US3196828A - Apparatus for continuous coating of elongated articles - Google Patents

Description

July 27, 1965 F. E. TURNER 3,196,828

APPARATUS FOR CONTINUOUS COATING OF ELONGATED ARTICLES Filed Sept. 27, 1962 9 Sheets-Sheet l lNVENTOR FRANK E. TURNER W 1 /ATTORNHEYS.

y 7, 1965 F. E. TURNER 3,196,828

APPARATUS FOR CONTINUOUS COATING OF ELONGAIED ARTICLES Filed Sept. 27, 1962 9 Sheets-Sheet 2 ywmw 1 E. 5; :1 u

?\ g INVENTOR. FRANK E. TURNER 1 8W W film/M YLATTOENEYS' July 27, 1965 F. E. TURNER APPARATUS FOR' CONTINUOUS COATING OF ELONGATED ARTICLES 9 Sheets-Sheet 3 Filed Sept. 27, 1962 .INVENTOR. FRANK L. TURNER.

ATTORNEYS July 27, 1965 F. E. TURNER 3,196,828

APPARATUS FOR CONTINUOUS COATING OF ELONGATED ARTICLES Filed Sept. 27, 1962 9 Sheets-Sheet 4 INVENTOR.

FRANK E. TURNER z; iTToRNsw y 27, 1965 F. TURNER 3,196,828

APPARATUS FOR CONTINUOUS COATING OF ELQNGATED ARTICLES Filed Sept. 27, 1962 9 Sheets-Sheet 5 INVENTOR F24 M: Z. 752N512 A TTOF/VEYJ.-

July 27, 1965 F. E. TURNER 3, 95,8

APPARATUS FOR CONTINUOUS COATING OF ELONGATED ARTICLES Filed Sept. 27, 1962 e Sheets-Sheet e INVENTOR fen/w .5 Tut/me ATTORNEYS.

July 27, 1965 F. E. TURNER 3,

APPARATUS FOR CONTINUOUS COATING 0F ELONGATED ARTICLES Filed Sept. 27, 1962 S'SheetS-Sheet 7 July 27, 1965 v F. E. TURNER 3, ,8

APPARATUS I 'QR CONTINUOUS COATING 0F ELONGATED ARTICLES Filed Sept. 27, 1962 9 Sheets-Sheet 8 I N VENTOR. E64 NK :7 Wax/5e United States Patent E. Co

This invention relates to the treatment of elongated article" with liquid material and more particularly to an improved apparatus for use in the continuous hot galvanizing of metal products such as pipe, bars, shapes, etc.

This application is a continuation-in-part of my copending United States patent application Serial No. 791,- 612, filed February 6, 1959, now Patent No. 3,063,409.

lin the accompanying drawings and the following specification there is described and illustrated an apparatus for hot galvanizing metal pipe, but it will be understood that the invention may advantageously be employed in numerous other applications where it is desired to treat elongated articles such as pipe, bars, shapes, etc., in a liquid hath. Accordingly where reference is made to galvanizing herein, it is intended to include not onl galvanizing per se but also other coating operations such as the application of paint, enamel, cleaning or pickling solutions, etc., and where reference is made to pipe it is intended to include other elongated articles such as bars, shapes, etc.

in galvanizing steel pipe it is common practice to submerge the pipe in a bath of molten zinc so that both the inner and outer surfaces of the pipe are completely covered, The lengths of pipe are then withdrawn and drained. The pipes have customarily been manually lifted from the galvanizing bath and brought into engagement with suitable rolls or conveyors which remove the pipes from the tank.

lt an object of the present invention to provide, in a fully automatic continuous pipe galvanizing machine or the like wherein the pipes or other elongated articles mainain the same positive relation to each other throughout the entire process, improved means for withdrawing pipe fromthe coating tank, holding the pipe and removing excess zinc or other coating material therefrom, and transferring the pipes in proper sequential order and spacing to a conveyor or the like, all in a continuous and automatic manner.

The above and other objects of the invention will appear from the following description of an apparatus for galvanizing steel pipe or the like in which the present invention is incorporated, reference being made to the accompanying drawings in which:

FIGURE 1 is a plan view, partly in horizontal cross section, illustrating the invention as incorporated in pipe galvanizing apparatus;

FEGURE 2 is an enlar ed vertical cross-sectional view taken substantially on line 22 of FIGURE 1;

PEGURE 3 is a vertical cross-sectional view taken substantially on line 33 of FIGURE 2, the pipe conveying and sinking screws, however, being illustrated in the positions they assume as a pipe is being moved endwise out of the galvanizing bath;

FIGURE 4 is an end elevational view taken substantiaily on line l-4- of FIGURE 1 and illustrating the internal and external coating control stations and the magnetic roll conveyor means for removing coated pipe from the galvanizing tank;

FIGURE 5 is a vertical cross-sectional view taken substantially on line 5-5 of FlGURE 1 and illustrating the indexing transfer means for moving pipe from the magnetic roll conveyor to the internal coating control station, the water bosh, the spray coating unit, etc.;

FIGURE 6 is a view generally similar to FIGURE 4 but illustrating a modified arrangement of the electromagnetic drag out rolls and indexing transfer units for handling the pipes as they are withdrawn from the coating bath; and

ElGURE 7 is an enl rged cross-sectional view, taken substantially on line 77 of FIGURE 6, illustrating the angular relation and mode of operation of the transfer racks to convey the coated pipes from the electromagnetic rolls to the internal coating control station and the conveyor that takes the pipes to the water bosh;

FIGURE 8 is a diagrammatic view of the transfer racks and supporting arms shown in FIGURE 7 but in their positions when the pipes are transferred from one set of racks to the other;

ElGURE 9 is an elevational view generally similar to FIGURES 4 and 6 but illustrating another form of my indexing transfer mechanism;

FIGURE 10 is a plan view taken substantially on line 1tllil of FEGURE 9; and

EEGURE 11 is an enlarged cross-sectional view taken substantially on line lit-ll of FIGURE 10.

Referring particularly to EEGURES l and 2, the illustrated automatic continuous pipe galvanizing line in which the present invention is incorporated includes a loading rack comprising a plurality of inclined skid members 1 adapted to receive bundles of pipe from storage or previous processing operations. On these racks the pipes P are arranged in a single layer and rolled downwardly by gravity. At the lower end of the loading rack the pipes are picked up by an automatic selector unit comprising a plurality of rotating conveying screws 2 which are simultaneously driven by suitable gearing and shafting such that their rotation is in a direction to advance the pipes one at a time in a direction perpendicular to their length. The pitch of the screws 2 and the shape of the entering ends of the threads thereon is such that one individual length of pipe will be removed from the loading skids 1 at every 360 of rotation of the screws.

Thus the pipes P are removed one at a time from the skids l and are individually advanced in spaced apart relation in a direction normal to th ir longitudinal axes. From the screws 2 the pipes are delivered to a rotating purge chamber 3 in which a varied rotary gas seal and transfer whee i is mounted. As illustrated, tii wheel 4 has a plurality of vanes (six as illustrated) separating the unit into a plurality of compartments. As seen in FIG- URE l, the shaft 5 on which the transfer wheel 4 is supported is connected by a chain 6 to the drive shaft 2 for the rotating screws 2, and thus the rotation of the screws 2 is synchronized and interlocked with the transfer Wheel i so that the screws 2 will successively discharge pipes, one into each of the compartments formed by the vanes of the transfer wheel. As seen in FKGURE 2, the wheel 4 rotates in clockwise direction and has a fairly close fit with the walls of the chamber 3 so that a seal is provided for preventing undesired entry or escape of atmosphere to or from the furnace F. A controlled atmosphere of suitable type is preferably caused to enter the compartments formed by the rotating wheel t in the purge chamber 3 to purge the air from the compartments and pipes contained therein before they enter the furnace.

Immediately beyond the purge chamber and rotating transfer wheel in the direction of pipe travel is a chain transfer or conveyor comprising a plurality of conveyor chains 7 which extend through the furnace F and carry the lengths of pipe P therethrough. Screw conveyors may be employed in place of chains 7 if desired.

Each of the chains 7 is supported on end sprockets 8 and 9 mounted respectively on shafts l and f1 and is guided by suitable idler sprockets as seen at 12, 13 and 14 in FIGURE 2. Floating counterweights l maintain the desired tension on the chains 7 which are provided with spaced upstanding lugs 7 which engage the pipes P and move them on suitable rails or skids 7* through the furnace F. The shaft which supports the sprockets 8 is connected to the shaft 5 of the rotary transfer wheel 4 by chain 15 so that there is positive synchronization of the automatic selector screws 2, the vanes transfer wheel 4, and the chains 7 or conveyor screws. As the lugs 7 on the individual chains 7 are transversely aligned, the pipes will be rolled thereby over the skids 7 in individual sections or compartments in a direction perpendicular to their longitudinal axes. The furnace F, as best seen in FIGURE 2, consists of an entry chamber 16, a heating chamber 17, and an exit end and galvanizing machine housing section 18.

Disposed within the galvanizing chamber section 13 of the furnace F is a galvanizing machine unit which includes a galvanizing kettle 19, adapted to contain a bath of molten zinc and a pair of spaced pipe conveying and sinking screws generally indicated at S and S. These screws are mounted respectively on shafts and 21 which extend across the top of the galvanizing kettle 19 and through the end wall 22 of the furnace F. A suitable frame structure 23, within the exit end portion 13 of furnace F, is provided for supporting shafts 2t) and 21, and the feed screws S and S are so disposed that their entering or pick-up ends 29 (left-hand as seen in FIGURE 2) are positioned to take the pipes P one at a time as they leave skids 7 at the exit end of the conveyor chains 7 and move them in an advancing series on spaced guides or skids G (see FIGURE 3) toward the galvanizing kettle 19.

The shaft 11 which carries the sprockets 9 for the conveyor chain 7 is connected through gear box 24 and shaft 25 to gear box 26 which is driven by the motor 27. Shaft 28 extends from gear box 26 and has geared connection to shafts 20 and 21 which support the conveying screws S and S. This interconnection of the conveyor screw drive and the chain drive provides positive synchronization of the chains '7 and the screws S and S so that at each complete rotation of the screws a length of pipe P will be picked up from the conveyors '7 and moved along the guides or skids G by the entering or pick-up portion 29 of screw S and a corresponding portion on screw S.

As clearly seen in FIGURE 3, the pipe guides or skids G are spaced longitudinally of the galvanizing kettle 19 and are offset from the front and rear conveying screws S and S. Although the size and contour of the several guides G vary for reasons which will be later referred to, they each have a horizontal entering portion 31, the top edge of which is disposed approximately at the level of the outside of the thread 32 on the pick-up portion 29 of screw S. Just beyond the entering portions 31 of guides G are downwardly inclined portions 34 which extend into the galvanizing kettle 19 and have their upper edges sloped to impart the desired travel of the pipes P into the coating bath in kettle 19.

In addition to the pick-up portion 29 of the screws S, it has a flaring or enlarging portion 35 and screw S has a corresponding enlarging portion. The pick-up thread portion 32 of screw S continues on the flaring portion 35 thereof and is indicated at 35.

Just beyond the last pitch of the thread on front screw S is an annular groove (see FIGURE 3) to which the last pitch of the thread 35 connects and into which the pipes are moved by said thread. This groove 49 is circular and has a permanent magnet portion 41 which extends around a portion only of the base of the groove. At the end of the enlarging thread of conveying screw S is a groove 42 formed on an enlarged cam portion indicated at 43. A permanent magnet 44 is mounted in the cam portion 43 and is effective over the portion of the bottom of the groove 42 that is most remote from the shaft 21 (see FIGURE 3).

In the operation of the galvanizing apparatus just described, the pipes P are picked up from the ends of the conveyor chains '7 and are traversed by conveying screws S and S successively over the horizontal portions 31 of the guides G and down into the galvanizing bath in the kettle 19, the axis of each pipe being tilted during movement into the galvanizing bath so that the front end enters first and then the rear end being moved down so that the pipe is horizontal when fully submerged in the bath. The pipes are traversed through the bath in a direction perpendicular to their length and ultimately move into the grooves 40 and 42 on screws S and S respectively. When a pipe first enters these grooves, its axis is substantially horizontal but, as the screw S continues to rotate, the rear end of the pipe is further submerged into the galvanizing kettle to a position such that the pipe will have a substantial inclination upwardly (for example about 18). As seen in FIGURE 3, as the rear end of the pipe is lowered the front end will be elevated somewhat because it pivots on the screw S a short distance back from the front end.

As the conveyor screws S and S rotate, the permanent magnet portions 41 and 44 thereof will hold the pipe firmly against the base of the grooves 40 and 42 and cause the pipe to be fed longitudinally in the direction of its length. Two permanent magnet rolls and 51 having V-grooves on their outer surface to assist in gripping and guiding the pipes, are mounted just beyond conveying screw S in the direction of pipe travel. The axis of roll 51 is vertically otfset from the axis of roll 50 so that, as a pipe P is moved into its upwardly inclined position by the action of the cam portion 43 of rear conveying screw S and is moved longitudinally by magnets 41 and 44 on screws S and S, the forward end of the pipe will engage magnetic rolls 50 and 51. These rolls are driven by suitable means (not shown) and will continue to move the pipes P in the direction of their length completely out of the coating liquid in kettle 19 after the magnets 43 and 41 have moved out of contact with the pipes. The rearward inclination of the pipes as they are withdrawn from kettle 19 insures prompt and complete draining of the coating liquid from the pipes back into kettle 19.

The advancing ends of the pipes P, as they are moved out of the galvanizing kettle 19, are moved into engagement with the lower rolls of a magnetic roll conveyor unit that is seen in FIGURE 4. This unit includes at its lowermost end a pair of driven permanent magnet rolls 52 and 53 which are aligned with the path of travel of the pipes as they exit from the galvanizing tank. These rolls 52 and 53 engage and pick up the pipes as they come along. Supported on an inclined frame 54 are a series of driven electromagnetic rolls 55, 56, 57 and 53 which are adapted to be energized and tie-energized by suitable electrical connections and controls (not shown) in a well-known manner.

As seen in FIGURE 4, the pipe P has been moved in the direction of its length by the permanent magnet rolls 52 and 53 and has engaged the electromagnet rolls 55, 56, 57 and 58, which are energized at all times except when 'the limit switch 59 is actuated. The depending contactor 59 of limit switch 59 extends into the path of the end of the pipe P. As seen in FIGURE 4, the pipe P has left next single rotation cycle of the-support members 63 of indexing transfer units T. I

It will be noted that the magnetic rolls 59, $1, etc. ar illustrated as having two pipe receiving grooves therein. These double grooves are provided so that when double thread screws are used in place of single thread screws S and S, and the pipes are moved through the galvanizing kettle in pairs, they are handled in pairs as they are moved longitudina iy out of the galvanizing kettle. In like manner, the suppo g edges of the racks 6t 63 and 66 of the indexing tran. as units T are illustrated as having two pipe receiving notches. This also is to permit them to be used with double thread conveying and sinking screws.

In FIGURES 6, 7 and 8 there are illustrated modified forms of magnetic drag-out conveyor and indexing transfer units for taking the ipes from the galvanizing kettle, transferring them to the internal blow-out station, supporting them during the blow out operation, and then transferring them to the exit conveyor.

As seen in FIGURE 6, permanent magnet rolls 52 and 53 (also seen in F1 URE 4-) are disposed above the exit end of the galvanizing kettle 19. They overlie the path of travel of the pipes as they leave the coating bath. A plurality of magnetic rolls litit), 1431, 1'92, 103 and 164 are rotatably supported on an inclined frame structure 165 and are adapted to be driven by any suitable means (not shown). These rolls mil-10 i are disposed to receive the pipes as they leave the rolls 52 and 53, engage them on the under side thereof, and advance them into the position indicated at P" in FTGURE 6. A plurality of indexing transfer units T are also mounted on the inclined frame 1*?)5 between the rolls mid-104.

As best seen in FTGURES 7 and 8, each of the indexing transfer units T includes a first or initial movable rack 1% supported for circular orbital movement on the arms 197 and 108 which are mounted on the ends of shafts (not seen in the drawings) projecting from the housing The shafts which support arms 167 and 103 are driven by suitable means and are interconnected for simultaneous rotation. It will be apparent that each rack 196 will be moved by its arms lttfl and 1&3 in a circular orbital path when said shafts are rotated. All of the racks 1% are angularly aligned and are maintained in horizontal position at all times by their supporting arms. The direction of rotation is as indicated by the arrow in FIGURE 7.

On the opposite sides of the housings N9 from the racks 1&6 a series of second movable racks 116, 111, 112 and are each supported on arms Hi4 and 115. As seen in FIGURE 7, the racks 119-113 are of successively diminishing height from adjacent the galvanizing kettle 19 outwardly for purposes that will be later explained. The arms 114 and 2.15 are supported on shafts 114 and 115 which extend into the housings 139. When these shafts lid and 115 are rotated the racks Mil-113 will move in circular orbital paths in the same direction and at the same rate as the racks M26. Suitably interconnected drive means (not shown) are provided for the shafts 114 and 115' which support the arms 107, 163 and 114, 115 and it will be noted from FIGURE 7 that the racks lid-5.13 are angularly displaced 180 from the racks 105.

Each of the racks 1% and 1194.13 are provided with a pair of pipe receiving grooves or notches (seen at 116 and 117 in FlGURE 7) so that two pipes may be simultaneously handled as has been previously described in connection with the indexing transfer units T. An internal blow out station C, substantially identical to that seen in FIGURE 4, is also mounted on the inclined frame 105 and the function of the indexing transfer units T is to move the pipes from the rolls wt ltl i into position in alignment with the bell mouth 77 of the blow out unit, hold the pipes in position during the blow out operation,

and then convey them on to the exit conveyor B (seen in FIGURE In the operation of the above described apparatus pipes leaving the galvanizing kettle 19 are moved by the permanent magnet rolls Nil-134 as has been previously explained. As a pipe P is moved its forward end (left in FIGURE 6) engages a limit switch (not seen in FIG- URE 6 but which might be similar to that shown at 59 in FIGURE 4) at a predetermined point before it reaches the final position seen at P" in FIGURE 6. This limit switch is connected to start the operation of a single revolution drive mechanism (also not shown but of any suitable type) for the transfer units T and racks 106 and llii13 thereof which, while the pipe is being advanced by the rolls mil-1&4 to the limit switch actuation point, are in their normal or at-rest positions as een in FIG- URE 7.

As noted above, when the end of pipe P trips the limit switch the advance end of the pipe has not yet reached the final position seen in FIGURE 6 and the pipe continues to be moved by the rolls -1-34. However, after the racks 1% have moved through slightly more than 90 of their single revolution movement they will be in position to lift the pipe or pipes P from the rolls ltit21tl4. At this time the forward end of the pipe P" will have reached the position seen in FIGURE 6. Concurrently, by a suitable switch actuated by one of the racks 106, the magnetic rolls rec-m4 if of the electromagnetic type are momentarily deenergized to facilitate the pipes being lifted therefrom by the racks 1% as they continue their counter-clockwise travel. As rotation of racks 106 continues the pipe carried thereon will be moved laterally and at the end of a full revolution the racks 106 and 110-113 will stop in their at-rest positions (seen in FIG- URE 7). The pipe P" will then be held by the racks 1153-113 (as will be later explained) in alignment with the pipe receiving bell portion 77 of the blow out units C and the pipes may be subjected to a blast of air or steam to control the interior coating as has been previously described.

When the single revolution operating cycle of the transfer racks is again started by actuation of the limit switch by the advancing end of a new pipe P", the racks Ht 113 will move the pipe or pipes P supported thereon to the left (FIG. 7) away from blow out unit C and deposit same on the conveyor B in the same manner as previously described in explaining the operation of the racks 63 in FIGURE 5.

As the arms 197, 16 3 and 114, 115, which support the racks 1% and 110-113 respectively, are the same length and as they are so spaced apart that in one point in the rotation of the two sets of racks their paths cross with the grooves 116 and 117 therein in alignment (see FIG- URE 8), the pipes that are lifted off of the rolls Nt 1194 by the racks 106 will be picked up by the racks 119 113 at the point where this alignment takes place. This transfer point is illustrated in FIGURE 8 and it will be understood that after this occurs the racks 110-113 will carry the pipe and continue their rotation until they are stopped at their at-rest positions in alignment with the internal blow out unit C. The racks 1% in like manner will stop in their at-rest positions, seen in FTGURE 7, and will be ready to start another transfer cycle when another pipe engages the limit switch to start the single revolution rotation of the racks.

As explained in connection with the apparatus of FIG- URE 4 this single revolution rotation of the transfer racks is controlled by any suitable means which, as it per se forms no part of the present invention, is not illustrated herein. In order to maintain the pipes in position on the racks 106 and 119413 permanent magnet inserts indicated at 118 are disposed in the grooves 116 and 117 of at least some of the racks of each set.

As previously noted, the racks 1ltl1ll3 are of successively lower height from the one (110) closest to the galvanizing kettle l9 outwardly. The object of this variation in size is to effect tilting of the pipes P from the s,19e,sas

angle at which they are disposed while on the rolls 11th-- 164 and racks 1% closer to a horizontal position so that, when they are deposited upon the conveyor which transports them to the next processing station, they will be more nearly horizontal.

The apparatus illustrated in FIGURES 6, 7 and 8 eliminates the intermediate transfer racks 66 of the embodiment shown in FIGURE 5 and also eliminates the dropping of the pipes from the drag out rolls to the first set of racks which occurs when th drag out rolls are disposed on top of the pipes as seen in FIGURE 4. Otherwise the mode of operation of the apparatus shown in FIGURES 6, 7 and 8 is substantially the same as that shown in FIGURES 4 and 5.

Another form of my pipe transfer mechanism is illustrated in FIGURES 9, and 11. In common with the previously described mechanisms this embodiment includes a frame structure 125 at the left-hand end of which (FIGURE 9) a blow out unit similar to that shown at C in FIGURES 4 and 6, is adapted to be mounted (but not shown in FIGURE 9). Also mounted on the frame 125 are a series of magnetic rolls 126, 127, 128, 129 and 13d. These rolls are adapted to be simultaneously driven at the same speed by any suitable means (not shown) and are disposed to receive coated pipes as they leave the drag out rolls 52 and 53 (see FIGURE 6) in the same manner as the rolls M64164 of FIGURE 6. A plurality of indexing transfer units generally indicated at T" are also mounted on the frame 125 between the adjacent pairs of rolls IZd-ISi).

As best seen in FIGURES 10 and 11 each of the indexing transfer units T includes a movable walking beam member, generally indicated at W, supported for orbital movement on arms 131 and 132 which are pivotally secured at their outer ends to bracket members 133 and 1.3 which in turn are formed integrally with the walking beam W. The arms 132 and 133 are mounted on and adapted to be rotated by shafts 132 and 133' which are driven by any suitable means such as the motor and gear box indicated at 135.

Mounted on the supporting bar 136 of each walking beam W are three tube racks 137, 138 and 13%, best seen in FIGURE 11, each of which has a pair of tube receiv ing grooves Mil and 141. As seen in FIGURE 11, the racks 137, 138 and 139 are equally spaced on the supporting bars 136 and, when the shafts 132' and 133" are rotated to move the arms 131 and 132 in the direction of the arrow in FIGURE 11 these racks will be moved in corresponding orbital paths.

Each transfer unit I" also includes a pair of stationary tube racks 142 and 143 which are supported on bars 144 which in turn are carried by vertical posts 145 and 1 2-6 supported on the frame 125 (see FIGURE 11). When the walking beams W are at their at-rest positions, as seen in FIGURE 11, these stationary racks 142 and 143 are aligned with the movable racks 138 and 139. It will be observed that the rolls 12613lt and the stationary racks and 1 53 each are provided with a pair of tube receiving grooves or notches, the grooves in roll 12% being indicated at 128' and the grooves in the stationary racks 1:12 and 1435 being indicated at 142 and M3, respectively (see FIGURE 11).

As previously noted, the at-rest position of the walking beams W is illustrated in FIGURE 11 and it will be noted that the movable rack 137 is in alignment with the magnetic roll 128 but with its pipe receiving grooves 14 and 14-1 slightly below the level of the top of the grooves 128' in the roll 12%. In like manner the tube engaging grooves 14d and 141 of the movable racks 138 and 139 are slightly below and in alignment with the grooves 142' of stationary rack 142 and 143' of stationary raci 143, respectively.

In the operation of the apparatus of FIGURES 9-11, the tubes that are moved from the coating bath by the drag out rolls 52 and 53 (seen in FIGURES 4 and 6) are carried along by the magnetic rolls 126-139 until the advancing end of the pipe moves beyond roll 13% into a predetermined position whereupon a limit switch actuated by the pipe end, or other suitable means, initiates a single revolution movement of the shafts 132 and 133' which actuate the walking beams W. Substantially concurrently with the starting of the rotation these shafts and the starting of the movement of the walking beams W the magnetic rolls 126-13tl are deenergized. After the first few degrees of movement of the walking beams W the grooves of movable racks 137 will pick up the pipes that are on the rolls 126-139, the grooves in the movable racks 138 will pick up pipes that are on the stationary racks 142, and the grooves in the movable racks 139 will pick up pipes that are on the stationary racks 143.

Referring to FIGURE 11, the pipes 147 which are on the rolls 126-134 will be picked up by the racks 137 and will be transferred, at the end of of movement of the arms 131 and 132, to the grooves at 142 of the stationary racks 142. Concurrently the pipes 143 that are supported on the stationary racks 142 (which is in alignment with the blow-out station C at which the pipes are subjected to steam or the like under pressure to remove excess zinc from their inner surfaces) are transferred by the movable racks 138 to the stationary racks 143. In like manner, and during the same movement of the walking beams W, the pipes 149 that are supported on the stationary racks 143 will be moved to the right (FIGURE 11) and will be deposited on a conveyor (not shown in FIGURE 11 but which may be similar to conveyor B seen in FIGURE 5).

After the pipes 147, 148 and 149 have been transferred during the first 180 of movement of the walking beams W and their supporting arms 131 and 132, the rotation continues until a single revolution of arms 131 and 132 is completed. The walking beams W then stop in their at-rest positions (seen in FIGURE 11) and are ready for another pipe indexing and transferring cycle as soon as another set of pipes have been moved into position by the rolls 126-130 and the transfer cycle has been initiated by the limit switch or the like referred to above. It will be understood that time is permitted during the advancing of another set of pipes on the rolls 126430 for the internal blow out operation carried out by blow out unit C to take place on the pipes when they are supported on the stationary racks 142.

In order to prevent longitudinal movement of the pipes while on the movable and stationary racks magnetic in serts are preferably provided in some or all of these racks. It will also be understood that the magnetic rolls 126439, if of the electromagnetic type, are only momentarily deeuergized at the time when the movable racks 137 pick the pipes oii of these rolls. They are then re-energized so that they will be effective in moving the pipes longitudinally out of the coating bath. If these rolls are of the permanent magnet type such deenergization of course, does not occur. The apparatus of FIGURES 9, 10 and 11 will perform the same pipe indexing and transferring functions as the embodiments of the other views of the drawings. It, however, requires only a single orbiting member for each indexing transfer unit as distinguished from a pair of orbiting members for each transfer unit in the previously described embodiments.

Although the illustrated embodiments of my invention have been described in considerable detail it will be understood that variations and modifications may be made in the form and arrangement of the parts making up my improved apparatus. I do not, therefore, wish to be limited to the exact structures and proportions herein shown and described, but claim as my invention all em bodiments thereof coming within the scope of the appended claims.

I claim:

1. In continuous pipe galvanizing apparatus having a plurality of electromagnetic rollers disposed to support and move a pipe longitudinally out of a galvanizing bath with its axis inclined and switch means engageable by said pipe and effective upon such engagement to de-energize said rollers and release the magnetic grip thereof on said pipe; an indexing transfer unit disposed adjacent said rollers and including a pair of movable pipe carrying racks supported for movement in orbital paths the centers of which are offset from each other, a stationary rack supported between said offset centers and out of alignment with the path of said pipe when carried by said rollers, interconnected driving means for said movable racks whereby a constant angular displacement is maintained between said movable racks during movement thereof in said orbital paths, one of said movable racks, when in an at-rest position, being disposed in alignment with and below said path of said pipe and being adapted to receive a pipe released from said rollers, said stationary rack being disposed to receive a pipe from said one of said movable racks after a predetermined rotation thereof from said at-rest position, the path of movement of the other of said movable racks being such that a pipe deposited on said stationary rack by said one of said movable racks will be lifted from said stationary rack by said other of said movable racks after a predetermined movement from its at-rest position and transferred to a position laterally offset from said stationary rack, and means for holding a pipe against longitudinal movement on said other of said movable racks.

2. In continuous pipe galvanizing apparatus having electromagnetic rollers for moving a pipe longitudinally out of a galvanizing bath, said rollers supporting said pipe on the undersides of said rollers whereby, when said rollers are de-energized, a pipe supported thereby will drop off said rollers; a series of indexing transfer units disposed below said rollers in the path of fall of a pipe dropped therefrom, said units each including a pair of movable pipe carrying racks supported for movement in orbital paths the centers of which are offset from each other; a stationary rack supported between said offset centers, interconnected driving means for said movable racks whereby a constant angular displacement of about 90 is maintained between said movable racks during movement thereof in said orbital paths, one of said movable racks being disposed belowsaid rollers when in an at-rest position at the top of its orbital path and being adapted to receive a pipe dropped from said rollers, said stationary rack being disposed to receive a pipe from said one of said movable racks after about 90 rotation thereof, the path of movement of the other of said movable racks being such that a pipe deposited on said stationary rack by said one of said movable racks will be lifted from said stationary rack by said other of said movable racks after movement of about 180 from its at-rest position, and means effective on a pipe on said other movable rack when in said at-rest position for blowing excess zinc from the inside of said pipe.

3. In pipe coating apparatus having a plurality of rollers adapted to move a pipe out of a coating bath and an internal coating control station adjacent said rollers; an indexing transfer unit disposed adjacent said rollers and including a first movable rack means adapted to pick up and convey pipes from said rollers in a direction parallel to the axes of said rollers, means for moving said first rack means in an orbital path whereby pipes removed from said rollers will be moved transversely of their length into a position to be treated by said internal coating control station, a second movable rack means, and means for moving said second rack means concurrently with but in a different orbital path from said first rack means, said second rack means being adapted to move pipes away from said position concurrently with the bringing of pipes to said position by said first rack means' 4. In pipe coating apparatus having a plurality of magnetic rollers supported in spaced apart relation with their axes parallel and adapted to move pipe out of a coating bath and an internal coating control station adjacent said rollers; a first movable rack means disposed between an adjacent pair of said magnetic rollers and adapted to convey pipes from said rollers in a direction parallel to the axes of said rollers, means for moving said first movable rack means in an orbital path whereby pipes removed from said rollers will be moved transversely of their length into a position to be treated by said internal coating control station, a second movable rack means adjacent said first rack means, means for moving said second rack means concurrently with but in a different orbital path from said first rack means, said second rack means being adapted to move pipes away from said position concurrently with the bringing of pipes to said position by said first rack means, and means for effecting concurrent revolution movement of both of said rack means.

5. In pipe coating apparatus having a plurality of magnetic rollers supported in spaced apart relation with their axes parallel and adapted to move a pipe out of a coating bath and an internal coating control station adjacent said rollers but spaced transversely of the path of pipes conveyed by said rollers; an indexing transfer unit disposed between an adjacent pair of said magnetic rollers and including a first movable rack means for conveying pipes from said rollers in a direction parallel to the axes of said rollers, means for moving said first rack means in an orbital path whereby pipes removed from said rollers will be moved transversely of their length into a position to be treated by said internal coating control station, means for holding pipes in said position, a second movable rack means, means for moving said second rack means concurrently with but in a different orbital path from said first rack means, said second rack means being adapted to move pipes away from said position concurrently with the bringing of pipes to said position by said first rack means, and means for effecting concurrent revolution movement of both of said rack means.

6. In pipe coating apparatus having a plurality of rollers disposed and adapted to move a pipe longitudinally out of a coating bath with its axis inclined; a plurality of movable pipe carrying racks supported for movement in different orbital paths, a stationary rack laterally offset from the path of a pipe carried by said rollers, driving means for said movable racks, a first one of said movable racks, when in an at-rest position, being disposed directly below said path of a pipe on said rollers, said stationary rack being disposed to receive a pipe from said first one of said movable racks after a predetermined rotation thereof from said at-rest position, the path of movement of a second one of said movable racks being such that a pipe deposited on said stationary rack by said first one of said movable racks will be lifted from said stationary rack by said second one of said movable racks and transferred to a position laterally offset from said stationary rack, magnetic means for holding pipes on said stationary rack, and means etfective on a pipe on said stationary rack for blowing excess coating material from the inside of the pipe.

7. Pipe coating apparatus including a plurality of rollers adapted to move a pipe longitudinally out of a coating bath, a series of three pipe carrying racks, a common support member for said racks disposed between an adjacent pair of said rollers and having an at-rest position, said racks being mounted in spaced relation on said support member on a line extending transversely of the path of movement of pipes carried by said rollers, means for moving said support member from said at-rest position in an orbital path whereby said racks are moved concurrently in separate orbital paths extending transversely of said path of movement of pipes carried by said rollers, one of said movable racks, when said sup- References Cited by the Examiner port member is in said at-rest position, being below said path of movement of pipes carried by said rollers, a pair UNITED STATES PATENTS of stationary pipe supporting racks disposed one in align- 1,799,760 4/31 Moon 118-63 ment with each of the other two of said movable racks 5 2 893 348 7 /59 Pearson 118 11 when said support member is in said at-rest position,

means for imparting orbital movement to said support 2906237 9/59 Bernhardt 118* member and said three movable racks, and means effec- RICHARD D NEVIUS Primary Examiner tive on a pipe on the stationary rack closest to said rollers for blowing excess coating material from the inside of 10 JOSEPH SPENCER Examiner the pipe.

Claims (1)

1. 2. IN CONTINUOUS PIPE GALVANCING APPARATUS HAVING ELECTROMAGNETIC ROLLERS FOR MOVING A PIPE LONGITUDINALLY OUT OF A GALVANIZING BATH, SAID ROLLERS SUPPORTING SAID PIPE ON THE UNDERSIDES OF SAID ROLLERS WHEREBY, WHEN SAID ROLLERS, ARE DE-ENERGIZED, A PIPE SUPPORTED THEREBY WILL DROP OFF SAID ROLLERS; A SERIES OF INDEXING TRANSFER UNITS DISPOSED BELOW SAID ROLLERS IN THE PATH OF FALL OF A PIPE DROPPED THEREFROM, SAID UNITS EACH INCLUDING A PAIR OF MOVABLE PIPE CARRYING RACKS SUPPORTED FOR MOVEMENT IN ORBITAL PATHS THE CENTERS OF WHICH ARE OFFSET FROM EACH OTHER; A STATIONARY RACK SUPPORTED BETWEEN SAID OFFSET CENTERS, INTERCONNECTED DRIVING MEANS FOR SAID MOVABLE RACKS WHEREBY A CONSTANT ANGULAR DISPLACEMENT OF ABOUT 90* IS MAINTAINED BETWEEN SAID MOVABLE RACKS DURING MOVEMENT THEREOF IN SAID ORBITAL PATHS, ONE OF SAID MOV-

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