Apparatus And Method For Automatically Filling Containers With Fluid Material

Abstract

An improved method and apparatus for automatically filling a plurality of containers in sequence with flowable material includes two valves and controls for selectively providing flow from one valve to one container at a time or simultaneous flow from both valves to two containers at a time. The operation of both valves is controlled by a single container position sensor and a material level sensor. Specifically, a line of containers feeds sequentially under each valve in turn. If simultaneous operation is selected, a first valve partially prefills one of the containers in line during the time that a second valve completes the filling of the container in the final position. Both valves are opened simultaneously by a signal from the container position sensor when containers are properly positioned beneath the valves, and are shut simultaneously by a signal from a material level sensor connected to the second valve when the container in the final position is filled to a predetermined level. Alternatively, either valve can be selected to operate independently to sequentially fill the line of containers while the other valve and its supply lines are cleaned. In the preferred embodiment the container position sensor is a mechanically actuated electrical switch and the fluid level sensor is a photoelectric system operated in conjunction with a fiber optic system. The preferred embodiment also includes an improved control circuit with safety provisions to prevent double-filling of a given container, false triggering of the fluid level sensor, and a timed shutoff control for the flow control valves in the event of failure in the fluid level sensor circuit.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This invention comprises an improved apparatus and an improved method which are related to the apparatus and method disclosed in my U.S. Pat. No. 3,536,925 entitled APPARATUS AND METHOD FOR FILLING A CONTAINER WITH LIQUID issued Oct. 27, 1970. That application discloses an automatic system for filling containers with flowable material from a single valve by the use of a material level sensing device which operates in conjunction with a photoelectric system to shut off the flow of material when the container is filled.

FIELD OF THE INVENTION

In prior art filling systems for containers, such as cans, it has been customary to increase the filling rate by providing a plurality of filling stations, at each of which a can is completely filled. Because of uncontrollable differences in filling rates at each station, these prior art systems require a fill level sensor at each station to avoid overfills or short fills. Such duplication of level sensing and flow control systems is expensive and adds to maintenance costs.

In prior art filling systems metering devices and volumetric measuring techniques have been employed. In certain prior art systems, photoelectric devices depending upon light reflected from the material within the can have been used to check the fill level but only after the act of filling has been controlled by some other device.

SUMMARY OF THE INVENTION

The invention comprises apparatus and a method of filling a receptacle such as a container by partially filling the container at a first station and completing the filling of the container at a second station while sensing the level of the filling material in the container at the second station and thereby controlling the filling operation at both stations. Since only a portion of the total contents of the container are filled at a given station, the time required at each station is reduced and thereby the production rate of the apparatus of the invention is increased.

The invention further comprises apparatus and methods for interlocking against faults such as incorrect operation of the level detecting system for sensing the level of material within the container which could cause double-filling or over-filling of a container.

The invention still further comprises apparatus and methods for sequentially and automatically filling a plurality of containers either by simultaneous partial filling at a plurality of filling stations or by complete filling of each container in sequence at a single station.

It is an object of the invention to provide a filling system capable of an increased filling rate.

It is another object of the invention to control a plurality of flow control devices from a single level sensing device.

It is another object of the invention to provide a filling system in which the filling rate is increased by filling each container in a series of partial filling operations.

It is an additional object of the invention to provide a completely automatic system for filling containers with liquid such as paint or the like which includes safety controls for preventing double-filling, short-filling or over-filling.

It is another object of the invention to provide a completely automatic filling system which can be selectively operated to fill a plurality of containers either by simultaneous partial filling at a plurality of filling stations or by complete filling at a single station.

A still further object of the invention is to accomplish all of the above simply, reliably, economically, and with a minimum number of components.

These and other objects of the invention will become apparent from the following description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a plan view of the automated filling system embodying the invention.

FIG. 2 is a fragmentary perspective view of the two-valve filling station of the system of the invention.

FIG. 3 is a vertical section view of a ball valve for controlling the delivery of material to the receptacles, shown in its open or flow position.

FIG. 4 is a vertical section view of the ball valve of FIG. 3 in its shut or cutoff position.

FIG. 5 is a perspective view of one embodiment of a material level sensing device used in the invention.

FIG. 5 is a perspective view of one embodiment of a material level sensing device used in the invention.

FIG. 6 is a section view of a portion of the level sensing device of FIG. 5.

FIG. 7 is a fragmentary perspective view of the sensing device of FIGS. 5 and 6 showing optical fibers for directing light toward the surface of material in a partially filled container and for transmitting light reflected from the surface.

FIG. 8 is a fragmentary perspective view of the embodiment of FIG. 7 showing light being reflected from the surface of material when the predetermined fill level is reached.

FIG. 9 is a diagram which illustrates the first filling step in establishing the automatic simultaneous filling sequence of the invention.

FIG. 10 illustrates the second filling step in establishing the automatic simultaneous filling sequence of the invention.

FIG. 11 illustrates the third filling step in establishing the automatic simultaneous filling sequence of the invention.

FIG. 12 is a block diagram showing the control circuit of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, empty receptacles 10, as for example empty metal cans to be filled with a flowable material such as paint are placed on turntable 11 of the can feeding device 12. Spring guard 13 feeds a single line of cans into chute 14 which discharges into filling line 15. Since the cans 10 are free to slide on the surface of turntable 11, the feeding line in chute 14 is kept full but stationary until there is a demand for cans on filling line 15.

Cans on filling line 15 are advanced one step (i.e., the distance of one can diameter) at a time by pusher 16 which is actuated by pneumatic or hydraulic cylinder 17. It will be understood that different sizes of receptacles can easily be accommodated by adjusting the spacing of side rails 18 of chute 14, side rails 19 of filling 15, and the location of cylinder 17 to change the effective stroke length of pusher 16.

FIG. 1 shows the cans during the filling portion of the cycle. For convenience of description, cans in each of four stages in the filling process are designated by distinctive numbers. Thus, previously filled can 21 is moving down conveyor 25 to cover-applying machine 26. Cans 22 and 23 are being filled and partially prefilled, respectively, under final fill valve 28 and prefill valve 29. Pusher 16 has been withdrawn, allowing can 24 to move from chute 14 into waiting position on feeding line 15.

Positioned above filling line 15 is a reservoir (not shown) containing the flowable material with which the cans are to be filled. Leading from the reservoir is a system of piping and valves for delivering the material simultaneously to two adjacent cans 22 and 23 in the filling line (FIG. 2). The delivery system includes header 30, flexible piping sections 31 and 32 and manual valves 33 and 34 leading to power operated valves 28 and 29. Valves 28 and 29 can be conventional solenoid valves; however, ball valves opened and shut by pneumtaic cylinders 35 and 36 are preferred to provide full flow with rapid shutoff.

Mounted on final fill valve 28 is an optical fiber sensing head 40, more clearly shown in FIGS. 2, 5 and 6. This sensing head 40 is one embodiment of the invention disclosed in my copending U.S. patent application, Ser. No. 643,220, filed June 2, 1967.

Sensing head 40 carries two groups of optical fibers in angled relationship; one group 58 conveys light from light source 60 and directs it through fibers 52 toward the interior of receptacle 22 when valve 28 is open (See FIG. 6). The other group 61 transmits a portion of the light reflected from the surface of the material within the can to photocell 64. The sensitivity of photocell 64 can be adjusted so that it will be energized by the light reflected at a predetermined level of material in the receptacle.

After the cans have been filled, they are advanced by pusher 16 onto conveyor belt 25 which carries them to cover-applying machine 26.

FIG. 2 shows the arrangement of filling valves 28 and 29. The valves are selectively spaced apart by a distance equal to the diameter of one can (or of multiples of one diameter if more convenient) and positioned so that the next empty can is positioned under valve 28 at the end of the stroke of pusher 16. Simultaneously, the partially prefilled can is advanced into alignment with valve 29.

FIG. 2 illustrates the situation when pusher 16 reaches the end of its advancing stroke and the filling cycle is about to begin. Previously filled can 21 has been pushed out of the way and is about to be carried away by conveyor 25 (FIG. 1). Can 22 which was partially prefilled under valve 29 is now in position under valve 28 for final filling. Empty can 23 has been pushed under valve 29 for partial prefilling during the time that can 22 is being filled to the predetermined level.

It can be appreciated that by means of suitable brackets in conjunction with flexible piping sections 26 and 27, the spacing between valves 28 and 29 and their height above filling line 15 can be adjusted to accommodate various sizes of receptacles. Furthermore, if desired, means can be provided to raise and lower filling valves 28 and 29 simultaneously with the operation of pusher 16 so that the outlets of the valves will be lowered into the cans during filling to reduce splashing and will be withdrawn after filling but before the cans move to the next station.

Manual valves 33 and 34 can be adjusted to provide optimum flow rates for different size cans to provide fastest fill without splashing. They can also be adjusted to vary the ratio of prefill and final fill amounts depending upon considerations of response time of the level sensing device, fill accuracy, and tendency of the material to splash.

Referring to FIG. 2, pneumatic cylinder 35 carries a piston rod 37 having a clevis end 38 pivotally attached to crank arm 39 of ball valve 28. Material level sensing head 40 is attached to clevis end 38 by means of bracket 41; so that it will be lowered into each can when valve 28 is opened and raised clear of the can when valve 28 is shut.

The construction and operation of prefilling valve 29 are the same as for final filling valve 28, and the clevis end for the piston of cylinder 36 carries a bracket 49 on which is mounted sensing head 40', identical to head 40 on valve 28. By this arrangement, sensing heads 40 and 40' will be positioned close to the desired fill level in the cans for maximum sensitivity yet will be withdrawn automatically before the cans shift for the next cycle. In addition, if it is desired to operate either valve 28 or 29 independently, the sensing head on the non-operating valve will stay retracted and will not be triggered by material in the cans passing beneath it.

FIGS. 3 and 4 are sectional views of valve 28 in the open and shut positions, respectively. Ball 42 having diametral passageway 43 is rotatably mounted in housing 44. Crank arm 39 is connected to ball 42 to rotate passageway 43 into and out of alignment with inlet 45 and outlet 46 of valve body 44.

Although the ball-type valve has desirable rapid opening and shutoff characteristics, the closing action tends to impart sideways motion to the flowable material, with resultant splashing. To counteract this effect and also to produce a smoother flow when the valve is opened, it has been found advantageous to insert disc 47 into the outlet passage of the valve. A number of small holes are drilled through disc 47 to provide flow straightening passages 48. The optimum size of the holes depends upon the viscosity of the material being handled. The holes should be small enough so that surface tension will prevent dripping of the material trapped in the flow passages when the valve is shut but large enough so as not to significantly impede flow when the valve is open.

In FIGS. 5 and 6 are two views of one form of material level sensing head 40 to illustrate the general principle of operation. This is an improvement of an embodiment described in U.S. Pat. No. 3,536,925. It will be appreciated, however, that other means for sensing when the material reaches a predetermined level in receptacle 22 can be used to shut off the flow from both valves 28 and 29. Thus the closing of both valves can be controlled by a single level sensor, and because filling is sequential, the final level in every can can be controlled by this sensor.

As shown in FIGS. 5 and 6, sensing head 40 includes angled support 50, attached to bracket 41 by bolt 51. Support 50 carries optical fiber 52, mounted in housing 53 and having a lower end 54 for directing a beam of light at an angle into the can to be filled. The opposite end 55 of optical fiber 52 is attached to the upper arm of support 50 by clamp 56 so as to be disposed adjacent to and aligned with end 57 of optical fiber 58, when valve 28 is open. Optical fiber 58 is attached to the body of valve 28 by clamp 59, and its opposite end is exposed to light source 60.

Fiber 52 travels up and down with the shutting and opening of valve 28 while fiber 58 remains stationary. By dividing the light path from the light source 60 to optical fiber and 54 into a stationary and a movable segment, flexing of a single fiber is avoided and problems of fiber breakage eliminated. When valve 28 is open, ends 55 and 57 of optical fibers 52 and 58 are in alignment, and the light from source 60 is transmitted through fiber 52 and emitted from end 54.

Support 50 also carries optical fiber 61, mounted in housing 62 and having a lower end 63 for receiving a portion of the beam of light emitted by fiber 52 and reflected from the surface of the material in the can. Housing 62 has an enlarged upper end 63 adapted to receive photocell 64 in contacting relation to the upper end 65 of fiber 61. Electric cord 66 connects photocell 64 to photocell relay 68 (FIG. 12).

Referring to FIGS. 7 and 8, with the fiber optics extending into the can, material such as paint 69 is delivered to the can from ball valve 28. The light beam from fiber optic 52 is a substantially concentrated beam which strikes the surface of the rising level of paint and is reflected toward the inner surface of the can. As shown in FIG. 6, when the surface of paint 69 has reached the predetermined level to which the container is to be filled, the beam of light from optical fiber 53 upon being reflected from the surface of the paint, enters into the end portion 63 of optical fiber 61.

In this way it can be seen that the vertical position of the ends of the optical fibers with respect to the predetermined level of the paint, the angle between the optical fibers and the spacing between the end portions of the optical fibers determine the exact level of the surface of the paint at which the reflected light can enter optical fiber 61. Thus it is possible by the positioning of the optical fibers with respect to the surface of the paint to determine in a precise manner the level of paint which causes the reflected light to enter optical fiber 61. At all other levels of the surface of the paint, the reflected beam of light substantially passes away from optical fiber 61.

At the predetermined level of the surface of the paint within the container 22, the light reflected into optical fiber 61 activates photocell 64 which in turn terminates the filling cycle of valve 28. Thus by means of crank arm 39 the ball valve is closed and at the same time the end portions of the optical fibers are raised free of the opening in the can. At this point pusher 16 can be operated to advance each can one position.

FIGS. 9, 10 and 11 illustrate in three-step sequence the startup of the simultaneous filling mode of operation. The can initially under final fill valve 28 is designated A, with the following cans designated B, C and so on. In the first cycle only prefill valve 29 is turned on, and the operator controls the extent to which can B is filled. Normally, if both filling valves deliver approximately the same flow rate, the operator will fill can B approximately half full. The exact amount is not critical because the proportion filled by each valve is self adjusting once the system goes on fully automatic operation. After experience is gained, the first partial filling at the start of a new run can best be gaged by time rather than level, depending on the size of can being filled.

The operator stops the prefill of receptacle B when it is half full by tripping the photoelectric cell with his finger under fiber optic sensing head 40. Pusher 16 then operates, advancing each receptacle one place, as shown in FIG. 9. Can A, which was needed merely to provide a safety receptacle in the event of inadvertent opening of valve 28 and to close position sensing switch 70, can be removed and placed with the other empties on turntable 11 (FIG. 1). Meanwhile partially filled can B moves under valve 28, and empty can C moves under valve 29. The movement of the cans operates position sensing switch 70, which recycles the machine. Pusher 16 retracts. At this point, the operator turns on final fill valve 28 as well as prefill valve 29, and both valves open simultaneously to fill and prefill cans B and C respectively. FIG. 10 shows the condition at the end of this first automatic filling cycle with can C filled and can B partially full. The filling operation is terminated and pusher 16 extends when sensing head 40 detects the presence of the surface of material at the predetermined level. FIG. 11 illustrates the situation at the completion of the extension stroke of pusher 16. Filled can B has been pushed onto conveyor 25 to be transferred to the cover-applying machine 26. Partially full can C has moved under valve 28, and empty can D has advanced to the prefilling station under valve 29. The above cycle then repeats automatically until all receptacles are filled.

FIG. 12 illustrates an improved circuit in block diagram form for automatically controlling the filling operation. Although the control circuit disclosed in U.S. Pat. No. 3,536,925, can operate with the two-valve system of this present disclosure, it has been found in practice that several safety features added to the basic system are desirable to insure positive filling without overflow in the event of failure or malfunction of any part of the system.

For example, when filling tin cans, such as paint cans, the shiny interior surfaces of the cans may reflect or "bounce" so much light that the photocell will be triggered prematurely, causing a short fill. To remedy this problem, the improved control system contains a "bounce" circuit which prevents the eye from triggering the system between the time that one can has been filled and the next can is nearly full.

A second feature is an improved recycle system. In the event of inadvertent removal and replacement of a can on the position sensing switch, the original system could recycle and start to fill the same can, with resulting overflow. The improved circuit eliminates this problem by requiring two signals, in alternate sequence, to recycle the system. The position sensing switch initiates the opening of the valves, as before, but the photocell circuit must trigger and the position sensing switch open and reclose before the machine can start a new cycle.

Finally, it has been found that the photocell does not provide protection from overfilling where the fault is one other than failure of the photocell light source. For example, certain fluids, such as paint of a dark color reflect less light than white paint or paint of a light color. As a result the photocell may receive insufficient reflected light and fail to respond and shut the filling valves. Another fault which can occur is that liquid may splash onto the end of the optic fiber and thereby prevent the reflected light from reaching the photocell. To provide positive shutoff under all possible malfunction conditions a "safety timer" circuit is provided. This circuit incorporates an adjustable time delay relay which shuts down the fill circuit shortly after the time when the photocell would trigger under normal operations.

The function of these additional safety circuits can be understood by referring to FIG. 12 in conjunction with the following step-by-step description of the startup operation as pictured in FIGS. 9 through 11.

When starting a new filling run or restarting after a shutdown, it is necessary first to establish the proper cycle. Initially, turntable 11 (FIG. 1) is set up with a number of empty cans ready to be fed under the filling valves. The first empty can (not shown) is in position, closing switch 70; the second can A is under valve 28; and the third can B is under valve 29. The status of other switches and relays is:

Main Power (not shown) -- ON

Recycle Switch 71 -- ON

Fill Switch 80 -- OFF

Fill Switch 81 -- ON

Pusher Switch 82 -- ON

Since switch 70 and recycle switch 71 are both closed, energizing power is supplied to relay 72. Relay 72 is a standard three-pole double-throw relay. At this point normally closed contact 72a is open, preventing hold relay 73 from turning on.

Hold relay 73 is a special "momentary on-momentary-off actuated" single-pole single-throw relay, such as the Gems "Flip-Pak." It is designed to provide energizing power when the "off" circuit is open and the "on" circuit is closed and to turn off the power when the "off" circuit is closed, whether or not the "on" circuit is closed. Its purpose in this system is to prevent switch 70 from recycling out of sequence and possibly overflowing an already full container.

Normally, hold relay 73 is left switched to the OFF condition at the end of the previous operations.

When main power is turned on, the following sequence takes place. Master relay 74 remains deenergized, and normally closed contacts 74a remain closed, thereby initiating bounce timer relay 75 and opening normally closed contacts 75a, thereby deenergizing bounce relay 76 and opening normally open contacts 76a, 76b and 76c.

Bounce timer relay 75 is of the type which is activated by momentarily closing an initiate switch. Initiation also starts a timer which automatically deactivates the relay after a period which may be set by an adjustment knob on the relay. The timer may operate on mechanical, pneumatic or thermal principles. By way of example, a timer of the elctronic type, such as the model TSR-00305 manufactured by Syracuse Electronics Corporation, Syracuse, New York, can be used.

Since bounce timer relay 75 has only one set of contacts, it is used to control the three-pole, double-throw bounce relay 76. Normally open contacts 76a and 76b are wired in parallel to provide an additional factor of safety in the operation of the bounce circuit. Contacts 76c operate the "bounce light" 83 on the control panel, indicating, when it goes off, that the bounce circuit is functioning (i.e., that photocell 64 is prevented from turning off hold relay 73).

Upon the initiation of bounce timer relay 75, the timer begins to run, and at the end of the set period bounce timer relay 75 is deactivated, contacts 76a close, bounce relay 76 is energized, and contacts 76a and b close again. During the bounce timing period, open contacts 76a and b close again. During the bounce timing period, open contacts 76a and b prevent any signal from photoelectric cell 64 from operating the OFF circuit of hold relay 73. In order to turn off hold relay 73, both contacts 76a and b and contacts 68a of eye relay 68 must be closed.

Eye relay 68 is a so-called "dark operated" relay. Thus the relay is de-energized when the photoconductive cell 64 is illuminated. Examples of this type of relay are the ERP series of transistorized photoelectric controls manufactured by the same Syracuse Electronics Corporation referred to above. These controls also provide power to the light source 60 and have an input from photocell 64.

When the cell 64 is darkened, the relay 68 is energized and normally closed contacts 68a are open, permitting hold relay 73 to be switched on by relay 72. In other words, two sets of contacts must be closed to turn off hold relay 73: contacts 68a, when the photocell is illuminated, and contacts 76a and b when bounce relay 76 is energized. As explained above, at the start of a new filling operation, bounce relay 76 will normally be energized or, if not, will energize as soon as bounce timer 75 times out. In either case, bounce light 83 on the control panel will light, indicating that contacts 76a and b are closed.

When the system is first turned on with the cans in place, position sensing switch 70 is closed by the first can, relay 72 is energized, and contacts 72a are open. To ensure that the machine is properly recycled, the operator momentarily turns off recycle switch 71, thereby causing the following sequence of events:

1. Relay 72 is deenergized

a. contacts 72a close

2. Hold relay 73 is turned on

3. Master relay 74 is energized

a. contacts 74a open

b. contacts 74b open

c. contacts 74c close

4. Control relay 78 is energized

a. contacts 78a in the fill circuit close and remain closed so long as hold relay 73 is on

b. contacts 78b open

The operator then closes recycle switch 71, with the following results:

5. Relay 72 is re-energized

a. contacts 72a open

b. contacts 72b close, supplying energizing power to safety timer relay 79

c. contacts 72c in the fill circuit close

Safety timer relay 79, and also safety delay relay 77, are of the same type as bounce timer relay 76, described earlier. This type of relay must have energizing power before it can be initiated, and loss of energizing power during the timing period after initiation will trip the relay and recycle the timer.

In step 5(b) above, although safety timer relay 79 has energizing power, it will not be initiated until hold relay is turned off later in the cycle. Consequently, contacts 79a in the fill circuit remain open. At this point the circuit is properly recycled, and the machine is ready to run.

To start the first cycle, the operator triggers photocell 64 by placing his finger near the end of the fiber. The normal amount of ambient light reflected from his finger will be sufficient to trigger the cell. This starts the following sequence of events:

6. Photocell relay 68 is de-energized

a. contacts 68a close

7. Hold relay 73 is turned off

8. Master relay 74 is de-energized

a. contacts 74a close

b. contacts 74b close

c. contacts 74c open

9. Bounce timer relay 75 is initiated

a. contacts 75a open and remain open for the duration of the bounce timing period

10. Bounce relay 76 is de-energized

a. contacts 76a and b open, disabling the off circuit of hold relay 73 for the duration of the bounce timing period

b. contacts 76c open, turning off the bounce light 83 for the duration of the bounce timing period

11. Safety delay relay 77 is initiated

a. contacts 77a close for the duration of timing

12. Safety timer relay 79, energized in step 5(b) above, is initiated by the closing of contacts 77a

a. contacts 79a close and remain closed until energizing power is removed (normal operation, see setp 14(b) below) or relay 79 times out (abnormal operation--i.e., malfunction of pusher 16 or position sensing switch 70)

13. Control relay 78 is de-energized by the opening of contacts 74c (step 8(c) above)

a. contacts 78a open

b. contacts 78b close, causing pusher 16 to extend, advancing each can one position

Pusher 16, by moving the cans one position, causes position sensing switch 70 to momentarily open and then reclose. The same sequence caused by the opening and closing of recycle switch 71 recurs, namely, when switch 70 opens.

14. Relay 72 is de-energized

a. contacts 72a close

b. contacts 72b open, interrupting energizing power to safety timer relay 79

c. contacts 72c open

15. Hold relay 73 is turned on by the closing of contacts 72a

16. Master relay 74 is energized

a. contacts 74a open

b. contacts 74b oepn

c. contacts 74c close

17. Control relay 78 is energized by the closing of contacts 74c

a. contacts 78a close and remain closed so long as hold relay 73 is on

b. contacts 78b open

When switch 70 recloses:

18. Relay 72 is energized

a. contacts 72a open

b. contacts 72b close

c. contacts 72c close

Since safety delay relay 77, initiated in step 11, is set to continue timing through the full stroke of pusher 16, reclosing of contacts 72b allows closed contacts 77a to reinitiate safety timer relay 79, closing contacts 79a. Since contacts 72c and 78a in the fill circuit were closed previously in steps 18(c) and 17(a), respectively, the closing of contacts 79a applies energizing power to open valve 29.

The purpose of safety delay timer 77 in the above sequence is to reinitiate safety timer relay 79 after the cans have reached their new position and energizing power has been reapplied through contacts 72b. The energizing circuit of safety timer relay 79 is interrupted during the can shifting stop to insure that relay 79 will be recycled at the start of each fill cycle regardless of whether or not it has timed out from the previous cycle.

When valve 29 opens, material starts to flow into can B. Shortly thereafter:

19. Bounce timer relay 75 (initiated in step 9 above) times out

a. contacts 75a close

20. Bounce relay 76 is energized

a. contacts 76a and b close, enabling a subsequent signal from the photocell relay to turn off the hold relay 73

b. contacts 76c close, turning on bounce light 84

After the bounce light comes back on the operator can trip level sensing head 40 (or 40') with his finger when can B is partially filled to the desired level. This causes the following series of events:

21. Photocell relay 68 is de-energized

a. contacts 68a close

22. Hold relay 73 is turned off by the closing of contacts 68a because contacts 76a and b are already closed (step 20(a))

23. Master relay 74 is de-energized

a. contacts 74a close

b. contacts 74b close

c. contacts 74c open

24. Bounce timer relay 75 is initiated

a. contacts 75a open and remain open during bounce timing period

25. Bounce relay 76 is de-energized

a. contacts 76a and b open, interrupting the off circuit of hold relay 73 for the duration of the bounce period

b. contacts 76c open, turning off the bounce light 83 for the duration of the bounce timing period

26. Safety delay relay 77 is initiated

a. contacts 77a close for the duration of timing

27. Safety timer relay 79 is initiated by the closing of 77a

a. contacts 79a close and relay 79 starts timing

28. Control relay 78 is de-energized

a. contacts 78a open, interrupting the fill circuit, shutting fill valve 29, and turning off fill light 83 on the control panel.

b. contacts 78b close, causing pusher 16 to extend, advancing each receptacle one position

After fill light 83 goes dark, the operator turns on fill switch 80 controlling final fill valve 28, thus completing the establishment of fully automatic operation. As the cans move forward in response to pusher 16, can B will disengage from position sensing switch 70, momentarily opening it until the second can reaches its new position when switch 70 is again closed.

The momentary opening of switch 70 has the same effect as described in steps 10 through 12 above. In short, hold relay 73 is turned on, thereby energizing master relay 74; the initiate circuit for bounce timer relay 75 is opened; and control relay 78 is energized, closing contacts 78a in the fill circuit so long as hold relay 73 is on.

Upon the subsequent reclosing of position switch 70 when the partially full can reaches proper position under final fill valve 28, relay 72 is re-energized, closing contacts 72b and 72c. Closed contacts 72b supply energizing power to safety timer relay 79, which can thus be re-initiated by closed contacts 77a (see step 22(a) above). Contacts 79a then close, thus completing the fill circuit and causing both valves 28 and 29 to open.

At this point the system is operating completely automatically; so when the partially filled can B is completely filled to the desired level by final fill valve 28, previously empty can C is partially filled by valve 29; then photocell 64 is tripped by the light from light source 60 reflected from the surface of the fluid in can B, causing both valve 28 and 29 to shut, pusher 16 to operate, and the above described cycle to repeat until all cans have been filled.

It can thus be seen that the invention provides an improved sequential filling system for cans comprising at least two material delivering stations from which the flow is controlled by the time required to incrementally fill the first receptacle in line to a predetermined level.

The specific embodiment of this invention described above provides a control circuit which not only performs the filling operation automatically but also guards against short fills, overfills, and double fills.

The specific embodiment of this invention described above has the additional desirable feature of easy conversion to single valve filling for short runs of different materials, such as small batches of different colored paints.

When a succession of small batches are run, the time saved by filling from two valves simultaneously can easily be exceeded by the machine time lost in cleaning the reservoir and piping lines between batches. In order to reduce or even eliminate machine down time, the single reservoir and supply header 30 (FIG. 1) can be replaced by two reservoirs with separate connections to flexible lines 31 and 32. The first batch of material can be placed in one reservoir and the second batch in the other.

The first batch is then run with only the final fill valve 28 operating (switch 80 turned on and switch 81 off). The entire can is filled through valve 28, with sensing head 40 detecting when the desired fill level is reached, precisely as in the two-valve filling procedure described above. When the first batch is completed, the operator merely turns off switch 80 and turns on switch 81. He then runs the second batch with only prefill valve 29 operating. Sensing head 40', whose optical circuit is in parallel with that of sensing head 40 will then detect when the desired fill level is reached.

While the second batch is running the first reservoir and piping line can be cleaned and filled with a third batch of material. In this way, machine down time is reduced or even eliminated.

Having thus described the invention, it is not intended that it be so limited; as changes may be made therein without departing from the scope of the invention. Accordingly, it is intended that the subject matter described above and shown in the drawings be interpreted as illustrative and not in a limiting sense.

Claims

What is claimed is:

1. A method for sequentially filling a predetermined aggregate amount of material into each receptacle of a plurality of receptacles as each receptacle is advanced along a path of travel with the plurality thereof comprising the steps of:

a. advancing the plurality of receptacles along the path of travel past at least a pair of stations disposed along the path and extending from a first station to a last station in the direction of travel of the receptacles;

b. delivering material at each of the stations to a receptacle adjacent thereto;

c. sensing the presence of the predetermined aggregate amount of material in each of the receptacles adjacent at least the last and the next to the last of said plurality of stations by determining the presence of the exposed surface of the material at a predetermined level within the receptacle, the sensing including,

i. directing radiant energy toward the interior of the receptacle, and

ii. producing a control signal in response to at least a portion of the radiant energy which is reflected from the exposed surface of the material when the exposed surface is at a predetermined level;

d. controlling the delivering of material at each of the stations when the sensing is being made in response to the sensing of the predetermined aggregate amount of material in the receptacle adjacent thereto to terminate the delivery of material to the receptacle; and

e. in one mode selectively activating the controlling of the delivering at the last station and the next to last station in response to the sensing at the last station and in the other modes thereof activating one alone of the controlling of the delivering at the last station and the next to last station in response to the sensing step related thereto,

whereby both the steps of delivering at the last station and the next to last station or either one of the steps of delivering can be selected to complete the filling of the receptacles with the predetermined aggregate amount of material.

2. A method for sequentially filling a predetermined aggregate amount of material into each receptacle of a plurality of receptacles as each receptacle is advanced along a path of travel with the plurality thereof comprising the steps of:

a. advancing the plurality of receptacles along the path of travel past a plurality of stations disposed along the path and extending from a first station to a last station in the direction of travel of the receptacles;

b. delivering a flow of material from a supply of an undetermined amount at each of the plurality of stations to the receptacle adjacent thereto the duration of the flow of material determining the amount delivered at each of the plurality of stations, the amount delivered collectively at the stations in advance of the last station being an amount of material which is less than the predetermined aggregate amount of material;

c. sensing the presence of the predetermined aggregate amount of material in the receptacle adjacent the last of the plurality of stations; and

d. controlling the delivering of a flow of material at each of said plurality of stations in response to the sensing of the predetermined aggregate amount of material in the receptacle adjacent the last station to terminate the duration of the flow of material at each of the plurality of stations, the flow of material at each of the plurality of stations in advance of the last station being terminated independently of the amount delivered by each of said delivering means in advance of said delivering means adjacent the last of said plurality of stations,

whereby the predetermined aggregate amount of material is sequentially filled into each receptacle.

3. A system for sequentially filling a predetermined aggregate amount of material into each receptacle of a plurality of receptacles as each receptacle is advanced along a path of travel with the plurality thereof comprising:

a. a plurality of stations disposed along the path and extending from a first station to a last station in the direction of travel of the receptacles;

b. means disposed adjacent each of said plurality of stations for delivering material to a receptacle adjacent thereto;

c. means for sensing the presence of the predetermined aggregate amount of material in the receptacle adjacent the last of said plurality of stations including

i. means for directing radiant energy toward the interior of the receptacle adjacent the last station, and

ii. means for producing a control signal, said control signal producing means being adapted to be exposed to the interior of the receptacle adjacent the last station and responsive to at least a portion of the radiant energy transmitted by said directing means which is reflected from the exposed surface of the material when the exposed surface is at a predetermined level within the receptacle adjacent the last station;

d. means for advancing and retracting said means for directing radiant energy and at least a portion of said means for producing a control signal with respect to an operative position adjacent to the interior of the receptacle adjacent to the last station of said plurality of stations for each receptacle at the last station, said advancing and retracting means enabling said radiant energy directing means and said portion of said control signal producing means to be advanced to the operative position and retracted from the operative position after the sensing of the presence of the surface of the material at the predetermined level within the receptacle adjacent to the last station; and

e. means for controlling said delivering means of each of said plurality of stations in response to the control signal of said sensing means produced in response to the predetermined level of material in the receptacle adjacent to said delivering means of the last station to terminate the delivery of a portion of the predetermined aggregate amount of material by said delivering means of each of said plurality of stations to the receptacles adjacent thereto,

whereby the predetermined aggregate amount of material is sequentially filled into each receptacle.

4. A system in accordance with claim 3 in which said means for directing radiant energy toward the interior of the receptacle adjacent the last station includes a source of radiant energy and optical fiber means extending from adjacent said source to adjacent the interior of the receptacle adjacent the last station when said radiant energy directing means is in the operative position, said system further comprising:

said optical fiber means having an interruption in the length thereof dividing the length of said optical fiber means into first and second portions;

means for mounting the first portion of said optical fiber means upon said advancing and retracting means, the end of said first portion adjacent said interruption being disposed in a predetermined location when said radiant energy directing means is in the operative position; and

means for supporting the second portion of said optical fiber means with the end of said second portion adjacent said interruption being disposed adjacent to said predetermined location and the end of said first portion to transmit radiant energy therebetween when said advancing and retracting means advances to the operative position.

5. A system for sequentially filling a predetermined aggregate amount of material into each receptacle of a plurality of receptacles as each receptacle is advanced along a path of travel with the plurality thereof comprising:

a. a plurality of stations disposed along the path and extending from a first station to a last station in the direction of travel of the receptacles;

b. means disposed adjacent each of said plurality of stations for delivering a flow of material from a supply of material of an undetermined amount, to a receptacle adjacent thereto, the duration of the flow of material determining the amount delivered by each of said delivering means, said delivering means in advance of said delivering means adjacent the last of said plurality of stations collectively delivering an amount of material which is less than the predetermined aggregate amount of material;

c. means for sensing the presence of the predetermined aggregate amount of material in the receptacle adjacent the last of said plurality of stations; and

d. means for controlling said delivering means of each of said plurality of stations in response to the sensing by said sensing means of the predetermined aggregate amount of material in the receptacle adjacent to said delivering means of the last station to terminate the duration of the flow of material by said delivering means of each of said plurality of station to the receptacles adjacent thereto, the flow of material at each of said delivering means in advance of said delivering means adjacent the last of said plurality of stations being terminated independently of the amount delivered by each of said delivering means in advance of said delivering means adjacent the last of said plurality of stations,

whereby the predetermined aggregate amount of material is sequentially filled into each receptacle.

6. A system in accordance with claim 5 and further comprising:

means responsive to each sensing by said means for sensing the presence of the predetermined aggregate amount of material in the receptacle adjacent the last of said plurality of stations for advancing each of the plurality of receptacles from the station to which it is adjacent and to the next station with respect thereto,

whereby each of the plurality of receptacles is advanced from the first to the last station of the plurality of stations.

7. A system in accordance with claim 4 and further comprising means for advancing and retracting said means for directing radiant energy and at least a portion of said means for producing a control signal with respect to an operative position adjacent to the interior of the receptacle adjacent to the last station of said plurality of stations for each receptacle at the last station, whereby said radiant energy directing means and said portion of said control signal producing means can be advanced to the operative position and retracted from the operative position after the sensing of the presence of the surface of the material at the predetermined level within the receptacle adjacent to the last station.

8. A system in accordance with claim 5 and further comprising:

means for detecting the advancement of a receptacle with respect to a station; and

means responsive to the detection of the advancement of a receptacle by said detecting means for activating both said means for controlling said delivering means and said additional means for controlling said delivering means at the last station,

whereby both said controlling means and said additional controlling means are interlocked to be activated only when a receptacle has been advanced.

9. A system in accordance with claim 5 in which said means for sensing the presence of the predetermined aggregate amount of material comprises:

means for directing radiant energy toward the interior of the receptacle adjacent the last station; and

means for producing a control signal, said control signal producing means being adapted to be exposed to the interior of the receptacle adjacent the last station and responsive to at least a portion of the radiant energy transmitted by said directing means which is reflected from the exposed surface of the material when the exposed surface is at a predetermined level within the receptacle adjacent the last station.

10. A system for sequentially filling a predetermined aggregate amount of material into each receptacle of a plurality of receptacles as each receptacle is advanced along a path of travel with the plurality thereof comprising:

a. a plurality of stations disposed along the path and extending from a first station to a last station in the direction of travel of the receptacles;

b. means disposed adjacent each of said plurality of stations for delivering material to a receptacle adjacent thereto;

c. means for sensing the presence of the predetermined aggregate amount of material in the receptacle adjacent the last of said plurality of stations;

d. means for controlling said delivering means of each of said plurality of stations in response to the sensing by said sensing means of the predetermined aggregate amount of material in the receptacle adjacent to said delivering means of the last station to terminate the delivery of a portion of the predetermined aggregate amount of material by said delivering means of each of said plurality of stations to the receptacles adjacent thereto;

e. means for detecting the advancement of a receptacle with respect to a station; and

f. means responsive to the detection of the advancement of a receptacle by said detecting means for activating said means for controlling said delivering means,

whereby both said controlling means is interlocked to be activated only when a receptacle has been advanced.

11. A system in accordance with claim 10 and further comprising:

means for blocking the termination of the delivery of material to the receptacle by said additional means for controlling said delivering means of the last station, said blocking means operating in response to said means for detecting the advancement of a receptacle with respect to a station, the predetermined duration of the blocking of said blocking means being less than the period of time for said delivering means adjacent the last station to deliver material sufficient to establish the predetermined amount of material in the receptacle adjacent the last station,

whereby said blocking means prevents false sensing by said sensing means from prematurely terminating the delivery of material to the receptacle adjacent the last station.

12. A system in accordance with claim 10 and further comprising:

means responsive to the detection by said detecting means of an advancement of a receptacle with respect to a station for generating a control signal after the passage of a predetermined time period extending from the detection, said predetermined time period substantially corresponding to the time period normally required for said delivering means adjacent the last station to establish the predetermined aggregate amount of material in the receptacle adjacent thereto; and

means responsive to the control signal of said control signal generating means for deactivating said additional means for controlling said delivering means adjacent the last station,

whereby a failure of said sensing means is prevented from causing an overfilling of the receptacle adjacent the last station.

13. A system for sequentially filling a predetermined aggregate amount of material into each receptacle of a plurality of receptacles as each receptacle is advanced along a path of travel with the plurality thereof comprising:

a. at least a pair of stations disposed along the path and extending from a first station to a last station in the direction of travel of the receptacles;

b. means disposed adjacent each of said stations for delivering material to a receptacle adjacent thereto;

c. a plurality of means for sensing the presence of the predetermined aggregate amount of material in each of the receptacles adjacent at least the last and the next to the last of said plurality of stations by determining the presence of the exposed surface of the material at a predetermined level within the receptacle, said sensing means including,

i. means for directing radiant energy toward the interior of the receptacle, and

ii. means for producing a control signal, said control signal producing means being adapted to be exposed to the interior of the receptacle and responsive to at least a portion of the radiant energy transmitted by said directing means which is reflected from the exposed surface of the material when the exposed surface is at a predetermined level;

d. means for controlling said delivering means of each of said plurality of stations having said sensing means in response to the sensing by said sensing means of the predetermined aggregate amount of material in the receptacle adjacent to said delivering means to terminate the delivery of material to the receptacle; and

e. means in one mode thereof for selectively activating said controlling means of said last station and said next to last station in response to said sensing means of said last station and in the other modes thereof activating one alone of said controlling means of said last station and said next to last station in response to said sensing means related thereto, whereby both of said delivering means of said last station and said next to last station or either one delivering means thereof can be selected by said selective activating means to complete the filling of the receptacles with the predetermined aggregate amount of material.

14. A system for sequentially filling a predetermined aggregate amount of material into each receptacle of a plurality of receptacles as each receptacle is advanced along a path of travel with the plurality thereof comprising:

a. a plurality of stations disposed along the path and extending from a first station to a last station in the direction of travel of the receptacles;

b. means disposed adjacent each of said plurality of stations for delivering material to a receptacle adjacent thereto;

c. means for sensing the presence of the predetermined aggregate amount of material in the receptacle adjacent the last of said plurality of stations including,

i. means for directing radiant energy toward the interior of the receptacle adjacent the last station, and

ii. means for producing a control signal, said control signal producing means being adapted to be exposed to the interior of the receptacle adjacent the last station and responsive to at least a portion of the radiant energy transmitted by said directing means which is reflected from the exposed surface of the material when the exposed surface is at a predetermined level within the receptacle adjacent the last station;

d. means for controlling said delivering means of each of said plurality of stations in response to the sensing by said sensing means of the predetermined aggregate amount of material in the receptacle adjacent to said delivering means of the last station to terminate the delivery of a portion of the predetermined aggregate amount of material by said delivering means of each of said plurality of stations to the receptacles adjacent thereto,

whereby the predetermined aggregate amount of material is sequentially filled into each receptacle.