US2639047A - Conveyer apparatus for heattreating metal parts - Google Patents

Description

May 1 9, 1953 H. N. msm 2,639,047

onvzym APPARATUS son rmATJRgA'rmG-mmrs med Feb. s. 195o s shmmfi if z M1 p ource of M.y19,*1953 l* .H "N, @EN .l 2,639,047

com APPARATUS FOR HEAT-TREATING mM. FAITS, I Filed Feb. s, 195o sfsnqm-snm a boaoenoo;

59 F57 saka f; 5 l 1 rif L i @harold 'CYL IPdeYk A., CQAJAM, 'www Home v May 19, 1953 H. N. IPSEN. 2639,@47

- Comm-APPARATUS rok mT+ TRBATING-mAL pms Fild Fb. 5', 1950 SCUYCS OF COOLING MEDIUM [Ill Patentedv May 19, 1953 GONVEYEBAPIPARATUS FGRYHEAFE- 'mamma METAL-1y BAM-1s Hamm' 125011, Bio-kfora .1.11: Application February 3, 195th 'Serial No.' 14%326 (c1. 2.14am),

ThisV invention relates-:tof furnaces forfffheat treating meta-1 parts :in which the'partstare 'frst heated in a heating chamber and:y then.;transf` ferred toa quenching position.

One object ofthe invention isto 'transfer` .heat-v ed Workpieces outof the heating chamberiof the furnace by a novel yn'iechanism which permits the use ofan endless conveyor and which prevents `any heated portion of theconveyorfrom being unduly stressed.

Other objects and advantages of :the invention:

will become apparent from dthe following ld'etaziled description taken in connection with theaccompanying drawingsinwfhich Figure 1- isavr vertical sectional `View takenfeentrail-yV and longitudinally through heat treating apparatus embodying -the'fpresent invention.

Fig. 2 isl `a -f-ragmentary=-sectional fview ytakenalong the line Z-Z-of Fig; l1. i

Fig. 3 is 4a diagrammatic View `showingith partsy infpositions shown in Fig. 1,

"'Figs.' 4 and A''fare `fragmentary sectional views similar to illig.v 1 showing Ldiagrammaticallydifferent positions of the parts ofthe apparatus.

'-Pg. -6 -is a'lfra-gmentarysectional viewfftaken.

along the line6-6iof Fig'.4 1.

The-heat treating apparatus 4show-n inf the drawings to illustratev the present invention .in-

cludes a box-like 4frame 'l U- having an v/enclosedj quenching `tank or `Vessel AH rigidiwith- `the fr-'ame at one end thereof and adapted at its otherend` tosupport a furnace l2 in which workl-Wiis heated. The work'W may beta singlepieceprseveral fuel burners 25 from which hea-ted lgases riseu through thechamber 24 `andescape throughe top opening 26. At the frontend, thefurnaceis closed by e brick wa11121- having an v.aperture L2.8 formedtherein lfor the passage of the :.WQrk W into vfthe"furnaceand AI.1 l.rr 1e1-1if jelesediby efslidingf. inlet .door y29 having ya power aetuetcr :ML ,A bricklwall 3| at the rea-ref the furnace y is formed with en aperture .732 thereinecmmunieatineiwth as.chamber 33 vabove thebody 3,4 lof iqiiencliingl liquidwithin the tank TI l whichiaperture'is nor-v;

latter issIidable, vertically ,in an extensionl SG1-o the: toptwall-i l5 `and across the aperture by@ power actuatorf3l:..and,.when in `a01056.C1;iltiizii911,', engagesuanlextension of'xthe voon .IELof the ,Blume- The .workpieces W .after being transferred herir, zontally from the-muie I4` and out thmuh, @11.1.6- endppeningz-l-zzadter raisingpf hedoorg 3413 received' in the chamber '83 ,unithe'fflsent e 1191' a horizontal zplatformz- `.whichcomprises.,fl erfie of-iclosely--spacedrollers ifjaurnazled Q hszl connected:y .by `Yvla. 4ydke, 4.l I. .The :platform iS ,1m17.- mally disposed substantially at the levelfnofg the mum@ 'minut-is slidableialong vertieailieuide railsiz '.withiink Athe tank A.into I `and sont; pf; stille quenchingl :fluidi 34 iwhich-ifillsgthe-tanl: k,up to la@ 1evtel\.-belowthe muiileeiioor. ,P'Ifoy raise `randlower the-platform, fthe `yokeAl: is fsusnended-f'romaithe: rod of-.a lfluid actuator. mountedionvftheitopiiall 44.015 the tank. ,Atzthe rear .end-lof thetplatform 38, .thequenohing ftankfis formed with. .an ...Qiitl aperturezil5:through:fichich` the work is Lrenewed fromithe chamber ,above ,the .quenching liquidgand which .is iclosecl by ya sslidingioutlet v,door-,Mi an factuatorfdl Dischargecf .thcwcrk from fthe heating chamber: zlontothe. platformzfi initliehamher 3.3 abouevzthe.quenchingfliquidfis effected by one-er morek endless chains ort flexible` comm/Qns 4,3; which are: slidableflongitudinally tof; .thevfhelat' .e chamber in recessesAS: extending alQng .thexfldlf |11 offthelatter. Herein, there are :two silenced parallelchai-nsv meshing .positively with axially spaced Xsprockets-.50;disposed. outsideiof thecham: ber. 2&8 .andsecured toa shaftl. -ilhewlatter is journaled `.in suitable l:bearingssupported;on ethe furnace `.frame f and is .connected to and;` driuenv l by a'imotorx indicated diagrammatieally in Rigs', 'I1-he lchains are pulled. by .the .sprockets along` rer. casses-.49' in the Lheating 'chamberoori and .to-,- ward and through the end aperture 32. Erom the latter, veach-chain follows a path extending first in-to Nthecharndberil above the quenching liquids-34, ithen,'downwardly and along a horizqnta1- passage 53l'below the plate 2l andfinally,l along 4a vertical passage v{il} between 4the yfront furneee well vvisi themume 11061 f1/@bwk into .its recess in' the letter.- iThe Passage x53 iS.. defined vby the., plate .2| ,end eeethe .etei pecedlielewthe .latter and .euppcrtedpr trie imma J.One Orimcle-1i1ee eriebiiimeete ere .Secured te-ftiletehailsi .te erieeeeiliewerlk-w. en veneethesemetmerfd @ad tiirpiiehtheend ep r.- ture 32 in the rear brilgwalllf. fyjheluprlg.-

ject outwardly from the chains and, as the chains are advanced along the mufile floor, project above the latter and engage the part of the work adjacent the floor and facing toward the inlet end of the heating chamber I8. In the continued movement of the chains and the lugs, the work is slid along the chamber floor, the portions of the chains between the lugs and the sprockets 50 being subjected to the tension of pulling the work.

To prevent stretching or breaking of the chains 48 and thereby prolong their service life, the invention contemplates arranging the lugs 56 on the chains and positioning the sprockets 50 in a novel manner with respect to the heating chamber I8 to insure that the work may be transferred out of the latter without unduly stressing those portions of the chains disposed within the chamber during heating of the work therein. For this purpose, each chain has only one lug 56 thereon which is effective to engage the Work and transfer the same out of the heating chamber. Also, the sprockets are spaced from the inlet end of the chamber oor I1 along the chains and in a direction reverse to the direction of movement thereof (counterclockwise as viewed in Fig. 1) a distance at least as long as the heating chamber. With this arrangement, the chains may be stopped in such a position during heating of the work that the portions of the chains disposed within the heating chamu ber during the heating will -always be on the slack side of the sprockets during transfer of the work.

Preferably, to minimize the length of each chain subjected to tension, the sprockets are located Within the chamber 33 adjacent the outlet aperture 32 of the heating chamber I8 between the muilie floor and the platform 38 and below the level of the muille iioor. Thus, the work may be transferred directly from the muffle floor onto the platform as shown in Fig. 5.

During loading of the work or heating thereof as shown in Fig. 3, the chains 48 are stopped to position the lugs 56 between the outlet end of the heating chamber I8 and a point, indicated at A, which is spaced from the inlet end of the chamber along the chains and in the direction reverse to the movement thereof a distance, indicated at B, at least as long as the spacing of the sprockets from the chamber inlet end taken in the reverse direction along the chains. Herein, this spacing B of the point A from the inlet end of the chamber is approximately equal to the length of the chamber since the sprockets 58 are located adjacent the outlet end thereof. The heated portion of each chain, that is, that portion disposed within the heating chamber with the lugs positioned between the point A and the outlet end of the chamber, is indicated at C and the remaining or cooler portion is indicated at D.

Means shown diagrammatically in Fig. 4 is provided for positioning the lugs 56 between the outlet end of the heating chamber I8 and the point A during the time that the chains are idle. Herein, this means comprises a normally closed switch 51 connected in parallel with a normally open manual starting button 58 (see Fig. 4) in one of two lead lines L1 and La connecting the motor 52 to a source (not shown) of electrical energy. The normally closed switch is shown in closed position in Fig. 4. An actuating arm 59 for the switch is positioned in the path of one of the lugs 56 for engagement by the latter to move the arm in a direction to open the switch as shown in Fig. 1.

. ing a continuous flow of gas in through the sup- Let it be assumed that the chains are in their idle position with one of the lugs engaging the actuating arm 59 :and the switch 51 opened. When it is desired to transfer the work from the heating chamber I8 onto the platform 38, the starting button 58 is pressed manually to complete the circuit to the motor 52 for driving the chains clockwise as viewed in the drawings and moving the switch actuating lug 56 away from the actuating arm to permit the switch 51 to close and to energize the motor upon release of the starting button. The lugs move with the `chains into engagement with the work. At the time that the lugs initially engage the work (see Fig. 4), theheated portions C of the chains have advanced beyond the sprockets 50 and only the cooler portions D are disposed along the chamber iioor between the sprockets and the lugs. Thus, only the cooler portions are subjected to tension in the continued movement of the chains in which the lugs engage the work to advance the same out of the chamber. At the time that the work is pushed by the lugs across the gap between the muflle floor I1 and the platform and onto the latter (see Fig. 5), substantially all of the cooler portions have passed beyond the sprockets and the heated portions have advanced back into the heating chamber. The motor continues to run until the chains are brought back to their idle position (Figs. l and 3) in which the switch actuating lug again engages the arm 58 to open the switch and deenergize the motor.

To minimize oxidization of the surfaces of the workpieces W during heating and quenching thereof, air and moisture are eliminated from the quenching liquid 34 as well as from the spaces within the heating chamber I8 and the chamber 33 above the quenching liquid. For this purpose, a non-oxidizing gas such as a hydrocarbon gas is introduced into the chambers I8 and 33 in this instance through a supply pipe 60 which extends from a source of gas (see Fig. 1) disposed outside of the furnace and which communicates with the passages 53 and 54 at the junction of the latter. Exhaust outlets 6I and 62 are located respectively in the upper part of the heating chamber near the inlet opening 28 and in the upper part of the chamber 33 adjacent the outlet opening 45 thereof. By maintainply pipe, the two chambers will be maintained under a slight pressure so as to preclude the flow of air in through the inlet opening 28 and the outlet opening 45. To further exclude air from v entering the chamber 33 above the quenching liquid 34 through the outlet opening 45, a flaming gas curtain, indicated at 63 (Fig. 1) of a well known character may be provided lacross the opening. If desired, a similar curtain (not shown) may be provided across the inlet opening of the heating chamber.

For the purpose of cooling the quenching liquid without exposing the same to air, the tank II containing the liquid is formed with a heatexchanging wall 64 of the proper surface area exposed on one side to the quenching liquid 34 and on opposite side to a cooling medium 65 circulated across the wall in sufiicient volume to maintain the liquid at a desired quenching temperature. In this instance, the heat-exchange between the quenching liquid and the cooling medium is effected by a plurality of closed tubes or conduits 66 the walls of which form the heatexchanging wall 64 and are joined to the tank walls so as to constitute a continuation of the latter and, in effect, form a part of the tank enclosing the liquid. While the tubes may be disposed outside of the quenching tank, in the present instance, they extend into the latter from a source of cooling medium disposed outside of the tank, the cooling medium flowing through the tubes and the quenching liquid flowing past the tubes on the outer side thereof.

The cooling medium 95, which may be water, is circulated through the tubes 86 by a pump indicated diagrammatically at 61 (Fig. 6) and disposed between the tubes and the source of the medium. The quenching liquid 34 is circulated past the tubes by agitators 68 in the form of fan blades fast on shafts 69 which are driven by motors it mounted on the outside of the side walls of the tank. Preferably, bales 7l are positioned in the tank to cause the liquid to flow in a denite path, indicated by the arrows in Fig. 6, and circulate efficiently past the tubes. The initial removal of oxygen from the quenching liquid is eiected automatically by immersing a few heated metal parts therein prior to immersing the workpieces which are to be maintained bright.

In the operation oi the apparatus above de scribed, the doors 29, 35, and 46 are normally closed with the non-oxidizing gas flowing continuously into the heating and quenching chambers I8 and 33 through the passages 53 and 54.

Assuming that the chambers and the quenching liquid have been purged of air and moisture and that the chains 48 have been stopped with the lugs 56 positioned between the chamber outlet end and the point A, the work W is loaded in the heating chamber by opening the inlet door 29 for a short time and pushing the work manually onto the chamber floor I1. After heating the work for the proper time at the desired temperature, the intermediate door 35 is opened for a short time to permit the chains to advance in the manner described above completely around their paths and push the work onto the platform 38 across the gap between the latter and the mutlle floor i1. During such advance, the lugs follow behind the trailing ends of the heated portions C of the chains a distance which is at least as long as the spacing of the sprockets from the chamber inlet end along the chain and in the direction of movement thereof.

After the work W is positioned on the platform 38, the intermediate door 35 is closed and the platform is lowered to submerge the Work in the quenching fluid 34 for the desired time. Following the quenching, the platform is raised and the outlet door 46 is opened to permit the work to be slid off from the platform and removed from the quenching tank through the outlet opening 45 and the curtain 63 of flame covering the same. Because the heating and quenching chambers I8 and 33 are maintained under a nonoxidizing atmosphere, the workpieces are as bright when unloaded from the chamber 33 through the outlet opening 45 as they were upon entering the heating chamber.

This application is a continuation-impart of my copending application Serial No. 83,735 filed March 26, 1949, now abandoned.

claim as my invention:

1n a batch type heat treating furnace, the combination of, an elongated heating chamber having an outlet opening at one end through which heated work may be removed, an endless ilexible chain supported for endwise movement longitudinally through said chamber and said opening and adapted to pass freely beneath the work disposed in the chamber, said chain having a heated section disposed within the chamber and a cooler section disposed outsidey of the latter during heating of the Work therein while the chain is dwelling in a normal rest position, a sprocket meshing with said chain outside of said chamber and operable during turning of the sprocket in one direction to move said heated section past the work and said cooler chain section away from its normal rest position and toward and through said chamber and said opening, and a single abutment projecting outwardly from said cooler chain section and operable after advance of said cooler chain section through said heating chamber and into mesh with said sprocket to engage the work in said chamber and advance the same out of the chamber through said opening, said abutment being positioned on said cooler section to follow behind the trailing end of said heated chain section before engagement with the work in said chamber a distance at least as long as said heating chamber whereby only said cooler chain section is disposed between said lug and said sprocket during actual movement of the work out of said heating chamber.

HAROLD N. IPSEN.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 737,079 Chase Aug. 25, 1903 786,365 Kenworthy Apr. 4, 1905 876,183 Herrick Jan. 8, 1908 890,251 Thompson i June 9, 1908 1,168,313 Kenworthy Jan. 18, 1916 1,920,652 McKee Aug. 1, 1933 2,063,784 Bechtel et al. Dec. 8, 1936 2,116,070 Hoffman et al. May 3, 1938 2,223,603 Darrah Dec. 3, 1940 2,246,675 Gronemeyer June 24, 1941 2,247,770 Cox July 1, 1941 2,394,002 Ness Feb. 5, 1946 FOREIGN PATENTS Number Country Date 31,938 France Mar. 15, 1927 (Addition to 553,561)

158,111 Germany Jan. 28, 1905 617,567 Germany Aug. 21, 1935

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