CA1045597A - Dispensers - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A dispensing device for flowable material comprises a rigid tubular housing having a dispensing outlet at one end and a relatively rotatable end cap. A flexible container for the flowable material is made of high tensile essentially non-stretchable material and is located in the housing with one end in communication with the outlet. The other end is connected to the end cap so that rotation of the end cap twists the end of the container to dispense the flowable material.
The connection is through a compensating device which, while transmitting the rotation of the end cap, allows the twisted end of the container to move axially in an essentially non-resilient manner but offers sufficient resistance to keep the twisted end along the axis of the housing.

Description

:IL045597 FIELD O~_T~E INVENTION
This invention is concerned with improvements in or relating to dispensers for flowable materials~
BAC~GROUND AND PRIOR ART
- Dispensing devices for pastey materials are kno~Jn, in which the pastey material is contained in a resilient bag located within a housing, one end of the bag communicating with '~
an outlet in the housing and the other end of the bag being connected to a rotatable member so that it can be twisted to extrude the material from the outlet. Since the bag tries to shorten on twis-ting, various compensa-ting de~ices have been proposed to allow the twisted end of -the bag to move axially -~
while transmitting the rotation of the rotatable member.
However, it is important that the twisting should start from the end remote from the outlet and progress steadily along the bag~ so that substantially no material is retained in the twisted portion. For ext~uding very viscous substances such as mastic, or to obtain a liquid spray, high pressures have -to be developed, and it has been found to be particularly important to control the twisting of the bag~ especially in the early stages, if efficient~ expulsion of material and sufficiently high pressures are to be obtained.
~rench Specification 1161905 shows a freely hinged buckle connecti~g the end of the bag to the rotatable end member, so that the buckle, which is initially flat against the end member, is li~ted by the bag as it twists. HoweYer~ in this arrangement the tw~sting~end o~ the bag is largely unrestrained, ~ -particularly in the inltial stages9 so that the twisting will ~ tend to become irregular and off-centreO
~ 30 U~S.~Specification 1491860 shows alte~lative! ~ ~

~045~;~7 compensatin~ devices. One uses a helical spring connecting the end of the bag with the end of the housing. The other has the tail of the bag held in a small aperture in a resi~ient disc at the end of the housing so that it can pull through the aperture as it is twisted. However9 the use of a resiliently extendable compensating member such as a spring has been found to be unsatisfactory, since the spring, if sufficiently extendable, does not maintain sufficient axial tension on the bag to adequately control ~ts twisting, and moreover tend.s to absorb too much energy during rotation and prevents the development of high pressures. m e resilient disc arrangement ~ -for its part does not hold the end of the bag sufficiently `
firmly to transmit the high rotational forces and maintain sufficient axial tension on the bag to achieve high pressures w~thin the bag.
U.S. Specification 2203313 describes a compensating de~ice oomprising a springy plate to the centre of which the tail of the resilient bag is attached. The plate is lntPrnally ~ -slotted so that the centre portion can be resiliently drawn upwards by the bag as it shortens during twisting. This suffers from the same disadvantage as the spring as described above, and further cannot transmit high torque to produce high pressure in the bag without risk of distortion or fracture of the plate at ~;
one of its many wsak points.
SUM~A~Y OF THE INVENTION
e present invention rests in the surprising discove~y ~
~that~to obtain high pressures in the bag any undue resilience ~ ~ -in the system should be avoided. More~specifically, although lt might be expected that a~rubber or other resilient bag would~
30 ~ perform best in llowing pr~ssure to be built up and in storing :; ~
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the twist energy, in fact it has been found that a bag of non-stretchable material produces much better results. Moreover, it is important that the compensating device should not only be able to transmit high torque, but also it should fulfil two ~ ~
~-~ further requirement~ Firstly, it should have sufficient ~ -;
resistance to axial extension to keep the t~isted tail of the - bag siraight and ensure that the twisting progresses steadily and efficiently from that end of the bag. Secondly, when it does allow the tail of the bag to advance axially, it should ~ ~
, : -do so in an essentially non-resilient manner, so as not to absorb the applied torque, nor apply increasing axial tension -~
on the bag as it rises further up the housing, as would happen with a spring device.
~or the bag material, polyester ~ilm has been found -to ~r prov~dc +ho d2sir~d ~.~ h tcns~lr n^n-stret~h qualities, although other materials are no doubt suitable and still others will be developed in future. ~;
For the compensating device, two particular forms have been found suitable, both of them being modifications o~ the arrangements shown in U.S. Specification 149~860, although they }
were not in fact devoloped from them. In one form, the end of the bag is formed into a flat tail which is firmly gripped in a ~- rlgid slot, so that although it can be pulled through the slot by-the application of suf~icient~force, the rigid slot does not yield, as~would a slotted rubber disc9 and thus the grip is ~
maintained e~ually effecti~ely under high toFque, and the high ~-torque can be effectively applied. In the other form the tail o~ the bag is~secured through a spiral member which c~an expand axlally ln an essentlally non-res1lient fashion/ but which -~
~0 exerts considerable resistanCe to such expansion. This ~ . : , .. - . .
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~045S5~7 resistance can be due to the thickness of the material of the spiral, e.g. a thick steel wire, or it may be due to the shear resis~ance of a plate having a spiral~line of weakening from which the spiral is gradually torn. The spiral device can transmit high torque in the direction of the spiral without great risk of undue distortion or fracture.
~ A particular advantage of the present invention :is thai it enables sufficient presæure to be built up in the bag ~
to provide an effectlve fine spray of a liquid, comparab:Le ,~ -with an aerosol s~ray. A preferred embodiment of the invention therefore employs a manually operated valve in the outlet passage and a spray nozzle at the end of the passage.
BRIEF DESCRIPTION OF THE DRAWINGS
ND DESCRIPTION OF SPECIFIC EMBODIMENTS ~
In order that the invention may be more clearly ` ~ , understood, various embodlments will now be described with reference to the accompanying drawings, wherein:
Fig. 1 shows a cross-sectional view of a first embodiment~ of dispenser; ;
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` - Figs 2 and 3 show perspective views of two different forms of compensating device for the dispenser;
Fig. 4 sho~s a cross-seotional view of a second embodiment of dispenser;
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Fig. 5 shows a cross-sectional view of a third embodiment of dispenser;
Fig. 6 shows a cross-sectional view of a four~
embodiment of dispenser;
; Fig. 7 shows an exploded perspective view of the bottom portion of the embodiment of Fig. 6;
Fig. 8 shows a cross-sectional view of a fi~th embodiment of dispenser; and Fig. 9 shows an exploded perspective view of an alternative bottom arrangement of the dispenser of Figs. 6 and , 8.
Referring to the drawings, and ~irstly to Fig. 1; the dispenser comprises a strong flex7 bl~ ~ag-' Ir~ ocntain~r 1û
carrying a liquid, for example a water-based insecticide, which is to be dispensed as a spray. The bag is suitably made polypropylene or (Trade Mark) from/"~elinex"/polyethylene terephthalate sheet material. m e container is l~cated within a rigid tubular housing 2, suitably ~-of plastics material. A dispensing component 11 o~ moulded plastics material is provided with an annular groove 12 which receives the rim of~the housing at one end thereof, the mouth of the bag 10 being turned outwardly over the rim of the housing and trapped between the housing and the dispensing component. The dispensing component is provided with an outlet ~ ;
passage 14 for the liquid, which has a conical inner end 16 opening into the housing. A valve 18 in the outlet passage 14 ~ ~ -is controlled by a spring-loaded plunger 20. A nozzle ~elemen-t

2~ is fitted at the outer end of the passage 14.
The lower end of the housing 2 carries a rotatable end cap 32 which is held captive by a flange 30 of the end lt:ap ,........... :.... , , -, . : ~ .. :: . ~ . .... .. ..

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entering a groove 29 of the housing. Ratchet teeth 31 are ~ ~
provided on the outer surface of the lower end portion of the ~ - housing, and complementary ratchet teeth ~3 are provided on the inner surface of the end cap; The ratchet teeth resilientl~ interengage, and are preferably sa~1-toothed in cross-section so that they allow the cap to be rotated in one direction but resist rotation in the opposite direction. The end cap is connected with the lower end of the bag 10 by means of a compensating element 40 which is hooked onto a lug 38 of ~0 the en~ cap and onto a ring 42 attached to the lower end of ~
the bag by means of a loop ~ormed in the lower end o~ the bag ~0 which ~s gripped and sealed by a crimping clip 44.
In operation, the end cap is rotated to twist the lower end portion/of the bag and thereby compress the liquid which is ,~
released as a spray from the nozzle 21 when the Plunger 2~ i5 depressed.
m e compensating device 40 is of the form shown ln Fig. -2, and comprises a length of wire~hooked at its ends 23,25 and twisted into the form of a coil 27. The material of the wire is permanently deformable so that the hooked ends can be drawn apart as continued use of the dispensing device causes the lower end of the bag to rise to within the housing. Ho~ever, the wi~e material must provide resistance to the axial movement of the bag and be capable of transmitting the rotation of the end cap/ ~ ~ -lower end of the containerO 12 or 14~ swg. mild steel wire is generally adequate for this purpose, but thinner wire, such as 1~ s~g. may be appropriate for smalIer packsO
; Fig. 3 shows an alternativé form of compensating , device/,wherein the end cap 32 ha-s an end wall, suitably of ~30 plastics or metal, which~is providéd with a centr~lly dlsposed loop~35 hrough ~h~ch the lower end portion ~ t . . . . . . . . . . . .. . . . .

~ 1045597 of the bag is passed and secured. The er~ wall is scored at ~;
39 to define a spirally shaped tear line. As the end cap is rotated, the rotation is transmitted to the end of the bag~
and axial tension is applied by the bag to the end cap, which offers a degree of resistance to the tearing of the score line, ~ -but under sufficient force the end cap gradually tears along the 't score line to provide a tear out strip in the form of a coil.
This is substantially equivalent to the device shown in Fig. 2.
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HoweYer, the coil 27 thus produced will take the form of a flat 10 ribbon of metal or plastics material which has a greater ~ 3 ability to transmit rotational force but has minimum resilience in the axial direction.
Re~erring to Fig. 4; the dispensing device comprises ~ a bag-like container 10, for example containing a pastey - substance such as pre-mixed mustard. It is located within a rigid tubular housing 2 of plastics m~terial, which has a substantially cylindrical tubular portion 1~ which merges into -a narrower neck portion 15 providing an outlet to the housing.
The neck portion has an out~ardly directed annular rib 17 at Z0 its extremity. The upper mouth of the bag 10 is turned over the flange ~7 and held in place by engagement in a co-operating annular rebate 19 of a dispensing component 11. An outlet passage 14 for the contents is provided in the nozzle componentO When not~in use,~the outIet orifice can be closed by an appropriately shaped plug 27. ~
The lower end of the housing i9 provided with a ~ .- .
rotatable cap 32, which is essentially similar to that of Fig.
1, except that instead of the two sets of co-operating ratchet ~`
~teeth, teeth 34 are formed on the inner cylindrical surface of ~30 the end cap to operate in the manner of a ratchet with pips 36 ~ ~' ~
~ _8 - ~ ~ ~

~0~55~7 .- ~ .
spaced at regular intervals around the outer surface of the housing. The lower end of the bag 10 is connected to the end cap by means of a compensating member 40 which is essentially similar to that shown in Fig. 10 '-.' l~ `
In this embodiment, the end cap can be rotated in either direction, the teeth and pips merely providing a resistance to rotation. After the required amount of material ~ r has been expelled, the end cap can be rotated a little in the reverse direction before replacing the plug so as to relieve any undue pressure in the container and prevent -the plug from ~
being forced off. ; ¦
~ The embodiment shown in Fig~ 5 consists essentially of ; f a combination o~ two of the dispensers of Fig. 4. A single `
housing 2 has two separate dispensing components 11 ~upplied by separate bag-like containers 10 within the housing. The lower ends of the two bags are closed and jointly connected to a single compensating device 40 which links them to a sLngle rotatable end cap 32. The two bags contain separate materials which it is desired to dispense simultaneously and in equal ~20 proportions. l'ypically, this may be a two-part adhesive .
composition. me dispensing components are arranged so that tbe two materials are dLspensed~to~ards each other. In this :
embodiment, the neck of each bag 10 is shown as being sealed ~to the inside surface of the neck portion 15 of the housing, ~`
instead o~ being turned over~the flange 170 . .
~ m e embodiment~sho~n in FigsO 6 and 7 is essentIally~ ;
; similar to that of ~igo 4~, except for the compensating arrangemen~ at ~he~lower~end of the contalner bag. In this ~ - ;
~ : case, the lower end~portion o ~the bag 10 is twisted in the~
;;~30 ~region 41, and its extremity is formed in the shape of a flat ~ ~ 9 ~ ;

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portion tai~ 43 which can be sealed by a crimped metal tie 45 which also provides an end stop. The tail portion extends through ~`
a trangular hole 47 in a transverse w~ll 49 of the end cap, ~ -and is trapped therein by a wedge 51. The hole 47 is provided with a re-entrant groove 53 intended to receive the tail portion 43, and the wedge 51 is provided wi-th retaining shoulders 55. me hole 47 and the wedge 51 are shaped so as to interfit in such a way that the tail po~tion 43 is frictionally gripped between the wedge 51 and the groove 5~ to a desired extentc The end cap extends be~ow ~he transverse wall 49~ and is provided with a groove 57 to receive an end plate 59 which portion retains the ~ail/43 and hides it from view. Initially, with `~
the bag filled with the material to be dispensed, as much as ~L
possible of the tail portion 43 is contained in the space between the trans~erse wall 49 and the plate 59. Rotation of ~ ~
the end cap causes the tail of the bag to be twisted, since ~ ;
the tail is prevented by the wedge 51 from rotating rela-tive -to the end cap. The continued twisting of the lower end of the container thereby causes the contents to be expelled when the plug 27 is removed. After the requir~damount has been dispensed the end cap will be rotated a little in the reverse direction and the plug replaced. The frictional grip exerted on the tail portion 43 by the wedge is arranged to be such as - to still permit the tail portion to be pulled by the bag through the wall 49, thus compensating for the shortening of -: '~
the bag as it is twisted.
Fig. 8 shows a modification to the embodiment o:E Fig. 6 similar to the embodiment of Fig. 5, in which there are t~lo containers in the-housing, each supp~ying separate material to a respective d~pensing component. The lower ends of the t~lo ,, ~10 - ~ ~

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containers are twisted together and taken as a single tail through the transverse wall 35.
Fig. 9 shows a modification to the end cap arrangement, suitable for the embodiments of Figso 6 to 8~ In this i-modificat~on, the end cap 32 is moulded from plastics ma-terial, -~
and is mounted to the housing 2 in the manner already described ,-~
It is provided with diametrically opposed perforated lugs 50 ~`
which receive end portions of a split pin 520 The tail portion 43 of the container is threaded through the split pin during -assembly, and is frictionally gripped between the legs 54 of the split pin. An end cover 56 is arranged to fit over the end cap 32 to hide the -tail portion from view. As in the previous embodiment, when the end cap is rotated so as to twist the lower end portion of -the container, axial -tension is built up~ which pulls the tail portion between the leg portions 54 *
of the split pin, which exert a ~rictional grip transmitting the rotational movement to the container and opposing to ~ -limited extent the movement o~ the tail portion between them.
As an al~ernative to the arrangements illustrated above? the rotatable member may be provided at the dispensing `
end, the dispensing outlet being Frovided in the rotatable member which is connected to the flexible container, the other end of the container being connected through a compensating element: to the other end of the housing. Howe~er, if the pressure in the container causes it to bear upon the sides o~ -the houslng, then the ro-tatable member should be at the end ~
of the housing remote from the outlet. . .
- ~ ;
~ The valved outlet arrangement o~ Fig. ~ can be app:lied ~
to other embodiments, even to dispensing pastey or viscous ~ ~;
materials, althougb n spray nozzle would not be used. In the , : -;

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~5;597 tw~ bag embodiments valves in the two outlets could be operated ,~ -simultaneously by a single plunger. One bag could contain a `~
liquid and the other a gas or highly volat:ile liquid, so that .
the two jets impinge on each other, the gas or vaporised liquid Jet servlng to atomise the other liquid jet.

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Claims (16)

I CLAIM:

1. A dispensing device for flowable material, comprising a rigid tubular housing having a dispensing outlet at one end and carrying a relatively rotatable member whose axis of rotation extends lengthwise of the housing, a flexible container for the flowable material located within the housing in communication with the dispensing outlet and secured at one end to the housing and connected at its other end to the rotatable member on the axis of rotation, whereby rotation of the rotatable member twists the end portion of the flexible container remote from the dispensing outlet to cause the flowable material therein to be discharged from the dispensing outlet, the end of the flexible container remote from the dispensing outlet being secured by a compensating device which, while transmitting the rotation of the rotatable member to the end of the flexible container, allows the adjacent twisted end of the container to move axially towards the dispensing end, characterised in that the flexible container is of high tensile essentially non-stretchable material, and the compensating device allows the twisted end of the container to move axially towards the dispensing end in an essentially non-resilient manner but offers sufficient resistance to said movement to maintain the twisted end portion substantially along the axis of the rotatable member.

2. A dispensing device according to claim 1 wherein the compensating device takes the form of a spiral connecting element which can transmit rotational force from the rotatable component to the container, and whose ends, attached one to the rotatable component or the housing and the other to the container, can be separated axially in an essentially non-resilient manner, but which offers substantial resistance to such separation of its ends.

3. A dispensing device according to claim 2 wherein the compensating device is a spiral of essentially non-resilient wire with hooked or looped ends.

4. A dispensing device according to claim 2 wherein the compensating device is formed from flat material having a spiral cut therein so that the centre of the spiral can be displaced out of the plane of the material to provide the axial compensation, and the rotational force is transmitted through the spiral flat ribbon of material thus formed.

5. A dispensing device according to claim 2 wherein the compensating device is formed from flat material having a spiral rupturable line of weakening therein so that the centre of the spiral can be displaced out of the plane of the material to provide the axial compensation, and the rotational force is transmitted through the spiral flat ribbon of material thus formed, the resistance to shear of the material providing a degree of resistance to axial advance of the twisted end of the flexible container.

6. A dispensing device according to claim 5 wherein said spiral is formed in a transverse wall of the rotatable member.

7. A dispensing device according to claim 1 wherein the compensating device is provided by a flattened tail portion of the container yieldably gripped in a rigid slot in the rotatable member or the housing, whereby the twisted end of the container can advance axially when the axial force overcomes the grip of the slot.

8. A dispensing device according to claim 1 wherein the rotatable member is at the end of the housing remote from the dispensing outlet, and the adjacent end of the container is connected to the rotatable member.

9. A dispensing device according to claim 1 wherein the outlet end of the housing has a manually operable valve with the outlet for the flowable material beyond the valve.

10. A device according to claim 9 for spraying liquid from within the container a spray nozzle being provided at the outlet beyond the valve.

11. A dispensing device according to claim 1 including means acting between the rotatable member and the body to resist the force tending to untwist the container when the flowable material is under pressure.

12. A dispensing device according to claim 11 wherein said resistance means takes the form of a series of shoulder forming elements arranged around one of the housing or the rotatable member, and one or more co-operating elements arranged on the other of the rotatable member or housing so as to resiliently engage the shoulders and thereby provide resistance to rotation.

13. A dispensing device according to claim 12 wherein at least one of a co-operating pair of said elements is of saw-tooth configuration so as to provide greater resistance to rotation in one direction than in the other direction.

14. A dispensing device according to claim 12 wherein a series of said co-operating elements is arranged around the rotatable member or housing.

15. A dispensing device according to claim 1 wherein the housing has a plurality of dispensing outlets at one end and carries a single relatively rotatable member, a plurality of flexible containers for different flowable materials being located within the housing each in communication with a respective dispensing outlet and secured at one end to the housing and connected at its other end to the rotatable member, whereby rotation of the rotatable member simultaneously twists the end portions of the flexible containers remote from the dispensing outlets so that pressure is applied to the flowable materials therein, enabling the materials to be simultaneously discharged through their respective dispensing outlets.

16. A dispensing device according to claim 15 wherein the dispensing outlets are convergent so that the different materials mix on being discharged therefrom.