US2342972A - Apparatus for aerating liquids - Google Patents

Description

Feb. 29, 1944. K. H. ROY :a1-A1.`

APPARATUS FOR AERATING LIQUIDS Filed Oct. 2, 1939 HOWARD 5. Ew/5 m n E a g mw R Wo T M5 mw .w me if om mm Patented F eb. 29, 1944 APPARATUS Fon lil-:RATING uQUrns Kurt H. Roy, Los Angeles, Bruce Burns, Santa Monica, Glen M. Larson, Los Angeles. and Howard B. Lewis, Venice, Calif., assigner: to Jean Burns, Santa Monica, Calif., as trustee Application October 2v, 1939, Serial No. 297,604 8 Claims. (Cl. 261--121) production of foam-like mixtures of various gases and various liquids for purposes in several arts, certain inherent advantages and capabilities make it especially adaptable to the aerifying of dairy cream to make Whipped cream. For the l purpose of the present disclosure, we elect to describe our invention as applied to this particular purpose, but those skilled in the art will readily appreciate that our election is not to be taken as restricting the invention to the one embodiment or to the one ield of application.

Whipped cream for household and restaurant use has heretofore been produced largely by purely mechanical mixers and beaters of manual and power-driven types. Some commercial establishments have been equipped with apparatus for producing whipped cream by aerating the cream with gases including carbonic acid gas. Such apparatus is relatively complicated, expensive, and bulky and involves the use of successive high pressure gas tanks. Smaller devices employing special gases have also been used, but such devices operate at relatively high pressure and must be charged either by high pressure gas bulbs or by replenishment from standard gas tanks.

In contrast to these high pressure devices of the prior art, one of the important objects of our invention is to provide apparatus operable at pressures low enough to be maintained ,conveniently by manually operable means. It is our purpose to provide an apparatus for aerating a liquid at moderate pressures, not exceeding 50 lbs. per sq. in. and preferably in the range of 20 to 30 lbs. per sq. in., and to employ such relatively 10W pressures in such manner as to achieve satisfactory rates of production.

Our device may take the form of relatively large apparatus for commercial use, or it may take the form of a relatively small self-contained device, and We shall describe such a device speciilcally to illustrate the principles involved. An object of our invention as herein disclosed, then, is to provide such apparatus that may be embodied in a device small enough, light enough, and simple enough to serve as a household device for occasional use.

Our invention is characterized by the discovery that dairy cream or other liquids may be aerated at pressures substantially lower than heretofore employed if the liquid and gas in intimate mutual contact are conducted through a relatively long processing passage of relatively small cross-sectional area, and then discharged into a processing chamber in which the stream of intermixed iiuid is allowed to expand to a suitable degree and is suitably subjected to turbulence before release from the device in nal form. One of our objects, then, with this discovery in mind is to design a hand-operated device incorporating such a passage in combination with such chamber for expansion and turbulence. We propose in such a device to provide a construction that is efficient, inexpensive, and relatively simple and is characterized by readily replaceable parts. One oi our important objects is to provide such a device for occasional use that is sanitary and rela tively easy to clean.

In the preferred form of the invention, it is our object to achieve simplicity and low cost of construction by having various members and subcombinations perform more than one function. Thus, one of our specic objects is to provide an expansile means to perform both the function of controlling the discharge from the device and the function of forming the aforesaid cha'mber when required. As a second example, we propose to provide a single means to function as a valve member when discharge is cut ofi. to serve as a baille for causing turbulence when the aerated product is being dispensed, and to serve as a safety valve to preclude excessive pressures. As a third example, we propose to provide a pressureresponsive yielding member in the device to serve both the function of a. pump valve member and the function of a sealing means to prevent escape of fluid through a removable closure.

The above and other objects and advantages of our invention will be apparent from the following detailed description taken with the accompanying drawing.

In the drawing:

Fig. 1 is a Avertical section through the preferred form of our invention;

Fig. 2- is a fragmentary portion of the same section on an enlarged scale showing the dispensing valve partly open; y

Fig. 3 is a similar view with the dispensing valve further open;

Fig. 4 is a fragmentary section on the same scale as Fig. 1, showing an alternate means for providing the processing passage; and

Fig. 5 is a graphic representation of the dimensional relationships involved in the passage of the device.

With reference to the drawing, which vis to be taken as illustrative only, Fig. 1 shows a manually processing portable container generally designated by the numeral I0, preferably of sheet metal construction, that includes a shell II with a closed top I2 from which extends a dispensing nozzle I3. The lower end of the shell II is expanded to form an inner annular shoulder I5 of sloping configuration and is finished at its lower edge with a bead I6 formed by rolling the metal outward.

The invention, as heretofore indicated, includes an air pump unitary with and preferably built into the container I0. In the preferred form of our invention the pump generally designated I8 includes a pump cylinder 20 coaxial with the shell I I, thel upper end of the cylinder being connected to the top I2 of the shell by a sheet metal seam 2|. Unitary with the bottom of the pump cylinder 26 and extending axially therefrom is a stud 22 by means of which a sheet metal bottom or closure 23 is releasably secured to close the open bottom of the shell II. The bottom 23 is formed to provide a radially extending peripheral shoulder 25 and an annular flange 26 extending downwardly from the shoulder, the annular flange terminating in a bead 21. The peripheral shoulder 25, annular flange 26, and bead 21 are arranged to form an annular groove to seat a sealing ring or gasket 30 of circular cross section, the various vparts being arranged and dimensioned for effective sealing action with the sealing gasket wedged against the sloping annular shoulder I5 of the shell.

'I'he bottom 23 is centrally apertured to receive the pump stud 22 and is releasably anchored by a wing nut 3l threaded onto the stud. Preferably the wing nut is rotatably mounted on the container bottom. For example, the wing nut may have an inner cylindrical flange 32 that is swedged for engagement by a ring 33, the sheet metal of the bottom 23 being retained between the ring and the body of the wing nut. Preferably a fiber gasket 34 is seated in a complementary annular groove in the body of the wing nut to provide a smooth surface for facilitating lrotation of the nut relative to the sheet metal bottom.

The pump I8 has a discharge passage 35 formed by suitable bores in the pump stud 22, the discharge passage terminating in the cylindrical periphery of the stud above the container bottom 23. One of the features of the invention, as heretofore indicated, is the conception of employing a resilient sleeve 38 of rubber or other suitable material to serve both the purpose of a valve member controlling the pump discharge passage and the purpose of a seal to control leakage from the container through the bottom 23 past the stud 22.`

The sleeve 38 has an upper cylindrical portion 38 snugly but yieldingly embracing the stud to seal the end of the discharge passage 35 and has a lower flared portion or study 48 lying against the bottom 23 outside the cylindrical flange 32 of the wing nut. It is apparent that the sleeve 38 both closes the pump discharge passage and seals the juncture between the bottom 23 -and the stud in response to the pressure inside the container.

The pump I8 includes a pump piston generally designated 4I mounted on the lower end of a pump rod 42, the pump rod extending upward through the pump cylinder 28 and terminating in an exterior handle 43 suitable for manual operation. The pump piston 4I is an assembly comprising an upper rigid disc 44, a lower rigid inverted cup 45, and an intermediate flexible piston cup 46 of leather or other suitable material, the assembly being held on a reduced end portion 41 of the plunger by a suitable nut 48. Such a piston serves as an intake valve for the pump in a well known manner, the piston cup 46 falling away from the surrounding cylinder 20 to permit air to pass below the piston but pressing outward into sealing engagement with the cylinder when the pressure below the piston predominates over the pressure above the piston. The piston rod 42 is slidingly embraced by a suitable guide bushing 50 which may be fabricated of relatively stiff rubber and dimensioned to fit relatively tightly into the upper end of the pump cylinder 20. Preferably the guide bushing 50 has a tubular liner 5I of metal or other suitable material held in place by upper and lower rings 52, the liner providing sufllcient clearance around the pump rod to permit the rate of air flow required by the pump.

Any suitable means may be utilized to provide the required processing passage and processing chamber in communication with the dispensing nozzle I3. If, as in the form of our invention shown in the drawing, it is contemplated that the container I0 is to be tilted to an inverted position for dispensing the aerated product, the intake end of the processing passage is at the upper end of the container to fall below the liquid level of the container at the dispensing position. In other forms of the invention in which the container remains upright during dispensing operation, the intake end of the processing passage may be near the bottom of the container.

In the preferred form Aof our invention, as shown in Figs. 1 to 3, the processing passage is formed in part by a, cylindrical body 55 which may be fabricated from relatively stiff rubber. The body 55 is formed with a helical groove 56 that passes downward around its periphery and then continued radially inward across the bottom of the-body as indicated at 51, and communicates with an upwardly extending axial bore 58 constituting the discharge end of the processing passage. A cylinder 50 with a closed bottom, which cylinder may be fabricated from non-corrosive sheet metal, surrounds the body 55 to define with the helical groove 56 and the radial groove 51 the major portion of the processing passage, the

entrance to such passage being over the rim of the cylinder. The body 55 may be mounted in the container I0 in any suitable manner. For example, the body may be provided with an upward tubular extension 6I by means of which the body may be suspended, the tubular extension being by preference enlarged or provided with a radial shoulder 62 at its upper end.

To complete the construction thus far described, it is necessary to provide a. processing chamber to receive the stream from the processing passage and to provide a dispensing valve for controlling flow/'from the processing passage and processing chamber through the dispensing nozzle I3. One 'of the features of the preferred form of my invention is the conception, as heretofore indicated, of providing an expansile means to serve more than one of the functions involved. Such an expansile means may, for example, be in the form of an elastic sleeve 65 of soft rubber or like material. The elastic sleeve 65 shown in the drawing has a lower tubular portion 66 that fits around and retains the tubular extension 6I ,of the passage body 55. This lower tubular portion 66 has a peripheral groove 61 to receive the rim 68 of a. discharge aperture in the container top I2 and also provides a radial sealing flange 69 that lies against the inner wall of the container around the rim 68 to seal the aperture in response to the pressure within the container.-

Spaced above the tubular extension 6I of the passage body 55 is an inwardly disposed radial liange 10 integral with the elastic sleeve 65, the flange forming a restricted throat 12. A closure member to span and control the passage formed by the elastic sleeve may be in the form of a small sheet metal closure cup 13 of slightly conical configuration having an outwardly flanged rim 14 in removable engagement with a complementary annular groove in the surrounding material of the elastic sleeve. The bottom of the closure cup 13 has a central blank portion 15 registered with the throat 12 and has one 01 more apertures 11 surrounding this central blank -portion. When the device is not being used to dispense the aerated product, the closure cup 13 lies against the flange 10, and in response to the fluid pressure within the container I the flange 18 presses against and effectively seals the apertures 11. When the elastic sleeve 65 is suitably stretched axially, the apertures 11 are moved into spaced relation to the flange to permit fluid flow through the apertures into the dispensing nozzle I3.

The dispensing nozzle I3 may be a conical sheet metal member such as is commonly employed for decorating pastries, the nozzle having a serrated discharge aperture 18. The lower end of the conical nozzle may, as indicated in the drawing, embrace the outer end of the elastic sleeve 65 and be held in place by a. suitable rubber bushing or collar 19.

Any suitable rneans may be employed to control the elongation of the elastic sleeve 55. In the preferred form of our invention we employ a control lever generally designated 80 having a transverse rib 8| to bear as a fulcrum on a shoulder 82 presented by the previously mentioned guide bushing 50 of the pump. The control lever 8B is retained in part by the guide bushing 50 being for such purpose formed with a central aperture 83 loosely surrounding a reduced neck portion 84 of the bushing. One arm 85 of the control lever is adapted to serve as a control handle and the other arm 81 is adapted for operative connection with the elastic sleeve 65. In our preferred construction the arm 81 has an aperture 88 surrounding the elastic sleeve below the collar 19, the aperture being smaller in diameter than the collar so that the arm may engage the collar to stretch the elastic sleeve.

The manner in which the described form'of our apparatus may be employed to practice our method of aerifying cream may be readily understood. With the container inverted and the bottorn 23 removed, the dairy cream is poured into the container to an intermediate level and then the bottom is replaced by threading the winged nut 3I onto the stud 22, the sealing gasket 38 then sealing the outer juncture of the bottom with the shell I I and the skirt 40 of the sleeve 38 sealing the inner juncture of the bottom with the pump stud. The container I0 isthen reverted to its upright position and the operator reciprocates the pump rod 42 by the handle 43 a sufficient number of times to bring the pressure within the container up to the desired value, which pressure in the preferred forms of our invention will range between and 30 lbs. per sq, in. `On the upward stroke of the pump rod, the sleeve 38 under the predominance of pressure within the container seals the pump discharge passage 35, and the piston cup 46 contracts to permit air under atmospheric pressure to move into the cylinder below the piston. On the downward stroke of the piston, air compressed in the lower end of the cylinder causes the cylindrical portion 39 of the sleeve 38 to yield sufficiently to permit the compressed air to enter the container, and simultaneously air passes into the pump cylinder throughgthe guide bushing 50 behind the descending piston.

While the pump is in operation, escape of fluid from the container through the nozzle I3 is prevented by the fact that the flange 10 of the elastic sleeve seals the apertures 11 of the closure cup 13. It is contemplated, however, that if the pumping operation is prolonged unduly, the pressure on the closurecup will cause the cup to yield to a fluid-releasing position before any hazardous or damaging pressure is reached.

After the required pressure is attained in the container I0, hthe operator preferably shakes the container for a few seconds to facilitatel general intermixture of the air and cream, tilts the container to an inverted position, and then presses the handle 85 of the control lever 8D to stretch the elastic sleeve 65. When the elastic sleeve is stretched to a maximum, as shown in Fig. 3, it forms a processing chamber 90 at the discharge end of the processing passage, the processing chamber being above the throat 12 between the flange 10 and the closure cup 13.

It will be noted that the processing chamber 90 is substantially larger in cross section than the processing passage to permit the fluid from the processing passage to expand. It will also be noted that the described arrangement causes the fiuid to be discharged into the processing chamber 'in the form of a jet and that such jet will be directed against the central blank portion 15 of the closure cup, the fluid stream impinging on the blank portion and being deflected-back with considerable resultant turbulence before escaping into the nozzle I3 through the closure cup apertures 11.

If for any reason the operator decides to dispense the liquid from the container in unprocessed form in substantially the state in which. it

was poured into the container, the operator presses the control handle 85 to a relatively slight extent as indicated in Fig. 2, to space the closure cup aperture 11 from the flange 10 sufficiently to permit only relatively slow flow or seepage past the flange 1II through the closure cup apertures 11 into the nozzle I3. If the flow velocity through the processing passage and processing chamber is suitably restrained in this manner, substantially no aerication of lthe cream is produced.

It is apparent that a device constructed as described may be efficiently cleaned after use in a convenient manner, since the bottom of the cony tainer may be completely removed to make the interior of the container accessible, since the sleeve 38 may be easily removed from the stud 22 and since the closure cup 13 maybe removed from the elastic sleeve 55 to expose the processing chamber 80. It is to be further noted that various parts of the device may be readily replaced without the necessity for any great mechanical skill, such parts including the passage body 55 together with the surrounding cylinder 60, the elastic sleeve 65, the nozzle collar 19, the pump bushing 50, the piston cup 46. the sleeve V 38, and the sealing gasket 30.

The modification suggested by Fig. 4 consists merely in the substitution of an alternate means for providing the processing passage. the remaining parts of the device being unchanged as indicated by numerals corresponding to the other figures. The passage means in this modification of the invention consists of a metal tube 85 having acoiled portion 96 to provide the desired length, the tube terminating in a rubber body 91. The rubber body 91 has a tubular extensionV 98 corresponding to the tubular extension 6l of the previously described passage body 55, the tubular extension 98 in the same manner cooperating with the elastic sleeve 65. i

We have not been able to identify and evaluate with any assurance all of the factors that enter into and account for the successful operation of our invention. Some discussion of the relation between the length and the cross-sectional area of the processing passage may be made on the basis of experiments. We have found that a passage .045" in diameter and approximately '4l/2" long and al passage .086" in diameter and 11" long both serve our purpose in a satisfactory manner, the latter dimensions being preferred. By serving our purpose in a satisfactory manner we mean producing whipped cream of suitably stiff consistency that will hold up for a substantial period of time and producing such Whipped cream at an acceptable rate, whereby the process may be completed within a reasonable operating Iperiod. Either of the two passages with the dimensions specified above may be used to produce whipped cream at a rate that will not try the patience of the operator and either passage may be used to produce vcream of such stiff consistency as to stand up for as long as five days at room temperature without bleeding, i. e., partially liquefying. I f the lengths of the two above specified processing passages are plotted against the corresponding diameters, two points a and b will be determined as indicated in Fig. 5, ipoint a representing a processing passage .045" in diameter by 41/2" long, and point b representing a processing passage .086" in diameter by 11" long. The points a and b in turn define an optimum line in Fig. which roughly represents the ratio between length and diameter covered by our statement that the processing passage is relatively long and is of relatively small cross-sectional area. Thus we have found that a processing passage .125" in diameter by 18" long represented by point c near the upper end of the optimum line in Fig, 5 is satisfactory, and at the other extreme we find it possible to employ a ratio represented by point d in which the processing passage is .031" in diameter and only 2" long. Most of the dimensions represented by the optimum line, Fig. 5, especially between point a and .point c, are quite satisfactory for operating pressures ranging between 20 and 30 lbs. It is to be understood, however, that ratios outside of this preferred range, either on or oif the optimum line, may be employed. The generalization may be made that if the length of the passage is short relative to the diameter, the consistency of the'product may be too soft and if the diameter is much smaller than represented by the preferred range of ratios between points a and b, the operator may be forced to choose between producing the whipped cream at a relatively slow rateV or using higher than 30 lbs. pressure to achieve a desired rate of production. It will be recognized, then, that we have discovered a relationship between cross section and length'of the processing passage which enables us to aerate liquids using relatively low gas pressure. and that we have disclosed to they art a preferred range of dimension ratios for the processing passage which permits the production of whipped cream of satisfactory consistency at satisfactory rates using gas pressure low enough to be produced and maintained manually without undue exertion on the parti of the operator.

Apparently turbulence and vexpansion are desirable at the end of the processing passage and the particular kind of agitation and the expansion provided by our processing chamber seem to be important in the operation of the device; but it will be readily recognized that our invention is not to be restricted to the particular form and construction for the processing chamber disclosed herein. Other types of processing chambers as well as other means for attaining turbulence in such chambers may be employed in conjunction with a processing passage to achieve the same results as produced by the herein described apparatus. i

Another feature of our invention is that the device specifically described above, as well as other forms of the invention, may be employed to practice a novel method of making butter out of cream. 'I'he discovery involved is that if cream is confined in a chamber under the pressure of compressed air or other gas at a suitable temperature and is agitated, the butter fat of the cream will be converted almost instantly into butter. To employ the described device to carry out this method, it is necessary merely to place the cream in the container, pump air into the container to a pressure of approximately 25 lbs., and then shake the container bodily to agitate the contents. If the cream is` at approximately 50 F., the shaking of the container need not be prolonged more than thirty seconds for completion of the process.

Our detailed description of a preferred form of our invention will suggest to those skilled in the art various changes, modifications, and substitutions that may be made without departing from our underlying concept, land we reserve the right to all such changes, modifications, and substitutions that properly come within the scope of our appended claims.

We claim as our invention:

1. A device for aerating a liquid such as cream to produce a gas-liquid colloid such as whipped cream, comprising: a container adapted to confine the liquid and a gas under pressure; means providing an extensive passage of a cross-section restricted relative to its length leading to the exterior of the container; expansile means normally contracted to seal the discharge end of said passage, said expansile means being adapted when expanded to form a processing chamber at the discharge end of said passage; and manually operable means to expand said expansile means.

2. A device as set forth in claim 1 in which s aid expansile means includes a tubular sleeve of elastic material vand a wall member mounted in said sleeve, said wall member sealing off said passage when the sleeve is contracted and forming a baiiie in the path of the stream from said passage when the tubular sleeve is expanded.

3. A device for aerating liquid cream or the like to produce whipped cream vor the like, comprisf ing: a container adapted to confine the liquid and gas under pressure; means providing a proc- `essing passage having an internal diameter a:

which bears a relation to its length y substantially as expressed by the formula x=0.006y+0.02; a processing chamber at the end of said processing passage. said passage being adapted to discharge the intermixed gas and liquid into said chamber in the form .oi a jet, said chamber providing a surface extending transversely of the path of the iet to cause the Jet to be mushroomed,

said chamber having a discharge port to the exv terior of the container; and means controlling the release ofl iluid from the container through said passage, chamber, and port.

4. A manually portable device for aerating liquid cream or the like to produce whipped cream or the like, comprising: an upright container adapted to coniine said liquid under pressure, said container having a discharge port; a manually operable air pump built into and surrounded by said container for compressing air into the container, said air pump being unitary with the top of the container and extended toward the bottom of the container; a removable closure for the bottom of the container, said closure having an aperture; means tlxedly connected to the container to pass through said aperture for releasable anchorage of said closure; a tubular member of elastic material responsive to pressure within the container to seal said aperture; means providing a processing passage having an internal diameter :c which bears a relation toits length y substantially as expressed by the formula x=0.006z/+0.02; means forming a chamber for turbulence and expansion of liquid from said processing passage, said chamber being adapted to discharge through said port; and means controlling the iiowv of fluid through said passage means, chamber, and port.

5. A devicev as set forth in claim 4 in which said anchorage means is mounted on said Pump. and in which said tubular member responsive to Pressure within the container*y both seals saidaperture and serves as a discharge valve for the pump.

6. A manually portable device for use at pressures under nity pounds per square inch for aerating liquid cream or the like to produce whipped cream or the like. comprising: a relatively light, manually portable container adapted to contine the liquid under pressure; a manually operable air pump carried by said container for compressing air into the container; means providing a processing passage having an internal diameter :r which bears a relation to its length y substanair pump carried by the container for compressing air into the chamber; means providing a processing passage having an internal diameter x which bears a relation to its length y substantially as expressed by the formula x=0.006y+0.02; a processing chamber positioned to receive the stream of iluid from said passage, said chamber being shaped and dimensioned to permit expansion of the iluid and having an impingement surface in the path of said stream to favor turbulence within the chamber, said chamber having a port to the exterior of the container; and means controlling the ilow ot iluid through said passage and chamber.

8. A manually portable device for use at pressures under fifty pounds per Square inch for aerating liquid cream or the like to produce whipped cream or the like, comprising: a manually portable, upright container adapted to connue the liquid under pressure. said container having a discharge port toward its upper end and being adapted to discharge through said port from an inverted position; a manually operable air pump carried by said container for compressing air into the container; means-providing a processing passage having an internal diameter :c which bears a relation to its length 1l substantially as expressed by the formula =0.006y+0.02, said passage having its entrance toward the upper end of said container; means forming a processing chamber at the discharge end of said passage: and means controlling fluid discharge through said port.

KURT H. ROY. BRUCE BURNS. GLEN M. LARSON. HOWARD B. LEWIS.

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