US1835411A - Annealing apparatus - Google Patents

Description

Dec. 8, 1931. L. L. LEWIS,

ANNEALING APPARATUS 2 Sheets-Sheet 1 Filed Feb. 4, 1950 LESTER L.LEWI5/.

Dec. 8, 1931. 1.. LEWIS ANNEALING APPARATUS 2 Sheets-Sheet 2 Filed Feb. 4. 1930 11,15 dam Patented Dec. 8, 1%31 NIT'E STATES ATENT OFFICE LESTER L. LEWIS, 01* NEW GASiTLE, PENNSYLVANIA, ASSIGNOR. OF TWO-THIRDS T BLAIR EETRIP STEELQOMPA NY, OF NEW CASTLE, PENNSYLVANIA, A. CORPORATION- OF PENNSYLVANIA ANNEALIN'G APPARATUS Application filed. February 4, 1930. Serial No. 425,812.

This invention relates to improvements in,

apparatus for heat treating metal for increasing its ductility while largely eliminating discoloration, and has as itsessential object the improvement of apparatus such as set forth in detail in my co-pending patent application Serial No. 411,17 9, filedvDecember 2, 1929.

Reference is had to that application for details of problems anddifliculties met and overcome by the present invention which accom-' plish all ofthe advantageous results set forth in the said application with the additional advantages of increased efiiciency in safeguarding against air leakage and increased facility of uniformity of distribution of the protecting gas. 7

The invention comprises certain novel constructions, combinations, and arrangements of parts especially well adapted for annealing metal work while precluding access of air to the work being treated, all as will hereinafter he set forth and subsequently pointed out in the appended claims.

In the accompanying drawings Figure l is a transverse, vertical section through a work receptacle or housing incorporating an embodiment of the invention.

Figure-2 is a horizontal section taken on the plane indicated by line 22 of Figure 1 and looking downward, the work vbeingomitted.

Figures 3 and 4 are sections similar to Figure 1 of slightly modified embodiments.

Figure 5 is an enlarged, detailed, fragmentary, sectional perspective of one of the flanges of the tray of Figures 1 and 2,1

Figure 6 is a imilar fragmentary sectional perspective of a part of one of the side walls of the pot or housing which in operation is mounted on the tray.

Figures 7 and 8 are views, respectively, similar to Figures 5 and6 of slightly modifled embodiments of the parts shown.

Figures 9 and 10 are views similar, respectively,to Figures 7 and 8 of further slight identified, (Jo-pending application. It is common practice to place metal work to be annealed 111 an appropriate housing, seal the housing, and then insert the housing in a furnace where the work is raised to the requisite temperature for the required length of time for accomplishing the annealing operation, after which the housing and its contents of work are withdrawn and allowed to cool. A popular form of housing consists of a tray provided with grooves in its under face to guide the tray on a track of rollers which leads into the furnace, and upon the tray is commonly mounted an inverted, trough-like receptacle customarily referred to as a pot. The tray is provided with upstanding flanges, and the pot is proportioned to rest on the upper surface of the tray within the flanges spaced sufficiently therefrom to accommodate sealing material for sealing the joint between the pot and tray. Various forms of comminuted matter have been used to effect the sealing operation. Sand hasbeen successfully usedby me.

Referring to the drawings by numerals, 1 indicates the tray having the track-receiving grooves 2, 2 and the upstanding and surrounding marginal flange 3. During opera tion, the casing or pot l is mounted on the tary 1 and is dimensioned toallow an appropriate maacebetweenthe lower part ofthe side walls of the pot and the surroundingfiange 3 to provide a sealing space in which is placed the sand or other comminuted sealing mate rial 5. The lower edge of the casing or pot 4. may rest directly on the upper surface of the tray 1, but, as a further means of sealing, a portion of the 'comminuted material is preferably disposed beneath suchedge so as to be caused to become'compact'by the weight of the pot and thus resist movement of air past the line of jointure between the pot and the tray. Work of any appropriate character, such as indicated at 6, isarranged on the tray 1 within the pot 4. 7

As made clear in my above-identified copending application, I have discovered and proved by successful tests thatthe attempts heretofore made to protect the work 6 by the seal and by supple-mental means, such asthe direct introduction of gas into the pot 4,

have not fully accomplished the ends in view and have not safe-guarded the work against discoloration; whereas I have succeeded fin effectively preventing discoloration ot the work by distribution of gas not within the pot t but within the sealing sand 5, ,and, as set forth in my said co-pending application, I have been especially successful when distributing the gas by a tube or gassupply pipe embedded in the sand 5 approximately midway between the pot 4 and theadj acent flange oi? the tray, the pipe being proyided with appropriate jets for the dischargingpf gas and the gas being supplied under pressure sufficient gfOl causing the gas to envelop the entire area about the pot 4 within the flange 3. The pressure of gas employed is sufficiently above atmospheric pressure to effect sealing against ingress of air despite formation of vacuum within the pot 4. In the practicing of the invention according to the specific embodiment set forth in my said co-pending application, however, it is necessary to apply and remove the gas supplying coil or tube with each successive operation, and the present invention avoids the necessity for such labor and the inconvenience of handling the parts under the surrounding conditions.

To this end, a gas supplying passageway is formed in one of the parts adjacent the seal 5 in position to jet gas into the seal entirely about the same so as to effectively take the place of the removable coil or pipe disclosed in my said co-pend'ing application, and for purposes of this application a structure may be considered as preferred by me when providing such a passageway at both sides of the seal 5, though I have suceesstully accomplished very desirable results with such passageway at one side only. In the carrying out of a physical embodiment of the invention, the flange 3 is provided with a gas passageway or port 7 entirely about the flange with which communicates a gas supply pipe 8, the passageway or port 7 being provided with appropriate vents discharging into the sand seal 5. Also, in'the preferred embodiment a port or passageway 9 is formed in the wall of the pot 4 entirely about the pot and is supplied with gas through a pipe 10 having a flexible hose connection 11 detachably connected to the pipe 10. The port 9 is vented into the space occupied by the seal 5, so that gas may be jetted from both sides of the sealing sand 5 into the same to maintain a. sul'ficiently high resistance to prevent iii-- gress of air. The details of the mode of formation of the passages or ports 7 and 9 are susceptible of almost innun'ierable variations, and it will be understood that all such variations are within the intent, purpose, and scope of the present invention. One effective embodiment is illustrated in Figure 1 of the drawings and consists of the provision of an inwardly-opening rabbet about the upper -margin oi the flange 3, which rabbet subexaggerated for purposes of disclosure, but,

in tact, the opening is so narrowas to hardly be discernible in a drawing of the proportions employed. It will be obvious, of course, that the total cross sectional area of the entire passageway 14 about the entire flange 3 should be slightly less or certainly not more than the total cross sectional area of the gas supply pipe 8, so as to insure eliective jetting of the gas into the sealing material 5. The port 9 similarly is provided by forming a groove in the outer face of the vertical wall of pot 4, which groove extends entirely about the pot, and an angle bar 15 is arranged with its horizontal flange extending into said groove and welded along a line 16 to the pot 4. The lower or pendent flange ot the angle bar 15 is spaced from the lower wall of the said groove similarly tothe spacing of the pendent things of angle bar 12 from the base of the rabbet 0t flange 3, whereby an appropriate jetting opening 17 corresponding in location and dimensions to the opening 14 is provided so as to jet the gas supplied through pipes 10 and 11 into the sealing material 5 from the opposite side from the jetted from the passageway 7.

As clearly shown in Figures 7 and 8, the jetting openings 14 and 17 may assume the form of perforations 14; and 17, respectively, or any other form adapted for effective distribution of gas across the area be tween the flange 3 and the pot 4. As the structural parts seen in Figures 7 and 8 are otherwise identical with those seen in Figures 1, 5, and 6, the same description will equally apply and the same reference numerals have, therefore, been applied to said Figures 7 and 8. I

As seen in Figures 9 and 10, the jetting openings may be provided by having the pendent flange of the angle plate overlap the adjacent surface of the wall of the pot or flange, as the case may be, to produce a downwardly instead of laterally directed opening, as seen, respectively, at 14 in Figure 9 and at 17 in Figure 10. The structural parts shown in Figures 9 and 10 aside "from this overlapped condition with the resulting directional change in the jet being identical with that above described, the same description will equally apply and the same reference numerals have been employed on said Figures 9 and 10.

The operation is the same as that described in my above-identified co-pending application except for the deliveryof the gas at the sides of the sealing space instead of substantially midway thereof. The coils, strips, bars, or

, other work 6 are placed on the tray 1 and the potl lowereddown over such work;- "The sand or other appropriate comminuted sealing material 5 18 then tamped in the space about the pot 4 within the fiangeB. Ordinarily, -a smallv portion ofsand will have been placedinposition to receive, the lower edges of the pot t as they come to rest on the trayl so as to :en-

hance the sealing effect. Theis'eali'ng mate.

rial is preferablytamped inplace untilwthc entire space is filled, and then the housing or enclosure for the work consisting of the tray and pot is moved into the annealing furnace. It should be understood, of course, that the flexible pipe 11 is detached and a sufficient portion of the connections for the pipe 8 is also detached to allow the structure to move freely into the furnace. After the required baking, the work and its enclosure are withdrawn and allowed to cool. Just as soon as the parts are removed from the furnace,

, the connections for pipes 8 and 10 are made the upward pressure and such upward pres sure cou'nterbalances atmospheric pressure and prevents any air from finding its way into the pot 4 under the edges thereof. Also, since the gas burns freely little if any finds its way into the pot, or at all events, whatever gas does find its way into the pot does no injury since through numerous successful tests I have been able to produce steel work having a highly polished surface absolutely T free from spots or stains or other discolorations such as occur when air finds it way into the pot l, or as occur under whatever con-- ditions arise when a counterbalancing pressure of gas is introduced directly into the pot 4 rather than into the sealing space.

I also find that it is entirely feasible to produce highly satisfactory results by the employment of a single gas-discharging passageway. For instance, the passageway T may be employed without the employment of the passageway 9, or the passageway 9 may be employed without the employment of the passageway 7, and if the gas under pres-- sure is continuously supplied during the cooling operation, the finished work is found to be free from discoloration.

In Figure 3, I have illustrated the struc ture provided with the single passageway in the flange of the tray, while in Figure 4 l have illustrated the same combination with the passageway' provided in thepot alone, and as these structures are otherwise identical with those shown in Figures 1,2, 5, and 6, thesame reference numerals have beenapplied to these figures of the drawings and the same descriptive matter is applicable.

It will be of course, understood that the jet openings 14, 17, 14 and 17.will all be of sufficiently reduced cross sectional area to allow substantially uniform distribution of gas from the supply pipe and, accordingly, the total cross sectional area of the jets in any instance will not exceed the cross sectional area of the gas supply pipe. And it should also be understood that while the gas passageways have been thus illustrated and describedas produced by a substantially integralformation of the material of the Walls of the enclosure, other modes of providing the gas passageways may well be employed, such as the welding of an appropriate tubing in properlocation with respect to the parts.

. The art or process disclosed herein isnot made the subject of claim in this application because it is claimed in my co-pending application Serial No. l79,051, filedAugust 80,

' What is. claimed is '1. In apparatus for heat treating metal work, anenclosure'for work having a sealing space and having a gas passage in the wall of the enclosure extending along and dis charging into said space throughout the length of the space.

2. In apparatus for. heat treating metal work, an enclosure for work having a sealing spaceand havinga gas passage in the wall of the enclosure extending along and discharging into said space throughout the length of the space, in combination with means for supplying gas under pressure to said passage.

. 3. In apparatus for heat treating metal work, anenclosure for work having a sealing space and having a gas passage in the wall of the enclosure at each side of said space extendingalong and discharging into said space throughout the length of the space.

4. In apparatus for heat treating metal work, the combination of separable enclosure parts spaced to provide a sealing opening be tween said parts, one of the parts being formed with a gas passageway extending along and commui'iicating with said opening substantially continuously throughout the length of the opening.

5. In apparatus for heat treating metal work, the combination of separable enclosure parts spaced to provide a sealing opening between saidparts, each of the parts being formed-with a gas passageway extending along and communicating with said opening substantially continuously throughout the length of-the opening.

6. In apparatus for heat treating metal ids rio

its

work, the combination of separable enclosure parts spaced to provide a sealing opening between said parts, one of said parts being formed with a cutaway portion, and a cover plate for said cutaway portion enclosing a space to provide a gas passageway and means for supplying gas under pressure to said passageway, the passageway venting into the sealing-opening space.

7. In annealing apparatus, a tray adapted to receive work and to receive an enclosing housing for the work, the tray being formed with a gas passagewayin outer portions of its walls having discharging outlet means eX- tending substantially continuously throughout the margin of the tray for discharging gas inward from and along said margin.

8. In annealing apparatus, a tray adapted to receive work and to receive an enclosing housing for the work, the tray being formed with. a gas passageway in outerportions of its walls discharging inward from and along the margin of the tray substantially continuously of said margin, and means for supplying gas under pressure to said passageway.

9. In apparatus for annealing metal work, the combination of a tray for receiving metal work to be annealed, an enclosing housing adapted to surround metal work on the tray, the tray and housing being formed with gas passageways in their walls, and means for delivering gas under pressure to said passageways, the passageway for the tray having discharge openings toward the housing and the passageway of the housing having discharge openings toward the tray.

10. In annealing apparatus for metal work, the combination of a tray and a pot adapted to be removably mounted on said tray, the tray being provided with an enclosing flange surrounding and spaced from the pot to provide a sealing space therebetween, and means providing gas passageways about the pot andabout the flange of the tray, each of said passageways having means of discharge into said sealing space;

11. In annealing apparatus 'for metal work, the combination of a tray and a pot adapted to be removably mounted on said tray, the tray being provided with an enclosing flange surrounding and spaced from the pot to provide a sealing space therebetween, and means providing a gas passageway in the wall of and about the pot, said passageway having means of discharge into said sealing space.

. 12. In annealing apparatus for metal work, the combination of a tray and a. pot removably mounted on the tray, the tray being provided with an enclosing flange surrounding and spaced from the pot to afford a sealing space therebetween, and means providing a gas passageway within and about the wall of one of said parts, the passageway LESTER L. LEWIS.

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