US2525851A - Air supply control for can filling machines - Google Patents

Description

Oct. 17, 1950 H. D. AYARS 2,525,851

AIR SUPPLY CONTROL FOR CAN FILLING MACHINES Filed May 16, 1946 4 Sheets-Sheet INVENTOR. HARRY 0. A YA R5 I BY y Mtg A 7' TORNE Y5 Oct. 17, 1950 H. D. AYARs 2,525,351

AIR SUPPLY CONTROL. FOR cAN FILLING MACHINES Filed May 16, 1946 I 4 Sheets-Sheet 2 INVENTOR. HARRY D. AYARS ATTORNEYS AIR SUPPLY CONTROL F OR CAN FILLING MACHINES megjia 16, 1946 H. D. AYARS Oct. 17, 1950 4 Sheets-Sheet .3

28 Fig.3;

INVENTOR- v HARRY 0. AYARS BY M/MZMM A TTORNE rs Patented Oct. 17, 1950 UNITED STATES PATENT OFFICE AIR SUPPLY CONTROL FOR CAN FILLING MACHINES Claims.

This invention is an improvement in the automatic supply control for can filling machines. More particularly it is an improvement in the structure disclosed and claimed in my prior patent granted November 14, 1944, No. 2,352,793.

Fluent materials such as liquid fruit juices, pulps, syrups and oils can be filled into cans by machines of the type represented by my prior patent. As shown in that patent, the flow of the liquid or even viscous material is subject to gravity under atmospheric pressure due to the air supply pipe shown in Fig. 1 of said .patent. When the cans are being filled with liquids of relatively high viscosities, however, such as the higher viscosity lubricating oils, it may be desirable to utilize air pressures greater than atmospheric in order to accelerate the fiow of liquid from the measuring chambers to the cans, so that the productive filling capacity of the machine, in terms of filled cans per minute, may be maintained at an optimum regardless of the viscosity of the liquid being filled.

In order to achieve this objective, the air pipe shown in said patent may be connected to a source of compressed air as hereinafter described, instead of being open to the atmosphere.

When super-atmospheric pressure is applied to the pipe it is transmitted to all of the measuring tubes at that moment underlying a fixed cover plate. The air pressure serves to empty the measuring tubes as long as the discharge valves are open over empty or partially filled cans. If the supply of cans ends it is then generally desirable to cut off the air supply. This may be done by manual operation of the air supply valve. Unless the air supply is stopped, the air under pressure will escape from beneath the cover plate and bubble up through the liquid in the tank. Such introduction of air to the material, if long continued while the feeding operation is interrupted, may adversel affect the material being packaged.

If the supply of cans is interrupted or cut off,

it is more practicable, however, to automatically shut off the supply of compressed air to the measuring tubes after the last can has been filled with liquid, and the valve closed on the measuring tube from which the last can has been filled.

It is, therefore, an important object of my invention to provide automatic control mechanism for the air supply valve on a liquid filling machine such that the air valve will be open for providing air pressure on the liquid in a measuring chamber when the liquid discharge valve for the m uring chamber is open for releasing the liquid contents thereof to a container.

Another object of my invention will be to maintain the air inlet valve open only as long as cans are being filled and to close it automatically when the last can has been filled.

A still further object of my invention is to provide means to delay closing of the air pressure valve long enough to permit the last empty can of the series to traverse its path beneath the cutofi plate and thus be completely filled.

Among the objects of my invention is an automatic control for the air supply valve which will be opened by the advance of the cans to be filled but which will be closed independently thereof.

A further object of my invention is to establish a predetermined interval of time for closing the air supply valve after the last empty can of the series has been advanced to filling position.

Among the objects of my invention is the prevention of undesirable discharge of air upwardly through the liquid in the filling reservoir, when no cans are being filled.

Further objects of my invention will be apparent from its description and the accompanying drawings in which:

Fig. 1 is a vertical section of a can filling machine supplied with compressed air showing a single set only of cooperating measuring tube, valve and can;

Fig. 2 is a plan view of the can feeding turret and operating mechanism for the compressed air;

Fig. 3 is a fragmentary side elevation of the actuating mechanism;

Fig. 4 is a vertical section of the timing device and associated parts taken on the line 4-4 of Fig. 2;

Fig. 5 is a horizontal section of the timing element taken on the line 5-5 of Fig. 4;

Fig. 6 is a similar sectional view of the same element and related electrical switch also taken on line 66 of Fig. 4 and Fig. 7 is a horizontal section of the outlet valve on the line l'! of Fig. 1.

By way of illustrating the invention without limitation to the detailed structure disclosed, I have shown in the accompanying drawings the preferred embodiment of my invention in an automatic air supply control for the usual can filling machines.

As disclosed in my earlier patent, the structure includes the, reservoir l of a filling machine. This reservoir is adapted to rotate around a ver 3 tical axis in conjunction with the cans C which are to be filled.

Carried as a part of the filling machine structure and rotating below the reservoir i is a series of measuring tubes 8. These tubes, as is usual, may be telescoped to accommodate difierent volumes of liquid. For this purpose each of the tubes consists of an upper member 9 attached to an opening from the bottom of the tank I. The lower member l telescopes in liquid tight manner with the upper member 9. The lower member is also supported on a spider H which is a part of the rotating structure.

The lower member If! carries a valve structure [2 by which the measuring tube 8 is emptied into the open top of the can C as the lat er advances with the rotatable structure of the filling machine. As illustrated and described in detail in the aforesaid patent, the structure i2 is operated to open the valve on the approach of an empty can to be filled. For this purpose the structure l2 includes an apertured base plate oscillated about a central pivot by means of a valve actuating member controlled in turn by a movable cam rail. An advancing empty can displaces a shoe 22 which lifts the cam rail into the path of the valve actuating member thus causing the latter to open the valve. The valve l2 remains open after the measuring tube 8 is emptied into the can and until closed by independent means.

Depending within the reservoir 1 but mounted to remain stationary is a second spider it. This spider has pins l4 upon which are loosely carried a cut-off plate [5, such as is disclosed in my prior Patent 2,358,680.

The cut-off plate has an arcuate channel on its lower surface which overlies a limited number of measuring tubes 9. A pipe it rising above plate 85 is connected to the channel. This serves for the introduction of venting air in the manner described in the prior patent. It will be understood that the cut-off plate 55 rests by its weight slidably over the surface of the bottom of the filling reservoir.

In the present instance the pipe i6 is continued to an air supply, not shown, and the air is controlled by means of an air valve ll actuated by a solenoid from the mechanism about to be described. The air valve is normally biased to closed position.

Fig. 1 also shows a part of the plate l8 which is fixed in position and serves as a platform over which the open top empty cans are being fed beneath the valves l2. Outside of the plate I8 is a circular guide rail H]. A turret 2i} rotatable with the reservoir 1 and turret has outside pockets 2! which receive individual cans and advance them in a circular path against the outer rail l9.

To actuate the opening of the discharge valves l2 I have provided the shoe 22 similar to that described in my prior patent. This shoe is pivoted in a rocking shaft 23 which, in turn, is mounted on a bracket 24.

The bracket 24 also has a bearing 25 for a vertical rock shaft 26 rocked by shoe 22. This is the actuating shaft for the valve control cam rail 26' described in the prior patent.

The bottom of shaft 26 is extended below bracket 2:! where it carries a clamp 2?. This clamp has a radial yoke 28 loosely connected to a link 29 extending to the time delay mechanism (Fig. 4).

The time delay mechanism is contained in a casing 36 which is mounted on a bracket 3! on 4 the base of the fillin machine adjacent the bracket 24 and the shoe 22.

Casing St has a pair of bearings for a hollow vertical shaft The lower end of the shaft 33 carries a worm gear 34 which is keyed to the shaft. The gear is driven by a horizontal worm, not illustrated, and this, in turn, is rotated by a flexible drive chain 35 connected to the operating mechanism for the rotatable turret of the filling machine. In this way the shaft 33 rotates constantly in timed relation with the filling machine.

At the upper end of hollow shaft 33 there is keyed an upper clutch 1 lember 36. The keying of the clutch member as is such that the latter is permitted to slide axially on the Shaft 33. The clutch member is held down by a spiral spring 3?. The latter rests against the upper abutment or lock-nut 38 on the hollow shaft 33.

The lower end of clutch member 36 has a liaring conical face 39.

A sleeve Ail is loosely carried on the hollow shaft 33 above the upper bearing 32- and is held down by means of a collar 4! fixed to the hollow shaft. A lower clutch member s2 is keyed to the sleeve Gil and has a flaring conical face 43 with an outer friction pad The friction pad 45 on the lower clutch member conforms to the surface of the clutch face 39 with which it engages.

A pin 4-5 in the hub of clutch member 42 serves as an anchor for a coiled spiral spring 46. This coil spring is wrapped around the sleeve M} and the opposite end is anchored to pin 4'! on the casing 30.

The casing also has a stop member 48 On one side. The lower clutch member 42 carries two spaced limit stops or pins 49 and 5E! on opposite sides of the stop pin 38. Pin 5! with a rounded end projects radiall from the lower clutch member $2 at an appropriate spacing from the stops it and 583. On one side of the casing 30 there is a fixed bracket 52. This has a precision-electric switch 53 connected to the solenoid of the air supply Valve H. The switch 53 is biased to open position. Its plunger 54 is engaged by the pin 5| when the lower clutch member 42 is rotated to its extreme position against the force of the spring 46.

The casing 3&3 has a base 55. This base has two eccentrically disposed upstanding pins 56, 56. These pins serve to support a cam plate til which rides vertically on the pins 56, 56.

Centrally disposed in the base 55 is a Vertical shaft 58. The upper portion of the shaft ends in a cam 59, which is brought into engagement with the cam plate 51. The lower end of the shaft 53 carries a fixed clamp Ell having a yoke 6| connected to the link 29 from the opera-ting mechanism.

Rising vertically from the cam plate 51 and through the hollow shaft 33 is a push rod 52. This push rod projects beyond the abutment 38 on the hollow shaft.

A cap 63 is bolted on the upper clutch member and extends in spaced relation over the upper end of the push rod 62. An adjusting bolt 65 screw threaded in the cap maintains the desired spacing arrangement with the end of the push rod 62.

The upper part of the casing 353 has a dome 64 enclosing the operating parts of the clutch.

It is, of course, understood that the advance of the first empty can by the turret 2Q past the shoe 22 serves to open the discharge valve and effect the filling in the manner described in my prior patent. Simultaneous with this operation, link 29 rotates the cam 59 and through cam plate 51 lifts the push rod 62 through the hollow shaft 33. As push rod 62 arises against adjustment bolt 65 it lifts the clutch member 39 from the lower clutch 42 and allows the sprin 46 to move the lower clutch member 42 counterclockwise until stop 50 rests against stop 48. In this position pin 5| is spaced from plunger 54 as shown in Fig. 5, whereupon switch 53 is released to energize the solenoid for opening the air valv l1.

The upper clutch member 36 is held up out of engagement with the clutch member 42 by the continued upward pressure from push rod 62. Meantime, the upper clutch member 36 is rotated continuously by means of the Worm gear connection from the driving mechanism.

However, as soon as there is a momentary interruption in the feed of empty cans, shoe 22 moves inwardly and link 29 is retracted. This drops the push rod 62 and permits the drive clutch member 36 to engage the face 44 of lower clutch member 42. Lower clutch member 42 is thereupon rotated in timed relation to the feed of the empty cans for moving the pin 5| toward the switch plunger 54. The pin 5| continues to move toward the switch plunger 54 as the turret continues to rotate with no cans fed into the pockets thereof until the moment when the last can preceding the first vacant pocket is brought into position for closing the corresponding discharge valve, at which occurrence the lower clutch member 42 has been rotated far enough to bring the pin 5| over the switch plunger 54 thus closing the switch and cutting off the air supply.

At this moment stop 49 will come to rest against stop 48. The clutch will thus be caused to slip but the pin 5| will continue to hold switch 53 closed as long as the machine operates without the advance of an empty can.

However, as soon as an empty can is advanced against shoe 22, link 29 is retracted, the clutch faces are separated and spring 46 rotates the lower clutch plate 42 until stop 50 comes against stop 48 as shown in Fig. 5. Switch 53 then opens and the compressed air supply is restored for as long as there is an advancing empty can.

The time interval required for causing the counter-rotation of the clutch member 42 against the tension of the spring 46, corresponds to the time required between opening and closing the air valve, which, in turn, is determined by the time provided for the filling operation while the measuring tube is traveling the length of the cut-oil plate. As long as empty cans are entering the machine, the shoe 22 normally extending into the path of cans will be held out of the path by the passing cans for holding the clutch in disengagement and the air valve open. A vacancy in the line of cans will cause the clutch to engage which, in turn, will result in closing the air valve when the last can preceding the vacancy has been filled, unless the next succeeding can follows close enough to disengage the clutch again before it can operate to close the valve.

The air pressure required is determined by the viscosity of the liquid and the time allotted for the filling operation, the filling time being further determined by the speed of the machine. Thus it will be observed that air under the pressure required may be supplied to the measuring tubes from the time the liquid filling valve is opened until it is closed, whether one can or a line of cans are passing through the filling machine.

The mechanism thus provided and arranged is effective and advantageous to control a supply of compressed air for emptying the measuring tubes into the empty cans as they are advanced.

The pressure of the air supply can be varied in accordance with the viscosity and mobility of the liquid being filled into the cans. Thus a relatively low pressure is effective for fruit juices and similar liquids. However, in the case of viscous syrups or lubricating oils of high viscosity such as Nos. 50, 60 or '70 S. A. E., an increase in air pressure will serve to greatly expedite the emptying of the measuring tubes and the filling of the empty cans.

The control of the air pressure after once being admitted to the pipe H5 is no longer dependent upon the presence of the can being filled, but on the contrary is timed to cut off as the last can in the line is filled. In this way excess or long continued pressure that is not utilized cannot occur. Air under pressure is, therefore, not apt to leak between the cut-off plate and the bottom of the filling tank to the detriment of the liquid being packaged.

In the above description I have set out in particular the preferred form of the invention. However, considerable latitude is possible in specific details of construction, material and proportion within the scope of the invention as defined in the following claims.

What I claim is:

l. A machine for filling cans comprising a frame, a tank rotatably mounted in said frame, a plurality of measuring tubes carried by said tank, an outlet valve for each tube, a stationary cutoiT plate extending over a limited number of said tubes, means for opening said outlet valves when beneath said plate, a compressed air supply down through the plate and over the tubes beneath the plate, an inlet valve for said air supply, means for advancing empty cans beneath the tubes and cutoff plate, means for closing said air inlet valve and means actuated by said advancing cans to prevent closure of said air inlet valve.

2. A machine for filling cans comprising a frame, a tank rotatably mounted in said frame, a plurality of measuring tubes carried by said tank, an outlet valve for each tube, a stationary cutoff plate extending over a limited number of said tubes, means for opening said outlet valves when beneath said plate, a compressed air supply down through the plate and over the tubes beneath the plate, an inlet valve for said air supply, means for advancing empty cans beneath the tubes and cutoff plate, means for closing said air inlet valve, means actuated by said advancing cans to prevent closure of said air inlet valve and means actuated by interruption in the supply of cans to close said air inlet valve after a predetermined period of such interruption.

3. A machine for filling cans comprising a frame, a tank rotatably mounted in said frame, a plurality of measuring tubes carried by said tank, an outlet valve for each tube, a stationary cutoff plate extending over a limited number of said tubes, means for opening said outlet valves when beneath said plate, a compressed air supply down through the plate and over the tubes beneath the plate, an inlet valve for said air supply, means for advancing empty cans beneath the tubes and cutoff plate, a solenoid circuit for closing said air inlet valve, a time delay mechanism operated by the filling machine to close the solenoid circuit and means actuated by interruption in the supply of cans to initiate the operation of the time delay mechanism.

4. A machine for filling cans comprising a frame, a tank rotatably mounted in said frame, a plurality of measuring tubes carried by said tank, an outlet valve for each tube, a stationary cutoff plate extending over a limited number of said tubes, means for opening said outlet valves when beneath said plate, a compressed air supply down through the plate and over the tubes beneath the plate, an inlet valve for said air supply, means for advancing empty cans beneath the tubes and cutofi plate, a solenoid circuit for closing said air inlet valve, a switch in said circuit, a continuously driven clutch member, a spring restrained oscillatable clutch member, a pin carried by said second clutch member for closing said switch and means actuated by the supply of cans to hold said clutch members separate.

5. A machine for filling cans comprising a frame, a tank rotatably mounted in said frame, a plurality of measuring tubes carried by said tank, an outlet valve for each tube, a stationary cutoff plate extending over a limited number of said tubes, means for opening said outlet valves when beneath said plate, a compressed air supply down through the plate and over the tubes beneath the plate, an inlet valve for said air supply, means for advancing empty cans beneath the tubes and cutofi plate, means for closing said air inlet valve, a pair of separable clutch members the first of which is continuously driven and the second is oscillatable, means operable by said second clutch member to actuate said valve closing means, cam means for separating said clutch members and means actuated by interruption in the supply of cans to inactivate said cam means.

HARRY D. AYARS.

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

UNITED STATES PATENTS Number Name Date 1,965,246 Meyer July 3, 1934 2,145,765 Huntley et al Jan. 31, 1939 2,362,793 Ayars Nov. 14, 1944

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