US2457846A

US2457846A - Slide rail support for inductor furnace workpieces

Info

Publication number: US2457846A
Application number: US661234A
Authority: US
Inventors: Jr Harold A Strickland
Original assignee: Ohio Crankshaft Co
Current assignee: Ohio Crankshaft Co
Priority date: 1946-04-11
Filing date: 1946-04-11
Publication date: 1949-01-04
Anticipated expiration: 1966-01-04

Description

Jan. 4, 1949. H. A. STRICKLAND, JR 2,457,846

SLIDE RAIL SUPPORT FOR INDUCTOR l 6 S4 E9 Cl E Il'. Ml Wn Wr p @A Md Re UU. FF

INVENTOR Harold 7@ Stcklandjr.

ATTORNEY Patented Jan. 4, 1949 SLIDE RAIL SUPPORT FOR IDUCTOR FURNACE WORKPIECES Harold A. Strickland, Jr., Detroit, Mich., assignor, by mesne assignments, to The Ohio Crankshaft Company, Cleveland, Ohio, a corporation of Ohio Application April 11, 1946, Serial No. 661,234

6 Claims. 1 This invention relates to furnace construction, with particular reference to structure for sup,- porting the charge in the furnace chamber.

In induction heating furnaces primarily a tu- -bular heat chamber is provided lined with iirev brick or the like in which, as shown in my copending application Serial No. 384,503 for Electric furnace machine, now Patent No. 2,408,350, a group of axially aligned tubes is embedded in the rebrick but projecting above the inner surface of the iirebrick to afford an all-metal grille support for the workpiece. These tubes are laterally displaced along the surface of the rebrick wall. Heretofore the front or inlet extension of these tubes connecting to a. source of coolant projected radially from the furnace mouth. These projecting sections afforded no meansof support in themselves and hence it became necessary to weld or otherwise secure to the tubing at the inlet end supporting rods which were bolted to the coil supporting structure.

A primary object of this invention is to provide a. support tube shape at the mouth end of the furnace which lends itselfl to easy support of the tubes without requirement for additional fastening means.

Another object of the invention is to provide a support tube structure which will lpermit easy assembly of the support grille withinthe furnace coil and into engagement with the external supporting means of the tube.

Still another object is to provide a support tube structure which allows construction of sealing cylinders at the front end of the furnace without important modification of the cylinder.

I attain the above-mentioned objects by the construction hereinafter described and shown in the accompanying gure of the drawing, wherein the vapor-sealing construction is shown in a 'longitudinal sectional elevation of the furnace unit.

The furnace of the invention as shown is in general similar to that shown in 'my copending application above referred to. The furnace is in the type of an induction coil unit, generally indicated by the numeral I. The coil 2 is formed of a number of turns of hollow square conductor appropriately insulated from each other by mica or mica-containing strips and on the inner and outer sides also by mica or mica-containing tubing which is appropriately heat-resistant as well as electrically non-conducting. As shown, there are two layers of tubing interior of the coil, as indicated by the numeral 3. A tube 4 formed of asbestos-containing material, such as Transite, is blocked onto the coil surface to serve as protection therefor, there #being an additional outer tubing of mica insulation intermediate the protective layer and the coil tube. Interior of the inner mica tube insulation is a layer of iirebrick in which is embedded axially extending and circumferentially displaced load-bearing rods or rails 5. These rails are hollow for the passage of coolant and bear on their inner surfaces projecting lugs 6 of relatively hard metal which take the friction and wear of the workpiece in its movement in and out of the furnace chamber. These rails also bear butterfly plates l which extend over the rebrick edges to retain the same in place. At the rear end of the furnace chamber a push-out rod 8 for forcing out the workpiece after the heating thereof is shown. A holding tube 9 fastened to the casing wall Ill forms a support for the push-out rod.

The furnace coil and associated layers of insulation and rebrick are held in place and supported by end plates I I and I2 to which the unit is xed by means of support rods i3. These rods carry end coil springs I4 so that the pressure of the rod acting as a bolt is yieldable between the plates II and I2 thus holding the unit yieldably in position. These plates are preferably formed of asbestos-containing material, such as Transite.

Intermediate the rear support plate II of the coil unit and the casing I0 is placed a cylindrical drum I5 of insulation material. This drum makes close contact at either end adjacent the adjacent plate and casing surfacesso as to be substantially vapor and gas-proof.

At the front end of the furnace there is positioned a mouthpiece 20 having inwardly and annularly projecting fingers 2|, the ends of which being in alignment with the inlet opening of the furnace chamber. This mouthpiece serves as a guide to workpieces being inserted within the furnace. The mouthpiece is supported on the front casing wall 22, as shown. Intermediate the casing 22 and the front Transite plate I2 a second cylindrical insulation drum 23 is provided, similar in placement to the drum I5 at the rear furnace end. This drum 23 also makes close contact with the plate I2 and casing 22 to provide at the front of the furnace a substantially vapor and gas-proof enclosure.

In the disclosure of my copending application hereinabove referred to the projecting ends of the rails at the front end of the furnace are ex' tended outwardly radially to the point of connection with the coolant source or to the flexible couplings employed. This construction requires the welding of holding rods to the rails at the front end for attachment to the front plate support. In the present arrangement I have found it desirable to reverse the front ends of the rails so that they extend for a short distance parallel to the main rail section in a reverse section 24. This reverse section of each rail is passed through registering openings in the front plate I2, which openings are parallel to the axis of the coil and the main section of the rails. Accordingly, it is apparent that these rails may be slid outwardly for removal or inwardly for assembly as desired and that such rail movement does not disturb `the fixed seal of the drum 23. It is noted that ithis parti-cular hook curvature of the front end `of the rails with insertion of the apertures through the plate I2 serves as support means for the front end of the rails making the addition of auxiliary holding means unnecessary. The rear en'd ofthe rails is supported by I-bars 25 on the rear support yplate lil, as shown.

As exemplifying the electrical conductor system of the furnace there is shown the supply'bus `bars 26 and 2l spaced by insulation 28 at the base-of the furnace. Appropriate taps to the coil rare made through bus liars 29 and the end con `cluctors 3B which also supply coolant for the coil. The close placement of the bus bars -26 and 21 is desirable to reduce reactance in the electrical circuit, but such placement brings up the problem vof leakage as induced by penetration of oil vapor from the furnace chamber. The arrangeiment as described hereinabove'and illustrated in `thedrawing effectively obviates leakage and consequently efficiency drop arising from oil vapor penetration.

The showing of the drawing is primarily for illustration of the proper of the vinvention. Obviously modifications may be made inthe general arrangement and details of the disclosure ycoming within the scope of the appended claims.

What is claimed is:

l. In furnace construction includinga tubular induction heating coil, heateresistant tubing -fnr'mingan-inner lining for saiducoil, heati'esist "aritceramic tubing within said lining and :form- Iing a iheat chamber, workpiece-suppo1-ting tubes said extensions being reversely turned to form 4reverse end sections external to the grille, and

end support plates for the coil, the front end plate having direct connection to the reverse end sections of the support tubes.

3. In furnace construction, a tubular refractory lining for the furnace chamber, a plurality of axiallyaligned and `radially displaced support tubes partially embedded in the inner surface of said lining, said tubes having a front furnace end extension having sections outwardly turned relative to the lining tube axis and terminal sections parallel to the lining tube axis, and end supports 4for said lining and tubes, the terminal front .extensionof `the support tubes being adapt- Jed to seat in apertures formed in the front sup i `port for .holding Ithe tubes and lining in fixed position.

j. In furnace construction having a tubular furnace chamber, a support tube adapted for insertion in said furnace chamber for support of a workpiece to be heated, said tube consisting of an extended section normally positioned within the `furnace chamber and a front end section extended Ioutside the chamber, said front end section including a reversely turned terminal parallel to the mainstraight section of the tube. anda joining connection between the straight section-and said terminal.

5. In `furnace construction having ya tubular .furnace chamber, a 'support tube adapted for insertion in `said furnace chamber for support of a workpiece ,to be heated, said tube consisting of lan extended Ysection normally positioned within the furnacechamber'and a front end section positioned outside the chamber, said front end section including a reversely turned terminal and a -joining section between the extended section and said terminal.

6. In furnace construction, a tubular refractory lining lfor the furnace chamber, a plurality of axiallyaligned and -radiallydisplaced support tubes secured to the inner surfaceof said lining, said tubes having a front `furnace end extension beyond said lining having `sections outwardly turned relative to the lining tube axis and reversely turned terminal sections parallel to the lining tube axis, and end supports for said lining and tubes, vthe terminal sections of the support tubes being adapted for direct connection to the front support for holding the tubes and lining iniixed position.

HAROLD A. STRICKLAND, Jn.

REFERENCES `CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,689,369 Tama Oct. 30, 1928 1,691,349 Harrington et al. Nov. 13, 1928 2,365,021 Strickland Dec. 12, 1944 2,373,719 Strickland Apr. 1'7, 1945