US3452710A

US3452710A - Liquid applicator system

Info

Publication number: US3452710A
Application number: US643992A
Authority: US
Inventors: Rudolf G Hentschel
Original assignee: Baker and Gubbins Co
Current assignee: Baker and Gubbins Co
Priority date: 1967-06-06
Filing date: 1967-06-06
Publication date: 1969-07-01
Anticipated expiration: 1986-07-01

Description

July 1, 1969` R. G. HENTSCHEI.

` LIQUID APPLICATOR'SYSTEM Filed June 6, 1967 Sheet NIQNBW INVENTOR RUDOLF G. HENTSCHEL BY @MM Il '.4 .1l

ATTORNEYS `uly 1, 1969 R. G. HENTscHEl.

LIQUID APPLICATOR SYSTEM Sheet Filed June 6, 1967 Mfg MUIINW" TACH INPUT INVENTOR TIG. 4 RUDQLF G. HENTSCHEL MOTOR com' RoLLER Box l l ATTO R N EYS United States Patent Oftice 3,452,710 Patented July 1, 1969 3,452,710 LIQUID APPLICATOR SYSTEM Rudolf G. Hentschel, Ann Arbor, Mich., assignor to Baker & Gubbins Co., Clawson, Mich., a corporation of Michigan Filed `lune 6, 1967, Ser. No. 643,992 Int. Cl. B05c .l1/02; B05b 7/06, 13/02 U.S. Cl. 118-7 12 Claims ABSTRACT OF THE DISCLOSURE Liquid applicator apparatus for applying lubricants and rust inhibitors to strip or sheet metals being processed in rolling mills or the like. A liquid applicator is positioned transversely above the path of travel of the metals and a plurality of solenoid operated discharge valves are spaced across the header. Remote control switches are provided for selectively varying the number of valves that are open or closed, and an electronic switch is provided which is responsive to the rate of travel of the conveyor for the metals for opening or closing all of the valves simultaneously if the conveyor speed is above or below a predetermined magnitude, and the rate of discharge of the liquid `also is controlled as a function of the rate of travel of the conveyor.

CROSS REFERENCE TO RELATED APPLICATION This application relates to the liquid applicator system of copending application Ser. No. 588,967, led Oct. 24, 1966, now Patent No. 3,402,695 and assigned to the assignee of the present application. The present application contains improvements over the liquid applicator system of the pending application.

BACKGROUND OF THE INVENTION The persent invention relates to a liquid applicator system for use in applying liquids to sheet metal and strip workpieces of a variety of widths which are being processed in rolling mills or the like, and the invention is directed in particular to an improved applicator header for use in the system as Well as to improved controls for regulating the operation of the applicator header.

As is pointed out in the prior copending application, a variety of liquids are employed in industry to aid in the processing of materials. Typical examples in the metal processing industries are the application of oils when metals are to be reduced in size, to be cleaned, or to be prepared for storage. Thus, hot rolled strip and sheet metals are frequently treated with rolling lubricants, and rust inhibitors are also applied to such workpieces. Similarly, in the reducing processes of cold rolled sheet and strip metal, lubricants and/or cleaning agents are applied prior to annealing of the metal.

The procedures commonly followed today for carrying out operations of this character normally involve employing a liquid reservoir containing the liquid or fluid to be applied, and such reservoir is placed suiiciently high, so that it may feed the applicator header by gravity, the header being located in a position over a conveyor which is used to move the workpieces. The header consists essentially of a `steel tube equipped with spigots which dispense fiuid by gravity onto the workpieces passing below on the conveyor. The spigots are equipped with knobs permitting manual adjustment or stopping of the flow of liquids. The workpieces to be coated are passed below the header by means of the conveyor, and normally the spigots are fully or partially open so that liquid falls upon the workpieces as they pass.

lil

The liquid not clinging to the workpieces or conveyor is normally not recovered and reused, because the required filtering and other recovering procedures needed would make the operation uneconomical.

The procedures used heretofore have a number of shortcomings. The fact that the liquid source for supplying the header is normally placed above the header is both inconvenient and impractical, particularly when it is kept in mind that the workpieces that are being passed under the header may change in width on frequent occasions during a normal working shift in the steel mills. The conveyor width represents the limit of the maximum width of a workpiece that can pass under the header, and the header, therefore, in order to meet its intended purpose, must have a width sulicient to allow 4a liquid distribution to cover the entire width of the conveyor. Under these conditions, the liquid is wasted if the workpiece has a width which is less than the full width of the conveyor, unless certain spigots are manually closed. It is found in practice that the operators or workmen along the conveyor do not frequently close the spigots which are not needed, and consequently a waste of the liquid occurs.

Another shortcoming of the existing system is that the liquid will be dispensed continually and at a substantially constant rate -regardless of the rate of movement of the conveyor. Thus, if the conveyor should stop for any reason, the liquid will continue to be dispensed as long as the liquid reservoir and header contains such a liquid. Again, it is recognized that the spigots could be closed, but it is frequently found that because of the inaccessibility of the header, the workmen do not close such spigots each time a stoppage of the conveyor occurs.

Since the conveyor does stop frequently during a normal work shift, the rate of speed of the conveyor will also vary frequently, that is, during acceleration and deceleration phases associated with the stop. At these time periods, the liquid dispensation will occur, because the rate of liquid flow has ybeen set to correspond to the proper liquid coverage on the metal or workpiece at maximum conveyor speed.

Thus, it is apparent that a great waste of coating liquid is associated with the systems now employed in the industry for coating workpieces, because the :shutdown time and acceleration and deceleration time periods comprise a substantial percentage of the time associated with the normal metal processing operations, and during such time periods and during the shutdown periods, substantial amounts of liquid are dispensed which are wasted or are in excess of that required for coating the workpieces. This waste is in addition to the waste that occurs due to the lack of width control of the header outlet. Furthermore, no control of the liquid flow rate exists, which means that no correction can be made to change the rate of liquid flow in case the combination of gravity feed and header and spigot design fails to coincide with the maximum required rate of liquid flow at maximum conveyor speed. These shortcomings also create the additional problems that the operator may set the spigots .at positions well below the position required at maximum conveyor speed in order to reduce the waste of liquid in the shutdown time periods as well as in the time periods of deceleration and acceleration of the conveyor.

The invention disclosed in the aforesaid copending application Ser. No. 588,697 overcomes the shortcomings of the perior art structures discussed above, in that it discloses a header mounted transversely above the conveyor having outlet means for discharging liquid onto the workpieces carried by the conveyor, and the header has a valving arrangement for selectively varying the effect of transverse width of liquid discharged from the header. The header also contains means for simultaneously opening or closing all of said discharge outlets so that the entire system can Ibe interrupted simultaneously, if this is desired. This invention also discloses puunp means for pumping liquid to the header, and regulating means responsive to movement of the conveyor are provided for interrupting operation of the pumping means if the speed of the conveyor falls below `a predetermined amount and for varying the rate of liquid iiow from the header in accordance with the rate of travel of the conveyor.

The system disclosed in the present application is similar to that set forth in the aforesaid copending application, in so far as the general operation is concerned. However, the present invention discloses a header of substantially different construction having an entirely different valving system, and also a separate and independent type of electrical control system is provided for remotely controlling the operation of the header and its valves. Also, improved means are provided for controlling the quantity of liquid delivered to the header.

According to a preferred form of the present invention, ya liquid applicator system is provided having a liquid applicator header adapted to be mounted transversely over a conveyor for transporting workpieces, and having a plurality of spaced solenoid operated valves for discharging a liquid across the width of the conveyor, there being provided a liquid supply means for maintaining liquid in the applicator header, and remote control means for selectively opening and closing the solenoid operated valves. The control ymeans include rotary switches for opening the solenoid operated valves sequentially from the center area toward each end of the header so that the operator can selectively Nary the width of coverage of the liquid being discharged onto the workpieces carried by the conveyor. An electronic control switch is also responsive to movement of the conveyor for starting or interrupting flow of liquid through the header in accordance with the Speed of movement of the conveyor. A controller is provided for the pumping means and is responsive to a tachometer associated with the conveyor whereby the rate of output of the pumping means is proportioned to the conveyor speed. A by-pass valve arrangement is also provided to enable the operator to select the desired quantity of liquid that is to be delivered to the header.

It is an object of the present invention to provide a liquid applicator system for use in processing workpieces of various widths, which has an improved uid distribution header and valving, and'in addition which has improved remote control means for supplying the liquid to the workpieces at controlled rates and to desired areas of the conveyor system.

Other objects of the invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

In the drawings:

FIGURE 1 is ai schematic diagram of a preferred embodiment of the invention, showing a conveyor in transverse section for moving workpieces during rolling mill operations, and also showing the general components of the system embodying the invention;

FIGURE 2 is an enlarged fragmentary section of one end of the header taken on the line 2-2 of FIGURE 3;

FIGURE 3 is a section of the header, taken on the line 3 3 of FIGURE 2; and

FIGURE 4 is a schematic wiring diagram of the electrical controls for operation of the system.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Referring now to the drawings, the invention will be described in greater detail. The liquid applicator system 10 will be described rst with respect to the general arrangement of parts shown in FIGURE l. As there shown, a conveyor belt 12 adapted for carrying workpieces at the rolling mill is shown, and supported on the stationary supports 14 above the belt 12 is the applicator header assembly 16. A plurality of discharge nozzles 18 are arranged in spaced relationship across the entire width of the header assembly 16 so as to permit discharge of liquid from the header 16 onto the conveyor belt 12. A reservoir 20 is provided for storage of the liquid to be applied, and the reservoir 20 is in communication -with a positive displacement gear pump 22 through the suction line 24. Coupled ot the pump 22 for driving the same is the adjustable speed electric motor 26. The gear pump 22 is of a type yso that the volumetric output of the pump varies linearly with the rate of revolution at which it is driven 'by the adjustable speed electric motor 26, and the pump 22 and motor 26 comprise a liquid supply means for maintaining liquid in the applicator header 16. Thus, the output of the gear pump 22 is connected by a conduit 2.8 to the inlet side of the header 16. The discharge line 28 is also provided with an adjustable orifice valve 30 for selectively limiting the peak ow rate of liquid through the header 16.

Also forming a part of the liquid supply system is the by-pass valve 32 lwhich is a conventional adjustable pressure relief valve which serves to by-pass liquid discharged from the gear pump 22 and in cooperation with valve 30 is utilized to set the desired rate of tiow of liquid from header 16 onto metal products being conveyed by the conveyor 12. Safety valve 34 is also provided in the circuit so that if any malfunction or other condition occurs, resulting in the pressure in line 28 exceeding a desired maximum, valve 34 will open and by-pass liquid from the pump to reservoir 20.

The adjustable smed electric motor 26 is electrically connected to the motor controller 'box 36 by the cable 38. The controller box 36 receives electrical signals through cable 40 from a tachometer 42 which is responsive to the rate of movement of conveyor 12, and controller box 36 is also electrically connected to the system control box 44 by cable 46. Another electric cable provides electrical connection between the system control box 44 and the header assembly 16 for operating the solenoid operated valves 18.

The header assembly 16 in which the solenoid operated valves 18 are located comprises a compartment S0 which normaily is completely closed with the exception of the inlet provided for receiving liquid from the conduit 28 and the plurality of outlets 52 which communicate directly with the solenoid operated valves 18. If desired, an air fitting 52, see FIGURE l, may also be provided for venting the compartment or for introducing high pressure air to blow out the compartment 50, if this should be desired.

Mounted 'below the compartment 50 is a panel housing 54 on the yback of which are mounted the solenoid operated valves 18. As shown in FIGURE 3, the electrical leads 56 from the solenoid operated valve 18 extend through openings in the housing S4 to a panel 58 which is electrically connected with the conduit 48. The details of the solenoid operated valves 18 will not be described, since these valves are conventional in construction. Each of the valves employed in the present invention are twoway normally closed valves, which are opened when the associated solenoids are energized. Discharge orices 60 are provided vfrom each of the valves for discharging a thin stream of liquid onto the surface of workpieces being carried by the conveyor 12.

Attention is next rdirection to FIGURE 4 for a brief description of certain of the electrical circuits employed in the present invention.

The electrical system is connected to a line voltage at 62 by the conductors `64 through the control switch 66 to the transformer 68. The latter steps down the line voltage to a level suitable for operation of the solenoid valves 18. In a preferred embodiment of the invention the voltage is stepped down to 24 volts. The secondary of the transformer is connected to the coils 70` of the solenoid valves 18, and it will be noted that a total of 35 such coils are provided, one for each solenoid operated valve. The number of such valves will depend upon the size of installation involved, and in the present embodiment there are three sets of such solenoid operated valves, one including the live valves in the midportion of the header, which are identified by the

numbers

0, 1 and 2 in FIG- URE 4; the second set representing num-bers 3 through 17 inclusive on the right side of the series of coils, and the third set representing numbers 3 through 17 on the left side of the coils 70 illustrated in FIGURE 4. The coils 70 in the rst set 72 are energized via conductors 76 and 78, when normally open relay operated switch 74 is closed. The second set of the coils 70 are adapted to be energized in the same manner, but this must be done through the rotary switch 80. Similarly, the third set of coils 70 can be energized by use of the rotary switch 82. 'Ihe rotary switches 80 and 82 are operated from the external side of the system control box 44, as shown in FIG- URE 1.

The normally open relay operated switch 74 is controlled by the electronic switch 84 which is conventional in construction and will be described generally.

The electronic switch 84 is connected by means of cable 40 to receive from tachometer 42 an input voltage across lines 86. The switch `84 also receives an alternating current voltage from the secondary of transformer 64 via conductor 88. The diodes D1, D2, D3 and D4 condensers C1 and C2, and resistors R1 and R2 generate the direct current to operate the amplitiers 90 which is operated as a voltage comparator and receives signals from the tachometer across lines 86. An adjustable bias voltage is obtained from variable resistor R3, and in the present embodiment this adjustable bias range voltage is set to be from zero to ve percent of the maximum tachometer input voltage. If the tachometer input voltage exceeds the bias voltage the amplifier 90 ouput voltage will switch from a negative ten volts to a plus ten volts to turn the silicon controlled rectifier on, thereby energizing the relay operated switch 74. If the amplifier 90 again goes negative ten volts, the silicon controlled rectifier 92 turns itself olf when the voltage on its anode goes negative. The diode D serves to limit the maximum input voltage to plus ten volts and thus protects the amplier 90.

Thus, the electronic switch 84 operates to open and close the switch 74 in response tol the tachometer input voltage across lines 86. This input voltage reflects the rate of travel of the conveyor 12. Normally the switch 74 will be closed by electronic switch 84 when the conveyor 12 is traveling at or above tive percent of its maximum rate of travel. When the rate of travel is below live percent of maximum, the tachometer input voltage to electronic switch 84 will drop below that required to keep switch 74 closed, and the latter will open, resulting in all of coils 70 of the solenoid operated valves 18 being deenergized, thereby simutlaneously closing all of the normally closed valves which may have been open.

As previously indicated, the iive valves 18 in the rnidportion of the header 16 which comprise the lrst set of valves, will always be energized and thereby open when switch 74 is closed. Also, the same will be true of those valves in sets two and three which are controlled respectively, by

rotary switches

80 and 82, and whose coils are energized because of the positions of such rotary switches. Thus, with respect to the group two valves, the rotary switch 80 is closed with respect to solenoid operated valves 3 through 12, on the right side; and with respect to the group three valves, the rotary switch 82 is closed with respect to the solenoid operated valves 3 through 9, on the left side. Obiously, additional valves can be closed on the right side by rotating switch in a clockwise direction, and additional valves could be closed on the left side by rotating switch 82 in a counterclockwise direction. Thus, the operator can sequentially close or open the valves on either side of the conveyor 12 to vary the effective coverage of the liquid being discharged. Furthermore, whatever effective coverage that has been established will be under the control of the electronic switch 84 so that all valves which provide the desired coverage will be opened or closed simultaneously in response to action of the electronic switch 84.

The tachometer input also is utilized to control the rate of pumping of the gear pump 22. As shown in FIG- URE 4 conductors 94 are connected to the motor controller box 36 and across the tachometer input lines 86. The motor controller is conventional in construction, and in response to changes in the voltage input from conductors 94 will change the motor eld, and therefore, the motor speed. This, of course, will then directly affect the ouput of the positive displacement gear pump 22.

In normal operation of the present invention, the operator will initially set the rotary switches 80 and 82 so as to provide the desired coverage of liquid discharge onto the conveyor 12. The mill is then started, and when the mill speed reaches ve percent of maximum speed, the electronic switch `84 will change state, thereby closing switch '74. This will have the efect of energizing those of the solenoid operated valves which have been selected for opening so that liquid can flow therethrough.

Simultaneously with starting the mill, the motor 26 will be energized to rotate at its idling speed so as to slowly turn the gear pump 22. At this initial starting, the solenoid operated valves 18 are still closed and the header assembly 16 will be lled with liquid and the pressure in line 28 will rise to a level determined by the setting of the by-pass valve 32, which setting will establish the volume of liquid being returned to the reservoir 20. The safety valve 34 will operate to discharge liquid to reservoir 20 only if a malfunction occurs in the system restricting the normal discharges from the header 16 and/ or reservoir 20.

When the speed of the mill rises above the live percent rate, the solenoid operated valves selected to be opened will be energized by virtue of action of electronic switch 84 so as to change them to the open state, thereby allowing liquid to pass through the header assembly 16 to the conveyor 12. The rate of liquid ow is also controlled by the magnitude of the tachometer signal by virtue of the connections 94 to the motor controller box 36, which controls the rate of turning of the motor 26 and thereby the rate of liquid delivery from the gear pump 22. Thus, by proper setting of the

valves

30 and 32 the proper quantity of liquid will be discharged onto the workpieces on the conveyor 12, irrespective of the rate of travel of the conveyor 12. Also, proper coverage of liquid discharge from the header assembly 16 can readily be obtained by operation of selector switches 80* and 82. Still further, the valves selected to be open will be closed simultaneously when the mill is stopped. This operation assures use of minimum quantities of the liquid while realizing optimum coverage of the workpieces. This system of applying the liquids also eliminates undesirable atomization of the liquids and avoids undesirable dripping from the header.

Another signiiicant feature of the present invention is that it allows the operator to set the peak discharge of liquid to any desired amount without varying the normal controls of the motor 26 and gear pump 22 so that for any peak discharge selected, the complete range of discharge from maximum to minimum output is realized in accordance with the signals received by the motor con- 7 troller 36 from the tachometer `42. This setting of the peak discharge is obtained merely by making proper selective settings of

valves

30 and 32.

Thus, if it is `desired to discharge liquid from the header assembly 16 at the peak rate of ten gallons per minute, the

valves

30 and 32 will be set accordingly, and if the motor 26 has an effective speed range, for example, of twenty to one, the pump 22 will discharge liquid at a range so that at maximum conveyor speed, the peak amount of ten gallons per minute will be discharged from header assembly 16, and at minimum conveyor speed onehal gallon per minute will be discharged from header assembly 16. If different requirements of the liquid applicator should occur, whereby the maximum or peak discharge of liquid from the header assembly should be a lesser amount, such as tive gallons per minute, for example, the

valves

30 and 32 will be reset accordingly, and the same twenty to one ratio of applying the liquid in response to the tachometer 42 signals will still be realized so that atminimum conveyor speed one-quarter of a gal-` lon of liquid per minute will be discharged from header assembly 16.

Having thus described my invention, I claim:

1. In a liquid applicator system for use in processing Workpieces of various widths wherein said workpieces are moved on a conveyor, the improvement comprising a liquid applicator header adapted to be mounted transversely of said conveyor and having a plurality of spaced solenoid operated valves for discharging a liquid across the width of the conveyor, liquid supply means for maintaining liquid in said applicator header, and remote control means for selecting at least certain of said solenoid operated valves to be opened when the rate of travel of said conveyor has risen to a preselected magnitude above the stationary condition of the conveyor, said remote control means including means responsive to the rate of travel of said conveyor or opening simultaneously all of said certain valves when the rate of travel of said conveyor has risen to said preselected magnitude.

2. In a liquid applicator system, the combination according to claim 1, wherein said control means includes a rotary switch for opening said solenoid operated valves sequentially when rotated in one direction and for closing said solenoid operated valves sequentially when rotated in the other direction.

3. In a liquid applicator system, the combination according to claim 1, wherein said control means includes two separately operable switches one for opening certain of said solenoid operated valves sequentially from the center area of said applicator header toward one end thereof, the other switch for opening certain of said solenoid operated valves sequentially from the center area of said applicator header toward the other end thereof.

4. In a liquid applicator ssytem, the combination according to claim 3, wherein said solenoid operated valves are in three sets, one set including the valves in the midportion of the header, the second set being controlled by said one switch and extending from one end of the header to said midportion and the third set being controlled by said other switch and extending from the other end of the header to said midportion.

5. In a liquid applicator system, the combination according to claim 3, wherein said control means includes a switch for closing and opening simultaneously all of said certain solenoid operated valves.

6. In a liquid applicator system, the combination according to claim 3, wherein said control means includes a switch means responsive to the rate of travel of said conveyor for closing simultaneously said certain solenoid operated valves when the rate of travel of said conveyor drops below a preselected magnitude.

'7. In a liquid applicator system, the combination according to claim 3, wherein said control means includes a switch means responsive to the rate of travel of said conveyor for closing or opening simultaneously said certain solenoid operated valves when the rate of travel of said conveyor drops below or exceeds respectively a preselected magnitude.

8. In a liquid applicator system according to claim 1, wherein means are provided for selectively adjusting the rate of flow of liquid trom said supply means to said certain valves for any selected rate o travel of said conveyor.

9. In a liquid applicator system according to claim 1, wherein said liquid supply means is responsive to the rate of travel of said conveyor for synchronizing the rate of ow of the liquid to the rate of travel of said conveyor.

10. In a liquid applicator system for use in processing workpieces of various widths wherein said Workpieces are moved on a variable speed conveyor, the combination with said variable speed conveyor of a liquid applicator header adapted to be mounted transversely of said variable speed conveyor and having outlet means for discharging liquid across the eiective workpiece-carrying width of the variable speed conveyor, liquid supply means for continuously delivering liquid from a source to said applicator header, means responsive to the rate of travel of said variable speed conveyor for regulating the rate of delivery of said liquid supply means in proportion to the rate of travel of said variable speed conveyor, adjustable means for allowing only selected portions of the proportioned liquid to be delivered to said header and control means for closing said outlet means when the rate of travel of said Variable speed conveyor is at a preselected magnitude above the stationary condition of said conveyor.

11. In a liquid applicator system, the combination according to claim 10, wherein said control means is operable for selectively varying the etective width of liquid discharged from said header.

12. In a liquid applicator system the combination according to claim 11, wherein said control means is operable to initiate ow of liquid from said header when the rate of travel of said variable speed conveyor rises above a preselected magnitude.

References Cited UNITED STATES PATENTS 2,804,764 9/1957 Runton 118-313 X 2,960,060 ll/ 1960 Chatterton. 2,963,002 12/1960 Glaus 118-602 X WALTER A. SCHEEL, Primary Examiner.

JOHN P. MCINTOSH, Assistant Examiner.

U.S. Cl. X.R. 118-315, 324