Closure assemblies

A hollow tubular outlet member and a cap fitting over the outlet member and rotatable relative thereto, the outlet member and cap having complementary conical end portions, an aperture in each conical end portion which can be aligned to define an opening which can be closed by rotation of the cap and wherein the cap and outlet have a co-axial tubular portion, one of such tubular portions being provided with at least one formation directed towards the other tubular portion and co-operating with a cam surface on the other tubular portion, the cam surface being shaped such that the conical end portions are urged axially into tighter engagement with each other during rotation of the cap to close the opening.

This invention relates to closures which may be used for releasably closing 
off any type of outlet as required. 
Of particular interest is a closure for a container and of still more 
particular interest are closures for flexible tubes such as toothpaste, 
shampoo and cosmetic containing tubes. However, the invention is in no way 
confined in application to such closures and includes within its scope, 
closures such as those used for bleeding air out of liquid containing 
systems; dispensing containers for pharmaceutical products in either 
liquid or unit dosage form; and adjustible water jets on garden sprinklers 
or garden hoses. 
SUMMARY OF THE INVENTION 
It is the object of this invention to provide a closure which, has a 
sufficiently large aperture for allowing passage of a substance 
therethrough, provides an effective seal in the closed condition thereof, 
and wherein the closure member itself is permanently associated with the 
outlet with which it co-operates and is moved from an open to a closed 
position by a simple rotational movement. 
In accordance with one aspect of this invention, there is provided a 
closure assembly, comprising: 
a hollow tubular outlet member; and 
a cap fitting over the outlet member and being rotatable relative thereto; 
said outlet member and said cap having wall means defining complementary 
conical end portions; 
means defining an aperture in each said conical end portion which apertures 
can be aligned by rotation of the cap relative to the outlet member to 
define an opening and which can be offset by rotation of the cap relative 
to the outlet member to close said opening; 
the cap and outlet each having wall means defining a co-axial tubular 
portion; 
one of such tubular portions being provided with at least one formation 
directed towards the other such tubular portion; 
one of such tubular portions being provided with at least one formation 
directed towards the other such tubular portion; 
said other such tubular portion being provided with a cam surface 
co-operating with said at least one formation; 
said cam being shaped such that said conical end portions remain 
substantially axially stationary relative to each other during initial 
rotation of the cap from when said apertures are aligned and define said 
opening, in a sense to offset and thus close the opening, but once the 
opening is closed, further offsetting rotation of the cap causes said 
conical end portions to be urged axially into tighter engagement with each 
other; and 
said cam surface further being shaped to provide a click stop for when said 
apertures are fully offset and said conical end portions are urged axially 
into said tighter engagement. 
Further features of the invention provide for the tubular outlet to be 
integral with at least a shoulder portion of a container or for the outlet 
to be provided with a spigot or socket to enable it to be connected to a 
complementary socket or spigot. 
Still further features of the invention provide for both the cap and outlet 
to be manufactured from injection moulded plastics material and for the 
cap to be a snap-fit onto the outlet for assembly purposes. 
The invention also provides a closure assembly comprising a hollow tubular 
outlet member and a cap fitting over the outlet member and rotatable 
relative thereto the outlet member and cap having complimentary 
substantially conical end portions substantially in engagement with each 
other, an aperture in each conical end portion which can be selectively 
aligned or non-aligned by relative rotation of the cap and outlet member 
and wherein the cap has a tubular portion adjoining with the conical end 
portion and located over the hollow tubular outlet member so as to be 
co-axial therewith, one of such tubular portions having at least one 
formation directed towards the other tubular portion and co-operating with 
a cam surface on said other tubular portion where-in said cam surface is 
shaped such that the conical or truncated conical end portions are urged 
axially into tighter engagement with each other during at least a part of 
the allowed rotation of the cap in a direction away from that in which the 
apertures are aligned, the closure assembly being characterized in that 
the tubular portion having the cam surface therein is provided with one 
axially extending channel shaped to receive each formation carried by the 
other tubular portion such that each channel receives said formation when 
the cap is moved axially onto the outlet and wherein the cam surface 
communicates with each channel through a zone adjacent the channel such 
that after introduction of each formation fully into a channel formation 
to align with the cam surface, rotation of the cap relative to the outlet 
forces the formations into co-operation with the cam surface by way of 
said zone which is formed to act as a catch to inhibit movement of a 
formation past said zone. 
Further features of this aspect of the invention provide for the cam 
surface to be defined by one side wall of a channel shaped formation 
extending circumferentially about said other tubular portion, for there to 
be either one formation and channel or two symmetrically disposed 
formations and co-operating channels, for the conical end of the outlet to 
be truncated so as to provide at least a space between its ultimate end 
surface and the inner end surface of the cap, for the tubular outlet to be 
of constant diameter along its length and to carry at a position removed 
from the conical end the formations defined above, and for the tubular 
portion of the cap to be of a truncated concial shape wherein the cone 
angle is substantially smaller than the cone angle of the end portion.

In the embodiment of the invention illustrated in FIGS. 1 to 4 the 
invention is applied to a closure for a flexible cosmetics tube, such as a 
toothpaste tube. In this application of the invention a tubular outlet 1 
is formed integral with a shoulder portion 2 of a tube 3 with which the 
shoulder portion may be integral if required. The tubular outlet is formed 
in three sections whereof a section 4 adjacent the shoulder is of constant 
circular cross-section; a second section 5 more removed from the shoulder 
tapers slightly inwardly whilst being of circular cross-section, and a 
third section 6 defines and end to the outlet and is of conical shape. 
A cap 7 of complementary shape to the outlet fits over the latter and is 
formed such that the adjacent surfaces of the outlet and cap are 
substantially in contact throughout their area. Since the conical end 
portions serve to centre the cap on the outlet, it is not essential that 
the slightly tapered section 4 and cylindrical end portion 3 be tightly in 
contact with the adjacent cap surfaces and a small space can, in fact, be 
provided. The conical portions 8 and 6 of the cap and outlet respectively 
are each provided with apertures 9 and 10 respectively in the walls of the 
conical portions. The cone angle is selected so that an aperture of 
reasonable diameter can be provided relative to the diameter of the 
tubular outlet. These two diameters can, in many instances, be of 
comparable size. A preferred cone angle is thus about 80.degree.. 
In order to facilitate injection moulding from plastics material, the lower 
region 11 of each aperture has its edge substantially parallel to the axis 
of the outlet to allow for withdrawal of a male mould member from the 
moulded article located in a female mould member. At least in the case of 
the cap this provides an aperture which increases in diameter from the 
outer surface to the inner surface thereof, thereby providing an inclined 
edge to the aperture. In use, this inclined edge has the effect of wiping 
material back into the outlet during closure of the cap. 
The apertures and adjacent inner surface of the conical portion 6 of the 
outlet are shaped substantially smoothly to provide an outlet passage 
which will not interfere to any appreciable extent with the dispensing of, 
for example, toothpastes having stripes of mouthwash or the like therein. 
The portion 4 of the outlet of constant circular cross-section has on the 
outer surface thereof a pair of diametrically outwardly extending 
formations 12 which extend into grooves 13 defining cam surfaces in the 
inner surface of the cap. It will be understood that the operative cam 
surface is provided by the lower sidewall 14 of the groove since the 
sidewall co-operates with the formations 12. 
There are two identical grooves 13 as shown clearly in FIG. 2 and each is 
adapted to co-operate with its associated formation in an identical 
manner. The grooves provide for approximately 170.degree. of rotation of 
the cap relative to the outlet and the ends 15 of the grooves define stops 
limiting further rotation of the cap. The grooves extend circumferentially 
for approximately a 90.degree. angle which corresponds to the various 
degrees of correspondence of the apertures in the cap and outlet. The 
grooves then become somewhat upwardly inclined and again downwardly 
inclined in the axial direction relative to the apertures to terminated in 
end portions 16 of the grooves. The end portions correspond to the locked 
closed position. The end portions are further located so that they are 
axially displaced from the major portion of the length of the grooves in a 
manner ensuring that a slight axial movement of the cap into tighter 
engagement with the outlet is promoted when cap is rotated to a locked 
position. This axial movement may be very small and, in fact, it is 
envisaged that with fairly accurately moulded components, an axial 
movement of approximately 0.1 to 0.2 mm is all that will be required. The 
inclined portions provide a raised region 17 of the groove which ensures 
that the cap cannot rotate out of the locked closed position without 
overriding this raised portion. The latter structure provides what is 
commonly termed a "click" stop in the closed portion of the cap. 
It will be understood that rotation of the cap between a closed and open 
position can easily be effected using the thumb of a hand used to hold an 
article carrying such a closure. To this end the cap may be provided with 
any type of formation or friction affording surface to ensure that this 
can be effected easily. 
A slightly modified form of the invention is illustrated in FIGS. 5 to 7. 
In this instance the tubular outlet 18 is of substantially constant 
diameter up to the position where it joins up with the conical portion 19. 
The cap 20 is dimensioned to be a fractionally loose fit on the outlet and 
has a conical outer surface 21 to provide a thickened region in the wall 
remote from the conical portion 22 of the cap. 
The outlet in this case has a single outwardly directed formation 23 in the 
form of a flange extending circumferentially around the outer in an arc of 
about 60.degree. to 80.degree.. This single formation co-operates with an 
annular cam surface 24 directed towards the conical end portions and 
defining one wall to a groove 25 in the inner surface of the cap towards 
its lower end. The groove extends around substantially the entire 
circumference of the cap but for a short portion 26 which defines a stop 
to prevent the cap from being rotated by more than about 275.degree.. 
The cam surface has a single raised portion 27 joining a large portion 28 
of the cam surface and a smaller portion 29 thereof. The smaller portion 
29 is, as above described, in respect of each half of the groove 13, 
somewhat nearer the conical end portion than the larger portion 28. This 
provides the slight clamping action of the cap upon closure thereof and 
will not be further described. 
The cam surface 24 in this case could be provided on a separate ring which 
fits into the cap to provide a join as indicated by dotted lines 30 in 
FIG. 5. These two parts would be bonded together at this join upon 
assembly of the closure. The purpose of making such a separate ring would 
only be to avoid the use of a collapsible female die for forming the 
groove in the interior of the cap. 
In use the closure assembly just described will function in the same way as 
that described with reference to FIGS. 1 to 4. 
As mentioned above the outlet will generally be integral with at least a 
shoulder portion of a container but it may equally well be integral with a 
lid for a container other than a tube. Also the outlet could be formed 
with a socket at its open end so that it can be installed on an existing 
screw threaded spigot associated with a dispensing tube for example. 
In addition, as shown in FIG. 8, the outlet may be provided with a screw 
threaded spigot 31 to enable it to be installed in a socket or screw 
threaded hole in a pipeline as a bleeder valve for gasses contained in 
liquid streams for example. In such application it will be appreciated 
that the closure may be made of metal for high pressure used and in such a 
case an O-ring may be installed around the aperture in the outlet so that 
the cap seals on to the O-ring in the closed position. Alternatively, an 
insert made of a suitable material for providing a seal may be included 
around the aperture. Suitable materials are, for example, plastics or 
elastomeric materials such as polypropylene, polytetrafluoroethylene or 
polyurethane. 
In the embodiment of the invention illustrated in FIGS. 9 to 11 and 13 the 
closure assembly is adapted to be screwed onto an existing externally 
screw threaded outlet to a container such as a toothpaste tube or other 
container for liquid materials or pastes. However, it will be understood 
that the outlet could equally well be manufactured as an integral portion 
of such a container as clearly described in application Ser. No. 843,045 
filed Oct. 17, 1977, now abandoned. 
In this embodiment the outlet member has a tubular portion 101 of constant 
diameter and having at its outermost end a truncated conical portion 102 
having in this case a cone angle of approximately 70.degree.. The tubular 
portion 101 has an integral screw-thead 103 adapted to be secured onto a 
toothpaste or like tube having a complimentarily screw-threaded spigot 
(not shown). Thus, in this particular instance the internal diameter of 
the tubular portion of the outlet is about 10.7 mm. This diameter enables 
an aperture 104 to be formed in the conical end portion wherein the 
aperture has a diameter of about 6.25 mm. 
A co-operating cap 105 has a tubular portion 106 fitting over the tubular 
portion 101 of the outlet and a complimentary conical end portion 107 
co-operating with the conical end portion 102 of the outlet. However, the 
conical portion 107 of the cap is arranged to provide a small space 108 
between the end face of the outlet and the inner adjacent face of the cap 
thereby allowing for the axial movement of the cap into tighter engagement 
with the conical surface of the outlet when the cap is rotated into a 
position in which the outlet assembly is locked in a closed position. 
The tubular portion 106 of the cap is also of truncated conical shape but 
in this case the cone angle is only about 11.degree. in the preferred 
form. Thus the outer surface of the tubular portion of the outlet diverges 
from the inner surface of the tubular portion of the cap in a direction 
away from the conical portions thereof. 
The tubular portion of the outlet is provided with an outwardly extending 
flange 109 at its end remote from the conical portion and the flange 109 
carries a pair of oppositely directed, outwardly extending lugs 110, which 
co-operate with a groove 111 in the inner surface of the cap. The side 
wall 112 of the groove nearer the conical portion of the cap is simply an 
annular wall formed in one plane. However the side wall 113 of the groove 
most remote from the conical portion is formed to define cam surfaces. 
This side wall has a portion 114 defining the co-operating wall for the 
lugs 110 corresponding to various degrees of coincidence of an aperture 
115 in the cap (which is of the same diameter as the aperture 104 in the 
outlet) and the aperture 104 in the outlet member. Adjoining this section 
114 of the side wall of the groove is a raised nib 120 which communicates 
with a raised section 116 of the cam surface. The latter section 116 of 
the cam surface is adapted to co-operate with the lugs when the apertures 
in the cap and outlet are in non-coincidence with each other and thus 
corresponds to a closed and locked condition of the cap wherein the cap is 
urged more tightly onto the outlet. 
At the end of the section 116 of the wall 113 defining the cam surface is a 
raised stop member 117 which ensures that the width of the groove in this 
region is somewhat less than the thickness of the lugs 110. This narrowed 
zone of the groove communicates directly with a channel 118 formed in the 
inner surface of the cap to extend to its end remote from the conical 
portion in a generally axial direction. It will be understood that the 
above described cam surface and channel arrangement is duplicated so that 
the various sections thereof have diametrically opposed counter-parts on 
the opposite side of the cap. Also at the end of each section 114 of the 
wall of the groove remote from the associated nib 120 is an end stop 
member 119 past which the lugs cannot, in use, proceed. 
The stop member formation in the wall of the groove defining the cam 
surfaces is preferably pointed as shown in FIG. 11 so that a lug 
introduced up the channel 118 can be forced past the stop formation 117 
and into the groove proper. The stop formation thus acts in the manner of 
a catch. It will thus be appreciated that the dimensions of the channel 
118 are chosen such that they comfortably receive the lugs 110 on the 
outlet member and thus assembly of the closure assembly is greatly 
facilitated since the cap can be introduced axially onto the outlet member 
with the lugs located in the channels and then the cap can simply be 
rotated to locate the lugs in the grooves having cam surfaces associated 
therewith. Also by correctly proportioning the depth of the groove and of 
course the corresponding dimensions of the lugs, the cap portion can be 
injection moulded in a simple male and female type of injection die 
assembly and, whilst the material is still fairly plastic the cap can be 
forced off the male die. Thus a collapsible die assembly may be avoided 
with its attendant high cost. 
In use the closure will, for the purposes of transport, storage and 
vending, be in a condition in which the lugs 110 co-operate with the 
raised portions 116 of the cam surface to hold the cap tightly onto the 
outlet. In this condition accidental rotation of the cap is substantially 
prevented as the lugs have to snap past the nibs 120 in order to align the 
apertures 104 and 115. Accidental rotation of the cap in the opposite 
direction is even more difficult to achieve as the lugs must pass the 
stops 117. 
When desired, the cap can be rotated such that the lugs ride over the nibs 
120 to a position in which they co-operate with the section 114 of the 
side wall 113 defining the cam surface. This section is sufficiently long 
to enable the cap to be rotated between a fully closed and a fully open 
position in which the apertures are aligned. With the lugs co-operating 
with this section of the cam surface the axial force urging the two 
conical end portions together has been released and the cap can easily be 
rotated, usually by means of a thumb only, between the open and closed 
positions without axial movement of the cap relative to the outlet. For 
travelling purposes the cap can again be rotated such that the lugs pass 
the nibs 120 and co-operate with the raised portions 116 of the cam 
surface in which position the cap is urged axially onto the outlet member. 
FIG. 12 illustrates an alternative outlet member 121 which, instead of the 
screw threads therein, has one or more circumferentially extending groove 
122 in its inner surface towards the end remote from the conical end 
portion thereof. These grooves are arranged to co-operate with 
complementary riges 123 on the outer surface of a spigot end 124 to a 
container 125. 
It will understood that certain restrictions as to the maximum permissible 
angular rotation of the cap, once installed, relative to the outlet. As a 
consequence, the size of aperture relative to the overall size of the cap 
and outlet is also limited. In cases where this limitation is restrictive 
for the desired purpose the embodiment of the invention illustrated in 
FIG. 14 of the accompanying drawings can be used. 
In the case of the embodiment of FIG. 6, only one lug 126 is provided on 
the flange 127 carried by the outlet member 128. The circumferential 
length of the lug can be greater than that of the two lug arrangements 
described above and yet provide for substantially greater relative 
rotation of the cap and outlet. In this case only one channel 129 is 
provided, one stop 130 adjacent the raised portion 131 of the cam surface, 
and one nib 132 between the latter and the remainder 133 of the cam 
surface with which the single lug co-operates for normal rotation between 
open and closed conditions. 
It will be clear that whilst the closure assemblies described above are all 
intended to be moulded from plastics material, metal closures of this type 
could be desirable for many applications and in particular for the purpose 
of bleeding liquids or gases from liquid systems such as bleeding air from 
vehicle hydraulic brake systems. 
For the above-mentioned application, to metal closure assemblies, it has 
been found convenient to provide an insert 134 (see FIG. 15) wherein the 
insert has a tubular part 135 extending out of the aperture 136 in the cap 
itself and has a flange 137 located inside the cap and between the inner 
surface of the cap and the outer surface of the co-operating conical 
portion 138 of the outlet member. This insert is preferably made of a 
deformable or elastomeric material such as a suitable plastics material 
such as those mentioned above and being somewhat compressible and of a 
material providing a good seal allows for the axial urging of the conical 
portions together to create an effective seal in the locked position. It 
will be understood that the flange region 137 of the insert actually 
defines the seal. 
Also in the case of a metal cap it will not be possible to provide the 
restricted zone at the position where the cam surface communicates with 
the channel where such is provided. In such a case, as illustrated in FIG. 
16, a leaf spring 139 could be provided at the inner end of the channel 
140 so that its free end obstructs the entrance to the groove 141 defining 
the cam surface 142. In order to introduce a lug located on a suitable 
outlet member (not shown) the lug could simply be forced against the leaf 
spring to deflect it sufficiently away from the entrance to the groove 141 
so that the lug can pass into this groove. Once in the groove the spring 
deflects back to its relaxed condition in which it obstructs the entrance 
to the groove 141 and thereby prevents removal of a lug simply by rotating 
the cap relative thereto. It will be understood that other catch 
arrangements could equally well be provided and these could embody helical 
springs or any other resilient member performing the general function just 
described. 
It will be understood that many variations may be made to the above 
described embodiments of the invention without departing from the scope 
hereof. In particular the lugs or equivalent formations may be provided on 
the cap and the cam surface and channels on the outlet member. Also, it 
will be noted that the outlet member could easily be formed integral with 
certain types of containers.