US2916266A - Apparatus for foaming beer - Google Patents

Description

Dec. 8, 1959 R Y 2,916,266

APPARATUS FOR FOAMING BEER Filed May 1, 1956 2 Sheets-Sheet l FIG.4.

G OUTPUT 35 36 37 TRANSFORMER GENERATOR I I OUTPUT I l 1 VARIABLE BUFFER OUTPUT FREQUENCY AND DRIVER AMPL'HER R.C.O5CILLATOR AMPLIFIER J I TRANSDUCER 38 k x I R.F. BYPAS5\ I 39 4 4: ll: T

1 4g' REGULATED VARIABL E o.c. FIELD LOW VOLTAGE HIGH VOLTAGE Supp SUPPLY SUPPLY v INVENT OR G. EMERSON PRAY n5 V.A.C.

so CYCLES HIS ATTORNEYS Dec 8, 1959 G. E. PRAY 2,916,266

APPARATUS FOR FOAMING BEER Filed May 1, 1956 2 Sheets-SheetZ 4 INVENTOR G. EMERSON PRAY UM ZLQZ M HIS ATTORNEYS United States Patent APPARATUS FOR FOANIING BEER George Emerson Pray, Plainfield, N.,l., assignor, by mesne assignments, to Electronic Assistance Corporation, Red Bank, N.J., a corporation of New York Application May "1, 1956, Serial No. 581,887

4 Claims. (Cl. 259-54) This invention relates to apparatus for inducing foaming of liquids, and it relates particularly to apparatus by means of which a quick and controlled foaming of beer and other gas-containing or carbonated beverages can be produced.

In the production of beverages of the kind indicated, it is necessary to remove air from the bottles or other containers before sealing in order to increase the shelf life of the beverage. The air is commonly displaced by causing the beverage to foam. Inasmuch as high production rates must be achieved, the beverage must be caused to foam very quickly without, however, causing excessive overflow of the beverage from the containers.

Foaming can be produced by applying vibratory energy to the bottle or other container, using suflicient power to cause adequate foaming. If this is done within the audible frequency range, the required power level is so great as to be very objectionable and impractical from the operators point of view.

In the brewing industry, foaming of beer is commonly produced by subjecting the filled, but uncapped bottles or cans to impact by means of a knocker or hammer. When the impact is hard enough to cause the beer to foam, it frequently breaks imperfect bottles, or causes varying amounts of foam to be produced, thereby displacing the liquid unequally with consequent variation in the contents of the containers. When bottles are broken, the bottling machine must be shut down to clear the broken glass. Inasmuch as bottling machines operate at the rate of 200 to 300 bottles per minute, even short shut-downs cause marked reduction in output.

I have discovered that by employing ultrasonic frequencies, that is, frequencies above the audible range, to vibrate the beverage in the containers, the etficiency of energy transfer through the container is improved, the accelerating force applied to the liquid is greatly increased, and uniformity of foaming is achieved.

These results are obtained by means of an electronic generator which supplies alternating current power at a frequency of the order of 20 kilocycles per second to an ultrasonic transducer which converts the electrical energy into mechanical vibrations and applies it to the bottle or other beverage container. The vibrations are transmitted to the liquid to release the gas therein in the form of bubbles or foam and thereby displace the air from the neck or top of the bottle or other container.

The transducer is associated with the filling or bottling machine so that the foaming is produced immediately following filling or bottling. High production rates can be maintained by arranging the transducer so that it applies vibrations to the containers over a path equal in length to several times the diameter of the containers.

Close regulation of the power of the vibrations can be obtained by controlling the power supplied to the transducer so that there is little variation in the amount of foam produced in successive containers. Moreover, the vibrations are of small amplitude so that while a substantial amount of energy is transmitted to containers, there is little or no possibility of breakage of containers even if they are formed of glass of quite irregular thickness and strength. i

2,916,266 Patented Dec, 8, 1959 ICC For a better understanding of the present invention, reference may be had to the accompanying drawing in which:

Figure 1 is a perspective view of an apparatus for foaming beverages in accordance with the present invention, the transducer of the apparatus being shown as positioned adjacent to the conveyor carrying bottles after filling;

Figure 2 is a plan view of the transducer of the apparatus with a portion of the casing therefor removed to disclose details thereof;

Figure 3 is a view in section taken on line 33 of Figure 2; and

Figure 4 is a schematic wiring diagram of the power supply and transducer.

The apparatus chosen for purposes of illustration includes two units, namely, an ultrasonic generator G and a transducer T by means of which vibrations of ultrasonic frequency can be imparted to the beverage containers and the beverage therein. The generator may be any well-known type including a variable frequency oscillator for generating a signal in the ultrasonic range, for example, of between about 15 kc. and 35 kc. and an amplifier to supply suflicient energy to the transducer to produce foaming. In practice, a power output of watts is adequate to energize several transducers.

The electronic generator G is housed in a cabinet 10 which is provided with a door 11 giving access to the controls of the generator for tuning and regulating its power output. A window 11a is provided in the door 11 to enable the voltmeter V and ammeter A in the front panel to be observed. The cabinet 10 and door 11 are provided with gaskets and seals to render the unit water tight inasmuch as it may be used in a wet or moist environment.

Bottles B are carried through the bottling machine by means of holding members 12 or saddles and the transducer T which has an elongated shoe or contact member 13 is positioned so that it is pressed resiliently against the bottles as they are moved rapidly by it. The shoe 13 is long enough to engage two bottles simultaneously. Inasmuch as the shoe 13 is in contact with the surfaces of the bottles which may be wet due to overflow while filling and foaming, the shoe is formed of a strip of corrosion-resistant material such as stainless steel. As best shown in Figure 2, the ends of the shoe are curved to enable the bottles to slide by them. To allow the shoe to engage bottles of varying diameter and assure good contact with the bottles, the shoe 13 is biased toward the bottles by moderate spring pressure. A suitable supporting and biasing structure may include a pair of rods 14 and 15 fixed to the back of the shoe and slidably received in U-shaped brackets 16 and 17 extending inwardly from and fixed to the ends of a casing 18 formed of stainless steel or other corrosion-re sistant material. Springs 19 and 20 are mounted on the rods and engage the back of the shoe 13 and the brackets 16 and 17 to normally urge the shoe outwardly to the limit permitted by the cross pins 21 and 22 in the inner ends of the shafts 16 and 17. A removable cover (not shown) is provided for the casing 18 and is secured to the flanges 24, 25 and 26 at the open side of the casing.

Vibration at ultrasonic frequency is imparted to the shoe 13 by a magnetostrictive vibrator which includes a core 27 formed of a plurality of thin strips or laminations 28 of nickel or nickel alloy having magneto-strictive properties. See chapter IX, Magnetostriction in Ultrasonics, by Carlin, published by McGraw-Hill Book Company, Inc., 1949. The laminations are welded, silver soldered or brazed at one end to the mid-portion of the shoe 13 and are supported by the shoe 13. As shown in Figure 3, the core 27 has a centrally located hole 29 through which the turns of coils 30 and 31 pass, each coil being wound on a leg of the core at each side of the hole. One of the coils is wound clockwise and the other is wound counter-clockwise and they are joined at their adjacent ends. A plastic insulated wire, such as a stranded Nylon covered wire is used for the coils in order to render them waterproof.

A magnetostrictive vibrator of the type described having a total of 80 turns in the coils has a resonant frequency in the vicinity of 20 kc. When the generator G is tuned to produce a frequency corresponding to the resonant frequency of the vibrator, maximum etficiency is obtained. For example, the dimensional changes in nickel are on the order of 25-30 parts per million at frequencies other than the resonant frequency of the vibrator, while at resonance, the change may be as high as one part per thousand. Moreover, in accordance with recognized principles of such vibrators, a DC. biasing field should be provided so that the core 27 can be operated over a wide portion of its magnetization curve resulting in maximum amplitude of oscillation without overheating or causing fatigue of the metal.

A typical transducer T constructed as described above has an impedance of about 16 ohms with a polarizing DC. of approximately one ampere which is supplied together with the ultrasonic signal by the generator G. The vibration of the shoe is produced essentially by reaction, i.e., as the freely suspended core expands and contracts, it sets up oppositely acting forces which cause almost imperceptible vibration of the shoe 13.

As shown in Figure 4, the ultrasonic generator G supplies a signal at ultrasonic frequency by means of a variable frequency oscillator 35 provided with an appropriate tuning condenser and a non-linear ballast resistance. The signal emanating from the oscillator is amplified in a buffer amplifier and driver amplifier 36 and then in a push-pull output amplifier 37. The output of the amplifier 37 is supplied to an output transformer 38 connected to the transducer T. A conventional low voltage supply 39 is connected to and energizes the oscillator 35 and the buffer and driver amplifier 36, and a variable high voltage supply 40 supplies the output amplifier 37 and enables the output of the generator to be regulated as required. A single transducer T of the kind described requires 20 to 25 watts to drive it so that a generator having an output of 100 to 125 watts will supply several transducers and allow for substantial overload.

Direct current for supplying biasing voltage to the transducer is provided by the DC. field supply 41 which includes a full Wave rectifier bridge and a condenser 42 to by-pass the radio frequency signal. Current is supplied to the rectifier bridge from the filament supply of the oscillator at about 6.3 volts.

With the generator and transducer in operation and the output of the generator supplying a signal at about the resonant frequency of the transducer, an almost imperceptible vibration of the shoe 13 occurs, that is, a vibration of an amplitude of only a few thousandths of an inch. However, a very substantial amount of power is supplied by the vibration of the shoe. When containers of beverage move along in contact with the shoe, the beverage foams almost instantly so that the air above the beverage in the container is displaced. Inasmuch as the power supplied to the shoe 13 is constant and the shoe is pressed against each container with essentially the same force, foaming is uniform in the containers as they pass by the transducer T even at rates of about 200 to 300 per minute.

Breakage of bottles is completely avoided by the new apparatus for the reason that the amplitude of the vibrations is insufficient to flex the container beyond its breaking point even with non-uniform and poorly annealed glass.

It will be understood that the generator G may be modified as to type and power output, and that the length and shape of the shoe of the transducer and the manner in which it is mounted may be altered.

Accordingly, it will be understood that the foamproducing apparatus described herein is illustrative of the invention and is susceptible to considerable modification in its design and in structure without departing from the invention.

I claim:

1. An apparatus for foaming beverages in open top containers comprising conveying means adapted to move open top containers having a gas-containing beverage therein along a path, a casing adjacent to said path, a pair of rods slidably mounted in substantially parallel relation in said casing, a shoe mounted on said rods for movement toward and away from said casing and overlying a portion of said path thus adapting said shoe to engage any containers moving along said path, spring means interposed between said shoe and said casing biasing said rods and said shoe outwardly for engagement with containers moving along said path, and a reaction type ultrasonic vibrator mounted on and movable with said shoe and disposed in said casing for vibrating said shoe at ultrasonic frequency to vibrate said containers and cause the beverage therein to foam.

2. The apparatus set forth in claim 1 in which said vibrator is a magnetostrictive vibrator having a core of magnetostrictive material fixed to and supported by said shoe and a coil wound on said core.

3. An apparatus for causing foaming of beverages in open containers to displace air therefrom comprising conveying means adapted to move open top containers of beverage along a path, a transducer adjacent to said conveying means having a shoe overlying a portion of said path, means for supporting said shoe for movement toward and away from said path, resilient means biasing said shoe toward said path for resilient engagement against any container moving along the path, an elongated magnetostrictive core member having a resonant frequency in the ultrasonic range fixed at one end to said shoe and supported thereby, a coil encircling said core member for energization by an electrical signal to expand and contract said core member and vibrate said shoe by reaction, and power supply means connected to said coil for supplying a signal at about the resonant frequency of said core member to vibrate said shoe at ultrasonic frequency.

4. An apparatus for foaming beverages in open top containers comprising conveying means adapted to move open top containers having a gas-containing beverage therein along a path, a casing, a shoe at one side of said casing overlying a portion of said path and adapted to contact any container moving along said path, means in said casing supporting said shoe for movement inwardly and outwardly relative to said casing, resilient means interposed between said casing and said shoe for resiliently urging said shoe outwardly relative to said casing for contact with said containers moving along said path, a core of magnetostrictive material fixed at one end to said shoe and supported thereby, and a coil encircling said core to magnetize and demagnetize said core and thereby change its length for vibrating said shoe relative to said casing and the containers in contact with said shoe to cause said beverage to foam.

References Cited in the file of this patent UNITED STATES PATENTS 1,820,676 Pickop Aug. 25, 1931 2,114,964 MacKenzie Apr. 19, 1938 2,119,174 Nicolas May 3, 1938 2,237,636 Schmutzer Apr. 8, 1941 2,341,498 Bell Feb. 8, 1944 2,498,990 Fryklund Feb. 28, 1950 2,620,894 Peterson et al. Dec. 9, 1952 2,660,414 Von Ludwig Nov. 24, 1953 2,815,193 Brown Dec. 3, 1957

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