US2670708A

US2670708A - Means for controlling the coating rollers and for replenishing the coating bath for strip galvanizing machines

Info

Publication number: US2670708A
Application number: US324460A
Authority: US
Inventors: Herman J Kalberkamp
Original assignee: Mesta Machine Co
Current assignee: Mesta Machine Co
Priority date: 1952-12-06
Filing date: 1952-12-06
Publication date: 1954-03-02
Anticipated expiration: 1971-03-02

Description

KALBERKAMP MEANS FOR CONTROLLING THE COATING ROLLERS -M arch Z, 1954 H, J.

7 AND FOR REPLENISHING THE COATING BATH FOR STRIP GALVANIZ ING MACHINES 3 Sheets-Sheet 1 Filed Dec. 6, 1952 v INVENTOR Herman JiKalberkamf 7 March 2,1954

-H. J. KALBERKAMP 2,670,708 MEANS FOR CONTROLLING THE COATING ROLLERS AND FOR REPLENISHING THE COATING BATH FOR STRIP GALVANIZING MACHINES Filed Dec. 6, 1952 I 3 Sheets-Sheet 5 Jay. 4,

INVENTOR Herman J Kalberkamp l atented Mar. 2, 1954 VMEANYS FORCONTROLLING THE COATING MACHINES 1 ROLLERS AND FOR REPLENISHING THE COATING BATH'FOR STRIP GALVANIZING Q Herman J. Kalberkainp, Whitehall, Pa., assignor to Mesta Machine Company, Pittsburgh, Pa., a corporation of Pennsylvania Application December 6, 1952, Serial N 0. 324,460 I reclaims. (01.:118-11) This invention relates to galvanizing and like coating of metal strip, andmore particularly to means and method of controlling the coating rollers and replenishing the coating bath.

In a galvanizing line a continuous strip of steel is passed through a furnace and thence down into a-pot full of molten zinc. The strip comes up from the pot between apair of coating rollers and thence through a cooling tower to solidify the zinc adhering to the strip. In the form of galvanizing line with which the present invention is concerned, the coating rollers are journaled between a pair of brackets mounted on opposite sides of the zinc pot and are vertically movable to raise the centers of the coating rollers to above the level of the zinc bath while the strip is moving and to lower the rollers entirely into the zinc bath when the strip stops. In a conventional line the exit end of the furnace hood extends for a relatively long way down toward the zinc pot, adjacent one side-of the pot between the bracket mountings, and beneath that end of the furnace hood a motor is mounted to drive two sets of shafts extending around the pot to operate screw jacks for raising and lower--' ing the coating rollers brackets. This blocks access to the pot on three sides and leaves only the fourth side, adjacent the portion of the strip leaving the zinc bath, accessible for replenishing the bath with additional blocks of zinc and general maintenance purposes.

In'accordance with the present invention provision is made for replenishing the zinc bath by automatically operating machinery mounted on the side of the pot nearest the furnace hood, which is advantageous because the cold zinc is thus added where the heat is greatest, i. e., where the preheated strip first enters the bath. In order to avoid interference with this automatic machinery, and yet at the same time to leave the opposite side of the pot clear for access to workmen, the conventional shafted drive arrangement is replaced by an arrangement comprising a motor on one side of the pot directly geared to move one of the pair of brackets supporting the coating rollers, a Selsyn generator adjacent and driven by said motor, and a Selsyn motor adjace'nt the other bracket and directly geared to operate the other bracket while receiving its power through the Selsyn generator. The electrical connections between the Selsyn generator on one side of the pot and the Selsyn motor on the other side of the pot are readily concealed to allow access to the pot by workmen, and the Se'lsynconnections synchronize the movement of the brackets so that the coating rollers remain in correct horizontal alignment as they are raised and lowered.

Other objects, advantages and details of the" invention will become apparent from the follow! ing detailed description and in the accompany-. ing drawings, in which I have shown for purposes of illustration only, a present preferred embodiment of my invention. In the draw-i ings: Figure 1 is a partially sectioned and broken away View of a portion of a galvanizing line em! bodying the invention; Figure 2' is a plan view corresponding toFigure 1;

Figure 3 is a section taken on thelineIII-III in Figure 4, in the scale of Figure 4;

Figure 4 is an enlarged top plan view of the zinc pot and associated structure shown in Figure 1, with details not shown in Figure 1 and with the zinc replenishing means omitted; and

Figure 5 is a partial section taken on the line- V-V in Figure 3.

Referring now in more detail to the drawings,-

there is provided a galvanizing line, one section of which includes a furnace with a hood ID for heating a continuous length of steel strip I I which passes out of the furnace around a guide roller 1 2 and down through an exit section II; of the hood to a sinker roller l4,'and thence vertically up between a pair of coating rollers I 5 and 16 to a guide roller II at the top of a cooling tower. The coating rollers l5 and I6 have parallel horizontal axes in the same horizontal plane on opposite sides of the strip II, and operate to squeeze excess molten zinc from the strip H as it leaves the upper surface [8 (Figure l) 01 a molten zinc bath 19 in a heated pct 20. I

The sinker roller 14 is journaled between a pair of brackets 2| (Figure 3) rigidly suspended beneath a beam 22 extending across the pot-'20 transversely of the direction of movement of the strip II. The beam 22 is vertically slidable between a pair of pillars 23, and a pair of handwheels 24 operate screw jacks (not shown) to adjust the vertical position of the brackets 2| and sinker roller i4.

The coating roller I5 is jo urnaled between a pair of brackets rigidly suspended beneath a beam-and the coating roller [6 is journaled between a like pair of brackets 21 rigidly suspended between a like beam 28. A pair of knives 29 are also suspended beneath the

respective beams

26 and 28 to scrape the respective coating rollers l5 and I6.

TENT OFFICE The beams 26 and 28- are secured at one end (the left in Figure 3) to a vertically movable member 30 which is in the general form of an inverted U and has oppositely projecting Vertical flanges 3! along the outer sides of its legs 39a; The flanges 3,1. are retained by and{ slidable along a pair of vertical channels 32 in a fixed frame structure 33. The member 30 rests on a nut 34 nonrotatably received in a cavity formed underneath the central portion of the membertii; and the threadedupper end of a vertical shaft 3% is screwed through the nut 34 to jack the member 30 up and down. The lower end of the shaft 35 is journaled in the fixed structure 33 and iskeyedto a worm wheel 36 driven: by aworm 31. keyed. on a shaft 58 driven by a reversible electric motor 40. The motor 40 is connected to a source of power through suitable controls and is operable to rotate the shaft 35 and thus jack the adjacent ends of the

beams

28 and 28 up and down simultaneously,

The other ends of'the beams 2t and-28 (to-the right in Figure 3) are jacked up and down through identical mechanical connections by a Selsyn motor 4!. A corresponding. selsyn-gfinerator 42 is driven directly by the rear end of the; drive shaft of the motorllhand powersthe motor 4|. through five transmission lines carried in a buried conduit 43 extending around the pot-.20 (as indicated diagrammatically in Figure 4- The operating characteristic of the generator 42 isto drive the motor 4:! atcxactly the same'rate and in the same direction as the motor 49, so that when the motor 40. raises and lowers the end of the

beams

26 and 28 adjacent to it the Selsyn; motor 4|. simultaneously raises and lowers the other ends of these beams to exactly the same extent. The coating rollers l and it are thus kept inhoriz-onta-l alignment in their raised and lowered positions. When the strip H is moving regularly through the baththe coating rollers i5 and l6 are disposed with their centers-at about the level of the bath, the exact level being adjustable through the motorsdfi and to control the coating, weight. Whenever the strip isstoppedforany reason the motor 4iis immediately oper-' ated to lower the rollers l5 and it below the surface of the bath in order to prevent the zinc. from, solidifying-on the, rollers while waiting for, the strip I I to resume its regularmovement.

The motors 4i! and 4.! and generator 42 are. mounted on opposite sides of the pot 2E} and do not obstruct entry to the other two sides of thepot. The coating rollers l5 and were mounted relatively close to the exit side of the pot, in terms of the general line of movement ofthe strip H, in order to increase the-clearancebertween the exit section l3 ofthe-furnace hoodand; the-entry sideof the pot therebeneath. A receivenmember- 44 is mounted against the entry; side ofthe pot, with an -open top abovethe bath to receive blocks of zinc to replenish the bath [9; withsubmerged openings 45' in the bottom toallow the melted blocks to flow into the bath. (Figures 1 and 2). This arrangement is-.advantageous because it introduces the relatively cold. blocks of zinc close to the place where the pres heated strip: ll enters the bath; thereby melting theblocks relatively quickly. blocks are introduced relatively far from. theplace where the strip leaves the bath,- thereby.- minimizing fluctuations of temperature of the,-

coated strip passing to the coating rollers I5. and.

i6. Theupper end of the replenishing member Moreover, the:

roller conveyor 41 extending in the general direction of movement of the strip II. A second inclined roller conveyor 48 discharges onto the conveyor 41, and in turn receives zinc from a third inclined: roller conveyor- 49; fed by a belt conveyor so driven by avmotor 51: for. dep si zinc blocks at a controlled rate onto the roller conveyor 49, from which the blocks roll freely into the receiver 44. The belt 56 is positioned to one side of'thelineof movement of the strip Ii, andgext'end's generally parallel to it for a cOIlSiderable distance, so that a row of spaced zinc blocks can be placed at one time alon the length of theabelt 5D and thereafter the motor 5| operates: the-belt 50 to send the blocks one after the otherinto the'bath'at a predetermined rate, such asoneaboutevery three minutes. The motor 5| can be operated at a very slow continuous rate with electrical control connections to the drive means for the strip 8 I inorder to synchronize the rate of, replenishment; directly with the; speed? of movement of the strip ll. Howeventhe speedoh movement of the strip is not the sole factor. goy-- erning the rate of replenishment of the.- zinc: bath; and it is preferable to; operate, the beltintermittently, under control; of, an electric; time clock: 52; which; is adjustable to. control the periods be.-- tween operationof themotor- 5| in such. manner; as to. coordinate the, automatic replenishment: with. the current operation; of; the galvanizing line, The, motor 5,! is; also, preferably intercone nected. by automati electric controls; with the power system for mov ng the strip It so that. when the strip H stops themotor 51 1511113313171? vated-until, the strip resumes movement; Thiszis' preferably accomplished by connecting the time: 52; iii-parallel. withthedriye; motor 53cwhichoperates the pinch. rolls 5.4: pulling. the strip [:I; through; the line. In: this. way the motor. cone troller 55, cuts outthe'currenttothe motor at at; the same timeit cuts outithepinch roll motor 53. With suchautomatic replenishing systeinthe-task; ofsuperyisingand replenishing thebath requires less time,-and attention and is performed with: greater ease and regularity. Moreover, the exit side of the: pot 29.: is unobstructed by the;- drive. means, for. raising and lowering: the; coatin rollers; or by the means'forsupplyingzin'c tothe: bath; and'this-makes the-potlilreadily accessible;

\ for supervising. the; galvanizing; operation. and;

maintaining the galvanizing equipment.

While Iphave illustratedland describeda present preferred embodiment of the; inyentiorrzand methodqoi practicin thesame, it will begundeitstood that; the invention: may be otherwisevariouslyembodiedand practicedwithin the scopeof: thevfollowing claims.

I claim:

1. A galvanizing or-like line comprising. apot for; a, bath. of molten coating metal, a; furnace; hood with a terminal; portion extendingv above? andacross one side of theipot'. and down; towarda; central portion. of the pot, means; to passe. metal strip through the furnace hood into the.

. potand thence up'outtoi: the pot, apair of. coat-- ing rollers disposed on opposite sides of the path; of the strip emerging from tl1e=p0t, supporting; means from which the coating rollers. are $115.?- pendcd extending above and across the: pot transverse of the line of movement of the strip.- separate jacking means adjacent the opposite; ends ofsaidsupporting means to raise and lower said ends, a pair ofmotorsradjacent and meohane' ically. connected tooperate:the.respectivejacking;

receives blocks of zinc 46 fromaminclinedflid means,- a=.Selsyngenerator adjacent:andlmechaneically driven by one of said motors, and the other of said motors being a Selsyn motor electrically connected to the Selsyn generator and thereby driven in synchronized relation with said one motor, whereby said one motor is operable to raise and lower the coating rollers while maintaining their alignment with each other and the strip.

2. A galvanizing or like line comprising a pot for a bath of molten coating metal, a furnace hood with a terminal portion extending above and across one side of the pot and down toward a central portion of the pot, means to pass a metal strip through the furnace hood into the pot and thence up out of the pot, a pair'of coating rollers disposed on opposite sides of the path of the strip emerging from the pot, supporting means from which the coating rollers are suspended extending above and across the pot transverse of the line of movement of the strip, separate jacking means adjacent the opposite ends of said supporting means to raise and lower said ends, a pair of motors adjacent and mechanically connected to operate the respective jacking means, a Selsyn generator adjacent and mechanically driven by one of said motors, the other of said motors being a Selsyn motor electrically connected to the Selsyn generator and thereby driven in synchronized relation with said one motor, whereby said one motor is operable to raise and lower the coating rollers while maintaining their alignment with each other and the strip, and a conveyor for pieces of cold coating metal to be added to the bath, said conveyor being mounted adjacent said one side of the pot beneath the terminal portion of the furnace hood.

3. A galvanizing or like line comprising a pot for a bath of molten coating metal, a furnace hood with a terminal portion extending above and across one side of the pot and down toward a central portion of the pot, means to pass a metal strip through the furnace hood into the pot and thence up out of the pot, a receiver member mounted in the pot adjacent said one side, said receiver member having an open top and a perforated lower portion, and conveyor means for feeding pieces of cold coating metal into the upper end of the receiver member.

4. A galvanizing or like line comprising a pot for a bath of molten coating metal, a furnace hood with a terminal portion extending above and across one side of the pot and down toward a central portion of the pot, means to pass a metal strip through the furnace hood into the pot and thence up out of the pot, an elongated inclined motor-driven conveyor belt mounted in spaced relation from one side of the pot and adapted to support and elevate pieces of cold coating metal to be added to the pot, and roller conveyor means descending from the raised end of the conveyor belt to said one side of the pot to discharge said pieces into the pot, whereby the bath is replenished when necessary through operation of the belt.

5. A galvanizing or like line comprising a pot for a bath of molten coating metal; a furnace hood with a terminal portion extending above and across one side of the pot and down toward a central portion of the pot, means to pass a metal strip through the furnace into the pot and thence up out of the pot, a conveyor belt having an upper reach extending generally horizontally and adapted to support pieces of cold coating metal to be added to the pot, a motor connected to move the belt to discharge said pieces, means to convey the discharged pieces into the pot, and timing means controlling said motor to synchronize the rate of discharge of said pieces into the bath with the rate of withdrawal of the coating metal from the bath.

6. A galvanizing or like line comprising a pot for a bath of molten coating metal, a furnace hood with a terminal portion extending above and across one side of the pot and down toward a central portion of the pot, means to pass a metal strip through the furnace into the pot and thence up out of the pot, a conveyor belt having an upper reach extending generally horizontally and adapted to support pieces of cold coating metal to be added to the pot, a motor connected to move the belt to discharge said pieces, means to convey the discharged pieces into the pot, and control means to stop the belt motor when the metal strip stops moving.

7. A galvanizing or like line comprising a pot for a bath of molten coating metal, a furnace hood with a terminal portion extending above and across one side of the pot and down toward a central portion of the pot, means to pass a metal strip through the furnace hood into the pot and thence up out of the pot, a pair of coating rollers disposed on opposite sides of the path of the strip emerging from the pot, supporting means from which the coating rollers are suspended extending above and across the pot transverse of the general line of movement of the strip, separate jacking means adjacent the opposite ends of said supporting means to raise and lower said ends, a pair of motors mechanically connected to operate the respective jacking means, a Selsyn generator adjacent and mechanically driven by one of said motors, the other of said motors being a Selsyn motor electrically connected to the Selsyn generator and thereby driven in synchronized relation with said motor, a receiver member with an open top and a perforated lower portion mounted in the pot adjacent said one side of the pot, a series of descending roller conveyors having a final section disposed beneath said furnace hood terminal portion to discharge into the open top of the receiver member, and a motor-driven inclined conveyor belt for discharging pieces of cold coating metal onto the upper end of the series of roller conveyors, said belt extending generally parallel to the general line of movement of the strip in offset relation to one of said opposite sides of the pot.

HERMAN J. KALBERKAMP.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 806,900 Leonard Dec. 12 19 5 2,211,957 MacMichael Aug. 20, 1940 2,32 ,129 Harris May 25, 1943 2,634,009 Weitzenkorn Apr. 7, 1953