US3659831A

US3659831A - Integral quench furnace and transfer mechanism

Info

Publication number: US3659831A
Application number: US852671A
Authority: US
Inventors: Russell H Reber; Harold E Mescher
Original assignee: Pacific Scientific Co
Current assignee: Pacific Scientific Co
Priority date: 1969-08-25
Filing date: 1969-08-25
Publication date: 1972-05-02
Anticipated expiration: 1989-05-02

Abstract

An integral quench furnace system and transfer mechanism for removing a heat treated charge from the furnace chamber into the quench media and onto an unloading platform. The transfer mechanism includes a forked loading cart mounted on the quench chamber A-frame for movement into the furnace and onto the unloading platform through a hydraulic motor driven chain and sprocket arrangement.

Description

United States Patent Reber et al.

[54] INTEGRAL QUENCH FURNACE AND TRANSFER MECHANISM [72] Inventors: Russell H. Reber, Orange; Harold E.

Mescher, Pico Rivera, both of Calif.

Pacific Scientific Company, City of Commerce, Calif.

[22] Filed: Aug. 25, 1969 [21] Appl.N0.: 852,671

[73] Assignee:

[52] U.S.Cl. ..266/4A,148/153,214/18R,

214/26 51 im. Cl. ..C21d1/66 [58] Field ofSearch ..148/153, 155; 214/18 R, 23-26, 214/32; 266/4 R, 4 A, 4 B, 6 R

[56] References Cited UNITED STATES PATENTS 1,840,327 1/1932 Paulsen ..214/26 1,848,898 3/1932 McFarland ..2l4/26 [451 May 2, 1972 2,681,136 6/1954 lpsen ..266/4 R 2,747,855 5/1956 lpsen ..266/4 R 2,965,369 12/1960 Acker et al ..266/4 R 3,381,947 5/1968 Beggs ..266/4 R 3,410,547 11/1968 Bielefeldt... .....266/5 R 3,441,452 4/1969 Westeren ..266/4 R FOREIGN PATENTS OR APPLICATIONS 987,910 8/1951 France ..266/4 R Primary Examiner-Gerald A. Dost Atrorney-Fowler, Knobbe & Martens [57] ABSTRACT An integral quench furnace system and transfer mechanism for removing a heat treated charge from the furnace chamber into the quench media and onto an unloading platform. The transfer mechanism includes a forked loading cart mounted on the quench chamber A-frame for movement into the furnace and onto the unloading platform through a hydraulic motor driven chain and sprocket arrangement,

22 Claims, 13 Drawing Figures Patented May 2, 1972 i0 Sheets-Sheet l INVENTORS.

EL/iSEZL H E5551? M45040 5. M53045? FOWL 5/6 (M0555 M42 TEN5 10 Sheets-Sheet .FZ G Z INVENTORS. 0555 H. 2655? 144E040 6'. 4455045 BY POM/L 5 44/0555 MflETE/VS Patented May 2, 1972 i0 Sheets-Sheet l5 INVENTOR5. 2055624 A! E5556 #42040 5. MESKHEE BY ran 452, K/V055E ,4 WMFTzF/VS Patented May 2, 1972 10 Sheets-Sheet 4 INVENTORfi. 60.516224 4 E5552 ran 4 6, K/VOBBE a M4275;

Patented May 2, 1972 3,659,831

l0 Sheets-Sheet 5 INVENTORS. FUSSELL h. @5545? Patented May 2, 1972 10 Sheets-Sheet 6 INVENTORS. 2055621. HEEBEE A/flEOLD E M55095? BY K/V055E FOWL 2,

a Ame rlsws Patented May 2, 1972 3,659,831

10 Sheets-Sheet 7 EGQ INVENTORS.

EUSKSZZL H 5552 mf/QEOLD E. MESffi/EF Patented May 2, 1972 10 Sheets-Sheet 8 fi e. /0.

INVENTORS. H. 1655678 05562 L #41701 0 E. M556 47' TOIQNE K61 INTEGRAL QUENCH FURNACE AND TRANSFER MECHANISM This invention is directed to metallurgical heat treating equipment and more specifically to a transfer mechanism for use with integral quench vacuum or atmosphere furnaces.

Prior art heat treating furnaces which combine a quench chamber and furnace heating chamber are generally incapable of rapidly transferring the charge being heat treated from the furnace chamber into the quench media without dropping the charge into the quench tank. Such uncontrolled movement of the charge may cause distortion of the workpiece and usually cannot be tolerated. Additionally the prior equipment generally leaves a portion of the transfer mechanism in the furnace during the heat treating cycle and then immerses this same portion of the mechanism into the quench fluids. Usually no effective means is provided for cleaning the quench fluids from this portion of the transfer mechanism before it is reinserted into the furnace. This portion, whether it be support rollers, pallets or other equipment, due to the continuous thermal stress cycling and exposure to the high temperature of the furnace chamber may eventually contaminate the heat treating furnace or become corroded or cracked. Any time that extraneous materials, such as portions of the transfer mechanism, are left in the furnace chamber, the danger of outdiffusion and contamination of the atmosphere or the charge is present. Even small amounts of contamination cannot be tolerated for high quality heat treating work such as with vacuum or atmosphere furnaces.

Additionally, in the prior art furnaces it sometimes is necessary to slide the charge on the refractory hearths while at temperature. This may cause defacing of the hearths and the charge or introduce distorting stresses into the charge metals.

Another difficulty with integral quench vacuum or atmosphere furnaces presently available is that the furnace chamber and the quench chamber are generally separated by a hingemounted door which swings into the quench chamber. Such doors are provided since they must prevent radiation losses from within the furnace insulation lining and seal the heat treating chamber from the partial pressure of the quenching chamber. Because the entrance to the furnace housing is not flush with the entrance to the furnace chamber, the radiation seal protrudes beyond the vacuum seal. Consequently, it has been thought that the hinged doors were the only type usable. Such swing-in doors consume a large amount of space when opened causing unnecessary lengthening of the quench chamber.

In integral quench vacuum furnaces the transfer mechanism for transferring the heat treated charge into the quenching media must be capable of rapidly moving into the heat treating chamber once the heat treat is completed and the door has been opened, picking up the charge, and returning the charge into position over the quenching media. The return stroke of the transfer mechanism, however, must not be so rapid that the heated charge is jarred, slid or distorted by jerking movement or quick stops. i

To be completely acceptable, the transfer mechanism must also provide an effective means for removing the charge from the quenching media and the quench chamber onto an unloading platform where any portion of the transfer mechanism which may enter the furnace chamber can be wiped clean of the quenching fluids after the quench has been completed. This requires some precise manner of alignment of the transfer mechanism with the unloading platform which enables the charge to be correctly positioned on the unloading platform after removal.

From the requirements for the transfer mechanism, it is clear that the mechanism must be capable of both horizontal and vertical translation. The vertical translation must be accurately controlled in a stepped fashion so that the transfer mechanism can be stepped vertically to enter the furnace chamber beneath the charge and be raised to pick up the charge. During unloading, however, the transfer mechanism must be aligned with the unloading platform at a level which most conveniently is even with the level of the transfer mechanism after the charge has been picked up. This enables the mechanism to transfer directly from the heat treating chamber onto the unloading platform omitting the quench if desired. A third vertical position that the transfer mechanism must assume is a position which places the heat treated charge within the quenching media.

This invention is basically an integral quench furnace system and a transfer mechanism which is designed for use in conjunction with integral quench metallurgical heat treating furnaces, i.e., furnaces which are divided into a quenching chamber and a heating or holding at temperature chamber. The transfer mechanism comprises a loading cart which is horizontally translatable and a vertically translatable support frame which mounts and supports the loading cart. The support frame thus determines the vertical position from which the loading cart will translate horizontally. The heat treating equipment and transfer mechanism also includes a horizontally translatable alignment and unloading frame. Reversible means are provided for driving the loading cart and the alignment frame at different speeds in a loading and a reverse direction so that the loading cart can rapidly move from the quench chamber enabling a portion of it to enter the furnace chamber and retrieve the heat treated charge without having the alignment frame enter the furnace chamber.

The integral quench furnace system of this invention further includes control means for accelerating and then decelerating the loading cart as it retrieves the heat treated charge from the furnace chamber and returns it to position over the quenching media in the quench chamber. Actuatable pistons are provided for vertically positioning the support frame for the leading cart to enable the loading cart to be translated horizontally from various vertical levels to enter the furnace chamber, lift the heat treated charge, and immerse the charge in the quenching media.

After the quenching has been completed, the loading cart may be vertically returned to its initial or home" position within the quench chamber and both the loading cart and the alignment and unloading frame may be translated horizontally away from the furnace toward an unloading station. During this translation the loading cart is disengaged from its drive mechanism until alignment with the unloading platform has been achieved by the alignment frame. Means are then provided on the unloading platform for engaging the loading cart and translating the loading cart horizontally out of the quench chamber onto an unloading platform where the charge can be removed and the portions of the cart which enter the high temperature chamber can easily be wiped clean.

One feature of the apparatus of this invention is that a rapid translation of a heat treated charge from the furnace into the quenching media can be obtained without distortion, sliding, or uncontrolled movement of the heat treated charge.

Another feature of the heat treating furnace system of this invention is that the heat treatment and quenching of the heat treated charge can be accomplished rapidly in a controlled manner within a closed system.

Another feature of the apparatus of this invention is that it is not necessary to leave any portion of the transfer mechanism in the heat treating chamber during heat treatment of the charge so that contaminants are not thereby introduced into the heat treating chamber.

Yet another feature of the heat treating furnace and transfer mechanism of this invention is that the apparatus can be readily automated for heat treating a series of charges in a programmed heat treating, quenching and removal cycle.

Still another feature of the heat treating furnace of this invention is that the furnace chamber is separated from the quench chamber by means of vertically sliding gates which do not require elongation of the quench chamber to maintain a vacuum within the furnace chamber and to permit automatic translation of the heat treated charge from the furnace chamber into the quench chamber.

Yet another feature of the heat treating equipment of this invention is that the charge transfer mechanism lifts the charge off of the furnace hearth and accelerates and then decelerates in transferring the charge to the quench chamber.

Still another feature of the heat treating equipment of this invention is that atmosphere facing seals are eliminated by the use of hydraulic actuators to operate the furnace mechanism.

These and other features of the heat treating furnace and transfer mechanism of this invention will become more readily apparent from a consideration of the following detailed description and the appended claims when taken in conjunction with the attached drawings which may be briefly described as follows:

FIG. 1 is a partially sectioned view taken vertically through a plane substantially parallel to the longitudinal axis of an integral quench furnace system constructed in accordance with this invention;

FIG. 2 is an enlarged partially sectioned view through a plane substantially parallel to the longitudinal axis of the quenching chamber showing a transfer mechanism constructed in accordance with this invention;

FIG. 3 is a perspective view of an A-frame charge support member from the quench chamber, a forked loading cart, and an alignment frame of a transfer mechanism constructed in accordance with this invention;

FIG. 4 is an enlarged transverse sectional view taken substantially along lines 4-4 of FIG. 2;

FIG. 5 is a somewhat diagrammatic view of the drive system for a transfer mechanism as shown in FIG. 3;

FIG. 6 is a horizontal sectional view taken along the longitudinal axis of the furnace system showing the relationship between the hearth members and the transfer mechanism;

FIG. 7 is a partial sectional view taken through a vertical plane substantially parallel to the longitudinal axis of the system showing the furnace chamber and the quench chamber showing a transfer mechanism constructed in accordance with this invention in the charge pick up position;

FIG. 8 is a transverse sectional view through the quench chamber showing a transfer mechanism constructed in accordance with this invention with the support A-frame in the fully upward position;

FIG. 9 is an enlarged view of the vertical positioning mechanism for the transfer mechanism shown in FIG. 8 showing the pistons position when the A-frame support is in position for the loading cart to enter the furnace chamber;

FIG. 10 is an enlarged partially sectioned view of the drive chain and loading cart engaging mechanism used with the transfer mechanism constructed in accordance with this invention;

FIG. 11 is an enlarged segmental view of the alignment members for the transfer mechanism and loading platform constructed in accordance with this invention;

FIG. 12 is a vertical sectional view taken through a plane substantially parallel to the longitudinal axis of the integral quench furnace showing the transfer mechanism as the loading cart begins to be driven onto the unloading platform in accordance with the mechanism of this invention; and

FIG. 13 is a time sequencing diagram for operation of an integral quench furnace having a transfer mechanism constructed in accordance with this invention.

Referring now to FIG. I, the basic construction of the integral quench vacuum or atmosphere furnace with the transfer mechanism of this invention can be seen in cross-section. While the furnace can readily be adapted for vacuum or selected atmosphere heat treatment, it will be discussed for use with vacuum alone. The integral quench furnace system comprises a furnace chamber 10 and an integrally attached, horizontally disposed quench chamber 12. A horizontally and vertically translatable fork-type charge loading platform 14 is positioned adjacent the entrance door to the furnace chamber and an unloading platform 16 is spaced near the discharge door from the quench chamber 12 in fixed relationship with the quench chamber.

The furnace chamber includes a refractory insulating lining 20, a set of longitudinally extending elevated hearth members 22 (see FIG. 6), a vertically slideable furnace entrance door 24 and a vertically slideable furnace exit door 26. The doors 24 and 26 are juxtaposed in sealing relationship with the entrance and exit to the furnace chamber 10 by means of

resilient sealing members

25 and 27 mounted in appropriate grooves in the doors so as to slide into sealing relationship with the entrance and exit framework, respectively. The doors 24 and 26 include retractable refractory radiation shields or plugs 27 and 28 which are extendible by means of

hydraulic piston actuators

29 and 30 into closing relationship with the refractory lining of the furnace as shown in FIG. 1. The

actuators

29 and 30 in the piston extended position maintain plugs 27 and 28 in contact with the lining 20. The shields and the furnace lining, for example, may be graphite or other refractory material.

A vacuum tight compartment 31 is integrally connected to the furnace chamber 10 and the quench chamber 12 for receiving the door 26 when it is opened.

The hearth, as best shown in FIG. 6, actually in the preferred embodiment comprises four refractory hearth members 22. These hearth members 22 are constructed of a suitable metal having a refractory material liner and mounted on vertically extending support bars 32 above the radiant heaters of the furnace (not shown). Any conventional radiant heating units may be used. For example these may be the tubular resistant heating elements disclosed in Us. Pat. No. 3,368,022 to Mescher et a]. or other similar resistant type heating elements.

The heat treating chamber 10 includes a vacuum tight, cold wall housing 34. The housing 34 includes the entrance and exit frames 36 and 38, respectively, which sealingly engage the

resilient seals

25 and 27 for providing an airtight seal between the vertically slideable doors 24 and 26 and the furnace 10. A vacuum pump 39 with appropriate exhaust conduit is pro vided for evacuating the furnace 10. Conventional cooling fans (not shown) may be provided intermediate the housing 34 and insulated lining 20. Additionally, an agitator 37 may be provided within the quench chamber 12 (see FIG. 8).

The transfer mechanism 40 is mounted within the quench chamber 12 and basically comprises a vertically translatable quench chamber A-frame charge support member 41 which carries a horizontally translatable forked charge loading cart 42 and a horizontally translatable guide and alignment frame 43 (see FIG. 3).

The vertically translatable A-frame charge support member 41, as best shown in FIGS. 2, 3 and 4, includes a pair of Iongitudinally extending rectangular side base plates 44 which are each connected at about their centers to a vertically extending angle iron support beam 46. The vertical support beams 46 are connected to each other by a transversely extending support beam 48 which has a flat upper surface 49. Four support struts 50 are connected to the upper end of the vertical support beams 46 and are inclined downwardly where they are attached to the opposite end portions of the side base plates 44 to form the typical A-frame configuration. The entire A-frame 41 may be made from heavy gage angle irons and plate stock joined by welding, bolting or any other conventional manner.

The vertical support beams 46 are provided in their outer channels with two pairs of longitudinally spaced, peripherally grooved rollers 52 near their upper and lower ends for riding on vertical guide bars 54 (see FIG. 6) within the quench chamber 12.

With continued reference to FIGS. 3 and 4, the horizontally extending side plates 44 of the A-frame charge support member 41 on their inwardly facing surfaces near their upper and lower edges are provided with a series of longitudinally spaced, rotatably mounted, alignment frame guide rollers or

wheels

56 and 60 which are peripherally grooved. The upper guide rollers 56, as shown in FIG. 4, are mounted for rotation on bushings 57 which are bolted or otherwise affixed to the side plates 44 of the A-frame. Some of the lower guide rollers 60 are mounted on bushings 61 which pass over

cylindrical shafts

62, 64 and 66 shown in FIG. 2. The remainder of the lower rollers 60 are bolted to the side plates 44 in a similar manner to rollers 56 so that they are rotatable. As shown in FIGS. 2. 3 and 4 there are five upper rollers 56 which are vertically spaced from five lower rollers 60. Both plates 44 are provided with these rollers. The exact manner in which the rollers are mounted may be varied as long as they can rotate.

The horizontally translatable guide and alignment frame 43 comprises a pair of substantially rectangular, transversely spaced, substantially parallel side guide plates 58 mounted between the upper and lower

grooved wheels

56 and 60 on the A-frame side plates 44 for horizontal movement thereover. Each side guide plate 58 is a flat sheet of metal which is basically longitudinally coextensive with the side 44 of the A- frame of the transfer mechanism on which it is mounted. As best shown in FIG. 5, the side guide plates 58 are juxtaposed between upper and

lower guide wheels

56 and 60 respectively so that the side guide plates 58 can be translated horizontally into and out of the A-frame. Each of the side guide plates 58 at about their centers mount a cylindrical, longitudinally extending guide rail 59. The rails 59 may be attached to the alignment frame side guide plates 58 by any conventional means such as by welding.

With continued reference to FIGS. 3, 4, 5 and 6, it will be seen that the forked loading cart 42 basically comprises three longitudinally extending, transversely spaced, cylindrical, barlike prongs or

lift members

90, 92 and 94. These prongs are connected to three transversely extending

support plates

96, 98 and 100 (see FIGS. 3 and 6), which are connected to a pair of longitudinally extending side plates 102 and 104 to form the support structure for the prongs 9094. The support plate 100 on its surface facing the unloading platform 16 fixedly mounts a pair of depending fingers 101. A pair of depending stop brackets 103 are mounted on

support plates

98 and 100 to depend in transversely spaced relationship therefrom. The fingers 101 and brackets 103 may be bolted as shown in FIGS. 3 and 10.

Each of the side plates 102 and 104 carry two pairs of vertically spaced wheels or rollers 106 (see FIG. 4) which have concave peripheral grooves therein for riding on the guide rails 59 on the side guide plates 58. The rollers 106 are mounted for rotation on bushings 107 which are bolted to the side plates 58 as shown in FIG. 4. Alternatively these rollers may be journaled in the side plates or mounted in any other manner for facilitating movement of the forked loading cart 41 on the rails 59. In other words, the rollers 106 are mounted in a manner similar to the

rollers

56 and 60 on the side guide plates 58. The rollers 106 not only permit easy horizontal movement of the forked loading cart 42, but also prevent pivotal movement of the loading cart when the cart is extended into the furnace chamber and picks up a load on the prongs 90, 92 and 94 (see FIG. 7). The rollers 106 must, thus, be attached to the side plates 102 and 104 of the forked loading cart 42 by bolts which are sufficiently strong to resist the shear force momentum ofa load on the

prongs

90, 92 and 94.

With continued reference to FIG. 3 and with reference to FIG. 5, it will be seen that the drive mechanism for the transfer mechanism 40 comprises a series of continuous chains and sprockets driven by a hydraulic motor 110. The motor 110 is coupled to a linear operator motor speed control valve 112 which regulates the motor speed by controlling the flow volume of hydraulic fluid into the motor through conventional hydraulic circuitry. The drive shaft 113 of the motor 110 is rotatably connected to a sprocket 114. The sprocket 114 operatively engages a mechanism drive chain 116. The drive chain 116 passes over a larger sprocket 118 which is nonrotatably connected to a second shaft 120. One end of the shaft 120 is connected to another small sprocket 122 which drives a chain 124 connected to a cam shaft sprocket 126. The cam shaft 128 drives an eccentrically mounted circular cam disk 130 having a smooth peripheral surface 131 which rides on the linear operator of the control valve 112. A tab 133 is mounted on the cam 130 for operating a limit switch, as will be discussed.

The other end of the shaft is nonrotatably connected to another small sprocket 132. The central portion of the shaft 120 nonrotatably mounts a forked charge loading can drive sprocket 134 so that the sprocket 134 rotates with the shaft. The forked loading cart drive sprocket 134 drivingly engages a loading cart drive chain 136 for driving the forked loading cart 42 as will be discussed. A pair of transversely extending lugs 138 are mounted on the forked loading cart drive chain 136 as best shown in FIG. 5.

The small sprocket 132 on the other end of the shaft 120 is connected by means of a side guide plate secondary drive chain 140 to a larger side guide plate speed reducing sprocket 142 which in turn is nonrotatably connected to a side guide plate drive shaft 144. The shaft 144 carries a pair of side guide plate drive

sprockets

146 and 148. The

drive sprockets

146 and 148 each engage the same type of tension drive mechanism for the side guide plates 58 so that only one of these mechanisms will be discussed. Referring to sprocket 146 it will be seen that this sprocket drivingly engages a side guide plate primary linear drive chain 150. The linear drive chain 150 has one of its ends connected to a tension wire cable 152 by means of a turnbuckle 154 which enables the tension to be varied in the wire cable 152. The other of its ends is connected to the cable 152 by means ofa U-shaped bracket 156 which is fixedly connected to both the chain 150 and the cable 152 by means such as bolting, welding, etc. The chain 150 also passes over an idler roller 151 on the stationary shaft 66 as shown in FIG. 4. The cable 152 also passes over a pulley idler roller 158 which may be rotatably mounted on the shaft 62 so that

rollers

151 and 158 are in substantially horizontal alignment. The U- shaped brackets 156 are each fixed to one of the side plates 58 by welding or bolting so that when the drive chains 150 and consequently the brackets 156 move in response to operation of the motor 110 the drive chains 150 will horizontally drive the side guide plates 58 either toward the furnace 10 or toward the unloading platform 16. Due to the sprocket gear ratios of the various sprockets in the system, however, the side guide plates 58 of the alignment frame are driven much slower than the forked loading cart 42. Any desired drive speed ratio can be used. About a 3 to 1 ratio has been found to be satisfactory.

Referring again to FIG. 1 it will be seen that the transfer mechanism 40 in the quench chamber 12 is mounted on a hydraulic piston assembly for vertical movement into and out of a liquid quench media 172 in the lower portion of the quench chamber 12. The piston assembly 170 is more clearly shown in FIGS. 8 and 9. It can be seen that the assembly includes a main piston 172 having a cylindrical piston rod 174 which extends downwardly into the quench chamber so that in its extended position, shown in phantom lines, the A-frame is in the quenching media 171 and in its retracted position the A- frame is at the same level as the unloading platform 16. A pair of auxiliary charge pick up

pistons

176 and 178 are mounted on opposite sides of the main piston 172 and have

pusher members

180 and 182 at the lower ends of the piston rods. The

pusher members

180 and 182 have flat lower surfaces for contacting the upper surface 49 of the A-frame. The auxiliary charge pick up

pistons

176 and 178 only extend a small distance sufficient to lower the A-frame into position for entrance into the furnace chamber beneath the charge so that the

forklift members

90, 92 and 94 are intermediate the hearth members 22. The

pistons

176 and 178 override the upward retracting action of the main piston 172 and in this fashion control the vertical spacing of the transfer mechanism below the charge as it enters the furnace chamber.

A pair of

adjustable stop members

184 and 186 are mounted at opposite ends of the upper surface 49 of the A- frame so as to prevent the A-frame from canting when the main piston 172 is in its retracted position and the A-frame 41 is out of the quench media.

With reference to FIGS. 3, 4, 5, 6 and 7, the operation of the transfer mechanism will now be discussed. With

pistons

176 and 178 fully extended, the motor 110 is activated to drive the

prongs

90, 92 and 94 of the forked loading cart 42 into the furnace chamber by driving the sprocket 114 counterclockwise causing a counterclockwise movement of the chain 116. This drives the sprocket 1 18 and the drive shaft 120 in a counterclockwise direction. Counterclockwise rotation of the shaft 120 similarly rotates the forked loading cart drive sprocket 134 counterclockwise thereby causing the loading cart drive chain 136 to move counterclockwise so that the lugs 138 which extend transversely from each side of the drive chain 136 move toward the left hand end of the system as shown in FIG. 5. These lugs engage the downwardly and transversely extending fingers 101 and brackets 103 mounted on the transverse support plate 100 of the forked charge loading cart 42. The lugs 138 engage a shoulder 139 on the brackets 103 and drive the empty cart in a forward direction toward the position in the furnace chamber shown in FIG. 7. As shown in FIGS. 3 and 10 the bracket 103 is bolted to both

transverse supports

98 and 100.

At the same time, the sprocket 132 rotates counterclockwise with the shaft 120 driving the chain 140 and the sprocket 142 counterclockwise but at a much slower rate due to the gear ratio between the

sprockets

132 and 142. The rotation of the sprocket 142 additionally causes a counterclockwise rotation of the shaft 144 and the side guide plate drive

sprockets

146 and 148. Rotation of these sprockets drives the chain 150 and, concomitantly, through the brackets 156 synchronously drives the side guide plates 58 to the left as shown in FIGS. 6 and 7 toward the furnace chamber 10 but at a much slower speed than that with which the forked loading cart 42 is driven. The forked loading cart 42 and the side guide plates 58 of the alignment frame 43 are shown in their fully extended charge pick up position in FIG. 7. Only the

prongs

90, 92 and 94 of the loading cart 42 enter the furnace chamber 10, thereby reducing the possibility of contamination.

At the same time the sprocket 122 on the shaft 120 through chain 124 drives the sprocket 126 and the cam 130 so that when the loading cart has reached a predetermined position in the insulated furnace chamber the cam 130 through tab 133 may trip a limit switch causing the motor 110 to stop (the position of the forked loading cart may also be controlled by manual control of motor 110). The forks of the loading cart 42 at this time are positioned beneath the charge in the furnace chamber 10.

The

pistons

176 and 178 are at this time returned to their retracted position as shown in FIG. 9 causing the

forks

90, 92 and 94 to lift the charge off the hearth. The motor 110 is then reversed, the respective drive chains, sprockets and shafts are all driven in the opposite direction causing the lugs 138 to engage the fingers 103 and return the forked loading cart 42 from the furnace chamber into the quench chamber 12. The side guide plates 58 are also returned from their position adjacent the furnace chamber (see FIG. 7) into the quench chamber but again at a much slower speed. During return of the forked loading cart 41 and the alignment frame 43 from the pick up position to the quench chamber, however, the peripheral surface 131 of the eccentrically mounted cam 130 first rides out of contact with the motor control 112,. causing acceleration of the motor, then after a short period out of contact, depresses the motor speed control valve 112 as the cam rotates clockwise (FIG. 5 so that the motor decelerates as the forked loading cart 42 and the alignment frame 43 return into the quench chamber 12. This controlled acceleration, fixed speed operation and controlled deceleration of the transfer mechanism prevents distortion of the charge and damage to the charge due to jerking movement of the transfer mechanism which might otherwise occur.

While the horizontally translatable loading cart 42 and alignment frame 43 are operated by the motor 110 a synchronized vertical movement of the A-frame itself must be accomplished to enable the transfer mechanism to enter the furnace, lift the charge off the furnace hearth and return the charge to the quench chamber and then lower the charge into the quenching media. This is accomplished as discussed with reference to FIGS. 8 and 9 by means of the main piston 172 and the auxiliary charge pick up

pistons

176 and 178. lmmediately prior to the time the forked loading cart 42 is to enter the furnace chamber 10 the

pistons

176 and 178 are extended, as shown in FIG. 9, to lower the A-frame 41 by about 2 inches so that the straight cylindrical forklift members -94 can just pass under the load sitting on the hearth pallet members 22.

As shown in FIG. 6, there are four hearth members 22 and the three

forklift members

90, 92 and 94 are spaced to fit intermediate the hearth pallets. When these forklift members are lowered by action of the

pistons

176 and 178 they can enter the furnace chamber intermediate the hearth pallets 22 and be raised to pick up the charge. The forked loading cart can then be returned without touching the hearth on sliding the charge across the hearth pallets 22.

Once the forked loading cart 42 is returned to its home" position within the A-frame 43, the main piston 172 is fully extended so that the A-frame 43, the forked loading cart 42, the alignment and unloading frame 41 and the charge are all quenched in the quench bath 71. The only portions of the transfer mechanism actually in the furnace, however, were the

cylindrical forklift members

90, 92 and 94.

It has been found that this system can be automatically preprogrammed with conventional circuitry and limit switches to perform the necessary functions or the various functions can be manually controlled by the use of conventional hydraulic and electrical switchingv It has been found that the total time for movement of the forklift loading cart 42 into the furnace chamber, picking up the charge, returning it to the quench chamber, closing the furnace exit door 26 and vertically descending into the quench media can be maintained at about 5 seconds with little difficulty with the apparatus of this invention.

After the quench has been completed the piston 170 is again activated to return the rod 174 to its retracted position. In this position the forked loading cart 42 is substantially coplanar with the unloading platform 16 shown in FIG. 17 The unloading platform 16 is provided with a separately operable motor 190 which drives an unloading drive chain 192, as shown in FIG. I, by means of a sprocket and drive shaft arrangement similar to that of the loading cart 42. To accomplish unloading the exit door 194 from the quenching chamber is opened and the motor 112 is reversed so that the sprocket 118 is driven clockwise (FIG. 5). This causes the lugs 138 to pass beneath the depending fingers 101 on the transverse support plate (see FIGS. 10 and 12) thereby disengaging the forked loading cart 42 from its drive chain 136. The side guide plates 58 of the alignment frame 43, however, are still engaged (see FIG. 5) through the drive shaft 120, the sprocket 132, the drive chain 140, the sprocket 142 and the drive shaft 144 so that the side guide plate drive chains and the tension cables 1S2 advance the side plates 58 to the right as shown in FIG. 12 toward the unloading platform 16.

Referring to FIG. 11, the rails 59 on the side plates 58 of the alignment and unloading frame 43 are each provided with axially extending conical indentations 204. Similarly a pair of cylindrical axially extending alignment rails 206 are provided on the unloading platform 16 (see also FIG. 6). Each of the unloading platform rails 206 is provided with an axially extending conical end portion 208 which is adapted to mate with the conical indentation 204 on the side guide plate rails 59 of the alignment frame 43. As the side guide plates 58 are advanced toward the unloading platform 16 positive alignment is obtained by alignment of the

end portions

204 and 208. The side guide plates 58 by means of rollers 106 and rails 59 (see FIG. 4) guide the forked loading cart 42 toward the unloading platform 16. The depending fingers 101 on the forked loading platform are transferred to a position where they depend on each side of the platform unloading drive chain 192. At the same time the motor on the unloading platform 16 is energized to cause a clockwise rotation of the drive chain 192. Drive chain 192 is also provided with a pair of transversely extending lugs 210, best shown in FIGS. 6, 11 and 12, which engage with the depending fingers 101 on the forked loading cart transverse support plate 100. The drive chain 192 thus continues movement of the loading cart 42 off the A-frame structure 41 and onto the unloading platform 16. The rollers 106 move out of engagement with the rails 59 and into operative engagement with the unloading platform rails 186 as the loading cart moves fully onto the platform 16. The charge is now in position to be removed from the forked loading cart 42 and the

forklift members

90, 92 and 94 can be wiped clean before being returned into the quench chamber 12 and into the furnace chamber to retrieve the next heat treated charge.

There are several advantages to using a forked loading cart such as used herein. For example each of the prongs or cylindrical lift members on the fork can easily be wiped clean ofthe quench media so that these members do not carry a corrosive or contaminant surface coating which is transferred into the furnace chamber during charge pick up. The door 26 is closed immediately after the charge is removed and the refractory plug 27 is extended into radiation tight relationship with the furnace chamber. Thus the furnace chamber can be backfilled immediately with the desired gaseous atmosphere and cooled so that the charge receiving door can be opened to receive the next charge. Closing of the door 26 also prevents splashing of the quenching media into the furnace chamber.

After the forked loading cart has been wiped clean the motor 190 on the unloading platform 16 is reversed causing the drive chain 192 to drive the loading cart 42 back onto the side guide plates 58. Alignment of the forked loading cart with the drive chain of the unloading platform is assured by means of the positive alignment of the rails 59 on the side plates 58 and the rails 206 on the unloading platform 16.

The overall operation of the integral quench furnace of this invention and the transfer mechanism can perhaps better be described by discussing a time sequence of functions being performed during transfer and unloading, as shown generally in FIG. 13. Again these functions may be manually or automatically controlled. For example, conventional circuitry may be actuated by a series of limit switches which are located physically within the furnace and which are closed by the position of the various members of the transfer mechanism and the furnace or manual controls may be provided for mechanically accomplishing each of the various functions by operating the appropriate drive motor or actuator for the element being driven. The first step in heat treatment with the furnace of this invention is to load the charge on the forked front end loader 14 shown in FIG. 1. The charge is placed on the refractory hearth members 22 by opening the front door 24 and actuating the motor for the loader 14 to raise the loader and advance the loader on its tracks into the furnace chamber. The loader is then lowered to place the charge on the refractory hearth members 22 and the loader 14 is retracted. The door 24 is closed. This completes the charge loading step 1. If an atmosphere is to be used the appropriate atmosphere can be directed into the furnace through a conventional inlet (not shown). After the proper condition either atmosphere or vacuum has been attained in the furnace chamber and the treating temperature has been reached, the charge is maintained in the furnace chamber 10 for the necessary length of time for the desired heat treatment.

As shown in FIG. 13 step 2, after the heat treatment has been completed since the quench chamber is evacuated to the partial pressure of the quench media, the furnace is backfilled to compensate for the pressure in the quench chamber 12 and the quench agitator starts agitation of the quenching media. The A-frarne assembly 41 is then lowered to the charge retrieval position by extension of the

pistons

176 and 178 to their fully extended positions in the upper portion of the quench chamber. Activation of

pistons

176 and 178 lowers the A-frame by approximately 2 inches so that the

lift members

90, 92 and 94 can pass beneath the charge in the furnace chamber intermediate the hearth pallets 22.

In step 3, which may be manually controlled or activated by a stepping switch, the insulated door 27 intermediate the quench chamber and the furnace chamber is retracted into the intermediate solid door 26 by means of the hydraulic actuator 30 which may be manually controlled through an appropriate hydraulic circuit or automatically activated. The intermediate door 26 with the insulated door 27 retracted therein is then lifted to approximately a half open position as best shown in FIG. 7. When the door is in the half open position, step 4 is performed. The forked loading cart 42 is activated. as explained, to enter the furnace chamber, as shown in FIG. 7, the

pistons

176 and 178 are fully retracted and the door 26 is fully opened. In step 5, the forked loading cart is withdrawn into the quench chamber 12, as shown in FIG. 2, with the heat treated charge thereon. The loading cart undergoes controlled acceleration and then deceleration in this step due to cam 130, as explained.

In step 6 the door 26 is closed. Next, in step 7, the piston 172 is activated to its fully extended position so that the transfer mechanism and charge are immersed in the quenching media 71 as shown by the dashed lines of FIGS. 1, 2 and 8. The charge is maintained in the quench media for the desired time. During the quench, the furnace may be backfilled, cooled and reloaded with the next charge.

In the eighth step, the piston 172 is returned to its fully retracted position raising the A-frame 41 and the charge from the quenching media. In step 9, the quench chamber is returned to atmospheric pressure and in step 10 the unloading door 194 is opened to atmosphere. Step 11 is the activation of the motor in the unload direction to align the forked loading cart 42 for egress onto the unloading platform 16. In step 12 the unloading platform motor is activated to drive the cart 42 onto the unloading platform. The

forklift members

90, 92 and 94 of the loading cart 42 can then be wiped clean before step 14 in which the motor 190 returns the forked loading cart 42 back into position adjacent the A-frame 41. In step 15, the lugs 138 of the drive chain 136 are driven counterclockwise to engage the depending shoulders 139 on brackets 103 and return the cart 42 onto the A-frame 41. The mechanism and furnace are now ready for the next heat treatment to be completed so that the quench cycle can begin.

As can be seen from FIG. 13 the operation of the furnace and transfer mechanism can be easily automated through conventional circuitry using a main stepping switch controlled by function or time operated limit switches. The functionally operated limit switches in conventional manner may be placed conveniently within the apparatus for tripping by its moving parts.

Among the many advantages of the integral quench furnace mechanisms of this invention is that mechanical rotary or linear seals which face the atmosphere are eliminated by the use of hydraulic drive motors and actuators throughout the system. This prevents the possibility of air leaking into the system through worn seals. The hydraulic fluids generally are compatible with the quenching media so that worn seals do not ruin the charge being treated but yet can be easily de tected.

What is claimed is:

1. A metallurgical furnace having a quench chamber and an elevated temperature heat treating chamber comprising:

means for dividing said quench chamber from said heat treating chamber; and

transfer means in said quench chamber for entering said heat treating chamber at the completion of the heat treating cycle, lifting the charge vertically and transferring the charge being heat treated into a quenching media in said quench chamber without sliding and rolling said charge, said transfer means being maintained outside said heat treating chamber until time for quenching said charge, said transfer means comprises vertically translatable means mounted for movement within said quench chamber and horizontally translatable means mounted for horizontal translation from within said vertically translatable means.

2. A furnace as defined in claim 1 wherein said vertically translatable means is an A-frame support member.

3. A furnace as defined in claim 1 wherein said horizontally translatable means includes a forked loading cart mounted so that only the fork prongs enter said heat treating chamber.

4. A furnace as defined in claim 1 wherein said horizontally translatable means comprises an alignment frame mounted for horizontal translation from within said vertically translatable member and a loading cart mounted for horizontal translation from within said alignment frame, said furnace further including drive means operatively connected to said vertically and horizontally translatable means.

5. A furnace as defined in claim 4 wherein said alignment frame comprises:

a pair of spaced guide plates;

a pair of longitudinally extending guide rails attached to the opposing inner surfaces of each of said guide plates; and

said loading cart comprises:

a plurality of axially extending cylindrical members;

a plurality of transverse support members spacedly mounting said cylindrical members, a pair of loading cart side plates, and a plurality of spaced roller pairs mounted on the outer surfaces of said loading cart side plates for movably mounting said loading cart on said guide rails.

6. A furnace as defined in claim 1 further including hydraulically actuated drive means for said vertically translatable member and for said horizontally translatable member, said hydraulic drive means having no seals which interface with the atmosphere.

7. A furnace as defined in claim 6 wherein said drive means comprise:

a hydraulic motor;

a chain and sprocket drive system connected to said horizontally translatable member for driving said member in a forward and reverse direction; and

a hydraulic piston attached to said vertically translatable member for vertically driving said vertically translatable member.

8. A furnace as defined in claim 7 wherein said drive means further comprise a pair of overriding auxiliary pistons mounted in said quench chamber for lowering said vertical translatable member by a sufficient distance to permit at least a portion of said horizontally translatable member to enter said heat treating chamber beneath the charge being heat treated, said auxiliary pistons being selectively actuatable to vertically translate said vertically translatable member so that said horizontally translatable member picks up said charge.

9. A furnace as defined in claim 7 further including means for accelerating and then decelerating said horizontally translatable member in a predetermined manner when it is driven from said heat treating chamber to said quench chamber.

10. A furnace as defined in claim 9 wherein said accelerating and decelerating means comprises a hydraulic control valve for varying the speed of said hydraulic motor.

11. A furnace as defined in claim 10 wherein said accelerating and decelerating means further comprises a cam member operatively connected to said chain and sprocket drive system for controlling acceleration and deceleration of said horizontally translatable member.

12. In a metallurgical furnace having a heat treating chamber and a horizontally adjacent quench chamber, a transfer mechanism comprising:

a vertically displaceable support member mounted within said quench chamber;

a drive assembly connected to said support member and to a wall of said quench chamber for moving said support member into a charge pick up position, a quench position and an unload position;

an alignment frame mounted within said support member for horizontal movement from within said support member;

a loading cart mounted within said alignment frame for horizontal movement between a charge pick up position,

a quench position and a charge unload position, said support member and said loading cart positions determining the vertical and horizontal positions of said loading cart during charge pick up, quench and unload;

means for driving said loading cart to said positions; and

means for driving said alignment frame.

13. A transfer mechanism as defined in claim 12 wherein said alignment frame comprises:

a pair of spaced guide plates, a pair of longitudinally extending guide rails attached to the opposing surfaces of said guide plates, and means for attaching said alignment frame drive means to said alignment frame; and said loading can comprises longitudinally extending side mem bers, means on said side members for riding on said guide rails, longitudinally extending charge pick up members for extending into said heat treating chamber and lifting said charge, and

means for connecting said loading cart drive means to said loading cart.

14. A transfer mechanism as defined in claim 13 wherein said loading cart has drive engaging members depending therefrom and said loading cart drive means comprises a motor driven chain having transversely extending members thereon for engaging said depending members to drive said loading cart into said charge pick up position and return said loading cart to said quench position.

15. A transfer mechanism as defined in claim 14 further including an unloading platform positioned adjacent said quench chamber and means on said unloading platform for moving said loading cart into the unload position.

16. A transfer mechanism as defined in claim 15 wherein said means on said unloading platform comprises:

a motor, an unload drive chain operatively connected to said motor and members on said chain for engaging said depending members to drive said loading cart into said unload position after said alignment frame has been driven toward said unload position.

17. A transfer mechanism as defined in claim 16 wherein said unloading platform further comprises means for aligning with said alignment frame when said alignment frame is driven toward said unloading platform.

18. A transfer mechanism as defined in claim 12 wherein said loading cart and alignment frame driving means comprise a motor driven chain and sprocket arrangement wherein said loading cart is driven at a faster rate toward said charge pick up position and quench position.

19. A transfer mechanism as defined in claim 18 further including means for disengaging said loading cart from its drive means after said loading cart is driven toward said unloading platform and means on said unloading platform for driving said loading cart thereon after said alignment frame has positioned said loading cart.

20. A metallurgical furnace having a quench chamber and a heat treating chamber and a transfer mechanism comprising:

a horizontally translatable loading cart;

a horizontally translatable alignment frame for mounting said loading cart;

means for vertically lifting said loading cart when said cart is placed beneath a load; and

means for driving said loading cart and said alignment frame at different speeds.

21. A transfer mechanism as defined in claim 20 wherein said driving means comprises:

a drive chain mounted over said first sprocket for engaging said sprocket and said loading cart for driving said load mg cart;

a pair of second sprockets attached to said shaft; and

Claims

1. A metallurgical furnace having a quench chamber and an elevated temperature heat treating chamber comprising: means for dividing said quench chamber from said heat treating chamber; and transfer means in said quench chamber for entering said heat treating chamber at the completion of the heat treating cycle, lifting the charge vertically and transferring the charge being heat treated into a quenching media in said quench chamber without sliding and rolling said charge, said transfer means being maintained outside said heat treating chamber until time for quenching said charge, said transfer means comprises vertically translatable means mounted for movement within said quench chamber and horizontally translatable means mounted for horizontal translation from within said vertically translatable means.

5. A furnace as defined in claim 4 wherein said alignment frame comprises: a pair of spaced guide plates; a pair of longitudinally extending guide rails attached to the opposing inner surfaces of each of said guide plates; and said loading cart comprises: a plurality of axially extending cylindrical members; a plurality of transverse support members spacedly mounting said cylindrical members, a pair of loading cart side plates, and a plurality of spaced roller pairs mounted on the outer surfaces of said loading cart side plates for movably mounting said loading cart on said guide rails.

7. A furnace as defined in claim 6 wherein said drive means comprise: a hydraulic motor; a chain and sprocket drive system connected to said horizontally translatable member for driving said member in a forward and reverse direction; and a hydraulic piston attached to said vertically translatable member for vertically driving said vertically translatable member.

12. In a metallurgical furnace having a heat treating chamber and a horizontally adjacent quench chamber, a transfer mechanism comprising: a vertically displaceable support member mounted within said quench chamber; a drive assembly connected to said support member and to a wall of said quench chamber for moving said support member into a charge pick up position, a quench position and an unload position; an alignment frame mounted within said support member for horizontal movement from within said support member; a loading cart mounted within said alignment frame for horizontal movement between a charge pick up position, a quench position and a charge unload position, said support member and said loading cart positions determining the vertical and horizontal positions of said loading cart during charge pick up, quench and unload; means for driving said loading cart to said positions; and means for driving said alignment frame.

13. A transfer mechanism as defined in claim 12 wherein said alignment frame comprises: a pair of spaced guide plates, a pair of longitudinally extending guide rails attached to the opposing surfaces of said guide plates, and means for attaching said alignment frame drive means to said alignment frame; and said loading cart comprises longitudinally extending side members, means on Said side members for riding on said guide rails, longitudinally extending charge pick up members for extending into said heat treating chamber and lifting said charge, and means for connecting said loading cart drive means to said loading cart.

16. A transfer mechanism as defined in claim 15 wherein said means on said unloading platform comprises: a motor, an unload drive chain operatively connected to said motor and members on said chain for engaging said depending members to drive said loading cart into said unload position after said alignment frame has been driven toward said unload position.

20. A metallurgical furnace having a quench chamber and a heat treating chamber and a transfer mechanism comprising: a horizontally translatable loading cart; a horizontally translatable alignment frame for mounting said loading cart; means for vertically lifting said loading cart when said cart is placed beneath a load; and means for driving said loading cart and said alignment frame at different speeds.

21. A transfer mechanism as defined in claim 20 wherein said driving means comprises: a motor; a shaft operatively connected to said motor for rotation therein; a first sprocket connected to said shaft for rotation therewith; a drive chain mounted over said first sprocket for engaging said sprocket and said loading cart for driving said loading cart; a pair of second sprockets attached to said shaft; and a pair of second drive chains connected to said second sprockets and to said alignment frame for translating said alignment frame.

22. A transfer mechanism as defined in claim 21 wherein said first sprocket is larger than said second sprockets so that said loading cart is translated at a faster rate than said guide rails.