US2492405A - Atomizer head - Google Patents

Description

Dec. 27, 1949 w. v. sTRoKALl-ns ATOMIZER HEAD Filed April 23, 1948 ATTORNEY Patented Dec. 27,r 1949 AToMrzER HEAD William V. Strokalitis, Waterbury, Conn., assignor to Scovill Manufacturing Company, Waterbury, Conn., a corporation f Connecticut Application April 23, 1948Serial No. `22,829

3 Claims.

This invention relates to atomizer heads ,adapted to be applied to containers for discharging liquid therefrom in the form of a mist ror iine spray. The present invention is directed 'particularly to improvements in atomizers of the general type shown and described in the patent to Spender et al. No. 2,427,932.

The atomizer head shown in the Spender patent embodies an outer shell or retaining member adapted to be applied to the neck ,of a container. Within the retaining Amember are located atomizing elements consisting of a cup and a supporting disc which cooperate to form a liquid receiving chamber and between which a diaphragm is movable. The cup communicates with the liquid in the container through a tube, whereas the disc is covered by a compressible member such as a hemispherical rubber bulb adapted to be depressed to force air through an opening in the disc and to force air and liquid through a passage leading to a discharge orifice in the retaining member.

This type of atomizer has been produced and used extensively but it is found in practice that the amount of liquid discharge varies considerably in different atomizer heads made in a single manufacturing run. Thus, for example, tests on atomizers that were designed to have a 4 gram tolerance in dispersion per hundred strokes of the compressible bulb and which appeared to be identical have shown that the amount of liquid discharged may vary from 2 grams to 10 grams per hundred strokes. This variation is due to the fact that the elements forming the liquid receiving chamber are sometimes distorted slightly during the operation of assembling the atomizer and securing it to a container whereby the area ofthe diaphragm which is exed and the tension toy which the diaphragm is subjected are varied. Moreover, very slight diiferences in the temper or thickness of the metal or in the action of the forming dies by which the elements are produced are inevitable in any commercial operation. Therefore it has been practically impossible in a commercial operation to maintain the desired uniformity of discharge with constructions of the prior art. Furthermore, when it is desired to change the volume of discharge of the atomizers it is necessary to provide a new set of forming dies for each volume required.

It is also found that certain of the atomizers heretofore produced have a tendency to form bubbles that appear in the uid of the container upon compression of the bulb. This is presum- Cil ably due to the diiiiculty in eliminating all possi 55 ble vminute channels or openings lbetween the parts which could allow air to be forced downward through the liquid supply tube and into the container on operation of the bulb.

When the atomizer head is removed from `a container it is also diicult to drive out the liquid remaining .in the atomizer head by operation of the bulb. These objectionable features are believed to be due to the tapered form of the marginal portions of the liquid receiving chamber and perhaps also to some slight cramping, distortion or roughness along the edges of the diaphragm or supporting disc at their line of contact. The presence of capillary areas that exist in prior constructions create an undesired reservoir of iluid within the atomizer with the result that an abnormal number of strokes of the compressible bulb are' required to effect the removal of retained liquid from the atomizer upon removal from a container.

It :has now been discovered that these dimculties can be largely overcome and a much greater degree of uniformity can be maintained by forming the elements between which the diaphragm is secured and the space within which it is movable in such a way that the volume of the liquid receiving chamber and the area of the diaphragm which is flexed during operationV are of xed and unvarying dimensions and are sub'- stantially unaffected by the assembling operations. The diaphragm is engaged by retaining means which extend over a relatively wide portion adjacent its periphery and the capillary spaces andv pin hole openings are thus reduced or eliminated so that leakage, bubbling and the retention of liquid in the atomizer head is reduced to a minimum. l

One of the objects of the present invention is to provide an improved type of atomizer head which will serve to produce a more nearly uniform discharge f liquid upon operation thereof.

Another object of the invention is to eliminate the formation of -bubbles in the liquid when the atomizler is operated.

. Afurther object of the present invention is to reduce the difculty presented in removing liquid from the atomizer head on the removal of the head from a container.

A specic object of the present invention is to provide a novel type of assembly for forming the liquid receiving chamber and for supporting a diaphragm in an atomizer.

These and other objects and features of the present invention' will appear from the following description thereof in which reference is made to the figures of the accompanying drawing.

In the drawing:

Fig. 1 is a vertical sectional view of a typical form of atomizer head embodying the present invention;

Fig. 2 is a top plan view of the construction illustrated in Fig. 1 with a portion of the compressiblebulb removed; Y Y

Fig. 3 is an exploded view illustrating the various elements forming the assembly shown in Fig. 1; and

Fig. 4. is a vertical sectional view through the plate and diaphragm employed in the construction shown in Fig. l.

In that form of the invention illustrated in the drawing the atomizer head is formed with a retaining member 2 having a lower attaching portion 4 of suitable form for securing the head to a container such as the container 6. The upper wall portion 8 of the retaining member is connected to the attaching portion 4 thereof by a shoulder Ill, against which bears the marginal portion of a gasket I2. The gasket I2 is formed of rubber or other suitable material for sealing the space betweenv the retaining member and the neck of the container. The lower face of the gasket is formed with a centrally located, downwardly extending neck I4 having an opening I6 therethrough for receiving and frictionally holding a supply tube I8 formed of glass, metal or the like. The supply tube projects downward from the gasket into the container S for conducting liquid from the container to the atomizing elements located above the gasket.

The atomizing elements of theV head are surrounded by the wall portion 8 of the retaining member 2. llhe elements preferred and illustrated in the drawing include a cup 20 which is formed with a base 22 having a central opening 24 therein which communicates with the opening I6 in the neck of the gasket. In order to retain the central part of the gasket I2 against the underside of the cup base 22, that portion of the cup about the opening 24 is drifted downwardly as shown at 25 so as to project a substantial distance into the opening I6 of the neck. The lower extremity is flared outwardly at 25 and is adapted to be embedded in the rubber material of the neck as a form of anchorage.

The side wall 26 of the cup is formed with an atomizing aperture 28 which is located in alignment with a discharge port 38 in the wall portion Bof the retaining member 2. The lower face of the cup 2i) is formed with a vent groove 32 therein which extends inward from the marginal portion of the cup and communicates with an annular groove 34 in the upper face of the gasket I2. The gasket, in turn, is formed with a small opening 36 which passes from the annular groove 34 to the lower face of the gasket. In this way a vent opening is provided which extends from the interior'of the container through the opening 3S and annular groove 34 to the groove 32 in'the lower face of the cup and thence to the discharge port 30 in the wall portion of the retaining member.

vIn order to prevent the relatively soft rubber gasket I2 from being pressed into the groove 32 in the cup, so as to close the vent when the head is attached to the container, it is preferable to insert a thin annular metal washer 38 between the gasket I2 and the cup 20 as shown in Figs. 1 and 3.

Within the cup 20 is located a thin flexible diaphragm 40 formed of metal and conned at its edges between the base of the cup and an upper supporting disc 42. As shown to an exaggerated extent in Fig. l, the base 22 of the cup 2li is bowed downward or the parts are otherwise formed to provide a space 44 between the upper surface of the base of the cup 20 and the lower surface of the diaphragm 40,

In-accordance with the present invention the upper supporting disc 42 is formed in a suitable manner, as by striking up the central portion of the disc as shown at 45. As shown in Fig. 4 the supporting disc has a central downwardly facing cavity 46 which is substantially rectangular in vertical cross section so that the side walls of the cavity extend substantially at right angles to the diaphragm and the upper face of the cavity is nat and planished.

In order to assure that the central portion 45 be oiset relative to the disc 42 and remain as nat as possible, it is necessary to give the central portion a definite set relative to the rim. This may be accomplished by having the break on the opposite sides of the disc 42 disposed in a common cylindrical plane so that the indented shoulder 49 on the lower face of disc 42 as seen in Fig. 4 is coincident with the projecting shoulder 49 on the upper face of said disc. In other words, there is a tendency to actually shear the central portion 45 bodily out of the disc 42 that is effective .in eliminating strains in the disc that would otherwise tend to create an uncontrollable doming eiect in said central portion 45. By this 'construction it is possible to maintain eective con. trol of volume of the chamber portion 46 and to assure more accurate control of the amount of liquid discharged per hundred strokes of the compressible bulb.

Moreover, the depth and volume of the cavity can be varied while using the same forming dies by introducing shims to alter the relative positions of the dies in producing the supporting disc. The disc 42 when thus formed may have the cavity depressed or drifted into the lower face of the disc to any desired depth to secure the necessary volume of the cavity while maintaining the same area in horizontal cross section of the cavity. The space i4 between the cup and the lower surface of the diaphragm and the space 45 between the supporting plate and the upper surface of the diaphragm thus cooperate to form a liquid receiving chamber of xed and predeterminecl dimensions to which liquid is supplied from the container through the opening 24 in the base of the cup.

The supporting disc 42 is further characterized by the relatively wide at annular surface 41 which engages the upper surface of the diaphragm and cooperates with the base 22 of the cup to clamp the diaphragm 4D securely in ,place over an extended area about the periphery of the diaphragm. The disc thus serves to reduce and substantially eliminate narrow tapering spaces about the edge of the diaphragm whereby the retention of liquid by capillary attraction is prevented and any minute passages or channelswhich might be dueto slight roughness or cramping of the diaphragm are effectively blocked olf or smoothed out. In this way operation of the atomizer does not cause the formation of bub` bles in the liquid in the container.

The central portion of the metal diaphragm 4G is freely movable toward and away from the upper surface of the base 22 of the cup and the downwardly facing surface of the cavity 46.

However, the inneredge of the annular bearing surface'4'lv, of the supporting plate serves to provide arshoulder 48which acts as abridge or marginal nodal line which accurately defines the area of the diaphragm which is movable during the operation of the device. In this way the volume ofthe liquid receiving chamber and the active area of the diaphragm are effectively established so that their action is in no way dependent upon or variable with differences in the assembling operation or the pressure under which the disc, diaphragm and cup are secured together and held in place.

` The diaphragm is formed with openings 48 which are spaced from the central portion thereof so thatwhen the diaphragm is depressed the central portion may move into engagement with the upper face of the cup to close and seal the opening 24 through which liquid passes into the cup while at the same time liquid in the liquid receiving chamber 44 may pass readily from the lower to the upper surface of the diaphragm and Will not be-forced back into the container. As shown in Fig. 4 the openings 48 in the diaphragm are preferably positioned so that they will be located adjacent the shoulder 49 of the supporting disc 42 and may be partially closed by the flat bearing surface 41. The upper surface of the base of the cup is formed with an arcuate groove 58 which extends from a pointV near'the center of the cup (but spaced from the opening 24) to the side wall 26 of the cup along this wall to the atomizing aperture 28. The lower face of the supporting disc 42 is also formed with an arcuate groove 52 which extends from an opening 54 near the center of the disc to the edge of the disc at a point adjacent the atomizing aperture 28. These grooves serve to conduct liquid and air from both sides of the diaphragm 48 to the atomizing aperture so that liquid may pass Athereto from the liquid receiving chambers 44 and 46.

'Above the supporting disc 42 is located a compressible member, such as the rubber bulb 56. The bulb is formed with an air space 58 therein which communicates with the cavity 46 of the liquid receiving chamber 44 through an opening 54in the supporting disc 42 in registry with the inner end of disc groove 52. The openings 48 in the diaphragm 48 also serve to provide limited communication between the air space in the bulb and the portion 44 of the liquid receiving chamber beneath the diaphragm.

The upper surface of the disc 42 is formed with an air groove 68 which extends from the air space 58 in the bulb to the atomizing aperture 28 in the cup 20. Thus the construction provides both an air channel and liquid channels which extend to the atomizing aperture for mixing air and liquid and ejecting the same through the atomizing aperture 28 and the discharge port 30 in the head. As shown in Figs. 1, 2 and 3 the cup 28 is preferably provided with a depression or cavity 28 4formed on the inner surface of the wall portion of the cup adjacent the atomizing aperture 28. This cavity serves as acommon mixing chamber to which the air and liquid channels extend and in `which the jets of air and liquid are subjected vto vigorous agitation or swirling as they meet before being forced through the aperture 28.

The marginal portion of the bulb 56 is formed with e. bead 62 which is engaged :by the inturned upper edge 64 of the wall portion 8 of the retaining member. In this Way the atomizing elements are clamped togetherl within the upper wall portion of the head, and the head may be shipped lor handled las a unit without danger of displacing the elements or loss thereof. Similarly the liquid supply tube I8 may -be shipped separately from the head and inserted int-o the ldownwardly extending neck I4 on the gasket at the time of applying the head to the container.

In order to aid in the assembly of the atomizing elements and to avoid relative movement thereof after they are. assembled the wall portion 8 Vof the retaining member 2 is formed `with an in wardly extending projection or rib '66 and the gasket I2 is formed with sa complementary recess 68, lwhile the cup is formed with an indexing recess 18 which insures registry of the atomizing aperture 218 in the loup with the discharge port 38 in the retaining member. Similarly the flexible metal diaphnagm 48 is -formed with la, notch 'I2 and the supporting disc 42 is provided with a recess 'I4 so that the grooves 52 and 68 in the disc will be accurately positioned to terminate adjacent the eatomizing apertur-e 28.

The operation of the device illustrated in Figs. 1 to 4 is as follows:

The bottle or container to which the head is lapplied is gra-sped in one hand and the thumb or one finger is used to depress the bulb 56. Upon the first depression :of the bulb air is lforced from the air space 58 through the .airvdischarge groove 68 to the mixing chamber 28 and the atomizing aperture 28 in the cup. At the same time air is forced through the opening 54 in the supporting disc 42 and across cavity 46 against the exi-ble Imetal diaphragm 48 so that the central portion of the diaphragm is forced downward into engagement with the lbase 22 of the curp 28 and serves to seal the opening 24 therein. The air thus forced into cavity 48 and the liquid receiving chamber 44 passes out through the groovev 52 in the lower surface of the supporting disc 42 to the atomizing aperture and discharge port. Any air passing through openings 48 in the diaphragm also will serve to `force liquid from the portion 44 of the liquid receiving chamber through the channel 58 to the mixing chamber 28. In this ch'amber the jets or streams of 'air and liquid meet and blend as they 'are forced through the atomizing aperture 28 thus assuring effective dispersion of the liquid as it is discharged from the aperture through the Idischarge port 38 in the retaining member.

When the bulb 56 is released it expands due to the inherent elasticity, drawing air inward through the atomizing aperture 28 and groove 68. Air is also drawn into the air space within the bullo from the liquid chamber 44 through the opening 54 in the supporting disc 42 whereby the pressure of air within the liquid receiving chamber is reduced and the central portion of the diaphragm 48 is exed upwardly to uncover the' opening 24 in the base of the cup.

Continued expansion of the bulb 56 serves to draw 4liquid upward through the supply tube I8 into the liquid receiving cham-ber 44 between the base of the cup 28 and the supporting disc 42.

Some of the liquid usually iiows upward through the openings 48 in the diaphragm so as to lie in cavity 46 above the diaphragm and it may evenv pass through the `opening; 54 into the bulb air space itsel-f.

Thereafter, upon again depressing the bulb 56, the air from the air space, and any liquid that may have passed through the opening 54, are forced through the groove 68 to the atomzing aperture and are projected from the discharge 'i 'port 30 in the ywall portion of the head The air whichis forced lfrom theair space through the opening 54 in the discfis projected against the diaphragm 40 and thereby depresses lthe central portionthereof Vinto sealing engagement with the opening 24 in the base of the cup 20.. As the .diaphragm 40 is depressed, at :least a part of the liquid .in the chamber '44 .flows upward through theopenings. 4s in the diaphragm to cavity 46 @and both air and liquid are projected through the groove 52 in the .lower race of the supporting disc to the atcmi'zing .aperture -and discharge port. Since all of the lowersurace of the diaphragm 40 does not engage the upper face of the cup 20, addi'- tional liquid is forced from the space between the diaphragm. and the base of the 'cup through the groove 59 to the atomizing aperture and discharge port. Some air may ,also pass through the open'-Y ings 48 in the diaphragm to the space beneath the diaphragm and thence. through groove 50 to the atomizing aperture 28.

In this way air andiiquid are forced to the atcmizing aperture 2B and discharge port 30 and are co-'mingled so as to 4be projected from the headin the lform `of a ne mist.v Moreover, the construction and operation of the elem-ents are such that deterioration and cloggingV of the varie ous grooves and openings .cannot take vplace and the .device operates consistently and effectively for long periods of time.

It has been determined from actual practice thatthe quality of atomization can .be changed by omitting the openings l48 in the diaphragm Ml. By omitting the openings 48 it has been discovered upon operating the device that the quality of atomiaation is improved but the amount of liquid dispensed is decreased. In other words, in a dispenser-having a diaphragm `with openings the quality of atomiaation is lessened but the quantity is il'icreased,l `and in the case of a diaphragm without openings,` the quality is increased but the. quantity is decreased. However, when using either form of diaphragm the v'volume of the cavity 46 and capacityof the liquid receiving chamber lixed .and unaiiected by the operations of applying the atomizing head-to a container.v Moreover, the active area of the diaphragm is also lined by the` engagement of the shoulder 48 about the edgefof the cavity 46 `whereit bears against the diaphragm to establish a marginal nodal line determining the active `area of the fdialphragmin all assemblies. Movement of the diaphragm is therefore dependent only upon vthe action-o the-compressibie bulb and theiu'niformity of operation and discharge of liquid is assured.. 1

The atomizing head may be secured to a corb-Y tainer such as the container oi Fig` Il'by suitable cooperating elements thereon. As vshown x the head is secured to the neck of the *container-6 by spinning or votherwise inwardly turning the' lower extremity 96 of the `attturhing portion 4 of the `retaining member so that it extends beneath the collar S8 on the top of theneck of the con-v tainer.

Although certain preferred form'sof the inven tion have been shown .in the drawing and described above, it will be 'evident that `the inventionis capable of numerous changes and modi-v cationsin the, form, arrangement and construc tion of the various elements thereof. It 'should th'f'r be llhdrstodth'at th prsent iilv'l'ition contemplates the use of such alernatives and equivalents and that such constructions 'areintended vto be included within the 'scope of 'the following claims.

I claim:

l. In an atomizing head adapted to be applied to a container, upper and lower members located within said head, said upper 'memberchavinga at, annular marginal portion surrounding a circular downwardly facing cavity which is substantially rectangular in vertical cross section and presents a nat surface spaced from said lower member and cooperating therewith to definea liquid receiving chamber, a flexible diaphragm located between said members'and confined at its edges between said annular marginal portion of the upper member and the upper 'surface 'of the lower member and 'extendingfacross the. lower face of said cavity, theY side walls of said cavity extending angularlyirom the inner edge of said hat, annular, marginal portion to said flat surface of the cavity and forming a circular shoulder engaging the Adiaphragm and bounding a central active area ,portion of the diaphragm, said lower member having an opening therein and said ac tive portion of the diaphragm being movableto seal said opening, a tube leading to said opening for conducting .liquid to said liquid receiving chamber, a compressible member located above said upper member and formed with an air space therein, said upper member .having an opening therein communicating `with said air space and positioned to direct air from said space against the active portion of said diaphragm to actuate the same, and means extending about said members and diaphragm and formed with an .atomizing aperture therein, said .members being Yformed with grooves therein extending from the air space in the com'pressible member and from the liquid receiving chamber to said aperture for conducting liquid from said liquid receiving chamberand air from said air space to said atomzing aperture.

2, An atomizing device as defined by claim 1 wherein the central portion of the upper member overlying the diaphragmis iiat and offset bodily relative to the annular surface of Said member.

3. An atomizing device as defined by claim wherein the upper surfaceof the upper member is .formed with a central offset and upwardly projecting portion, the edgeof Whichis coincident with the sides of the downwardly facing cavity in the upper member, as may be produced by the shearing action of 'forming diesl WILLIAM V, STROKALITIS.

.REFEREN CES ,CITEDV The following .references are of record 'in the.

file of this patenti UNITED STATES PATENTSy Number Name llatcA 2,220,229 Grove Nov. 5, 1940` 2,241,056 Chilton May 6, 1941 2,311,496 Spender Feb. 16, 1943. "2,393,255 Limbach Jan. 22, 1946 2,427,932 Spender et al Sept. 23, 1947

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