US2536300A

US2536300A - Vacuumizer for filling machines

Info

Publication number: US2536300A
Application number: US589800A
Authority: US
Inventors: Earnest E Martin
Original assignee: JESSIE F SMITH
Current assignee: JESSIE F SMITH
Priority date: 1945-04-23
Filing date: 1945-04-23
Publication date: 1951-01-02
Anticipated expiration: 1968-01-02

Description

Jan. 2, 1951 Filed April 25, 1945 E. E. MARTIN VACUUMIZER FOR FILLING MACHINES 2 Sheets-Sheet l .[17 Veni-D1" /BJAAI Sum Jan. 2, 1951 E. E. MARTIN 2,536,300

VACUUMIZER FOR FILLING MACHINES Filed April 2s, 1945 2 Sheets-Sheet 2 :ggg

Patented Jan. 2, 1951 VACUUDIIZER FOR FILLING MACHINES Earnest E. Martin, Pasadena, Calif., assigner, by by mesne assignments, to Jessie F. Smith Application April 23, 1945, Serial No. 589,800

9 Claims.

This invention relates generally to a method and devices for iilling containers with measured charges of liquid, and is more particularly concerned with a method and a filling machine wherein there is incorporated means for vacuumizing or reducing the pressure of the air within the container to a value below atmospheric pressure prior to the introduction of the liquid.

The device is particularly well adapted to the partial filling of relatively small containers with measured quantities of extracts and oils (such as pyrethrum and sesame, respectively) to which is later added a charge of dichlorodiuoromethane, the whoe going to make up a bomb of pesticide aerosol. I `will therefore describe the invention as put to this particular use, but it is to be distinctly understood that this is not to be construed as in any way limiting the invention. Not only is the invention capable of advantageous use in connection with liquids of many different types, but it is effective in situations where only a single liquid is to be delivered to the container and where accurate pre-measurement of the quantity of liquid for each container is not essential.

Typically, a usual iiling head includes a nozzle applied to a container neck, and means for pressurally discharging liquid through the nozzle into the container. Such discharge of the liquid tends to build up air pressure within the container. This built-up pressure not only tends to retard the now of liquid into the container but, more important, it tends to eject or spray liquid from the container (particularly from zones adjacent the orifice of the container neck) when the container is withdrawn from the nozzle. The amount of liquid thus discharged varies with the varying snecii'ic characteristics of the head, liquid and container. In some cases the discharge may be very slight, but in any and all events it is obviously undesirable. In certain cases it is extremely harmful, however slight it may be. It not only tends to leave undesirable residue on the exterior surfaces of the container neck. but, ii the liquid is of `corrosive or poisonous nature or is irritating to human beings, such discharge may present definite hazards.

Therefore it is among the objects of my invention to provide means for preventing such ejection by vacuumizing the container prior to the introduction of the liquid or liquids, it following that when the container is subsequenty disengaged from the filling head, there is no compressed air within the container to cause liquid ejection. To the contrary, the lowered air pressure is ordinarily such that, upon disengagement of the container, such liquid as may coat either the inside of the container neck or the outer end of the neck, is drawn into the container, proper, leaving the speciiied neck. surfaces entirely clear of the liquid.

It is a further object of the invention to provide such exhausting means iu a form which is sure and accurate in operation and which will accomplish its ends in minimum time. Other objects and features of the invention will be made apparent in the following detailed description, reference being made to the accompanying drawings, in which Fig. 1 is a partially schematic view of a device embodying my invention;

Fig, 2 is an enlarged. medial section through the filling head;

Fig. 3 is a view similar to Fig. 2, but showing the valve in changed position; and

Fig. 4. is a section on line A-d of Fig. 3.

In Fig. l I have shown a container IE! applied to the filling head Il. While the container may be of any suitable shape and type, as may also be its iilling fitting I2, my device is particularly well suited to the filling of a container of the illustrated type and having the illustrated type of fitting. Therefore I will describe the invention by reference to containers and iittings of these types, but it will be understood this is done solely for illustrative purposes and is not to be construed as limitative on the broader claims appended hereto.

Metal container Il] is provided at one end with a filling neck or iitting I2 having an upper portion with an external conical seat lli, a bore I5 and counterbores i6 and l1. An apertured web IB at the bottom of counterbore I1 serves as a retainer for a resilient valve ball (not shown) adapted to be inserted through bore l5 into the counterbored portion of the fitting subsequent to the lling operation described and claimed in the instant specification. The fitting, resilient valve and the application of the valve to the cage, are described with particularity in my copending application entitled Valve and Fitting, filed November 20, 1944, under Serial No. 564,352, but these features are of no significance here except insofar as the tting presents a unique iilling problem which is effectively overcome by my present invention. This problem comes about by the tendency of liquid, during the filling operation, to lodge on the walls dening the 'core and counterbores and on top the web I8. In the absence of preventative means the liquid thus lodged, as well as liquid or mist particles suspended in the gas space within the container, are blown outwardly from the nozzle when the container is disengaged from the head, with obvious disadvantage.

Filling head Il consists of a body member having a central vertical bore or chamber 2| and a pair of diametrically opposed

inlets

22 and 23 adapted for connection with ow lines 24 and 25, respectively. However, the number of inlet ports and flow lines depends entirely on the number of ingredients to be simultaneously delivered from the head in any given installation, and it will therefore be apparent that the provision of more or less than two inlets and two flow lines comes within the scope of the invention.

Bore 2| extends downwardly into the integral neck 25, and the wall 21 defining the end of the bore has a central outlet opening 23 bounded by a conical Valve seat 29. Outlet or orice 28 opens to an outwardly flaring conical counterbore 30 which is substantially complementary to the conical seat I4 on fitting I2. Set in and projecting from the defining wall of this counterbore, and retained by the cap 3l screwed onto the neck 25, is a ring washer 32.

Head I| is supported by legs 33 in axial alinernent with container elevator 34 which is normally urged upwardly by spring 35. A pedal 35 is linked at 31 to elevator rod 3B, whereby pedal depression lowers the elevator against the` resistance of spring 35. To remove the container I0 from the head and replace it with an empty one, elevator 34 is depressed sufficiently to allow litting I2 to be cleared from neck 2E. The empty container is then placed on the elevator and foot pressure is relieved from pedal 36 to allow spring 35 to act through the elevator to press seat i4 tightly against washer 32 and thus effect a seal between the tting and filling head, with orice 28 and bore l5 in registration.

Vertcally slidable within bore 2| is a piston 39 having an upper reduced-diameter portion or coaxial stem 40 and a lower reduced-diameter portion or coaxial stem 4|. The piston may have one or more rings 42. The upper end 43 of stem 4| is of still further reduced diameter and has sli-ding lit through a bore 44 in the cap 45 threaded on the upper end of head Il and closing off the end of bore 2|. However, the portion 2m of bore 2| above the piston is preferably vented to the atmosphere, for instance by providing a loose fit of cap 45.

Shoulder 46, in its contact with cap 45 (Fig. 3) limits the upward movement of piston 39, the piston in its uppermost position being above

inlet ports

22 and 23.

The lower end of stem 4| is externally shaped to form an integral needle valve 41 adapted to be normally urged into engagement with complementary seat 29 by spring 48 which encircles stem 40 and has opposite end bearing against cap 45 and piston-shoulder 49. The engagement of valve 41 with seat 29 limits the downward movement of piston 39, the piston, in its lowermost position being, in effect, above

inlets

22 and 23.

The piston and stems are hollow, their bores serving, together, as a duct 5|) opening to the upper end of stem 43 and to the lower end of needle valve 41. However, for purposes later to be described, the duct orice 5I is of relatively restricted diameter, In other words, the lower end of duct is choked down at 52 sa it ls of about half the cross-sectional area of the upper and major portion of the duct. In actual installaticns, it has been found satisfactory to give duct a diameter of about .052" and oriice 5I a diameter of about .049".

When piston 39 is in its lowermost position (Fig. 2) under the influence of spring 48, and as established by the sealing engagement of valve 41 with seat 29, chamber 2| is closed off from fitting bore l5 by valve 41, but duct 55 is in communication with the exterior of the head, and hence with bore I5 through orifice 5|.

Applied to the upper, externally presented end of hollow piston stem 43, is a flexible tube 55 which makes up a part of the vacuumizing line 55. This line includes a pipe 51 communicating at one end with tube 55 and at the other end with trap 58. Leading from the top of trap 5B is a pipe 59 which opens to the interior of transparent dome or sight-glass Eil. Tube 5| leads from the upper portion of the dome to a line 52 which in turn leads to a low pressure creating medium such as, for instance, vacuum pump 63.

Opening to the atmosphere from pipe 51 is a Vacuum relief port 64. Pump 63 may run continuously during operation of the filling device, but, so long as port 54 is open, the pump is incapable of inducing low pressure in line 55, duct 5i! or container Il). In order to control the vacuum line so low pressure may be induced in the containers at selected periods, I provide a flap valve or closure 65, movable to and from a position closing port 64. Valve 65 is carried at one end of lever E5 which is pivoted at 61 on post 63. The other end of the lever is connected by rod (i9 to pedal 1H, while spring 1I is applied to the lever in a manner to normally and yieldable hold valve 65 clear of port 54, thus breaking the vacuum at this point. Depression of pedal 10 acts through rod E9 to close port 64 by valve 65, whereupon pump 63 is effective to lower the pressure in duct 5D and hence in container IU.

Should liquid from the lling head be accidentally drawn into lines 55 and 51, it dumps into trap 58, from whence it may be drained through pet cock 58. If the trap should become overloaded, liquid will be drawn into transparent dome 50 which serves not only as an auX- iliary trap but also as a sight-glass to warn the operator of the undesirable condition. The two traps 58 and 6D thus serve to protect against the damaging entrance of liquid to pump 63.

Flow lines 25 and 24 lead to outlets 15 and TB, respectively, of meter 11. Check valves 15' and 'i6' are provided at the meter ends of these respective lines. The particular type of meter here illustrated is not necessary to the present invention, though it may be used with decided advantage.

For illustrative purposes only, it is assumed that the container is to be partially filled with a mixture of pyrethrum and sesame oil and that the amount of sesame oil in a metered batch of mixture is to be greater than the amount of pyrethrum.

Meter 11 is duplex in the sense that there are two independent metering chambers and pistons, though the two pistons are connected for simultaneous movement under a single application of power. A relatively small displacement piston 'i8 is adapted to be reciprocated in chamber 19, while a relatively large displacement piston is adapted to play through chamber 8|. Line 82 leads from a supply tank 83, containing pyrethrum, to meter chamber 19, a check valve 8.4 being introduced in the line. Line 85, provided with check valve 86, leads from tank 81, containing sesame oil, to meter chamber 8|.

Pistons 18 and 80 are supported by a single cross head 88 which carries a power piston 89 adapted to be reciprocated through cylinder 90 by alternate application and relief of air pressure to the lower end of the cylinder. For instance, two-way valve 9|, introduced in the compressed air line 92, is shiftable to provide such alternate application and relief of lifting pressure, the cross head and piston arrangement dropping by gravity as aided by pressure from spring 11' when valve 9| is in the full line position of Fig. l, since the valve, in this position, blanks off the compressed air line and opens cylinder 90 to the atmosphere.

Stops 93 and 94 establish the extent of piston travel, and it will be apparent that movement of the crosshead from stop to stop causes pistons 18 and 80 to alternately draw in and force out predetermined, measured amounts of liquid from tanks B3 and B1.

Figs. l and 2 represent the condition of the apparatus at the beginning of a filling cycle. The container has been applied to the filling head, but valve 65 is open and valve 9| is in position to allow pistons 18 and 8D to be at the bottom of their strokes. However, chambers 19, 8|, lines 24, 25 and fitting head chamber 2| below the piston will be filled with liquid supplied during the last preceding cycle of operations. Valve 41 prevents such liquid from flowing through orifice 28 into the container.

'Ihe operator rst depresses pedal 10 to close port 64, whereupon pump 63 becomes effective to reduce the air pressure in container I9; that is. to evacuate the container so there is sub-atmospheric pressure therein. Port 64 is kept closed until this depression reaches predetermined value, as registered on gage G. In practice, it has been found that a vacuum of from eight to twelve inches of mercury is usually sufficient to perform the intended purpose.

As soon as the vacuum reaches the predetermined value, pedal 1|l is released, with the result that spring 1| reopens port 64 to break the vacuum at this point. However, duct 5|) and, particularly, the needle valve orifice 5| are so small that air entering line 55 through port 64 will not increase the air pressure in the container, within the time required to complete the filling cycle, to an extent which materially interferes with proper functioning of the vacuumizer.

Immediately after opening port 54, the operator swings valve 9| to the dotted line position of Fig. 1, thus imposing compressed air from line 92 against the bottom of piston B5 and causing elevation of the latter. Pistons 18 and 80 thereupon start delivering liquid from meter chambers 19 and 8| to lines 25 and 24, respectively, pressurizing the liquid in these lines and hence in head chamber 2| below piston 3S. The p-ressurization of this liquid acts against the lower end of piston 39 and thus elevates said piston against the resistance of spring 4B. Upward movement of the piston withdraws needle valve 41 from orifice 23 (see Fig. 3) with the result that fluid entering chamber 2| from

inlets

22 and 23 is forced through orifice 28 and the fitting bores into container Il), the reduced air pressure within the container offering correspondingly reduced resistance to liquid-entrance.

lThe forced ow of liquid from lines 24, 2E into the container continues until pistons 18 and 8|) reach the tops of their strokes, whereupon spring 48 restores piston 39 and needle valve 41 to the positions of Fig. 1. Deseension of the piston 39 forces a slight additional amount of liquid from chamber 2| into the container but valve 41 seats before there is appreciable additional iiow.

It follows that metered charges of liquid are delivered to the container and, upon each repetitive cycle of operation, charges of like amounts are delivered to successivelly applied containers.

It requires only an instant to deliver the metered charge of liquid to the container, the time being so short that the air within the container is incapable of being restored to normal atmospheric pressure through the small orifice 5| before the liquid-filling is completed. Such small quantities of air as ow downwardly through orifice 5| after valve 41 is seated, serve the advantageous end of blowing bore 5| clear of liquid which may have lodged on the defining walls thereof. Furthermore, the downward flow of air through duct 50 tends to clear that duct and oriiice 5| of any liquid that may have been forced upwardly thereinto under the higher pressure existing in chamber 2| when valve 4'1 is elevated. Additionally the depression in container i0 tends to draw into bore |5 such liquid as may tend to lie between seat I4 and the wall of nozzle bore 3|l-that is, within the boundary of sealing ring 32. Thus, seat |4l is clear of liquid when the container is subsequently removed from the filling head-to obvious advantage.

Immediately the filling is completed (and the operator can tell this by listening for the noise of Contact when cross head stop 88' strikes stop 93) the operator depresses pedal 36 to lower elevator 34, and then removes the container from head thus exposing the open inlet I5 to the atmosphere. There will remain in container I0 a pressure of suicently low value that the inrushing gas (air, for instance) will cause all liquid which may have gathered on the walls of the fitting counterbores or on web IB, to be drawn into the container, so the container may be laid on its side (provided it is not too full) without danger of such liquid dripping externally, this capacity of being laid on side being of advantage in the transfer of the containers to other points of the filling line.

Furthermore, the depression created in the container will be of such value at the time of disengagement of the container from the filling head, that by no possibility can the liquid be ejected or sprayed through fitting I2, as is often the case when the filling involves building up the air pressure within the container to a value higher than normal atmospheric pressure.

If valve B4 be accidentally kept closed during the period of liquid delivery, there is a possibility that liquid will be drawn into duct 50, though the small size of orifice 5| reduces the probability. If such a thing occurs, the liquid will be trapped as previouslly described, in order to protect pump 63.

At any time subsequent to the closing of valve 41, valve 9| may be actuated to allow the crosshead and pistons of the meter to return to their lowermost positions. New charges of liquid are thus drawn into the meter chambers for subsequent delivery to an empty container.

While I have illustrated and described a preferred embodiment of my invention, it will be understood that various changes in design and arrangement may be made without departing from the spirit and scope of the appended claims.

I claim:

l. In a device for filling a container with liquid. a filling head having a chamber with a delivery inlet and a delivery outlet, a needle valve guided for axial movement through the chamber to and from a position closing the outlet, the valve being movable from said outlet closing position in a direction counter to the direction of liquid flow through the chamber when the valve is out of outlet closing position, means for so moving the valve, there being a duct extending axially of the valve and having at one end a restricted orifice opening to the exterior of the head near the outlet opening when the valve is in outlet closing position, the other end of said duct being adapted for communication with a low pressure, exhausting line.

2. In a device for lling a container with liquid, a filling head having a bore, there being a restricted outlet at one end of the bore, a piston in the bore, there being an inlet to said bore between the piston and said outlet, a stem carried by the piston and extending toward and in coaxial relation to the outlet, a needle valve at the free end of the stem and movable by piston reciprocation to and from a position closing said outlet, there being an axial duct through the stem and having an orice opening to the exterior of the head near the outlet when the valve is in outlet closing position, said duct being adapted for communication with a low pressure exhausting line.

3. In a device for filling a container with liquid. a lling head having a bore, there being a restricted outlet at one end of the bore, a piston in the bore, there being an inlet to said bore between the piston and said outlet, a stem carried by the piston and extending toward and in coaxial relation to the outlet, a needle valve at the free end of the stem and movable by piston reciprocation to and from a position closing said outlet, there being an axial duct through the stem and having an orice opening to the exterior of the head near the outlet when the valve is in outlet closing position, the orifice of said duct being of relatively restricted diameter, and said duct being adapted, at a point spaced from said orifice, for communication with a low pressure exhausting line.

4. In a device for filling a container with liquid, a lling head having a bore, there being a restricted outlet at one end of the bore, a piston in the bore, there being an inlet to said bore between the piston and said outlet, a stem carried by the piston at one end thereof, and extending therefrom toward and in coaxial relation to the outlet, a needle valve at the free end of the stem and movable by piston reciprocation to and from a position closing said outlet, a spring in the bore f and applied to the other end of the piston in a manner urging said stem in a direction to close said outlet, fluid admitted to the bore through the inlet being adapted to move the piston and stem in the opposite direction against the inuence of said spring, there being an axial duct through the stem and having an orifice opening to the exterior of the head near the outlet when the valve is in outlet closing position, said duct being adapted for communication with a low pressure exhausting line.

5. In a device for lling a container with liquid, a lling head having a bore, there being a restricted outlet at one end of the bore, a piston in the bore, there being an inlet to said bore between the piston and said outletga hollow stern carried by the piston and extending from one end thereof toward and in coaxial relation to the outlet. a hollow needle valve at the free end of the stem and movable by piston reciprocation to and from a position closing said outlet, the bores of the stem and needle valve being in communication, a second hollow stem carried by the piston and extending from the opposite end thereof, said second stem extending to the exterior of the head for connection with an external low-pressure, exhausting line, there being a duct through the piston connecting the bores of the two stems, and the bore of the needle valve opening to the exterior of the head when the valve is in outlet closing position.

6. In a device for lling a container with liquid from a flow line, a filling head having a chamber and having an outlet opening from said chamber, said outlet being adapted to be put into sealed communication with a filling opening of the container, the flow line and chamber being communicatable whereby liquid is suppliable to the chamber from the flow line, a valve member movable to and from a position closing said outlet, means acting through the filling head for reducing the pressure within the container while the valve member is in outlet closing position, interruptible means for pressurizing the liquid in the chamber after the container-pressure is thus reduced, and means responsive to the pressur'zed liquid and effective to move the valve member from outlet closing position whereby the pressurized liquid is delivered to the container while the container pressure is still reduced.

7. In a device for filling a container with liquid from a flow line, a lling head having a chamber and having an outlet opening from said chamber, said outlet being adapted to be put into sealed communication with a filling opening of the container, a positive displacement meter in the flow line and having its output side in communication with the chamber, a valve member movable to and from a position closing said outlet, means acting through the lilling head for reducing the pressure within the container while the valve member is in outlet closing position, and means for activating said meter to deliver a predetermined volume of liquid and thereby pressurizing the liquid in the chamber after the pressure Within the container is so reduced, said valve member being moved and held from outlet closing position under the influence of the pressurized liquid.

8. In a device for filling a container with liquid from a flow line, a filling head having a chamber and having an outlet opening from said chamber, said outlet beingadapted to be put into sealed communication with a iilling opening of the container, the ow line and chamber being communicatable whereby liquid is suppliable to the chamber from the flow line, a valve member movable to and from a position closing said outlet, means acting through the iilling heed for reducing the pressure within the container while the valve member is in outlet closing position, interruptible means for pressurizing the liquid in the chamber after the container-pressure is thus reduced, means responsive to the pressurized liquid and effective to move the valve member from outlet closing position whereby the pressurized liquid is delivered to the container while the container pressure is still reduced, and means acting automatically on the valve member to re- 9 store it to outlet closing position when the pressurizing means is interrupted.

9. In a device for filling a container with liquid from a now line, a lling head having a chamber and having an outlet opening from said chamber, said outlet being adapted to be put into sealed communication with a. filling opening of the container, a positive displacement meter in the flow line and having its output side in communication with the chamber, a valve member movable to and from a position closing said outlet, means acting through the lling head for reducing the pressure within the container while the valve member is in outlet closing position, means for activating said meter to deliver a predetermined volume of liquid and thereby pressurizing the liquid in the chamber after the pressure Within the container is so reduced, said valve member being moved and held from outlet closing Dosition under the inuence of the pressurized liquid,

10 and means acting automatically on the valve member to restore it to outlet closing position when said meter completes delivery of said predetermined volume.

EARNEST E. MARTIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 693,921 Stickney Feb. 25, 1902 1,437,917 Shelor Dec. 5, 1922 2,026,601 Young Jan. 7, 1936 2,041,735 Young May 26, 1936 2,107,987 Johnson Feb. 8, 1938 2,146,072 Howard Feb. 7, 1939 2,150,760 Cozzoli Mar. 14, 1939 2,204,131 Glunz June 11, 1940