CA2068985A1 - Dispenser with piston assembly for expelling product - Google Patents

Abstract

The present invention relates to a non-aerosol dispenser. The problem associated with aerosol dispensers is that many contain hydrocarbons which contribute to air pollution. The non-aerosol dispenser comprises an inner cylinder (224) defining a material chamber (211) with a discharge valve (214) at one end. A piston assembly (220) for pressurizing the contents carries a cutting edge (288, 289) and guides (280, 281). Outer housing (240) receives the guides (280, 281) which advances the piston (220) upon rotation of the housing (240) while forcing the cutting edge (288, 289) to cut through the inner cylinder (224). The piston (220) includes an energizer member (252). An ejector (250) and spring is disposed between the energizer (252) and the valve (214). The spring stores energy from advancement of the piston (220) and transmits such to the ejector (250).

Description

~: WO 91/07347 2 [~ ~ ~ 9 ~ 5 Pcr/usgo/~fi6so oISPEVL~R Wl-H PISTON ASSEMBLY
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The present invention relates to a dispenser, S especially a hand held spray can in which a piston is advanced to eject a spray upon manual actu~tion of a valve.
Hand-held spray dispensars are conventional i~ which a piston is hous~d within a container below a product to be dispensed. ~y advancing the piston toward a valved end of the con~ainer, the product i~
forced through the valve.
The present invention constitukes an alternative to aerosol spray dispensers which use pressurized gas as a propellant, th~ ga~ being mixed with the product.
Gases currently in use contain hydrocarhons which have increasingiy come under attack ac a serious contributor : to air pollution. For example, hydrocarbons released in the atmosphere can react with nitrogen oxid~ and -~. 20 sunlight to form ~mog.
: There hàve here~ofore been propo~ed gasless spray dispe~sers which prop~l the produc~ by ~: mechanically gen~rated propelling forces. ~or example, pump type di8pan~ers have been proposed which require a me~hanlcal displacemen~ of a pump stem each tim~ that a ~ user dispense~ a spray. Such dispen~er~ ar~ incapable : of ~toring en~rgy and thus eject the contents in the -~ form o i~t~rmittent spsay bursts rather than a prolonged spray.
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: , WO91/07~7 2 6 8 9 8 ~ PCT/US90/~66~0 Other dispensers have been proposed which rely upon mechanical actuatio11, as exemplifi.ed bv U.S.
Pat~nts No. 3,Rl5,787; No. 3,:L95,168; No. 2,728,097;
and No. 2,738,905.
In U.S. Patent 3,8lS,7l37, a dispenser is disclosed wherein a piston is mounted within a helical - groove formed on an inside surace of a cylindrical çontainer. By rotating the container relatlve to a top discharge portion of the dispenser, the piston is caused to ascend wi~hin the contai~er to discharge product located therea~ove. However, since tha helical groove faces the contents chamber, it i5 neçessary te confine the liquid within a bag, or else the liquid would escape along the helical groove. The need . for bays may incr~ase the manufacturing c05ts and presents . the risk that the bag can become ruptured as the res-~lt ! of being pinched betwe~n the pi~ton and either ~he helical groove or vertical guide slots which receive radial tabs of the piston.
I~ Patent No. 3ll95,l68, s11ch an axiaLly : threaded rod i~ pro~ided which extends axially within the container. and ~arries a ~hreaded follower.
Dispo~ed above ths follower i~ a pi~ton which ~eals again~t the in~ide ~urface of the content.~ chamber.
The rod i~ ro~a~0d by means of ~ knob ~ounted at th~ :
botto~ o~ the container. A ~pring between the follower ~d p~ston ~r~nsmit mo~ion from the followar to the pi~to~ ~o skor~.energy. By ro~a~ing the rod, the follower and pi~ton are raised ~o di~pen~e ~he co~te~ts~ To prevent ~he ollower ~rom rotating, ~ ~ ' . .,j .
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the follower and the wall of the contents chamber are formed with complementary non-circular cross-sections.
Such a non-circular cross-section reduces the inner volume of thP container and thus reduces the amount of S liquid product which can be held. Also, the need for a separate actuator rod and ~urning knob may incr2aqe the C05t and complicate the assembly o the apparatus.
While the spring effectively stores energy, it doe~ not transmit the energy to the piston a~ uniformly across the area of the piston as would be de5ired, thereby resulting in a less-than-optimum spray pattern.
U.S. Patent No. 1,762,943 discloses a dispenser for vi~cous material, such as toothpaste. The ~, dispenser includes a pis~on shell disposed within a cylinder. An outer shell is connected to the pis~on shell for common rotation and longitudinal move~ent therewith. It is necessary to cut off the bottom of the cylinder as the inner and outer shells tra~el toward the discharge valv~. Such an operation is inconvenient and creates cu~tings that mu~t be disposed of.
In Pat`ents No. 2,728,097 and No. 2,738,905 dispe~ser~ are disclo~ed which involve the ne~d for a threaded rod and which pr~sent th~ proble~ of leakage of produc~ pa t a dispensing pi~ton.
It would be de~irable ~o pro~ide a relatively low-co~, easily assembled, non-aero~ol di~penser whi~h does not require that ~he product be ~ored in a bag and which, lf a bag i~ u~ed, minimi~es the risk of the bag being ruptllred.
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I~ would also be desirable to provide such - a dispenser which makes it possible to store propulsion energy so that a continuous discharge can be effected with a highly uniform spray pat:~ern.
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The present invention involves a non-aerosol dispenser which compriseC an inner cylindrical wall defining a contents chamber. ~ discharge valve is disposed at one longitudinal end of the chamber.
10 A piston i5 disposed within the chamber in -~ longitudinally spaced relationship from the discharge valve. The pis~on includes a cu~ting edge dir~cted toward the cylindrical wall. An outer cylindrical wall is diqpo~ed around the insl~r wall. The outer wall is - 15 rotatable relative to ~he irlner wall and cooperate~
with the pi~ton, whereby ro~tion of the outer wall causes the piston to approach the discharge val-Je while for~ing the cutting edge to cu~ through the inner wall, characteri~ed in t~at the outer wall cooperates wl~h ; - 20 ~he piston ~uch that the piston travels longitudinally relativ~ to~the ou~er wall as the piston approach~s ~he di scharge valve .
~he irm~r wall includes a helical groove wh~ch recel~ guide mesnberec of ~he pis o~ac 'rhe pis~:c~n i5 preve~t~d ~ro~ ro~ating, by mean~ o~ lo~gi~dinal yrooY~ orm~d in the inner wall.
T~ pi3ton compx~s~s an e-jeG~or member and an energiz~r me~ ex spa~ed below it ~o d~fi~e a space be~ween the ejector and energi~er mem~ers~ The ~pace i5 filled with ~ompress~bls gas, such a~ air, which aets liXe 3 spring to ~to~e energyO

~ WO91/07~7 PCr/US~0/0~6S0 2~9~

The compressible gas may be confined in the space by means of seals on the ejector and energizer members, or the gas may be contained in an enclosure, such as a flexible bellows, which extends between the . ~,;
ejector and energizer members,.
The contents to be dispensed may be locat2d directly in the conten~s chamber, or contained within a flexible bag located within the contents chamber.
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The objects and advantages of the invention will become apparent from the following detailed description of preferred embodiments thereo~ in connection with the accompanying drawing~ in which like numerals designa~e -:~ like elements, and in which:
- l5 FIGURE 1 is a longitudinal sectional view taken through a dispenser according to the present invention;
..: FIGURE 2 is a perspective exploded view of the dispenser depicted in FIG. l;
FIGURE 3 is a longitudin~l sectional view taken through an energizer member of a pis~on assembly - according ~o the invention;
;, FIGURE 4 is a bo~tom plan view of the enerqizer member depicted in FIG. 3;
FIGURE 5 is a fragmentary side view of the energizer member;
FIGUR~ 6 is a fragmentary longitudi~al ~ec~ional view o~ ~he dispenser dep~c~ed in FIG. l;

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~ WO91/07~7 PCT/lJS')0/06fiS0 6 2~89~5 FIGURE 7 is a view similar to FIG. l of a modified piston assembly according to the inv~ntion;
: and FIGURE ~ is a view simil.ar to FIG. 6 of the . , .
piston assembly depicted in FIG. 7.
: Detailed Description of Pxeferred A dispenser (200) accord~ing to the present invention includes a first housing body (212) having a cylindrical wall t224) and an upper end wall (226).
Formed in a~ outer surface (228~ o the cylindrical wall (224) are a pair of longitudinal groo~es (230) which extend partially through the eylindrical wall from the outside to leave k~ock-out wall por~ions (232) ~see FIG. lS). An inside surf~e (234~ of the cylindsical wall remain~ smooth and con~inuousO
An annular flange (236~ projects radially outwardly from a lower end of ~he outer surace (228).
A cylindrical wall (240) of a second.hou~ing body (2l8~
rests on the flange 1236). ~hat cylindrical wall ~240) receives the cylindrical wall (224~ in telescoping fa~hion, wher~y th~ ~ylindrical wall~ ~224, 240) constitute in~er and ou~er cylindri~al wal~, re~pectively. The cylindrical wall (224) includes long~tudlnally exte~ding~ circ~mfer~n ially pac2d ~lot~ ~2~1~ at it~ lower end to enable the outer wall (240) ~o ~ ~a~er~d over the inner wall ~224). The outer w~ 2401 include~ inner and outer ~ux~a~es (242, 244). A dl~k i24S) inæer~ed in~o the inner ' ,. ' ' . ' , . . ' `' ',. ' ' " ' ~' . ," ' ". , .

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surface (244) of the cylindrical wall (224) clvses the bottom of the first housing body ~212).. That disk (245) can be suitably bonded t:o the cylindrical wall (224).
: 5 The inner surface (242~ includes a helical : groove (243) which face radially inwardly. Tha~
:-~ groove (243) serves to guide aL piston assembly (220), - as will ke explained. ~he hel.ical groo~e (2.43) is situated radially outwardly of the longitudinal grooves (230), whereby the helical groo~e (243) constitutes an outer groove and the longitudinal grooves (230 ~-: constitute inner grooves.
An upper end of the outer wall 1240) is recei~ed ~- within an annular channel defin~d ~etween the inner ~ 15 wall (224) and an outer cylindrical skir~ ~247~ which ~ is joined to he inner wall (2243 by an outwardly extending portion (24~) of the end wall (226).
~he piston assembly (Z20) compri~e~ an ejector ;` member 250, and an energizer me~ber (252) located below the ejector member i250~. The ej ec~or memb2r l250) , ~ includes a downwardly extending annular skirt portion (258) which c~rrie~ an O-ring (251).
; The energizer member ~252~ includeR a seal ~arrier compri~ing a disk portion (266~ and an annular skir~ (263) extending upwardly ~h~refrom. Disposed - wi hi~ ~h~ ~kirt ~268~ is an elas~ic ~ealing me~ber l264) which bear~ s~alingly again~t th~ inner u~ace (234) o~ the inner w~ 224~. The ~eal carri2r ~266, 26~ pre~erably for~ed of a sti.E plas~ic t ~
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W09~/07~7 PCr/US90~65(3 2~1~g~3~35 material, whereas ~he elastic sealing member (264) is preferably formed of rubbe~r or a suitably resilient plastic. Alternatively, the seal carrier and the sealing member could be integrally molded of a suitably S elastic material.
Formed between the seaLling memb~r (264~ and th2 ejector member (250) is a se~.led space (265~ capable of retaining pressurized air. Pressuri2ation of that space (26S) can be achi~ved by the in~ertion of a : 10 needle through the sealing member (264) after the components of the dispenser have been assembledO
Holes (267 and 269) orm~d in the disks (245) and (266), respectively, ac~ommodate the l~ertion o the .~ , needle. Pressurized air would be introduced throu~h the needle and into the space ~266) to pressurize the : space to a suitable pressure,~ e.q., 40 psi, When the needle is pull~d back ou~ of the sealing member, the latter i~ ~elf-sealing to seal the puncture made b~ khe needle. As will ke subse~uently explained, the air in the space (265) funct.ions as an air ~pring to stor~ and transmit the energyA
PrGjec~ing radially outwardly from ~he disk 52663 are gulde members ~280, 281j whl~h are receiYed within the h~ al groove (243). Carried by th~ di~k : 25 (266~ ar2 a paix of cu~ting el~e~ (288, 289~ having cut~ng edg~ ~291) faci~g lonqitudinally forwardly towa~d lower edge~ of ~he.k~ock~ou~ wall poxtion~ (232) o~ the tnner wall t224), The cutting element~
(288, 289~, whleh ~ould b0 fonmed o~ m2tal or a suitab}y hard plastif~, are initially po~itioned to lie within diam~3~rically opposff~d ones o~ the ~lot$ t241).
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.. g As a result, rotation o the energizer member (252) relative to the inner wall 1224) is preven~ed.
It will be apprecia~ed that the rotation of the : outer waLl ~240) relative to the inner wall )224) in a ~- 5 selected dixection produces ~orward longitudinal movement of the ~nergiæer member 1252) toward a valve ~ (214) mounte~ in th~ upper end wall (226), due to the :: presence of the guide members (280, 28l) within the heli~al groove (243). ~s a resul~, the cu~ing elements ar~ forced ~o cut through the knock-out wall por~ions (232). Simultaneously, an upper force is transmitted rom the energi~er member (2523 to the ejector member (250~ through the pressurized air . disposed within the space (265). The ejector me~ber (250) thus pressurizes ~he product located thereabove.
When the pressure of the product exceeds the pressure of air in the spao~-t26~3-,: fur h~ for~ar~ movem~nt ~ of the ener~izer member (252) causes the air ~o b~
- compressed, thereby ~oring energy. The air constitu~es a gas spring which ~ran~mits force~ to the ejector member (250) more uniformly than the spring 54 .~ of the easli~r~de~cribed embodim~nt and thu~ achie~s a more uniform spray through the v~lve (Zl4).
Th~ pr~Y~urized air wi~hin ~he space (2653 also for~e~ the skirt ~258~ of ~he ej~etor m~mb~r radially outwar~ly again~t the surface ~234) to a~d $n the sealing action. Su~h sealing actio~ may be suffl~i~nt to enable the O-ring (251~ to b~ om~tted.
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lo ~ 5 The upper end wall ~2~6) and the ejector member (250) ~re of similar inverted cup-shape, to ensure that all of the contents of the container have b~en dispensed when ~he energizer member (250~ finally engages the end wall (226~.
In operation, the u~er rotates the outer wall t240) to raise the piston a~sembly and pressurize the contents of the chamb~r (211) a~ well as the air in space (265~. Th~ energizer member (2S2) travel 5 longitudinally without rotation a~ the pi~ton assembly rises. It may be possible to eliminate the longi~udinal grooves (230) ~i~e., it may be unnecessary to orm knock-out wall portionq in the inner wall (244)) due to ~he ability of th~ energi~er member (252) to travel lcngitudinally without such groove~. The longitudinal movemen~ of the piston as e~bly (2203 is induced by the helical groove ~243) which acts on the guide~ (28~, 281). That longitudinal mov~ment o~ the piston assembly is made po~sible by the cutting action of th~ cutting ~lements (288, 289). The content~ will be ~xpelled under their own pre~sure as well as u~der the pres~ure of stored air energ~ within the 3pace ~265), whereater ~he pi~ton a~embly will b~ further raised to r~preR~urizP the ~ontents and the air space : 25 (265). Th~ por~ion of the surfac~ ~234~ whi¢h engag~s the con~nt~ ~an be made smoo h and continuou , i.e,, fr~e of gxoov~, whereby l~akage o~ ~h2 content~ a~d/or rupturing of a bag which con~in~ th~ contents can be pr~ented.

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~,~, . ~ ' ,, ' ' ' ' ', WO 91/1)7347 P~/VS90/06650 1 1 2 ~ 5 It will ~e appreciated that the piston assembly could be raised and lowered by any suitable manually actuable mechanism.
,l It would be possible to make the ~eal carrier (266) longer than shown, in order to provide an additional pair of guide members (280, 2~1) located below he shown pair. That woulld serve to stabilize the seal carrierO
It would be possible to rever~ the positions of the helical and longitudinal yrooves, i.eO~ by locating the helical groove t243) on the inner cylinder (224), and locating the longi~udinal grooves 1230) on the ' outer cylinder (240). The piston would include guide members slidably disposed in those grooves. In such a case, the energizing member ~2521 would be rotated along with the outer cylinder and would cut through a : :
helical knock~out port~on of ~h~ inner cylinder formed by the helical groove. A single cuttins edge (288~
would be proviaed which would be oriented to face in the direction of ro~a~ion. As ~he pi~ton i5 rotated, it would ~ravel longitudinally relative ~o the outer ~:: cylinder, as permit~ed by ~he longi~udinal grooves.
A modified embodimen~ of the pi3ton a~sembly i~ depicts~ in FIGS. 7 and 8. That modified piston as embly ~220A3 preven~s ~he air ~l~ua~ed b~tween ~he ejector member t250A~ and the energizer member ~252A3 ~ro~ e~caplng pa~t ~he ~nerqizer and/or ejec~or mem~er~
or mlqra~ing through the hou~.ing wall (~ o~ the dispen~er, a~ migh~ ocçux ~er a period of time in ~on~ection wi~h certain pla~ mat0rials from which ~, .
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,,..~, , WO91~07~7 P~r/U~S~0/06650 the housing walls could be formed. Such migra~ion of air would eventually destroy the air spring propertie~
of the piston assembly.
In accordance with the present invention, however, th~ air is retained between the ejector member ~250A~ and the energizer member (252A) by means of a flexible enclosure ~300). Th~ er~closure i~ preferably ~ in the form of a bellows formed of a suitable plastic - . or rubber material which is connected in an air-tight . 10 manner at its upper nd to a cylindric~l projection (302) of the ejector member (250AJ and at its lower end to a cylindrical projection (304) of ~he energizer member ( 25 2A) .
The en~rgizer member (252A) is of a more simplified ~tnlcture a~ compared with that of the earlier disclosed embodim~nt, because the confining o~
air within the bellows (30û) makes it unne~essa~y for the energizer member to form a seal with ~he surface (234) of the cylindrical wall (2241, The energizer member (252A~ includes a pas~3age (306) or enabling an inner chamber (308) defirled by the bellows ~o ba filled wi'ch air by m~an~ of a yringe, for exasnple. The syringe could be inserted through a self~sealing ru~ber plug ~310) dispo~ed a~ he lower end of th~ passage.
q~he ejector member (25QA) includes a ~ealing portion (312) whic:h orm~ a s~al aga$nst the surfao~
(234) as th~ pi~ton i~ r~ised to pre~suri2e the content~ o~ tlle di.~pen~r.

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Since the compressible air of the ~i5ton assembly is contained within the bellows (300), the air will not contact the wall of the dispenser ~nd thus will not be able to migrate therethrough or escape past .
the energizer and/or ejector members. Hence, the piston assembly (220A) is useful with all dispe1lsers, regardless of the mate~ials from which the cylinder wall i5 formed.
In operation, a5 ~he outer valve t240) is rotated to raise the energizer member t252A), the air within the bellows t300) i5 compressed, and the b~llows itself collapses. As the product is dispensed, the ejector member (250A) rises, thereby relieving the air pressure within the bellows chamber (308) and causing lS the bellows to re expand.
Although the presen~ invention has been described in conne~ion with preferred embadimen~s thereof, it will be appreciated by those sXilled in the art that additions, deletions, modifications, and substitutions not specifically described may be made without departing fxom the spirit and scope of the invention a~ defined in the appended claims.

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Claims (14)

WHAT IS CLAIMED IS:

1. A dispenser comprising cylindrical wall means (224) defining a contents chamber (211), manually actuable discharge valve means (214) disposed at one longitudinal end of said chamber, piston means (220) disposed in said chamber in longitudinally spaced relationship from said discharge valve means, and manually actuable means (240) operably connected to said piston means for displacing said piston means toward said discharge valve to pressurize the contents of the chamber, said piston means comprising an energizer member (252) and an ejector member (250), the latter disposed between said energizer member and said discharge valve means, characterized in that a compressible gas is sealed between said ejector and energizer member and defines means for storing energy for transmission to said ejector member in response to displacement of said energizer member toward said ejector member.

2. A dispenser according to claim 1, characterized in that a flexible enclosure (300) extends between said ejector and energizer member and defining a chamber (308) containing said compressible gas

3. A dispenser according to claim 2, characterized in that said enclosure comprises a bellows.

4. A dispenser according to claim 1, characterized in that said compressible gas is air.

5. A dispenser according to claim 1, characterized in that said energizer member includes an elastic seal for sealing against an inner surface of said cylindrical wall means.

6. A dispenser according to claim 5, characterized in that said seal includes a skirt (258) arranged to be pressed radially against said inner surface by compressed air between said ejector and energizer members.

7. A dispenser according includes a disk (266) which in that said energizer member includes a disk (266) which carries an elastic seal extending across the cross-section of said cylindrical wall means, said disk having a hole (269) therethrough to accommodate the insertion of a needle through said seal for pressurizing said space.

8. A dispenser according to claim 1, characterized in that said contents are contained in a flexible bag situated in said contents chamber.

9. A dispenser according to claim 1, characterized in that said piston means carries cutting edge means (288, 289) directed toward said inner wall means, said manually actuable means includes an outer cylindrical wall means (240) disposed around said inner wall means, said outer wall means being rotatable relative to said inner wall means and cooperating with said piston means whereby rotation of said outer wall means causes said piston means to approach said discharge valve means while forcing said cutting edge means to cut through said inner wall means, said outer wall means cooperates with said piston means such that said piston means travels longitudinally relative to said outer wall means as said piston means approaches said discharge valve means.

10. A dispenser according to claim 9, characterized in that said outer wall means includes a groove (243) having longitudinally spaced ends, one of said longitudinally spaced ends being situated closer to said discharge valve than the other of said longitudinally spaced ends, said piston means carrying guide means (280, 281) received in said groove for sliding movement therein as said piston means approaches said discharge valve means.

11. A dispenser according to claim 10, characterized in that said groove is helical.

12. A dispenser according to claim 11, characterised in that said inner wall means includes an outer surface (228), a pair of longitudinally extending grooves surface to form knock-out wall portions (232) of said inner wall means, said cutting edge means facing longitudinally toward said knock-out wall portions.

13. A dispenser according to claim 10, characterized in that said inner wall means includes longitudinally extending, circumferentially spaced slots (241) formed completely radially therethrough in an end thereof opposite said discharge valve means, said cutting edge means initially disposed in respective ones of said slots.

14. A dispenser according to claim 13, characterized in that said outer cylindrical wall means includes a radially outwardly projecting flange (236) at an end thereof disposed opposite said discharge valve means, said inner cylindrical wall means being seated on said flange.