US2940619A

US2940619A - Work transfer apparatus

Info

Publication number: US2940619A
Application number: US737070A
Authority: US
Inventors: Henry W Schramm; Warren H Tollefsrud
Original assignee: Midland Ross Corp
Current assignee: Midland Ross Corp
Priority date: 1958-05-22
Filing date: 1958-05-22
Publication date: 1960-06-14
Anticipated expiration: 1977-06-14

Description

June 14, 1960 I! uquw I: won! H QUINCH |1TRAN$FERII :{APPARATUS' mum.

! a WASHER l FIELL H. W. SCHRAMM ETAL WORK TRANSFER APPARATUS Filed May 22, 1958 ATMOSPHERE FURNACE DRAW FURNACE INVENTORS HENRY W- SCHRAMM BY WARREN H. ousrsnw hired States wonx TRANSFER APPARATUS This invention relates to work transfer apparatus for metal treating equipment and, more particularly, to a chain conveyor for transferring Work into and out of equipment located at either end of the conveyor.

The atmosphere batch type furnace with a vestibule outside the charge-discharge opening and which contains a quench tank below the opening is extremely popular in the heat treating field. Associated with this furnace other units of equipment are usually employed such as a washer, draw furnace, and liquid quench tanks containing other quenching media than the furnace quench tank. With this combination of equipment a large variety of heat treating processes such as annealing, tempering, carburizing, nitriding, hardening and carbon restoration can be accomplished.

The use of this equipment, however, presents a problem in relation to adequate means for charging and discharging the work from the various units of equipment that may be employed to heat treat the Work. The charging and discharging of work from a single unit of equipment such as the atmosphere furnace alone presents many problems since the work must be charged into and discharged out of the furnace vestibule through the same opening, and the area over the quench tank must be kept unobstructed for vertical movement of the quench elevator. It is thus desirable to be able to convey the work completely into and out of the furnace vestibule without the use of a complicated mechanism within the vestibule to move the work from the end of an external loading table or conveyor outside the furnace door to within the furnace.

Transfer between different units of equipment presents a more complex problem even when the two units are in line with their charge-discharge openings facing each otherbecause it is desirable to transfer the work into and out of each unit of equipment without manual assistance or auxiliary mechanism to transfer from one loading table to another. Various types of charge and discharge apparatus have been tried with only moderate degrees 'of success, and usually more than one mecham'sm is required when work is transferred from one metal treating unit to another.

Accordingly, novel work transfer apparatus has been developed which is capable of transferring work placed thereon into orlout of a unit of equipment located at either end of the apparatus. Further, the apparatus may be made'portable, as by the addition of wheels adaptable to run on tracks, so that the entire apparatus may be moved in a direction transverse to its chargedischarge motion whereby it may service several units of equipment located on either or both sides of its transverse direction of motion.

The novel work transfer apparatus employs a nonendless or double-ended chain with engagement means attached to each end of the chain and guide means for the chain whereby the end which is engaged with the work or a tray containing the work may be driven past the atent end of the mechanism to load or unload metal treating apparatus at either end of the work transfer apparatus.

For further consideration of what we believe to be novel and our invention, attention is directed to the following portion of the specification, the appended claims, and the accompanying drawing.

Figure l is a diagrammatic layout of metal treating apparatus in which the subject invention can be incorporated.

Figure 2 is a vertical cross-sectional view of the work transfer mechanism servicing a typical furnace.

Figure 3 is an enlarged, partial cross-sectional view of a portion of Figure 2 taken on lines 3-3.

Figure 4 is a plan view of one end of the chain with engagement means attached.

Figure 5 is a perspective, partial sectional view of the chain guides.

The illustrated apparatus according to the invention provides work transfer means suitable for use in conjunction with metal treating equipment for moving or transferring work to be treated to and from two stations located at opposed ends of the apparatus. The apparatus employs a double-ended chain comprising a series of pairs of wheels and interconnecting links. The wheels ride in guides which span the distance between the stations, and the guides are constructed to also prevent buckling of the chain. The work usually consists of articles to be treated which are placed on an article support tray, but the work may consist of the tray alone or the article themselves, for example, in the form of billets. Work support means is provided in the form of a roller conveyor comprising a series of pairs of aligned rollers which span the distance between the sta tions. Engagement means are attached to each end of the chain comprising a projection attached to each end of the chain which extends above the rollers for engaging the work when the work is being pushed, and adjacent each projection a releasable dog attached to the chain for engaging the Work when the work is being pulled. Means for releasing the dog such as a cam attached to the work transfer apparatus or the equipment being serviced may be provided to release the dog when the chain is in a predetermined position. Drive means is provided for reversibly driving the chain to push the work by means of said projections from the rollers to either of the stations and to pull the work by means of the dogs from either of the stations onto the rollers. Means may be provided for interrupting the continuity of the guides to permit the end of the chain which is not engaged with the work to be withdrawn from the path of travel of the engaged end of the chain.

Referring to the drawing, and specifically to Figure 1, a typical arrangement of metal treating equipment which the work transfer apparatus is adapted to service is shown in diagrammatic form. The work transfer apparatus is shown in position to load or unload work from the atmosphere furnace or the liquid quench. Also work may be transferred from the atmosphere furnace to the liquid quench or vice versa. Rails are provided on which the transfer apparatus can be driven or manually pushed to the second position, shown in phantom lines, to service the washer and draw furnace in a like manner. Work may be transferred in any sequence to each of the four metal treating units. For example, the work may be placed on the transfer appartus and moved to the washer where it will be loaded into the washer for degreasing. Next the work may be discharged onto the transfer apparatus and the apparatus positioned to charge the work into the atmosphere furnace for a heat treating process. The work may then be discharged from the atmosphere furnace and charged into the liquid quench and then back to the transfer apparatus. The transfer apparatus may then be positioned to transfer the work to the washer again and finally to the draw furnace for tempering. Of course, other sequences of operation and arrangement of equipment may be used to suit a particular need.

In Figure 2, the work transfer apparatus. 11 is shown in position to charge work'into and discharge work from the vestibule chamber 12 of atmosphere furnace 13. The heating chamber 14 of the furnace is formed by refractory wall'15, and the vestibule chamber 12 is formed by metal wall 16. A work support means in the form of a roller conveyor 17 extends through the vestibule and into the heating chamber and it consists of two lines of rollers 18. A similar roller conveyor 20 is located on transfer apparatus 11, and it consists of rollers 21 supported in holders 22 on angles 23. Rollers 18 are supported in the same manner, not shown, as rollers 21. Angles 23 are welded to frame 24.

Chain 25 of the work transfer apparatus comprises wheels 26, pairs of which are connected by axles 27; links 28 and 30 interconnect the axles in a linear manner. The chain meshes with

sprockets

31 and 32 which are driven by reversible motor 33 through reducer 34 a and drive chains 35 and 36. The reversible motor and reducer are located on platform 37 of frame 24. The chain is guided and prevented from buckling by guides 38 in which wheels 26 ride. Similar guides are provided in the vestibule of the furnace. If the chain utilizes links that interlock when in a straight line or if the chain is heavy enough, the guides would not have to prevent buckling, but merely guide the chain. Guides 33 are illustrated in the form of channels and will perform the dual purpose of guiding and preventing buckling. Work support 20 and chain guides 38 are commonly built as separate units as shown; however, theycould be combined into one structure.

On each end of chain 25 is located a rotatable dog, 40 on the left end of the chain and 40 on the right end, which is attached to a link 28 of the chain by means of pivot 41 and mountingjblocks 42. The lower end of the dog is heavier to maintain the opposite end in an upward engageable position with a projection on an article support tray, not shown, placed upon roller conveyor 7, 20, except when the lower end of the dog is moved upward by means to be explained later. Instead of a projection a recess or hole in the article support tray may be provided into which the upper end of the dog projects.

Spaced from each rotatable dog is'a projection, 43 on the leftend of the chain and 43' on the right end, which is attached to'a link 30 of the chain. The projection is of sufficient height to contact an article support tray on rollers 21. V V

Rotatable dogs 40 and projection 43 together cons'titute engagement means at each end of the chain. Dog 40 is adapted to engage an article support tray to pull it, and projection 43 is adapted to engage an article support tray to push it. For clarity in the appended claims work .is defined ;as the articles to be treated with or without a work support tray, or the work support tray alone. With the engagement means described an article support tray' will normally be used; however, a different type of engagement means, such as engageable jaws, may be used w-hen the work consists of billets or the like and no par- 45. This cam will move the lower end of dog 40 upward when the left end of the chain 25 is moved into the vestibule to load work therein.

In operation a tray of articles to be heat treated is placed on roller conveyor 20 of the work transfer apparatus and vestibule door 53 is opened.

Sprockets

31 and 32 are driven in a clockwise direction so that the upper portion of chain 25 is moved toward the furnace. Projection 43 on the left end of the chain as shown in Figure 2 then engages the forward edge of the tray and pushes it until it reaches the end of its forward travel near the forward end of platform 45 which is lowered into alignment with rollers '21 on the work transfer apparatus and rollers 18 in the heat treating chamber. As the left end of the chain advances the work towards the furnace, the right end of the chain will travel around sprocket 32 towards sprocket 31, sprocket 31 then being the only driving sprocket. Openings are provided in the lower side of guides 38 adjacent sprockets .31 and 32, to permit the non-engaged end of the chain, in this case the right end, to so travel around'the sprocket and be withdrawn from the path of travel of the engaged end of the chain. Hinged doors 54 and 55 may be provided adjacent each opening so that when the unengaged end of the chain passes out of the line of travel of the engaged end, the doors will drop to close the openings and permit the engaged end of the chain to slide easily in guides 38 over the closed .openings. Upon counterclockwise rotation of the sprocket the unengaged end of the chain will raise the doors and keep them open to permit the chain to travel around the sprocket to the top side of the loading apparatus. Figure 5 shows the hinged doors 54 and 55 on guides 38 from a position looking upward.

Guides similar to guides 38 are provided in the vestibule chamber 12 to permit the engaged end of the chain 24 to enter the vestibule and push the work tray'therein. This, of course, cannot be accomplished with an endless chain, and the fact that the chain can enter heat treating equipment at either end of the mechanism to load work therein serves as an important advantage over prior art structures 7 r I The upper end of dog 40 will be depressed by cam 52 located at the forward end of platform 45 as the chain enters the vestibule to charge the work therein. Dog 40, therefore, cannot catch on the work support tray to withdraw it when the chain is retracted. f

After the tray is properly positioned on rollers 18 in the vestibule, and the chain is withdrawn, vestibule door 53 will be closed and furnace door 56 will be opened; The tray will then be drawn into heating chamber 14 on rollers 18. The tray may be drawn into theheating chamsecondplatform 45, 'both containing rollers 18 and being interconnected. by bars 46. The elevator is moved vertically by a hydraulic or pneumatic cylinder 47 and directedby guides 48.and 50' into quench tank 51. The

ber by any suitable means such as hooked rods inserted into the chamber from the back of the furnace, not shown, or by a'transfer mechanism, not shown.

At the end of the heat treating period furnace door 56 is again opened and the tray pushed back'into vestibule chamber 12; Thetray then rests on'platform'44 which has been raised to the position as shown in Figure 2, and furnace door 56 is again closed. The work may be quenched in quench tank 51 or'removed from the furnace to be quenched in an external quench tank. If the work is to be quenched in tank 51, the platforms are again lowered so that the work is immersed in the quenching medium; platform 45 will again be at the level of the loading apparatus and the furnace hearth. While the work is being quenched another tray may be charged into the furnace in the same manner as the After the quenching period is over, platform 44 is raised and vestibule door 53 is opened. -'Ihe left end of chain 25 is then advanced into the furnace, and dog 40 engages with the work tray since there is no cam on platform 44 to lower the dog into a non-engaging posi-' tion.

Sprockets

31 and 32 are driven in acounterclockwise direction, and the work is drawn onto rollers .21 of the charging apparatus. Upon further counterclockwise rotation of the sprockets projection 43' on the right end of the chain will engage the work tray to push it into equipment located on the left side of the transfer apparatus, such as the liquid quench located opposite to the atmosphere furnace in Figure l. Similar-ily dog 40' on the right end of the chain will engage the work tray to withdraw it from the liquid quench.

Platform 37 of the transfer apparatus may be equipped with wheels 57 so that the apparatus may be pushed into another position on tracks 58. For example, work discharged from atmosphere furnace or the opposed liquid quench may be charged into the washer or draw furnace of Figure l by moving the work transfer apparatus to the position shown in phantom lines.

When equipment such as the liquid quench, washer, or draw furnace is being charged, means must be provided to release the rotatable dog 40 or 41 so that the work tray will not be withdrawn when the chain is extracted. Accordingly, various devices can be used to accomplish this purpose, such as a cam which is actuated by a solenoid switch through a hydraulic or pneumatic cylinder. Similarly, the dog may be released by mechanical linkage through a lever located on the transfer mechanism or the equipment being charged.

Various modifications can be made in the apparatus illustrated and described without departing from the spirit of the claims, as the embodiments of the invention shown and described are intended as illustrative only.

We claim:

1. Work transfer apparatus for transferring work to and from either of two stations which comprises, in combination: a double ended chain; guide means spanning the distance between said stations for guiding said chain; support means extending between said two stations for supporting work placed thereon; engagement means at each end of said chain for engaging said work; and drive means for reversibly driving said chain, whereby said chain by means of said engagement means is adapted to transfer said work on said support means to and from said stations.

2. Apparatus according to claim 1 wherein said engagement means comprises: a projection attached to each end of said chain for engaging the work when said work is being transferred to either of said stations; and a releasable dog at each end of the chain, spaced from said projection, for engaging the work when said work is being transferred from either of said'stations.

3. Work transfer apparatus for transferring work to be treated to and from either of two stations located at opposed ends of said apparatus which comprises, in combination: a double ended chain comprising a series of pairs of wheelsand interconnecting links; guide means spanning the distance between said stations for guiding said chain wheels and preventing buckling of said chain; a series of pairs of aligned rollers spanning the distance between said stations for supporting said work; a projection on each end of said chain extending above said rollers for engaging said work when said work is being pushed; a releasable-dog at each end of said chain, spaced from said projection for engaging the work when said work is being pulled; means for releasing said dog when said chain is in a predetermined position; drive means for reversibly driving said chain to push said work by means of said projections from said rollers to either of said stations and to pull said work by means of said dogs from either of said stations onto said rollers; and means to permit the end of said chain which is not engaged with said work to be withdrawn from the path of travel of said engaged end of the chain.

4. Work transfer apparatus adapted to be moved for charging and discharging work into and out of a plurality of metal treating units which comprises, in combination: a frame; a double-ended chain; guide meansattached to said frame and spanning the distance between two opposed ends thereof for guiding said chain; support means attached to said frame for supporting work placed thereon; engagement means at each end of said chain for engaging said work; means attached to and for moving said frame into alignment at either of said two opposed ends thereof with one of said metal treating units; and drive means attached to said frame for reversibly driving said chain whereby said chain by means of said engagement means is adapted to charge work into and discharge work out of said metal treating unit.

5. Apparatus according to claim 4 wherein said means attached to said frame for moving it comprises wheels adapted to ride on tracks, and said plurality of metaltreating units is located adjacent said tracks with chargedischarge openings of said equipment being aligned substaritially perpendicular to said track.

6. Apparatus according to claim 4 wherein said engagement means comprises: a projection attached to each end of said chain for engaging the work when said work is being charged; and a releasable dog at each end of the chain, spaced from said projection, for engaging the work when said work is being discharged.

7. Work transfer apparatus adapted to be moved on tracks for charging and discharging articles to be treated into and out of a plurality of metal treating equipment which comprises, in combination: a frame; a double-ended chain comprising a series of pairs of wheels and interconnecting links; guide means attached to said frame and spanning the distance between opposed ends thereof for guiding said wheels and preventing buckling of said chain; a series of pairs of aligned rollers attached to said frame, parallel to said chain and spanning the distance between opposed ends of the frame for supporting said work;a projection on each end of said chain extending above said rollers for engaging said work when said work is being pushed; a releasable dog at each end of the chain, spaced from said projection, for engaging said work when said work is being pulled; wheels mounted on said frame adapted to ride on tracks situated between a first pair of metal treating equipment consisting of an atmosphere furnace on one side of said tracks and an opposed liquid quench tank located on the other side of said tracks,

and a second pair of metal treating equipment consisting of a washer on one side of said tracks and an opposed draw furnace located on the other side of said tracks; and drive means attached to said frame for reversibly driving said chain whereby when said frame is located between said first pair of metal treating equipment, said chain is adapted to charge and discharge either of said pair by means of said projections and dogs, and when said frame is located between said second pair of metal treating equipment said chain is adapted to charge and discharge either of said second pair.

8. Work transfer apparatus adapted to be moved for charging and discharging a plurality of metal treating units which comprises, in combination: a frame; support means attached to said frame for supporting work placed thereon; a double-ended chain having at one end thereofengagement means for engaging said work; guide means attached to said frame for guiding said chain; means attachcd to and for moving said frame into alignment with one of said metal treating units; and drive means attached to said frame for reversibly driving said chain whereby said chain by means of said engagement means is adapted to charge work into and discharge work out of said unit.

frame; support means attached to said frame for support-' ing work placed thereon; a pair of sprockets located in a common plane, attached to said frame at opposed ends thereof; a double-ended chain of sufficient length tospan the distance between said sprockets so that said chain 5 chain whereby said chain by means of said engagement paratus and a releasable dog at the same end of the chain, spacedfrom the projection, for engaging said work when said'work is being pull ed to discharge it out of said unit. I

14. Work transfer apparatus adapted to be moved for charging and discharging work into and out of'a plu- V rality of metal treating units which comprises,in combinationda frame; a doubie-ended chain; first guide means attached to said framc and spanninga distance between means is adapted to transfer work to and from either -10 twoopposed ends thereof for guiding said chain; first sup- -of said stations; guide means spanning the distance be tween said stations for guiding said chain, andrneansfor' disrupting the continuity of said guide means adjacent to said sprockets to permit the end of said chain which port means attached to said frame for supporting work thereon; engagement means at each end oftsaidchain for engaging said work; second support means associated with feach of saidmetal treating units for supporting work isnot engaged with said work to, be withdrawn from thereon; second guide means associated with eachof said the path of travel of said engaged end of said chain. 5 i

11. Work transfer apparatus 'for transferring work to and from either of two stations located at opposed ends of said apparatus which comprises, in combination: a

engagement means on both ends of said chain for engaging said work; drive means for reversibly driving the chain whereby said chain by means of said engagement means is adapted totransfer work to and from either of said chain, said guide means having an apertureadjacent each sprocket to permit the unengaged end of said chain to be i withdrawn from the path of travel of the engaged end. of

said chain; and doors hinged to said guide means adjacent" said apertures therein whereby the aperture through which the unengaged end of said chain passes is closed by said doors to form acontinuous path in said guide means for the engaged end of said chain;

12,"In combination with metal treating apparatus hav- 40 ing a treating chamber, a charge-discharge opening, first support means for supporting work in said chamber, and; first guide means associated with said chamber parallel 'to the direction of travel of work to be treated, im-

proved work transfer apparatus comprising: a frame; a second support means attached to said frame for supporting work thereon; a double-ended chain having at one end thereof engagement means for engaging is being pushed to charge it into said metal treating ap- 60 units;'means attached to and for moving saidirame to align said first guide means at either end of said two opposed ends with the second guide means of one; of said units; and drive means attached'to said frame for reframc; support means attached to Said frame fors11pport- "versibly driving said chain in said first and second guide ing work placed thereon; a pair of sprockets located in g a common plane, attached to said frame at opposed ends: thereof; a double-ended chain of 'suflicient length to'jspan V the distance between said sprockets so that said chain will always be engaged with at least one of said sprocketsj ""engagement means comprises: a projection attached to xn'eans'whereby said chain by means of said engagement --means is'adapted totcharge and discharge'said metal treating unit. I

15. Apparatus according to claim 14 wherein said each end of the chain for engaging the work when said work is beingucharged; and a releasable dog at each end of the chain, spaced from said projection, for engaging a the work when said'workis being discharged. stations; guide means spanning the distance between said stationsfor guiding and preventing buckling of'said 16. Apparatus according to claim 14 wherein said means attached to said frame for moving it comprises wheels adapted toride on tracks and said'plurality of metal treating units is located'adja'cent said trackswith chargedischarge openings of said units being aligned substantially perpendicular to said tracks.

-17. Work-transfer apparatus adapted to be moved for chargingv and discharging work into and out of a plurality of metal treating units which comprises, incom bination: a frame; first support means attached to said frame for supporting work thereon; a doubld-endedchain haying at one end thereof engagement means for engaging; said work; first guide means attached to said frame for guiding said chain; second support means associated with each of said metal treating units for supporting work thereon; second guide meansassociated with each of said metal treating units; means attached to and'for moving said" frame to align said first guide means with the second guide means of one of said metal treating units; and drive means attached to said frame for reversibly drivin g'said chain in said first and second guide means whereby said chain by means of said engagement means is 'adapted to charge and discharge said metal treatingunits.

References Cited inthe file of this patent V UNITED STATES PATENTS 1,597,401 Cope Aug. 24,1926 1,631,125 Happel June 7, 1927 FOREIGN PATENTS Austria ;V ..V May 10, 1912