Note: Descriptions are shown in the official language in which they were submitted.
~: 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,
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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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W,'-~1/07~7
4 2@~9~
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
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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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FIGURE 7 is a view similar to FIG. l of a
modified piston assembly according to the inv~ntion;
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FIGURE ~ is a view simil.ar to FIG. 6 of the
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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
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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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2 ~ 8 ~
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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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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
12
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
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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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