within plus or minus one sixtyfourth (1/64")of an inch. As the temperature changes are great and frequent, any tendency of the rails to distort is fostered and in consequence there has been much diiiiculty in maintaining the required tolerances.

Heretofore furnace rails have usually been in the shape of a channel with the flanges turned down and the web forming the supporting surface. When such a rail is made of heat resistant alloy (which cannot be rolled) it must be cast.

In a channel section the corners forming the juncture of the flanges and the web solidify and cool more slowly than the other extremities of the section.

Retarded solidification and cooling cause respectively internal shrinkage at the said juncture and a non-uniform rate of contraction in the casting as a whole, the immediate result of which is a tendency to bow the rail and distort the surface of the web from a true plane, sometimes raising one edge and sometimes lowering it, rela tive to the other. The pattern for a channel 0 rail of heat resistant alloy can be arched to anticipate the sag, but the distortion is beyond .control.

The principal object of this invention is to provide a rail that can easily be made true and that will maintain its supporting surface in use. This is accomplished by making the rail of a plurality of vertical webs connected at intervals by cross webs but preserving symmetry at every cross section.

A preferred embodiment of the invention is shown in the acompanying drawing in which- Fig. 1 is a diagrammatical perspective of a heat treating furnace for cast iron cylinders;

Fig. 2 is a plan view of one of the furance rails;

Fig. 3 is a side elevation of one of the rails and the upper portions of five supporting chairs, shown in section;

Fig. 4- is a cross section on the line l4 of Fig. 3, and

Figs. 5, 6 and 7 are diagrams illustrating distortions and deformations in channel shaped rails.

But the drawing and the description are used for the purpose of illustration only and the invention may be embodied in other forms.

The furnace chamber is enclosed by walls ill, a top I I, and a floor H, the latter being equipped with several rails l3 running lengthwise through the furnace chamber and extending slightly above the surface of the floor.

The cylinders i l to be treated are rolled along the rails by fingers I5 on conveyor chains i6 running over sprockets H. The cylinders reach the furnace by rolling along approach rails l8, leading to the receiving end of the conveyor.

Each furnace rail l3 comprises four vertical webs IS in spaced relation and integral with cross connecting webs 20, spaced along their length. The corners of the intersections are filleted, as indicated at 2! and 22, and the volume at the intersections is reduced by cylindrical holes 23 and 24.

At each end there are cross connecting webs 25 and the upright corners 26 are rounded, making it unnecessary to have the cylindrical holes 23 at the corners, but they are included Where the intermediate vertical webs join the end webs.

As a specific example, the rail here shown is 84 inches long, 5 inches deep and 6 inches wide. The webs is are inch thick, leaving the spaces 1 inches wide. The fillets 2| are on a radius of inch and the fillets 22 are practically straight, lying at 30 degrees to a cross section through the center of the cylinders 23 and 24. The curve 21 at the left end, is on a 5 inch 'radius and the curve 28 at the right, on a 2 inch radius. The cross connecting webs are about 4 inches on centers.

The rails will be mounted to suit the conditions and personal preference. For example, the webs I9 may have transverse holes 29, 30, 3!, 32 and 33 to receive the pins or bolts 34, by which the rails are made fast to the supports 35. Some engineers will prefer to have the holes 30, 3| 32 and 33 progressively elongated to allow for expansion and contraction.

The rails made according to this invention may be reversed when wear or injury has impaired one surface, thereby doubling the useful life of the rails. When the bolt holes are used and the design throws them away from the center line, two sets may be provided, as indicated in Figs. 3 and 4.

From the drawing it will be clear to those familiar with casting heat resistant alloy that every cross section of the rail illustrated is practically symmetrical and, hence, the distortion and deformity caused by unequal shrinkage and unequal contraction and expansion are prevented.

An alloy suitable for such rails is Per cent Chromium 15 to 30 Nickel 8 to 40 And the remainder principally iron.

troubles are eliminated by the construction shown in Figs. 2 to 4.

I claim as my invention:

1. A rail for heat treating furnaces comprising a plurality of vertical webs extending lengthwise of the rail with integral cross webs, and having every cross section symmetrical.

2. A rail for heat treating furnaces comprising a plurality of vertical webs of equal depth integral with cross connecting webs spaced at intervals, said vertical webs being of substantially uniform vertical dimensions throughout their lengths.

3. A rail for heat treating furnaces comprising a plurality of vertical webs'of equal depth integral with cross connecting webs spaced at intervals, the junctures being marked by cylindrical holes.

4. A rail for heat treating furnaces comprising a plurality of thin vertical webs spaced wide apart and rigidly connected by a plurality of cross webs at spaced intervals.

HENNING KLOUMAN.

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