US2893348A

US2893348A - Removal of excess spelter from the interior of freshly galvanized pipe

Info

Publication number: US2893348A
Application number: US615049A
Authority: US
Inventors: William S Pearson
Original assignee: CLIFTON CONDUIT CORP
Current assignee: CLIFTON CONDUIT CORP
Priority date: 1956-10-10
Filing date: 1956-10-10
Publication date: 1959-07-07
Anticipated expiration: 1976-07-07

Description

July 7, 1959 w. s. PEARSON REMOVAL OF EXCESS SPELTER FROM THE INTERIOR 0F FRESHLY GALVANIZED PIPE 3 Sheets-Sheet 1 Filed Oct. 10, 1956 Ell E 12227 Wd/jam 5. Pearson m um m 4 4' l @mqzzz E July 7, 1959 w. s. PEARSON REMOVAL-OF EXCESS SPELTER FROM THE INTERIOR OF FRESHLY GALVANIZED PIPE Fil ed Oct. 10. 1956 3 Sheets-Sheet 2 M m a, r fi 5 C H M a I I f L w m T w A R m .M m

PINCH ROLL RE VERSE y 7 1959 w. s. PEARSON 2,893,348

REMOVAL OF EXCESS SFELTER FROM THE INTERIOR I OF FRESHLY GALVANIZED PIPE Filed Oct. 10, 1956 s Sheets-Sheet s Ill *2 27in 2-:

mum 5. Pearson Unite States atet':

REMOVAL OF EXCESS SPEL'DER FROM THE INTE- RIOR'OF FRESHLY GALVANIZED PIPE William S. Pearson, Baltimore, Md., assignor to Clifton Conduit Corporation, Baltimore, Md., a corporation of Maryland Application October 10, 1956, Serial No. 615,049

8 Claims. (Cl. 118-11) The present invention relates to improvements in methods and mechanisms for removing excess spelter from the interior of freshly galvanized pipe and for the automatic control of said mechanism.

One of the primary means in importance and utility for the protection of metals, such as pipe, from corrosion has been by galvanizing, which consists of applying a coating of zinc to the surface. Various means are utilized for the application of this coating with one of the primary being a hot dip process which gives an excellent coating for exposure to atmosphere and foreign elements. In the hot dip process, a container is provided containing molten spelter or zinc, and the article requiring to be galvanized is first thoroughly cleaned in hydrochloric acid, dried and carefully dipped in the molten zinc after the latter has been sprinkled with salammoniac. The surplus spelter must then be moved from the surface and the article is frequently plunged into water washing away any spent sal-ammoniac that may remain on the surface. The present invention contemplates an improved method of removing the spelter from these surfaces, especially from articles such as pipes having a self-enclosed surface. The removal of spelter is also necessary in other pipe treatment processes and the present invention may be utilized for the removal of spelter from items such as tubing treated by various coating processes.

It is accordingly an object of the invention to provide an automatic machine and improved process for the removal of excess spelter from the interior of items, such as lengths of tubing.

Another object of the invention is to provide an improved mechanism for removing excess spelter from freshly galvanized pipes and which will transport the pipes automatically and quickly in a lateral direction from a receiving or pick-up station to a spelter removing station and discharge the clean pipes after the excess spelter has been removed therefrom.

A further object of the invention is to provide an improved mechanism for forcing a high pressure fluid, such as steam, through the pipes at high velocity to carry the excess spelter from the interior and discharge it through the open end of the pipe.

Another object of the invention is to provide an improved pipe transporting mechanism which will obtain pipes from a pick-up station and transport them laterally over a transporting course to an intermediate station and will subsequently position the pipes at a spelter removing station to finally transport the pipes from the spelter removing station to a pipe delivery station.

A still further object of the invention is to provide an improved automatic control mechanism for automatically synchronizing and operating the related elements of a machine for sequentially cleaning a series of pipes by removing the excess spelter from the interior.

Another object of the invention is to provide an improved automatic electrical control system which is easily adjusted to obtain various time relationships for operation of the elements and which is of a simple and improved construction for use with a machine for removing spelter from freshly galvanized pipes.

Other objects and advantages will become more apparent throughout the following specification and claims taken in connection with the appended drawings in which like numbers indicate like parts and in which:

Figure 1 is a plan view, partially in diagrammatic form illustrating the improved machine for automatically moving excess spelter from the interior of lengths of freshly galvanized pipe;

Figure 2 is a detailed view, partially in section, illus trating an alternative form of a nozzle against which the end of the pipe may be placed for the removal of spelter;

Figure 3 is an end elevational view taken along line III-III of Figure 1 and illustrating the automatic spelter removing machine;

Figure 4 is a diagrammatic view illustrating the arrangement of the improved form of cam mechanism and circuit diagram used in co-operation with the preferred embodiment of the spelter removing machine;

Figure 5 is an enlarged detailed view, taken partially in section, of the individual mechanisms utilized for operating the control switches in timed relationship;

Figure 6 is an enlarged detailed view of the switch operating plunger and the enclosing sleeve with these elements removed from the rest of the structure to illustrate their structural details; and

Figure 7 is an enlarged detailed view, taken partially in section, of the mechanism of Figure 5 and illustrating the switch control mechanism in an advanced position relative to Figure 5.

Although the invention is fully disclosed and taught by the method and apparatus disclosed herein as being the preferred embodiment of the invention, the invention enjoying particular utility in the form shown, it is to be understood that it is not to be limited to the exact usage described, and may be used in other forms and may be utilized for purposes other than cleaning excess spelter from freshly galvanized pipe. Further, the various subcombinations of the invention, although they find particular utility in the combination shown, may be used to advantage in other arrangements as will be recognized by those skilled in the art.

In the mechanism illustrated, employing the features of the invention, a series of lengths of pipe, such as 10, 12 and 14, are positioned at a pipe pick-up station indicated by the letter A. A plurality of pipes may be supplied at this pick-up station as they are delivered in a freshly galvanized state from the galvanizing machinery, or they may be delivered individually from the galvanizing machine directly. Individual pipes are then transported in a lateral direction to an intermediate station indicated at B, wherein .the pipe is shown at 16. From the intermediate station, the pipe is next transported to a spelter removing station indicated at C with a pipe shown at 18 being in position for the removal of spelter from the interior thereof. When the spelter has been removed, the pipe is then transported to a delivery station indicated at D, with the pipe illustrated as 20. Thus, "a continual treatment is in process with the individual pipes continually moving from the pick-up station to the intermediate station to the spelter removing station to the delivery station, as indicated by the letters A, B, C and D in Figures 1 and 3. The path through which the pipes are carried in their movement between these stations is indicated by the dotted line path 22, illustrated in Figure 3.

As is still shown in Figures 1 and 3, the supply of freshly galvanized pipe is supported in a rack formed by a pair of inclined rack members 24 and 26. These rack members have

stops

28 and 36 at their forward lower ends so as to hold the pipes in a lateral horizontal position without rolling down on the racks. The individual pipes are removed from the rack by being lifted upwardly along the dotted line path, shown in Figure 3, and the pipes behind the lower-most pipe in the rack will then roll forwardly until they engage the

stops

28 and 30. A

relatively small supply of pipes is kept on the rack and the time consumed between the time when the pipes are on the rack to when the spelter is removed is relatively and 42. The crank wheels are or the same size and are synchronized in their rotation so that the bars will remain horizontal in all positions of the crank wheels and will remain parallel to each other. For'connecting to the crank wheels, each of the bars carries a pair of support legs, such as shown by legs 44 and 46 on bar 32 in Figure 3. These legs are pivotally journaled to a

crank pin

48 and 50, respectively, on each of the

crank wheels

38 and 36, respectively. Transport bar 34 likewise has a pair of'legs projecting downwardly from it which are rotatably journaled on crank pins 52 and 54 on the crank wheels 42 and 40, respectively. The legs for the transport bar 34 are not shown and are identical in construction to the legs 44 and 46 for the bar 32.

Opposing crank wheels 38 and 42, which carry the same ends of the

transport bars

32 and 34, are connected to each other by being secured to an axle 56. The crank wheels 36 and 40 are likewise rotated together by being mounted on an axle 58. The

axles

56 and 58 carry sprockets or

pulleys

60 and 62, respectively, over which passes a driving chain or belt 64. Any type of drive mechanism may be utilized to drive the axles at the same speed and in synchronism which maintains the axles in their same rotational position. For this purpose a toothed or a cogged belt or a chain should be used so that the wheels can not get out of phase. The drive belt or chain 64 is driven by passing over a drive pulley 66 on the drive shaft 68 of the pipe indexing motor 70. As will be seen from the description of the control mech- 1 anism, this pipe indexing motor is intermittently operated to rotate the

crank wheels

36, 38, 40 and 42 intermittently through 360 of rotation.

The crank wheels are shown in their temporarily stopped position in Figure 3, during which time the spelter is being removed from the inside of the pipe 18. When the spelter has been removed the wheels are rotated in a clockwise direction, as indicated by the arrows 72, to i move the

transport bars

32 and 34 through an arcuate path to deliver a new freshly galvanized pipe to the spelter removing station, and in the meantime, picking up a new pipe from the pipe pick-up station and delivering the clean pipe from the spelter removing station to the delivery station. 2 For carrying the pipes between the pipe pick-up station A and the intermediate station B, the

transport bars

32 and 34 are provided with

notches

74 and 76, respectively. These notches are concave in form, and are utilized to prevent the pipes from rolling off of the upper horizontal surface of the transport bars as they are shifted laterally.

- the arcuate path from station A to station B. At station B, the pipe is temporarily rested on a pair of intermediate supports 78 and 80, which are also notched or have a -concave upper surface to temporarily support the pipe.

In this manner, when the support bars again drop downwardly in their arcuate path, the pipe will be temporarily deposited on the intermediate supports 78 and 80, and will subsequently again be engaged by the transport bars by being lifted by the middle notch 82 and 84 on the

bars

32 and 34, respectively. These concave notches are similar to the

notches

74 and 76 on the ends of the transport bars. When the pipes are lifted in the notches 82 and 84 in the upward movement of the transport bars they are carried forward from the station B to station C with the pipe 18, as shown in Figures 1 and 3, being deposited on the roller supports 86 and 88.

These roller supports are suspended for free rotation on a horizontal axis by their shafts 90 and 92, which are freely journaled in bearings (not shown). The roller supports give temporary vertical support to the pipes of the spelter removing station and permit them to be moved freely in a longitudinal direction. 1

The pipes are moved longitudinally to force the end 94 of the pipe 18 against the nozzle96. The specially shaped nozzle 96 is located at the spelter removing station for injecting high pressure high velocity fluid, such as steam into the end 94 of the pipe to carry the spelter through the pipe and discharge it out of the free end 98. The nozzle is carried at the end of a steam conduit 100 with the flow of steam through the conduit being controlled by a valve 102 operated by a solenoid or another electrical operating means 104. The nozzle is specially shaped having an open end tapered inwardly with a frusto-conical surface which guides the end 94 of the pipe 18 against the conduit opening 108, so that the steam will be directed into the interior of the pipe without loss around the edges of the pipe end. With this surface, the pipe will be guided directly against the conduit 108, even though it may be slightly misaligned while being moved in the axial direction.

For moving the pipe axially, a group of pinch rolls are provided which move laterally against the pipe surface and which are rotated to move the pipe axially into engagement with the steam nozzle 96. The first opposing pair of pinch rolls are shown at and 112, and the second or rearward opposing pinch rolls are shown at 114 and 116. In the form of the invention shown, the pinch rolls 110 and 114 are carried at opposite ends of a yoke 118 and the pinch rolls 112 and 116 are carried at opposite ends of a yoke 120. The yokes are supported on the rods 122 and 124, respectively, of plungers slidably mounted in cylinders 126 and 128, which receive compressed air or steam to control the position of the yokes and hence the position of the pinch rollers. For admission of air or exhaust of air to control the position of the pinch rolls, each cylinder 126 and 128 carries a control valve 130 and 132 which regulates the supply of air through the

supply lines

134 and 136. The pinch rolls are moved apart or separated during the time an individual pipe is being carried along the arcuate path indicated by the dotted line between stations B and C in Figure 3. Thus, the pipe can be dropped between the pinch rolls to rest on the roller supports 86 and 88. The transport bars 32 and 34 are stopped at a position sufliciently low to free the pipe to be supported on the support rollers 86 and 88, and the pinch rollers then move together to engage the sides of the pipe. The rollers are then rotated in their forward direction as indicated by the arrows in Figure 1, to force the pipe axially against the nozzle 96. The rollers are then temporarily stopped until steam is driven through the pipe to carry the excess spelterout the free end. The rollers are then reversed to be rotated in a direction opposite that indicated by the arrows, and the pipe is moved axially to a position where it is in allgnrnent with its two neighboring pipes 16 and 20 at stations B and D. At that point, the pipe is lifted .up by-the notches 138 and 140 in the ends of the transport bars to be carried to the delivery station D,

For rotating the pinch rollers in each direction, and moving the pipes axially in the spelter removing station, the pinch rolls 1'10 and 114 at one side of the pipe are driven by a motor 142. This motor is controlled by the electrical system to be later described, and has a drive pulley 144 over which is threaded a drive belt 146, driving a pulley 148 on the pinch roll 110. A connecting belt 150 passes over another pulley on the pinch roll 110 and is threaded over a similar pulley on the other pinch roll 114 to drive it with pinch roll 110.

The same arrangement is used for the other set of pinch rolls with a separate motor 152 being provided, this motor being operated by the same set of, controls that drives motor 142. The drive pulley 154 for motor 152 carries a drive belt 156 which is threaded over a drive pulley 158 on the pinch roll 116. This pinch roll carries another similar pulley which drives another belt 160 passing over a similar pulley connected to the pinch roll 112 to drive it in rotation in the same direction and at the same speed as the pinch roll 116. Thus, the pinch rolls 110, 112, 114 and 116 are driven to move the pipe 18 axially against the nozzle 96 and withdraw it after the spelter has been removed.

At the delivery station D the pipes are dropped on a pair of parallel angular discharge rails 162 and 164 to roll away from the spelter removing machine.

In Figure 2, an alternative form of nozzle is shown connected to the steam conduit 100. This nozzle has a tapered end 166 which is of a diameter smaller than the end 94 of the pipe 18, so as to fit into the open end. Thus, when the pipe is pushed against the nozzle it slides over the tapered end thereof and a fit is achieved which prevents the escape of steam.

The control system is constructed integrally with the mechanism illustrated in Figures 1 and 3, and is shown partially in schematic form separated from the remainder of the mechanism in Figure 4 to better understand its detail. The electrical control for intermittently operating the pipe indexing motor 70 is schematically illustrated in Figure 4 by coil 166, and is also represented by a schematic representation of a coil box 166 in Figure 3. The controls 130 and 132 for controlling the position of the pinch rolls and moving them into engagement with a pipe or away from the pipe after 'the spelter has been removed are shown schematically at 130--132 in Figure 4. The forward drive of the rolls to move the pipe against the nozzle is controlled by a coil shown at 168 in Figure 4 and in Figure 1 for running the motors 142 and 152 in a forward direction. For reversing the motors and backing off the pipe from the nozzle, the motors are controlled by a reverse switch illustrated diagrammatically at 170 in Figure 4. Titles have also been added to the schematic showing of the controls in Figure 4 to better illustrate their functions.

Each of the control coils isoperated by a switch with the switch 176 controlling the motor indexing control 166, switch 178 controlling the pinch roll drive control 168 and the pinch roll position control 130-132, switch 180 operating the fluid nozzle control 104, and switch 182 operating the pinch roll reverse control 170. Each of the

switches

176, 178, 180 and 182 are respectively controlled by

cams

184, 186, 188 and 190. These cams are'carried on a cam shaft 192 driven by a motor 194 which operates the shaft through a torque clutch 196. This permits constant operation'of-a motor unless the cam shaft is locked and prevented from moving. For locking the cam shaft and temporarily preventing further operation of the machine, a locking disk 198 is carried at the end of the cam shaft 192 to be engaged by a locking arm 200. This arm 200 is connected to the core 202 of a solenoid 204 which draws the locking arm 200 out of the way to free the disk'198 and permit rotation of the cam shaft 192 when the coil is energized by closing the operating switch 206. A spring 208 is connected to the locking arm 200 to pull it to locking position when the solenoid 204 is deenergized by opening the switch 206. The switches for operating the individual elements in the machine are illustrated as being the contact type, as shown in detail in Figures 5 and 7. The switch bodies 208 form a casing or housing to enclose the switch mechanism and are mounted on a supporting frame 210 by

adjustable screws

212 and 214 with coil compression springs 216 and 218 surrounding the screws in position between the switch casing 208 and the frame 210 to push the switch tightly up against the head of the adjustment screws 212 and 214. By rotating the screws, the position of the switch plunger 220 relative to the switch operating plunger 222 can be controlled. The switch operating plunger 222 moves axially within its supporting sleeve 224 to engage the switch plunger 220 and thus close the switch. This axial movement is shown in Figures 5 and 7 with the switch plunger 220 being released in Figure 5 and being depressed in Figure 7 to close the switch.

The sleeve 224 enclosing the switch operating plunger 222 has a bracket 226 provided with an opening 228, Figure 6, for receiving a bolt 230, Figures 5 and 7, for supporting the sleeve and plunger on the frame 210.

The switch operating plunger 222 is rotated in a unique manner to obtain axial movement. The plunger is forced to the non-engaging position of Figure 5, either by gravity or by a spring which may be enclosed within the sleeve 224. To support the plunger 222 in the sleeve, the plunger carries a pair of cam pins 234 and 236 diametrically opposed, as shown in Figure 6. When the switch operating plunger is rotated in a counter clockwise direction, as shown in Figure 6, the cam pins 234 and 236 ride up the sleeve cam surfaces 238 and 239 to move the plunger axially with respect to the sleeve. For returning the switch operating plunger to its original position, from the position of Figure 7 to the position of Figure 5, the plunger is rotated in the opposing direction.

For rotating the plunger through its 90, the plunger carries a pair of operating

pins

240 and 242 which are separated 90 circumferentially with respect to the plunger and which are located at the lower end thereof. The plunger operating pins 240 and 242 are operated by striking

pins

244 and 246, respectively. The striking pins are carried on individual rotating disks or

cams

248 and 250, respectively, which are adjustably secured in rotation on the cam shaft 192. Disk 248 carries a set screw 252 which is threaded into the hub of a disk against the shaft to secure it in its rotational position, and disk 250 carries a set screw 254 threaded into its hub to adjustably secure it to the cam shaft 192. Thus, by properly setting the disks with respect to the cam shaft 192, the exact time relationship when the switch is operated with respect to the other elements can be accurately controlled.

Thus, as the cam shaft rotates the striking pin 244 will first engage the plunger operating pin 240 to rotate the plunger causing the cam pin 234 to climb the inclined surface of the cam 238 and rest on the flat portion at the top of the inclined surface. As the cam shaft 192 continues to rotate, the striking pin 246 will engage the cam operating pin 242 to rotate the plunger in the opposite direction and permit the cam pin 234 to again slide down the inclined cam surface 238 to thereby release the plunger 220 of the switch. Since each of the

cams

184, 186, 188 and is constructed similarly, only one need be described in detail, such as is discussed in connection with Figures 5 through 7.

Thus, it will be seen that by adjustment of the position of the individual disks on the cam shaft 192 not only can the time of operation of the switch be controlled, but also the period of time during which the switch is closed or open. Thus, the timed relationship between the operation of the transport bars, the pinch rolls, the direction of rotation of the pinch rolls and the operation of the steam valve for removing the spelter from the interior of the pipe can be'positively adjusted and very accurately controlled. The switch control arrangement is extremely simple in construction and yet will achieve positive and accurate control of the machine elements.

Although the overall operation and the co-operative function of the various elements in the machine will now be clear from the description of their individual structure and functions, an overall review of the operation of the machine will be helpful in understanding the objectives and advantages of the invention. The lengths of pipe, as illustrated by

pipes

10, 12 and 14, as they are received from a galvanizing machine, are first supported in rack means illustrated at 24 and 26. They are lifted out of the rack by intermittently rotated

transport bars

32 and 34, which are carried on the crank

wheels

36 and 38, and 40and 42 respectively. These wheels are intermittently rotated through 360 to move the transport bars and lift the lengths of pipe toward the spelter removing station.

The lengths of pipe are carried along the dotted line path 22 of Figure 3, and are first transported from the pick-up station A to the intermediate station B. The pipes are next carried by being supported in the notches 82 and 84 of the transport bars 32 and 34, to the spelter removing station where they are dropped on the freely rotating supporting rolls 86 and 88. At this time, the pinch rolls 110, 114, 112 and 116 are moved together by operation of the cylinders 126 and 128 to engage the length of pipe at the spelter removing station shown by the pipe 18 in Figures 1 and 3. The pinch rolls are rotated in a forward direction, as shown by the arrows in t Figure l, to force the end 94 of the pipe against the concave face 106 of the nozzle 96. The valve 102 is then operatedby the control 104 to force steam through the interior of the pipe to remove the fresh spelter therefrom. The pinch rolls are then reversed to move the pipe away from the nozzle and the pipe is then carried from the spelter removing station C to the delivery station D whereupon it rolls down the discharge rails 162 and 164. The pinch rolls are, of course, separated before the pipe is lifted from between them.

The operational control for the individual elements for handling and treating the pipe is obtained from the controls operated by the

individual switches

176, 178, 180 and 182. The switches are each operated by having their plungers 220, Figures and 7, depressed by a switch operating plunger 222. The switch operating plunger carries a cam pin 234 which, when the plunger is rotated rides up the inclined cam surface 238 in a sleeve 224 which encloses the plunger. The switch operating plungers are rotated by striking pins 244 carried on disks 248 on the cam shaft 192, engaging the plunger operating pins 240. This depresses the switch plunger 222 and it will remain in a depressed position until another striking pin 246 carried on the disk 250 engages the plunger operating pin 242 to rotate the plunger in the opposite direction and permit it to move accurately away from the switch plunger 220. The time when the switch is operated and the time during which it is depressed is controlled by individual adjustment of the various disks along the cam shaft 192. The machine may be permanently stopped by turning off a control switch by cutting off the flow of electricity to the control leads 172 and 174, but may be temporarily stopped by opening the control switch 206 to admit the stop arm 200 to engage the disk 198 thereby stopping further rotation of the cam shaft 192. The cam shaft is driven by the motor 194 through a torque clutch 96 which permits a continued rotation of the motor while the cam shaft is temporarily locked. This arrangement also insures that the machine will always be stopped at the end of its cycle so that there will be no danger of stoppage, such as during the time that steam is being blown through the Thus, it will be seen that I have provided an improved method and mechanism for removing the spelter from freshly galvanized pipes which meets the objectives and advantages herein before set forth. It will be recognized that the mechanism is adapted for operation at relatively high production speeds and is capable of operating over long periods of time without requiring adjustments to compensate forwear.

The mechanism can be constructed of rugged and durable parts and is still well adapted to very accurate and close control. The apparatus is well fitted to the removal of excessive spelter from freshly galvanized pipes and also may be utilized in other operational circumstances which take advantage of the many advantageous features of the invention. i r

I have, in the drawings and specification, presented a detailed disclosure \of the preferred embodiments of my invention, but it is to be understood that I do not intend to limit the invention to the specific form disclosed but intend to cover all modifications, changes and alternative constructions and methods falling within the scope of the principles taught by my invention.

I claim as my invention:

1. A mechanism for removing excess spelter from the inside of lengths of pipe comprising a member for supplying a plurality of lengths of pipe having excess spelter in the interior, a pair of spaced transport bars extending laterally of the individual lengths of pipe and lying in the same horizontal plane, a nozzle member having an opening for supplying a flow of high velocity fluid to remove the excess spelter from the pipe, means for moving said transport bars in a horizontal direction lateral of the pipe and in an arcuate path to move upwardly beneath and supportingly engage individual lengths of pipe and transport them to a position adjacent the nozzle, separate means for relatively moving the individual pipes with one end in juxtaposition to the nozzle to receive the flow of pressurized fluid to thereby discharge the excess spelter from the open end, and means to remove the cleaned pipes from their position against said nozzle and, to deliver them in a direction lateral of the pipe to a delivery station.

2. A mechanism for removing excess spelter from the inside of lengths of pipe comprising means for supplying a plurality of freshly galvanized pipes, 21 pair of laterally extending parallel transport bars, means for moving the bars in a lateral direction to receive individual lengths of pipe from the supply means and deliver them to a spelter removing station, a fluid discharge nozzle positioned at said spelter removing station to force a high velocity flow of fluid through the interior of the pipe to discharge the excess spelter from the interior thereof, opposed axial pipe positioning rolls located at said spelter removing station to receive the individual pipes from the transport bars, means to move said positioning rolls against the pipes to move them into position against the nozzle, means to reverse the direction of rotation of the rollers to remove the individual pipes from the nozzle, and means for receiving the cleaned pipes from the transport bars as the pipes are carried away from the spelter removing station.

3. A mechanism for removing excess spelter from the inside of lengths of pipe comprising a fluid supply nozzle member positioned at a spelter removing station, means for supporting pipes at a pipe pick-up station with -.a lower surface of the pipes exposed, laterally extending parallel transport bars'adapted for movement between the pipe pick-up station and the spelter removing station, rotating crank wheels supported on an axis extending horizontally and transversely to the transport bars with the bars connected eccentrically to said crank wheels and supported thereby, means for rotating the crank wheels to move the bars in a rotary motion in a vertical plane between the pipe pick-up station and the spelter removing station to move beneath the pipes and carry them upwardly arcuately to the spelter removing station, means to relatively move the pipes axially against the nozzle at the spelter removing'station, and means to 9 discharge pressurized fluid through said nozzle to carry the excess spelter through the pipe to be discharged out the unobstructed end.

4. A mechanism for removing excess spelter from the inside of lengths of pipe comprising a nozzle member having an (opening for discharging pressurized fluid through the pipe, electrical control means for releasing the fluid through the nozzle only when the pipe is in position to receive the fluid from the nozzle, transport means for carrying individual pipes from a pipe pick-up station to a spelter removing station opposite the nozzle, axial positioning means adapted to engage the pipe and force the individual pipes: relatively into the position against the nozzle and to remove the pipes from the nozzle after the fluid has forced the excess spelter therefrom, first electrical operating means fior controlling the position of the transport means, second electrical operating means for controlling the operation of the axial pipe positioning means, a notary cam shaft for timing the operation of the spelter removing mechanism, rotary switch operating plungers adapted for axial movement with rotation of the plungers, a plurality of contact switches positioned for engagement by the switch operating plungers, and plunger operating members mounted on the cam shaft and adapted to engage the plungers and rotate them to operate the cams at a predetermined position of rotation of the cam shaft, and another group of plunger operating members on the cam shaft adapted to engage the plungers and rotate them back to their original position with further rotation of the cam shaft to thereby release the switches, and electrical circuit means connecting the switches to the first and second electrical operating means to sequentially operate the transport means and the pipe positioning means of the spelter removing mechanism.

5. A control system adapted to control the operation of elements of machinery in related sequence comprising a plurality of electrical switches electrically connected to operate the machine elements, a plurality of control plungers adapted to axially engage and operate the individual switches, a sleeve for each of the plungers having a cam for advancing the plunger axially, follower means connected to the plunger in engagement with the cam surface of the sleeve, means for returning the plunger axially when rotated to the return position, a first element projecting radially from the plunger and positioned to be engaged to cause notation of the plunger, 21 second element projecting radially from the plunger and positioned to be engaged to cause the plunger to be rotated to return position, a pair of striker members fior operating each plunger and being rotatably adjustable with respect to the plunger and mounted on a common rotatable time control shaft, and means for rotating the shaft to cause said striker members to engage the radially projecting elements on the plungers to sequentially axially advance the plungers to close the switches and to subsequently return the individual plungers to the return position to release the switches.

6. A mechanism for removing excess spelter from the inside lengths of pipe comprising a fluid discharge nozzle positioned at a spelter removing station, means for controlling the flow of pressurized fluid from said nozzle, a supply of freshly galvanized pipes located at a pipe pick-up station, an intermediate pipe support positioned at an intermediate station located between the pipe pickup station and the spelter removing station, a pair of parallel horizontally extending transfer bars, means to oscillate said bars in an arcuate path, and pipe supporting elements on said bars spaced equal to the distance between said stations, certain pipe supporting elements carrying the individual pipes between the pipe pick-up station and the intermediate station and other elements carrying the individual pipes from the intermediate station to the spelter removing station.

7. A control system adapted to control the operation of elements of machinery in related sequence comprising a plurality of control plungers adapted to change the operation of machine elements with axial movement, machine elements positioned to be operated by axial movement of the plungers, operating means for causing axial movement of said plungers to advance position with rotation thereof in a first rotational direction and axial return with rotation in the other direction, means on each of the plungers coacting with said operating means for causing said movement to advance position and return, a pair of rotatable plunger-engaging elements for each control plunger, a rotating shaft supporting said plunger-engaging elements, means for rotating said shaft, a first member on each plunger positioned to be engaged by one of said plunger-engaging elements to cause rotation of the plunger in said first direction to advance the plunger axially, and a second member on each plunger positioned to be engaged by the other of said plungerengaging elements when the plunger is rotated to advance position to cause rotation of the plunger in the opposite direction to return the plunger axially.

8. A control system adapted to control the operation of elements of machinery in related sequence comprising a plurality of electrical switches connected to the machine elements for control thereof, a plurality of contnol plungers positioned adjacent the switches to engage and operate the switches with axial movement, operating means to cause axial movement of the plungers with rotation, means on each of the plungers coacting with said operating means to move the plunger axially to an advance position with rotation in one direction and to return the plunger with rotation in the other direction, and a control shaft having members engaging the plungers at one point in the rotation of the shaft and causing rotation of the said plungers in said one direction and consequent axial movement to advance position and operation of the switches and having members engaging the plungers at another point in the rotation of the shaft and causing rotation of the plungers in an opposite direction to return the plungers axially away from the switches to release the switches.

References Cited in the file of this patent UNITED STATES PATENTS 555,114 Oehring et a1 Feb. 26, 1896 1,919,199 Camerota July 25, 1933 2,042,794 Meyer June 2, 1936 2,400,763 Malo May 21, 1946 2,428,292 Queen Sept. 30, 1947 2,606,846 Pearson Aug. 12, 1952