US2349679A - Heat treating apparatus - Google Patents

Description

May 23, 1944.

WITNESSES:

W. ROTH HEAT TREATING APPARATUS FiiedApril 11. 1941 2 sheets-sheet 1 ATTORNEY- May 23, 1944. w. ROTH HEAT TREATING APPARATUS Filed April 11, 1941 2 Sheets-Shet 2 INVENTOR 14/17/0/"0 502 /7.

WITNESSES: 5 4 B. L

ATTORNEY Patented May 23, 1944 Willa-rd ingho'use Roth, Wilkinsburg, re, assignor to West- Elcctric & Manufacturing Gcmp'any,

East Pittsburgh, 'Pa,, a corporationof Pennsyl- Vania Application April .11, 1941 Serial 'No. 388,055 4 Claims. (01. 266-4) This invention relates generally to heat-treating apparatus including a charge-treating means for quenching a heat-*treatedflcharge, and more particularly relates to a charge-treating means of the type described which can bebeneficially incorporated into a suitable heat-treating apparatus of the continuous or semi-continuous type.

It is a primary object of my invention to provide a charge-treating means for quenching a heated charge, which charge-treating means will uniformly quench the heated charge with a minimum of delay from "the time thecha-rge. comes out of the heating furnace.

It is a further object of my invention toprovide a charge-treating means of thetype described having a charge-supporting-table, preferably a table provided with numerous openings, such as, for example, a roller table, aligned with the discharge opening of a heat-treating furnace so that the heated charge can be directly conveyed or moved onto the charge-supporting table; the table being constructed in such a manner that it can be immediately dropped. into cooperative relation with a charge-quenching means in the form of 'a quench tank below the table, without requiring time-consuming translation of the heated charge or table in any other direction. In the applied form of my invention the table is repeatedly raised and lowered in the quench tank so that the quenching liquid is stirred'and will completely envelop and wash the charge whereby the charge will be uniformly cooled in the mass of the quenching liquid, the agitation of the charge reducing temperature gradations in the liquid, except, of course, the part-of the liqhid in contact with the heated'charge. I

Additional objects "of my invention reside in providing the charge-trea-ting-.means with a charge-supporting table comprised of spaced ro tatable rollers forreceiving the charge, which may be, for example, elongated rods or bars, the rollers being oscillatable while in the quench tank so that all par-ts "of the charge can be contacted by the quenching liquid.

Additional features, objects, innovations and methods of my invention will be apparent from the following description of a preferred application thereof, which is to be taken in conjunction with the accompanying drawings in which I schematically illustrate the preferred form of my invention.

In these drawings:

Figure 1 is a side View, partly in elevation and partly in section, with parts omitted for clarity, illustrating my invention; and

Fig. 2 is a side view transverse to Fig. 1, partly in elevation and partly in section, with parts omitted for clarity, of my novel charge-treating means for quenching heated charges.

In order to describe and illustrate my' invention I have chosen a heating system or apparatus in which steel bars or rods must be gradually heated to a desired high temperature before quenching, and heat-treated after quenching, preferably in astrain-relieving or drawing furnace. The apparatus comprises a high temperature furnace 2 in which charges are heated, a charge-treating means 4 adjacent the high temperature furnace for receiving the heated charges and quenching them, and a secondary heating furnace 6-adjacent the charge-treating means for directly receiving the quenched charges for further relatively low-temperature heatetreatment. The high temperature furnace 2 comprises the usual insulating and refractory walls 8 provided with a discharge opening 10 through which a heated charge is discharged, the discharge or work opening 10 being covered and uncovered by a vertically sliding door 12 operated by any suitable door-operating mechanism l3. The high temperature furnace is provided with a roller hearth M comprising a plurality of spaced rollers [6 preferably driven in unison by any conventional-roller-dr'iving means including a driving electric motor.

The charge-treating means 4 comprises a vertically slidable skeleton framework l8 which, in the preferred form shown, is in the shape of an open regular parallelepiped. The framework comprises a substantiallyrectangular "open frame 2'0 at the top constructed by securing structural steel members together in any suitable way, and further comprises a lower charge-supporting table, designated in its entirety by the reference numeral '22, having channels 24 and 26 at its sides which are suspended from the upper frame 20 of the framework by means of a plurality of vertical angles and bars 28, which form the corners of the framework. Additional vertical bars 2 9, between, the corners of the framework, are

secured to the upper frame 211 and channel sides 2.4 and p216 for greater rigidity of the framework I8. I v

The charge-supporting table 22 includes a plurality of spaced charge-supporting rollers 30 journaled in bearings 32 and 34 secured to the channels .24 and 26, respectively. Each of the rollers is provided with a narrowed neck journaled in an associated one of the bearings, with one end extended for receiving a sprocket wheel 35 secured thereto. One of the rollers is made to act as a driving roller, and this roller is provided with a further driving sprocket wheel 38. A sprocket chain 40 meshes with all of the sprockets 36 of the rollers 30 so that they will be rotated in unison when the sprocket wheel 38 is rotated.

A driving means comprising an electric motor 42 is rigidly secured to the top of the framework I8 and drives the sprocket wheel 38 through a sprocket chain 44 and suitable gearing, the sprocket chain 44 also passing over an idler sprocket wheel 46 for maintaining the tension of the sprocket chain. The gearing by which the power of the motor is transferred to the sprocket chain 44 may take any suitable speed-reducing form and may include a jack shaft 48 driven by a sprocket chain 50, driven by th motor, which meshes with a suitable sprocket wheel on the jack shaft. A second sprocket wheel 5|, on the jack shaft, meshes with the sprocket chain 44 for driving the rollers of the charge supporting table 22. The framework I8, the charge-supporting table 22, the motor 42 and the driving means for the rollers 30 is movable as a unit into cooperative relation with a quenchingmeans for quenching any charge on the table, the quenching means comprising a quench tank 52 below the framework.

In the form of the invention here illustrated, the framework can be directly dropped so that the charge on the rollers 30 will be immersed in a quenching liquid 54 in the quench tank 52. Th motor 42 is preferably mounted on the framework I8 so that in the lowermost position of the latter the motor and its supporting means will be above and outwardly beyond one end 58 of the quench tank 52.

In order to raise and lower the framework I8 a second stationary rigid skeleton framework, indicated in its entirety by the reference numeral 51, is provided including upright legs 58 and 80 on each side of the quench tank 52, the legs being imbedded in the concrete floor or other suitable foundation 62. The secondary framework further comprises horizontal side members 64 across the tops of the spaced legs 58 on one side of the quench tank, and similar side members 66 similarly connecting spaced legs 60 on the other side ofthe quench tank. Cross channels 68, transverse-to the side members 64 and 86, and extending between transversely aligned pairs of legs 58 and 60, are also part of the secondary framework 51.

The side members 84 and 66 are extended to provide a support for a base plate I0 to which is secured an electric motor I2 driving a cable means 13 wrapped around a cable drum I4. A cable I6 is wrapped around one end of the cable drum I4 and a second cable I8 is wrapped around its other end, these cables passing over guide sheaves 80 and 82,,respective1y, which are rotatably carried by the secondary framework, these guide sheaves being disposed above diag- Onally opposite corners of the slidable framework I8. The cable I8 passes around a sheave 84, rotatably secured to the top of the framework I8 below the sheave 80, and an end of the cable I6 is secured to the secondary framework as indicated at 85. Similarly the cable 18 is wrapped around a sheave 86 rotatably secured to the framework I8 below the guide sheave 82, and an end of the cable I8 is also secured to the secondary framework as indicated at 90.

In order to guide the vertical movement of the framework l8. guides I00, in the form of vertical channels, are secured to the inside of sides I 02 and I04 of the quench tank 52, the framework I8 being provided with bars I 08 and I08 slidable in the guide channels I 00 and I02, respectively, these guide bars being rigidly secured to the framework I8 in any suitable manner. In the preferred embodiment four guide channels and four guide bars are provided disposed near the comers of the framework I 8.

The secondary heating furnace 6 comprises insulating walls IIO provided with a charge entrance or work opening I I2 which is covered and uncovered bya vertically sliding door II4 operated by any suitable door operating mechanism I IS. The secondary furnace 6 includes a roller hearth I I8 comprising a plurality of spaced rollers I20 driven in unison by any suitable driving mechanism, preferably including an electric motor. In the operation of the structure described the charge is heated in the high-temperature furnace 2, and after suitable soaking is moved onto the charge-supporting table 22 of the charge-treating means 4. As soon as the charge is on this table the framework I8 is dropped so that the charge is immersed in the quenching liquid 54. While the charge is immersed in the quenching liquid it is desirable to oscillate the framework I8 up and down to agitate the liquid for more rapid and uniform cooling of the charge, and in furtherance of this object it is also desirable to oscillate the rollers 30 slightly so that the charge not only moves up and down in the quenching liquid, but also moves back and forth therein. After quenching the framework I8 is raised and the charge rolled onto the roller hearth I I 8. of the secondary furnace 8 for further heat-treatment.

My invention can be used with known automatic control systems of the continuous or semicontinuous type in which the movement of the charge'between the different heat-treatment elements is automatically, or manually, controlled. It is desirable therefore to operate the motor 42, which drives the rollers 30, together with the motor drives of the rollers I5 and I20.

An intermediate roller I22 journaled in pedestal bearings I24 is provided between the high temperature furnace 8 and the charge-treating means 4; and a similar intermediate roller I28 is provided between the charge-treating means 4 and the secondary heating furnace 6 so that the roller hearths of the furnaces and the roller table of the charge-treating means are, in effect, a continuous roller charge-supporting means with the rollers all in alignment. The electric motors 42 and I2 are preferably reversible and controlled by any suitable motor control systems I28 and I30, respectively, these control systems being either manually or automatically operated, and each having a plurality of control conductors I32 and I34, respectively, connected to control equipment. Power conductors I36 supply power to the motor control systems and to the motors. The connecting conductors for the motor 42 are preferably flexible and of sufficient length to permit the required movement of the motor with the framework I8. Suitable switches, including limit switches may be provided to control the movements of the framework I8 and the oscillations of the rollers 36 in the quench tank 52. Suitable stops, such as bars I 40, may be provided in the top of the guide channels I00 to be engaged by the bars I06 and I 08 for properly positioning the framework I8 so that the roller table 22 will be aligned with the rollers of the furnaces 2 and 6 for receiving charges from the high-temperature furnace 2, and for moving quenched charges into the secondary heating furnace 6.

By means of my invention it is evident that elongated charges can be quickly and uniformly quenched without undue delay because the heated charges are directly conveyed to the chargesupporting table 22 which can then be immediately dropped into the quench tank 52. After quenching the charge-supporting table 22 can be raised to its proper position and the charges immediately passed into the secondary heating furnace 6.

While I have shown my invention in a preferred form thereof, it is evident that it is subject to many modifications and that the diverse elements thereof may have equivalents substituted therefor, thus the manner in which the framework IB is constructed can be varied in considerable detail. Similarly the means for moving the framework into, within and out of the quench tank may take any suitable form, and the other elements of the preferred form of my invention may be extensively changed without departing from the basic features and teachings of my invention.

I claim as my invention:

1. Heat-treating means comprising roller means having a plurality of spaced rollers in file arrangement capable of translating a charge thereon substantially transversely to the roller axes, adjacent ones of said rollers being substantially parallel, said plurality of rollers comprising a first portion and a second portion, means for heating a charge on said first portion of said rollers, quench tank means adapted to contain a quenching liquid, underneath said second separate portion of said rollers, moving means for lowering said rollers of said second portion into said quench tank means and for raising them out of the quench tank means back into file arrangement with the other of said rollers, for the quenching of a charge on said second portion of said rollers, said moving means comprising supporting means for said rollers of said second portion for maintaining them substantially level and parallel to the rollers of said first portion during the raising and lowering thereof, and means lowerable and raisable with said rollers for oscillating the rollers in said second portion of said rollers about their respective axes while in said quench-tank means.

2. Heat-treating means comprising roller means having a plurality of spaced rollers in file arrangement capable of translating a charge substantially transversely to the roller axes, adjacent ones of said rollers being substantially parallel, said plurality of rollers comprising a first portion and a second portion, means for heating a charge on said first portion of said rollers, quench tank means adapted to contain a quenching liquid, underneath said second separate portion of said rollers, moving means for lowering said second portion of said rollers into said quench tank means and for raising it out of the quench tank means, for the quenching of a charge on said second portion of said rollers, and means for oscillating the rollers in said second portion of said rollers about their respective axes while in said quench tank means.

3. An apparatus for quenching heated charges, comprising, in combination, a charge-treating means comprising a charge-supporting table comprising a plurality of spaced substantially parallel rollers, a liquid-containing quench-tank below said table, said charge-treating means including a movable supporting structure having means for carrying said charge-supporting table, means for lowering said supporting structure for placing said charge-supporting table into said quench-tank, and means for oscillating the rollers of said charge-supporting table about their respective axes while said charge-supporting table is in said quench-tank.

4. The apparatus of claim 3 characterized by means for reciprocating said charge-supporting table up and down while in said quench-tank.

WILLARD ROTH.

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