US2129670A

US2129670A - Means for cooling rails

Info

Publication number: US2129670A
Application number: US21035A
Authority: US
Inventors: Cora M Brunner
Original assignee: Individual
Current assignee: Individual
Priority date: 1935-05-11
Filing date: 1935-05-11
Publication date: 1938-09-13
Anticipated expiration: 1955-09-13

Description

Sept. 13, 1938. J, BRUNNER 2,129,670

MEANS FOR COOLING RAILS Filed May 11, 1955 3 Sheets-Sheet l INVENTOR. @[JH/VBE U/V/VEE.

ATTORNEYS Sept. 13, 1938. ,J. BRUNNER MEANS FOR COOLING RAILS Filed May 11, 1935 3 Sheets-Sheet 2' Fit .3

INVENTOR.

ATTORNEYS Sept. 13, 1938. J BRUNNER 2,129,670

MEANS FOR COOLING RAILS Filed May 11, 1935 5 Sheets-Sheet 5 -ooooooo & 000000 ooooooo INVENTOR cfOH/Vfi/FUN/VEE.

ATTORNEYS Patented Sept. 13, 1938 PATENT OFFICE MEANS FOR COOLING RAILS John Brunner, Chicago, 111.; Cora M. Brlmner executrixof will of said John Brunner, de-

ceased Application May 11, 1935, Serial No. 21,035

8 Claims. (01. 266-2) This invention relates to railroad rails and to means for cooling the said rails from the rolling temperature to atmospheric temperatures whereby the internal grain structure of the rail is refined throughout the length and section thereof and the head of the rail at and adjacent the end is hardened to a preferred degree over the remainder of the rail, the junction between the hardened and unhardened sections being tough, ductile and gradually merging one into the other.

This invention is an improvement of the inventions described and claimed in my Patents Nos. 1,894,551, 1,896,572 and 1,929,346 and has for its object the provision of a means for effecting the quenching of the head of the, rail at and adjacent the ends to impart thereto a greater degree of hardness than in the rest of the rail with a tough, ductile and gradual junction therebetween. Another object of the present invention is to provide suitable apparatus for eifecting the quenching of the head of the rail at and adjacent the ends thereof by the use of compressed air. Other objects and advantages will. be apparent as the invention is more fully disclosed.

Before further disclosure of the present invention reference should be made to the accompanying drawings wherein:

Fig. 1 is a plan view of the apparatus of the present invention;

Fig. 2 is a side elevational view of the same;

Fig. 3 is a sectional view along plane 3-3 of Fig. 2;

Fig. 4 isan enlarged view partly in section of one of the elements of the present invention;

Fig. 5 is a sectional view along plane 5-5 of Fig. 4;

Fig. 6 is a bottom plan view of the same;

Fig. '7 is a side elevational view partly in section of a modified structure of the element of Fig.

Fig. 8 is a sectional view along plane 8-8 of Fig. '7;

Fig. 9 is a bottom plan view of the same;

Fig. 10 is a side elevational view partly in section of a second modified structure of theelement of Fig. 4;

Fig. 11 is a sectional view of the same along plane ll of Fig. 10;

Fig. 12 is a bottom plan view of the same;

Fig. 13 is a side elevational view partly in section of a third modification of the element of Fig. 4;

Fig. 14 is a sectional view of the same along plane l4--l4 of Fig. 13; and

Fig. 15 is a bottom plan view of the same.

Referring to the drawings, thepresent invention consists essentially in a means for quenching the head of the rail at and adjacent the ends thereof by the use of compressed air while the remainder of the rail is cooling normally in air on the hot bed. J I

In accordance with the present invention, the rails when they leave the rolling mill have a temperature approximating 1000 C. to 1075 C. They are charged onto a so-called hot bed where they are permitted to cool in freely moving. air through the thermal transformation range commonly referred to as the critical range, and down to temperatures between 300 C. and 500 C. Before the temperature of the rail has dropped as low as 300 C. the rails are reheated through the thermal transformation range to temperatures approximating 800 C. to 875 C. (depending somewhat upon the specific steel composition of the rail). The rails are maintained at this temperature for a time interval sufficient to become uniformly heated throughout. The rails are then removed from the furnace and the head of the rail at and adjacent the ends thereof are cooled rapidly through the thermal transformation range down to temperatures not less than 300 C. while the remainder of the rail cools normally in the air. Thereafter the entire rail is permitted to cool to atmospheric temperatures at the normal rate in freely moving air or at a regulated or retarded rate as may be desired.

The specific rate and mode of rapidly cooling .the head of the rail at and adjacent the ends determines the degree of hardness that is imparted to the head at this point and also determines the character of the junction between the hardened and unhardened sections. It is also desirable to avoid handling of the rail during the cooling down to atmospheric temperatures so that stresses and strains are not induced in the rail. A

In accordance with the present invention therefore I cool the head of the rail at and adjacent the ends by means of compressed air without disturbing the rail as it lies on the hot bed. In efiecting the rapid cooling by means of compressed air the rate of cooling obtained depends primarily upon the air pressure. It is necessary however to provide hood means to direct the compressed air stream in such manner that the particular section which it is desired to cool only is cooled and to protect the remainder of the rail from the cooling effects of the compressed air. After a great deal of experimentation I have found that the four modified structures of hoods illustrated-in Figs. 4 to 15 inclusive of the drawings are the most satisfactory for the purposes of the present invention.

Referring first to Figs. 1 to 3 inclusive, the rails R-R. are charged onto the hot bed H after they have received the second or reheating step of the above described method. The rails RR which are indicated as lying on their sides have a temperature approximating 800 C. to 875 C. After they have been placed on the hot bed and before any consequential cooling takes place, hoods I-I are positioned over the heads of the rails at and adjacent the ends and air at pressures varying from 50 pounds to pounds per square inch, depending on the hardness desired and the depth of hardness required for the particular rail section employed, is applied to the surface of the rail. The time interval of application of the compressed air may vary between 1 to' 2% minutes depending upon the pressure employed and the depth of hardness required.

Hoods |-I to which compressed air is supplied by conduits 22 can be applied to the head of the rail on both ends thereof by' hand or mechanically as indicated in Figs. 1 and 2. -As' illustrated the compressed air is utilized as an actuating means for the hoods I-l which are carried on the ends of piston rods M-M actuated by compressed air cylinders KK. Compressed air lines L-L and triple valves VV control the operation of hoods II. Obviously in place of the compressed air means shown, the hoods I-I can be operated mechanically or by electrically energized means if desired. Whereas also I have shown two rails R--'R being treated it is apparent that any number of rails may be treated simultaneously if desired. The ordinary reheating furnace is designed to hold several rails at a time and the present invention contemplates the provision of a sufllcient number of hoods l-I to rapidly cool the ends of all of the rails simultaneously after they are removed from the reheating furnace and placed upon the hot bed before any consequential cooling in 'the open air has taken place.

. In the practice of the feature of cooling the heads of the rail at and adjacent its ends at a rate faster than the normal cooling rate for the remainder of the rail, it is highly essential that the area thus hardened should be joined to the remainder of the rail in a gradual junction which is tough and ductile. It is also essential that the more rapidly cooled area be confined substantially to the upper section of the rail head.

The various types of cooling hoods illustrated in Figs. 4 to 15 inclusive have been designed to accomplish these results. Hood I in its simplest concept comprises an open bottom chamber having side walls 9--9 adapted to engage the sides of the head of rail R to prevent the escape of air along the sides of the rail, and one end wall I0 adapted to locate the chamber upon the end of therail and the opposite end wall II open to the atmosphere. Means are provided to supply air under pressure into the chamber and conduit means 6 may be provided, if desired, to divert the air discharging through open end II away from rail surfaces not enclosed by the said chamber.

-Referring to'Figsfi, 5 and 6, as one specific embodiment of the present invention, I have indicated one modified form of the hood I wherein a perforated partitionmember 3 r is provided .dividing the hood I into upper'and

lower compartments

4 and 5 respectively. Air under pressureis supplied to the upper compartment-l as As indicated, by the location of the perforations I in partition 3 the maximum cooling effect is concentrated on the top head surface adjacent the extreme end and extends with diminishing. effect towards the longitudinal center'of the rail. The

hardened area thus obtained is in part reheated after the hood I is removed by transmission of heat by conduction from the remainder of the rail. In this manner the junction between the hardened and unhardened sections is rendered tough and more ductile. The hardness at the top of the head adjacent the end approximates 300-400 (Brinell) and the hardness of the balance. of the rail approximates 225-270 (Brinell).

Referring to Figs. '7, 8 and 9, the escape of the air inwardly along the rail length is prevented by the provision of curved extension or conduit means 6 which collects the air as it passes out of the opening II and diverts the air away from rail surfaces not enclosed by the hood I. In this arrangement the extent of hardening inwardly along the rail length may be limited as desired.

Referring to Figs. 10 to 12 inclusive, a third modification of hood I is indicated. For some purposes this kind of hardening is desirable. In this modification the open end wall II is oppositely located to that illustrated in Fig. 4. Partition 3 forming the top of lower chamber 5 and the bottom of upper chamber 4 is perforated substantially as indicated to provide for the application of the air pressure to the entire rail head surface enclosed by the chamber 5. For some purposes this kind of hardening is desirable.

Referring to Figs. 13, 14 and 15, a fourth modification is indicated whereby the hardening of the extreme end of the head of the rail can be avoided and the area of greatest hardening spaced from the end of the rail a desired distance. In this structure the compressed air is conducted into hood I by means of nozzle 1 which preferably is provided with a flattened outlet opening 8 substantially as indicated to direct the air blast the entire width of the rail. The cooling effect of the air blast extends inwardly towards the longitudinal center of the rail with gradually decreasing intensity as in the structure of Fig. 4.

While the process of the specific embodiment of the present invention as hereinabove described includes the step of reheating the rails to a temperature between 800 and-875 C. for the purpose of normalizing the internal structure prior to the application of the end cooling feature, it is apparent that if desired such normalizing heat treatment may be eliminated. In which case the rails at the conclusion of the rolling operation are charged upon the hot bed and are permitted to cool thereon in freely moving air until the rails have cooled to a temperature between 800 and 875 C. Then the head of the rails at and adjacent to the ends thereof may be cooled rapid- Iii the hot bed, substantially in the manner as hereinabove described. Thereafter the entire rail is permitted to cool to atmospheric temperatures ata normal rate in freely moving air or, at a regulated or retarded rate of cooling in boxes, hoods or otherwise as may-be desired.

From the above description and accompanying drawings, it is apparent that the present invention may be widely modified without departing from the nature and scope thereof and all such modifications and departures are contemplated as may fall within the scope of the following claims.

What I claim is:

1. A hood adapted for the air cooling of rail ends comprising a substantially rectangular chamber having an open bottom and having side walls adapted to engage with the sides of the head of a rail and an end wall adapted to engage with the end of a rail thereby positioning the chamber upon the end of the rail with the head surface of the rail for an extended distance inwardly from the rail end enclosed within the chamber, means to supply a pressure of air into said chamber, means to substantially uniformly distribute said pressure of air over a desired area of the said enclosed rail head surface, and means to permit the said air to flow freely from the chamber after contacting with the said rail head surface and to divert the same away from the rail surfaces not enclosed by said chamber.

2. A cooling hood for rail ends comprising an open bottom three-sided chamber having opposite s'lde walls and an end wall adapted to enclose a length of the head of a rail at the rail end with the top surface of the said rail head forming a bottom for the said chamber, means to supply air under pressure into said chamber directly uponthe said head surface, the open end of the chamber permitting substantially free egress of said air after passing over the said head surface.

3. A cooling hood for rail ends comprising an open bottom three-sided chamber having opposite side walls and an end wall adapted to enclose a length of the head of a rail at the rail end with the top surface of the said rail head forming a bottom for the said chamber, means to supply air under pressure into said chamber directly upon the said head surface, the open end of the chamber permitting substantially free egress of said air after passing over the said head surface and conduit means to conduct the said air leaving the open end of said chamber away from the rail surfaces not enclosed by said chamber.

4. A cooling hood for railroad rails comprising a rectangular chamber open at the bottom and at one end, the side Walls of the chamber being adapted to engage the sides of said rail to prevent the escape of air out of said chamber in that direction and means to supply air under pressure into said chamber.

5. A cooling hood for railroad rails comprising a rectangular chamber open at the bottom and at one end and having side walls adapted to engage the sides of a rail head to prevent the escape of air in that direction from the chamber, an air inlet opening through the top of said chamber and means to supply a pressure of air to said inlet opening.

6. A cooling hood for railroad rails comprising a rectangular chamber open at the bottom and at one end and having side walls adapted to engage the sides of a rail head to prevent the escape of air in that direction from the chamber and an end wall adapted toengage the end of a rail to locate the chamber upon the said rail end, an air inlet opening through the top of said chamber adjacent said end wall, means to supply a pressure of air through said inlet opening and conduit means to conduct the air leaving the open end of said chamber away from the rail surface not enclosed by said chamber.

7. A cooling hood for railroad rails comprising a rectangular chamber having a partition dividing the chamber into upper and lower compartments, the lower compartment being open at the bottom and at one end and having side walls adapted to engage the sides of a rail head to prevent the escape of air from the compartment in that direction, an air inlet opening in the upper compartment, a plurality of openings in the said partition to permit air to pass from the upper into the lower compartment and means to supply a pressure of air through said air inlet opening.

8. A cooling hood for railroad rails comprising a rectangular chamber having a partition dividing the chamber into upper and lower compartments, the lower compartment being open at the bottom and at one end and having side walls adapted to engage the sides of a rail head to prevent the escape of air from the compartment in that direction, an air inlet opening in the upper compartment, a plurality of openings in the said partition to permit air to pass from the upper into the low-er compartment, means to supply air under pressure into said upper compartment through said inlet opening and conduit means to conduct air passing through open end of the lower compartment away from the rail surfaces not enclosed by said lower compartment.

J BRUNNER.