US2906237A

US2906237A - Apparatus for wiping conduit sections

Info

Publication number: US2906237A
Application number: US494853A
Authority: US
Inventors: Bernhardt Otto
Original assignee: Rome Cable Corp
Current assignee: Rome Cable Corp
Priority date: 1955-03-17
Filing date: 1955-03-17
Publication date: 1959-09-29
Anticipated expiration: 1976-09-29

Description

P 1959 o. BERNHARDT 2,906,237

APPARATUS FOR WIPING CONDUIT SECTIONS Filed March 17. 1955 i 5 Sheets-Sheet 1 i l 23 I l 26 36 4 o V 15 a2 47 i 40 I 0 TTO BERNHARDT;

IN V EN TOR.

HUEENER, BE'E'HLER, WORRE'L 8 HERZIG,

A TTORNE Sept. 29, 1959 o. BERNHARDT 2,906,237

APPARATUS FOR WIPING CONDUIT SECTIONS Filed March 17. 1955 3 Sheets-Sheet 2 OTTO BERNHARDT,

IN VEN TOR.

HUEBNER, BEEHLER, WORRE L 8 HEIPZ/G,

A TTORNEVS- P 1959 d. BERI\ IHA RDT 2,906,237

- APPARATUS-FOR WIPING CONDUIT SECTIONS Filed March 17. 1955 3 Sheets-Sheet 3 OTTO BERIVHARDT;

INVENTOR.

HuEa/vEmaEEr/mk,

WORREL 8 HERZ/G,

ATTORNE K51 United States Patent APPARATUS FOR WIPING CONDUIT SECTIONS Otto Bernhardt, Gardena, Calif., assignor to Rome Cable Corporation, Torrance, Calif., a corporation of New York Application March 17, 1955, Serial No. 494,853 3 Claims. c1. 118-63) The present invention relates to internally and externally wiping freshly coated conduit sections free of exproblem becomes even more difiicult when the coating material is high melting point material such as a molten metal, for example, applied to metal conduit sections. A practical example is the wiping of excess molten zinc from steel conduit sections immediately after removal from a zinc pot in the hotedip galvanizing process.

Accordingly, an important object of the present invention is to provide a method and apparatus for continuously wiping excess coating material from the surfaces of coated conduit sections without injuring the coating.

Another object is the provision of an eflicient and auto matic method and apparatus for continuously withdrawing dip-coated steel conduit sections from a dip-tank and continuously wiping excess coating material pneumatically from both the internal and external surfaces of the conduit sections.

additional object is to provide a continuous, automatic method and apparatus for pneumatically wiping to a smooth and uniform finish the internal and external coating of steel conduit sections freshly galvanized by the hot-dip galvanizing method.

These and other objects will be apparent upon reading the following description.

Broadly stated, the present invention comprehends a method and apparatus, preferably automatic, for pneu- Inatically wiping excess coating material from conduit .sections, preferably continuously. It comprises conveyor means for conveying freshly coated conduit sections, preferably axially thereof, from the coating station to the wiping station. At the wiping station the coated conduit sections are passed axiallythrough a nozzle means arranged in a circle, such as a hollow ring provided with radially arranged nozzles directed toward the center of the ring. As the conduit section passes through the nozzle means,-stea m or other vapor or gas is ejected from the nozzle means and impinged against the external surface of the section to pneumatically wipe or blow the excess coating material therefrom. A second nozzle means, adapted to engage an end of the conduit section, is so engaged and air or other gas is blown through the section to wipe or blow excess coating material from the internal surface thereof. The operation of the conveyor means and the first and second nozzle means preferably automatically are actuated and timed for handling each ,COn-

.duit section in a continuous series thereof by suitable means such as time cycle switches.

A more detailed description of a specific embodiment of the method and apparatus of the invention as applied to wiping galvanized steel conduit sections freshly galvanized by the hot-dip method is given with reference to the drawings, wherein;

Figure 1 is a side elevational view of a magnetic roller conveyor and steam wiper showing a conduit section being conveyed from a zinc pot (not shown);

Figure 2 is a similar view showing the conduit section in position for internal air wiping;

Figure 3 is a similar View showing the wiped conduit section and the magnetic roller conveyer in position to commence a new cycle of operations;

Figure 4 is a detail perspective view showing an air injection nozzle for internal wiping of galvanized conduit e t Figure 5 is an end view of the magnetic roller conveyer taken along the line 5-5 of Figure l and showing a steam jet ring for external wiping of galvanized conduit sections;

Figure 6 is a detail perspective view of the conduit section carriage employed with the air and steam wiper;

Figure 7 is a fragmentary plan view showing the end of a conduit section, partially in section, and supported on the conduit section carriage;

Figure 8 is a detail elevational view, with a portion broken away, showing the steam ring externally Wiping a galvanized conduit section passing through the ring; W

Figure 9 is a cross-sectional view taken on the line 9:..9 of Figure 8 showing the relationship of the conduit section to the nozzles of the steam ring;

Fig. 10 is a schematic diagram illustrating the pneumatic and electrical system of the apparatus in sin;- plified form;

Fig. 11 is a vertical cross-sectional view as taken substantially along a line 11-11 of Fig. 6; i

Fig. 12 is a side view, with parts broken away for greater clarity, as seen substantially along a line 12-12 revolving electromagnetic roller 10 in a V-shaped groove 11 (Figure 5) formed peripherally of the roller in a middle portion thereof and having its bottom side ing away from the zinc pot. Roller 10 attracts the hot galvanized conduit section to the bottom thereof, draws it out of the zinc pot and passes it on to a battery of electromagnetic rollers 12 revolving in the same direction and otherwise resembling roller 10. After the end of the withdrawn conduit section passes beyond the bottom side of the first of the four rollers 12, it is passed through the circular opening of a ring 13. K

Ring 13, as is best shown in Figures 8 and 9, is hollow and is provided with a series of radially disposed nozzles 14 passing through the inner wall of the ring and angularly inclined about 20 (Figure 9) from the vertical with their inner ends nearer the conduit entrance side of the ring and adjacent the external surface of a condiiit section 15 passing through the ring. The ring 13 cornnunicates with a steam pipe 16 to which it is releasabl y connected by means of links 17 pivotally mounted on" he walls of the steam pipe 16 and carrying pivotally mounted toggles 18 for engagement with a collar 19 on i 20 of the ring 13. This arrangement permits speedy rfe placement of the ring during minimum shut down time. The ring 13 can be made with an inner sleeve 13a (Figure 9) provided with a flange at the front end and an external thread at the rear end tomesh withan inte a1 As the conduit 15 passes through the ring 13, a blast of steam, preferably in the range of about 900 to about 1,000 F. is ejected from the ring 13 through the nozzles 14 and caused to impinge on the external surface of the conduit to blow or wipe off excess amounts of zinc therefrom. When the leading end of the conduit 15 passes beyond the third roller 12, it contacts a time cycle switch 21 which, when the trailing end of the tube passes over the two

projections

41 and 42, de-magnetizes the magnetic rollers 12, dropping the tube onto carriage 27.

Instant de-magnetization of the rollers is accomplished by impressing a reverse field on the main electro-magnetic field. The position of carriage 27 is determined primarily by two

air cylinders

28 and 29 attached near each end thereof and suspended from the frame 31 of the wiping and conveying mechanism. As shown in Figure 1, when a conduit section 15 is conveyed into the wiping apparatus by rollers 12, the carriage 27 is held by the

air cylinders

28 and 29 below the conduit section and parallel thereto.

When the rollers 12 are de-magnetized and conduit section 15 is dropped, it falls into a V-shaped channel iron or holder 32 (Figure 6) attached to the upper portion of the carriage 27. Upon falling on channel iron or holder 32, the conduit section 15 actuates a time cycle switch 33 mounted in line with the channel 32 and positioned toward the trailing end of the conduit section.

The time cycle switch 33 initiates a series of actions. The operation is best understood by reference to Fig. 10, in conjunction with the various positions illustrated in Figs. 1, 2 and 3; Fig. being a simplified schematic diagram illustrating operative portions of the apparatus relative to pneumatic and electrical systems adapted to automatically and cyclically carry out the functions of the apparatus. The switch 33 is a time-delay switch having a pair of contacts 51 adapted to close a circuit and energize a solenoid of a solenoid-actuated valve 52 and having a source of electrical power indicated at 53 and referred to in broken lines at 53. The valve 52 diverts pneumatic pressure, from a pressure source (not shown) delivered to the valve by a conduit 54, to a conduit 56 communicating with the upper portion of the air cylinder 29 to extend its piston rod to lower the rear end of the carriage 27, as shown in Fig. 2, by depressing the lower cnd of a link 34 pivotally connected to the frame 31 and to the rear end of the carriage 27. The link 34, in its downward movement, actuates a timedelay switch, indicated at 57 in Fig. 10, to energize a coil of a solenoid-actuated valve 58 which diverts pneumatic pressure from a branch conduit 54' of the conduit 54 into a conduit 59 to cause the air cylnder 36 to retract its piston rod and draw inwardly a gooseneck section of conduit 37 until air injection nozzle 26 tightly engages the leading end of the conduit section 15, as best shown in Fig. 2. As the nozzle 26 is actuated into engagement with the conduit section 15, an arm 61 supporting the nozzle 26 closes a circuit 62 to actuate the solenoid of a solenoid-operated valve 63, opening the valve to admit steam under pressure into the conduit 37. After a predetermined period of time, the time-delay switch 57 de-energizes the coil of the solenoid-actuated valve 58 to cause the cylinder 36 to extend its rod and disengage the nozzle 26 from the conduit and opening the circuit 62 to cause the valve 63 to close and to shut off the steam. On its return travel, the arm 61 closes contact 64 of a circuit 66 to energize a solenoid of a solenoid operated valve 67 which controls pneumatic pressure to the air cylinder 28. The action and time cycle of air cylinder 39, mounted on the carriage 27, are determined by a cam operated air switch 40 located on the end of the piston rod of air cylinder 28.

As best seen in Figs. 11-13, the air switch 40 is actuated by the downward movement of the piston rod of cylinder 28 at the end of the preceding cycle until about two-thirds of the piston rod has been extended.

Energizing of the solenoid operated valve 67 causes the cylinder 28 to extend its rod and drop the forward end of the frame 27, thereby rotating a shaft 68 secured to the lower end 69 of the piston rod of the cylinder 28 as the angular relationship between the frame 27 and the piston rod changes, as best seen in Figs. 12 and 13. A cam 71 is secured to the shaft 68 for rotation therewith, which through a pivoted member 72 actuates a valve stem 73 of the air switch or valve 40 to divert pneumatic pressure from a branch conduit 54" of the pressure conduit 54 into a conduit 74 communicating with the cylinder 39 to cause the cylinder 39 to actuate lever 43, pivotally mounted in the carriage on a rotatable bar 44 to which a post 46 is fixed. In the upper position of the carriage 27, the piston rod of the cylinder 39 is extended to bring the

projections

41 and 42 into engagement with the conduit section which is elevated slightly when the leading end is engaged by the nozzle 26, as previously described, the conduit section being supported on its ends, free of the channel 32, and remains supported at only its ends in nozzle 26 and, as shown in Fig. 7, between two

projections

41 and 42 gripping the terminal edges of the trailing end of the conduit during the air injection period.

At this stage, the conduit section 15 is still hot enough to maintain the excess of zinc thereon in a molten condition. As the conduit section 15 is supported only at its extreme ends, it is not cooled by contact with channel 32 or any other carriage supporting members. A strong blast of air from nozzle 26 is then injected through the internal length of the hot conduit section 15 and excess zinc is cleanly wiped or blown free of the internal surface of the conduit without any occlusions forming on any cooled internal surfaces. The resulting blast of zinc and air dispels it through the trailing end of the conduit section 15 into a centrifugal cyclone (not shown) wherein the zinc particles are separated from the expelled air.

The air cylinder 36 is then caused, at the end of a predetermined period of holding by the time-delay switch 57, to extend its piston rod and retract the injection nozzle 26 from the forward end of the conduit 15, and the cylinder 39 retracts

projections

41 and 42 from the trailing end of the section while the carriage 27 is being lowered by the cylinder 28, the air switch 40 actuating the cylinder 39 as previously described. The conduit section again rests on channel 32 of the carriage 27. The air cylinder 28 then extends its rod to lower the forward end of the carriage so that it and the conduit section 15 thereon are lowered to a horizontal position, as shown in Fig. 3. In so doing, the piston rod on the air cylinder 28 actuates the air switch 40, as described above. The conduit section 15, which is at about 700 F. at this stage, then is engaged by a roller conveyor 47 and is conveyed into a chromate bath (not shown). After dipping in the chromate bath to form a conversion coating of zinc-chromate on the conduit section, it is ready for final inspection and shipment. The time-delay switch 64 then actuates the cylinder 28, through the valve 67 to retract its piston rod and raise the frame 27 into a position adjacent the rollers 12. The time-delay switch 33, at the same time, causes the valve 52 to reverse the pneumatic pressure in cylinder 29 to raise the arm 34 and thereby the rearward end of the carriage 27 to its position illustrated in Fig. 1.

The rollers 12 are again magnetized and turned and the above-described series of operations is cyclically repeated for each conduit section withdrawn from the zinc bath. The operations of the valves controlling the steam wipe or blow-off, the air wipe or blow-out, the air cylinders and the magnetization and de-magnetization, and starting and stopping of the rollers is controlled by time cycle switches. The timing of each of the operations is carefully adjusted so that the entire cycle of operations is automatic and continuous.

It will be seen that the hot-dipped conduit sections are wiped free of excess adhering zinc to a smooth and uniform finish both internally and externally by using the specific embodiment of the invention described and illustrated above. The wiping is done continuously and entirely automatically.

In the above description, the invention has been described as specifically applied to the wiping of ferrous metal conduit sections coated with a single coating of zinc. It will be understood, however, that the invention can be applied to wiping conduit sections during the application of multiple coatings of zinc or zinc alloys to ferrous metal conduit as well as single or multiple coatings of other metals. The invention also can be used in connection with coating conduit or pipe made of metals other than ferrous metals or of non-metallic composition with either metallic or non-metallic coatings. For example, the invention can be applied to wiping metallic conduit sections that have been enameled or painted or hot-dipped in pitch, tar or asphalt or compositions of these materials. Similarly, the invention can be applied to wiping plastic or other types of non-metallic conduit or piping that has been coated with liquid or molten coatings in single or multiple layers.

When non-ferrous or non-magnetic conduit sections are handled by the method and/or apparatus of the invention, the conveyer rollers and 12 are not electromagnetic rollers and the conduit sections are conveyed on the top side of these rollers through the external wiping ring 13. The externally wiped conduit sections are then grasped at the ends by the internal wiping nozzle 26 and

projections

41 and 42, or their equivalent, and the conduit section is hoisted somewhat above the rollers 12, or their equivalent, while the internal pneumatic wiping blast is effected. After the internal surface Wiping is completed, the wiped conduit section is placed on a conveyer 47 and the above cycle of operations is continuously and automatically repeated.

Although certain structures and design features have been shown in describing the specific embodiment of the invention shown, including structure and design of certain auxiliary equipment and drive means, it will be understood that such features can be varied and modified considerably as to details and structure, as will occur to one skilled in the art. Accordingly, although a specific embodiment of the invention has been described above, it will be understood that such changes and modifications in the method and apparatus of the invention can be made within the scope of the appended claims without departing from the spirit of the invention.

What is claimed is:

1. In an apparatus for wiping excess coating material from a section of a conduit; a nozzle arranged to engage one end edge of said conduit and to direct a blast of gas therethrough, a support engageable with the other end edge of said conduit, and clamping means for urging said support toward said nozzle to clamp and support said conduit section therebetween free of any intermediate support and free of contact with any portion of said apparatus between the ends of said conduit section.

2. Apparatus as defined in claim 1 wherein said support comprises spaced portions engageable with opposed edge portions of said conduit end whereby to provide a passageway therebetween for exhaust of gas and excess coating material from the interior of said conduit.

3. Apparatus as defined in claim 1 including a holder, means for delivering a section of said conduit to said holder, and means responsive to arrival of said conduit on said holder for actuating said clamping means, said support being arranged to simultaneously move said conduit free of said holder and into clamping engagement with said nozzle.

References Cited in the file of this patent UNITED STATES PATENTS 1,124,727 Greenfield Ian. 12, 1915 1,906,400 Moon May 2, 1933 1,917,918 Bedell July 11, 1933 2,424,808 Eckman July 29, 1947 2,495,093 Eckman Ian. 17, 1950 2,606,846 Pearson Aug. 12, 1952 2,669,217 Pearson Feb. 16, 1954