[0001] This invention relates to a material applicator and rod, more especially to an applicator
and rod for a cosmetics material, for example, mascara or hair dye, and to an assembly
comprising the applicator.
[0002] The assembly comprising the applicator normally comprises a container for the cosmetic,
a closure cap attached by the rod to the applicator and located within the container
a wiper plug or stripper having an orifice which, as the rod and applicator are withdrawn
from the container, wipes the cosmetic from the rod and removes excess material from
the applicator, leaving a desired quantity of material on the applicator.
[0003] Different designs of wiper have been proposed to try to ensure that the amount and
distribution of material over the applicator are as required to give the desired effect
on application. See for example, GB-A-2 097 662, GB-A-2312617 and EP-A-900 534. The
wiper is required to remove material from the rod and excess material from the edge
of the applicator and also desirably to remove any drop or thread of material from
the free end of the applicator. The wiper may also control the quantity of material
within the applicator when, for example, as is frequently the case with a mascara
applicator, the applicator is a brush in which the mascara lies on, between and sometimes
within the fibres of the bristles. Those wipers may comprise resilient fingers of
a plastics or rubber material which extend inward from the material defining the orifice
of the wiper. As the rod and applicator are withdrawn from the container the orifice
of the wiper and/or the fingers, usually both, wipe material from the rod and then
the applicator and finally the fingers close in and remove the drop or thread of material
that is present at the end of the applicator.
[0004] While the wiper devices used are at least partially effective, they are still less
than satisfactory. One problem they have is that they do not consistently remove the
drop or thread of material from the free end of the applicator. A second problem that
they have is that they tend to lose effectiveness over time and/or as a result of
use. For example, where a wiper is of the type having resilient fingers, the relaxed
diameter of the material defining the orifice is itself designed to be slightly less
than the diameter of the rod, and the fingers extend inward from there. When the assembly
is in its closed storage position, the material of the fingers is substantially deformed
from its equilibrium configuration by the rod. The fingers have a tendency to set
in the deformed position. In International Application WO 95/26147 it is proposed
to alleviate this by providing the rod with an annular groove in the location contacted
by the fingers. It has nonetheless been found that following prolonged storage the
fingers do not close sufficiently onto the applicator as it is withdrawn through the
wiper.
[0005] This tendency of the fingers to set in the deformed position (or, using other terminology,
to lose their memory) is a significant disadvantage in that it restricts the shelf-life
of the product and may inconvenience an infrequent user of a particular applicator
unit.
[0006] Shorter fingers, as described in EP-A-900534, do appear to provide improved effectiveness
over a longer period. They do not, however, eliminate the problem.
[0007] In DE-A-19744181 an applicator assembly is described which includes an applicator
rod having a groove, in which the fingers of a wiper device, formed from a rubber
type material, rest when the assembly is closed. The groove or stepped portion is
formed by a narrowing of the rod via a sloping face to a straight sided narrow portion
and then a broadening via a sloping face to its original width. In the closed position
the rubber fingers rest with their tips in the groove. As the applicator rod is drawn
through the wiper, the rubber fingers move against the broadening sloping side and
their tips are turned inwards. The turned in tips of the fingers exert a greater wiping
force on the rod and applicator. The assembly does, however, have the disadvantage
that the turning in of the fingers may cause the material of the wiper to split as
the rod is drawn through. A wiper made of a natural or synthetic rubber material may
withstand the extra tension caused but the wiper fails if made from a thermoplastics
type material.
[0008] In a first aspect, the present invention provides an applicator and rod suitable
for use in an applicator assembly for applying a viscous material, the assembly comprising
the applicator, the rod and a container, a closure means and a wiper device located
within the container through which, in use, the rod and applicator may be drawn, the
rod and the applicator each having a proximal end and a distal end, the distal end
of the rod carrying the applicator by the latter's proximal end, and wherein (a) the
rod has a constriction, the cross-sectional area of the rod between the part of the
constriction having the smallest cross-sectional area and the distal end being less
than that of the rod the proximal side of the constriction and the cross-sectional
area of that part of the rod forming the distal side of the constriction being greater
than the smallest cross-sectional area of the constriction or (b) the distal end of
the rod tapers toward the applicator, there being positioned on the proximal end of
the applicator a stop member, the cross-sectional area of the stop member being less
than that of the rod on the proximal side of the tapered part but greater than the
smallest cross-sectional area of the tapered part of the rod and, if there is any
part of the applicator between the distal end of the rod and the stop member, greater
than that part or (c) the proximal end of the rod has a greater cross-section than
that of its distal end, the rod tapering from its greater cross-section to its lesser
cross-section at a region of the rod closer to the proximal end than to the distal
end, there being positioned on the proximal end of the applicator a stop member, the
cross-sectional area of the stop member being less than that of the rod at the proximal
end but greater than that of the rod on the distal side of the taper and, if there
is any part of the applicator between the distal end of the rod and the stop member,
greater than that part.
[0009] In a second aspect the invention provides a material applicator assembly comprising
an applicator and rod according to the first aspect of the invention.
[0010] In a third aspect the invention provides a material applicator assembly comprising
a container for a viscous material, a closure member, an applicator and rod according
to the first aspect of the invention, the applicator being attached to the closure
member by the rod, and, located within the container, a wiper device comprising a
plurality of resilient fingers, advantageously positioned about the rod.
[0011] Advantageously, in embodiment (c) of the first aspect, the part of the rod with the
taper is enclosed by the fingers of the wiper when the container is closed by the
closure member.
[0012] The invention provides in a fourth aspect the use in a material applicator assembly
comprising a wiper device comprising a plurality of resilient fingers and a rod carrying
an applicator, of (a) a constriction in the rod to cause the resilient fingers of
the wiper device to turn inward toward the rod as the rod is drawn through the wiper
device and a cross-sectional area of the rod between the part of the constriction
having the smallest cross-sectional area and the applicator of less than that of the
rod before the constriction to inhibit or reduce failure of the material of the wiper
device or of (b) tapering the rod carrying the applicator in the direction of the
applicator and a stop member positioned on the proximal end of the applicator to cause
the resilient fingers of the wiper device to turn inward toward the rod as the rod
and applicator are drawn through the wiper device, the cross-sectional area of the
stop member being less than that of the rod before the taper, to inhibit or reduce
failure of the material of the wiper device.
[0013] The proximal end of the rod will normally be suitable for attachment to the closure
device. Attachment may be by any suitable means, for example, by use of adhesives,
or the rod and closure device may be integral.
[0014] The wiper device has an orifice which, as the rod and applicator are drawn through
wipes the rod of excess material and also removes excess material from the applicator.
As discussed above there are many different designs of wiper. The wiper usually comprises
a resilient portion with an orifice that is a close fit around the rod. The material
which defines the orifice acts as the wiping surface. The wiper may also comprise
a plurality of resilient members or fingers extending inward from the material defining
the orifice, on pillars which extend substantially parallel with the axis of the orifice
or, preferably, directly from the orifice. A part of each finger then provides a wiping
surface. This is usually in addition to the wiping surface provided by the material
defining the orifice. It is wipers with resilient fingers that are used with the rod
and applicator of the invention.
[0015] In the closed position, the applicator and applicator rod extend within the container
from the closure cap. The wiper is in position about the applicator rod. Where the
wiper comprises resilient fingers, in use, as the applicator rod is withdrawn from
the container the wiping surfaces of the orifice and of the fingers bear resiliently
against the rod and remove the viscous material from the rod until the fingers approach
the constriction or the tapered end of the rod. As the rod is drawn past the fingers
they are allowed by the narrowing of the constriction or the tapering to move towards
their equilibrium position, i.e., the position they take up when not deformed by the
rod, and then as the distal side of the constriction, where the cross-sectional area
of the rod increases after the narrowest part of the constriction, is drawn through
or as the stop member is drawn through the ends of the fingers are caused to turn
inward toward the rod thus being forced more tightly into contact with the applicator
rod or stop member than they otherwise would be. A different part of the finger now
becomes the wiping surface.
[0016] The ends of the fingers are turned inward to an extent that they are turned back
on themselves. As any remaining portion of the rod is drawn through and then as the
applicator is drawn through the wiper the fingers remain turned inward and remove
excess material from the applicator. When the end of the applicator is reached the
fingers "flip" or "snap" back to their rest or equilibrium position. As this occurs
the drop or thread of material at the tip of the applicator is removed.
[0017] The construction of the rod and applicator of the present invention at least partially
alleviates the problem of material failure associated with that disclosed in DE-A-19744181.
The portion of the rod or the stop member that must be wiped after the wiper parts
have been turned in is narrower than the widest part of the rod and so there is less
tension in the wiper material as the rod or stop member passes through the device.
Accordingly, there is a much lower risk of material failure, for example, splitting,
especially where the wiper device is formed from a thermoplastic material or a blend
comprising a thermoplastic material.
[0018] When the rod has construction (a), the constriction comprises a narrowing of the
applicator rod and then, toward the distal end of the rod, a widening of the rod out
to give a portion with a cross-sectional area which is still less than the cross-sectional
area of the rod before the narrowing. Between the narrowing section and the widening
section there may be a narrow section of substantially constant cross-sectional area.
The cross-sectional area of the rod from the narrowing of the constriction to the
point at which it is joined to the applicator is less than that of the cross-sectional
area of the rod before the constriction and preferably less than the cross-sectional
area of the 360( orifice, in its equilibrium state, of the wiper with which it is
to be used. If the rod were to be of greater cross-sectional area after the constriction
then the stress exerted on the wiper once the fingers have been turned inward would
be high and in many cases would cause it to fail, for example, by splitting.
[0019] When the rod has construction (b) or (c), the tapering of the rod performs the function
of the narrowing of the constriction of the rod of construction (a) and the stop member
performs the function of the distal side of the constriction, the broadening of the
rod.
[0020] The stop member is positioned, more especially supported, on the proximal end of
the applicator. It may be fixed firmly in place or may be loosely supported. The stop
member may be a separate body supported on the applicator or it may be integral with
the applicator or the rod, i.e., formed as part of the applicator or rod.
[0021] The narrowing or tapering of the rod may be rapid or more gradual. Preferably, the
rod narrows down relatively gradually to allow the fingers to relax back towards their
equilibrium position before they impinge on the shoulder as described below. For example,
narrowing from a diameter in the range of from 2.5 to 5 mm to a diameter in the range
of from 1.5 to 3 mm over a length of from 0.5 to 4.0 mm could be used.
[0022] For a rod of construction (a), the constriction comprises a narrowing of the rod
and then a widening to form a shoulder or collar. For a rod of construction (b) or
(c) the shoulder is provided by the stop member. As the rod is drawn through the wiper
the fingers impinge on the shoulder and are forced inwards so that they are drawn
backwards as the rod continues to be pulled through the wiper. The shoulder need not
be exactly perpendicular to the axis of the rod but must be of steep enough incline
to cause the required turning of the wiper parts. The acute angle, shown as θ in Figures
1 and 11, subtended between the line of the shoulder and the axis of the rod is preferably
greater than 70°, more preferably greater than 80° and most preferably approximately
90°, that is the shoulder is approximately perpendicular to the axis of the rod. The
angle may differ for use with different wipers. For example, if the material of the
wiper is formed from a thermoplastic then the angle θ may need to be greater than
if the wiper is formed from a rubber type material.
[0023] The shoulder or collar may be provided by any suitable shaping of the rod or stop
member. For example, the constriction may comprise a narrowing of the rod followed
by a small hemispherical portion or the stop member may be a small solid hemisphere.
In either case, the flat circular face forms the shoulder and the cross-sectional
area of the circular face is less than that of the rod before the constriction or
tapering. In an alternative embodiment, the shoulder may be formed by the larger circular
face of a frustum of a cone or of a solid cup shape (a frustum of a cone but with
a bulbous curved surface rather than a truly conical surface)
[0024] The constriction may be situated at any position on the rod between the rest position
of the wiper device's fingers, i.e., the position where the fingers contact the rod
when the applicator assembly comprising the rod is in the closed position, and the
distal end of the rod. Preferably the constriction is further towards the distal end
of the rod than the rest position and most preferably the constriction is near or
at the distal end of the rod.
[0025] The above applies equally to the embodiments in which a stop is provided; accordingly
in embodiment (c), in which the main part of the length of the rod is of narrower
cross-section, that part of the rod will not be so completely cleaned as in embodiment
(a) or (b); this configuration is, however, simpler to construct.
[0026] If the constriction is too far from the distal end of the rod then the wiping of
the rod thereafter may not be clean. When the wiper comprises fingers attached directly
to the orifice of the wiper then as the fingers are turned inward and back on themselves
they may come between the wiping surface of the orifice and the rod so that the wiping
surface of the orifice is no longer in direct contact with the rod. Hence from that
point on wiping of the rod only occurs in those places where the fingers touch the
rod and so some parts will not be wiped. Hence, in such a case it is extremely advantageous
for the constriction, i.e., the narrowing of the rod and the shoulder or collar, to
be close to, or at, the distal end of the rod.
[0027] The cross-sectional area of the shoulder and the remaining part of the rod or of
the stop member is governed by two requirements. The first is that it be large enough
for the fingers to impinge upon even if the material of which they are made has lost
some memory and they do not relax back to the full extent allowed by the narrowing
of the constriction or the tapering of the rod. The second is that the fingers must
be allowed to turn back on themselves without causing significant enlargement of the
orifice of the wiper as such enlargement could lead to splitting of the material of
the wiper.
[0028] For the avoidance of doubt, the cross-sectional area of the rod or stop member that
is to be considered is the area of the cross-section at the relevant part perpendicular
to the long axis of the rod (that axis is shown in Figures 1 and 11 by a broken line).
[0029] If the cross section of the rod, the wiper orifice and the shoulder are circular,
as they typically will be, then the diameter of the shoulder is preferably approximately
the diameter of the wiper orifice minus twice the thickness of one of the resilient
fingers. Typically the diameter of the shoulder will be at least 0.6 to 1.0 mm less
than that of the wiper orifice.
[0030] There are two sizes of rods commonly used in cosmetics applicator assemblies. The
rods are of circular cross section with a diameter of 4.3 mm or 3.5 mm. The resilient
fingers of a thermoplastic wiper may typically be of maximum thickness of 0.4 to 0.5
mm tapering down to about 0.25 mm at the tips. For use with a 4.3 mm diameter rod
the wiper has a circular orifice of diameter 4.2 mm hence the shoulder should preferably
have a circular cross-sectional area with a diameter of about 3.2 to 3.4 mm, especially
3.3 mm. If a 3.5 mm rod is used then the wiper has a 3.4 mm diameter orifice and the
shoulder should have a diameter of about 2.6 mm.
[0031] The narrowest part of the constriction or of the tapered rod must obviously be of
a lesser diameter than that of the shoulder and is preferably substantially narrower,
for example, it may have a circular cross-section with a diameter of from 1.5 to 3
mm.
[0032] In one version of embodiment (c) the wider and narrower portion of the rod may advantageously
have diameters of 4.8 and 3.0 mm respectively, while the stop has a diameter of 4.0
mm.
[0033] The rod according to the invention may comprise a groove at the rest position of
the wiper fingers, as described in WO95/26147, to reduce the deformation of the wiper
during storage. If desired the groove and the constriction can be combined as one
and the same but this is not preferred.
[0034] The rod may be formed from any suitable material, for example, it may be formed of
a thermoplastic material.
[0035] The applicator will preferably be a brush, especially a brush consisting of a helix
of bristles around a core or support, often formed from a twisted steel wire, but
may be of a different type, for example, a foam applicator. When the brush is on a
support, the cross-section of the support is advantageously less, and preferably considerably
less, than that of the distal end of the rod in embodiment (a) and of the stop in
embodiments (b) and (c). The cross-section is advantageously substantially uniform,
subject of course to the irregularities inherent in a twisted wire support. The diameter
of the orifice of the wiper device is generally smaller than the maximum diameter
of the applicator. If the applicator is a brush then the diameter is measured from
the tips of the bristles.
[0036] The wiper device may be formed of a thermoplastic, elastomeric, or thermoplastic
elastomeric material, for example, a synthetic or natural rubber, a polyurethane,
an olefinic homo- or co-polymer, e.g., polyethylene, especially low density polyethylene,
or an ethylene-unsaturated ester copolymer, for example, an ethylene-vinyl acetate
copolymer. The device may be formed of a laminate or blend of two or more such materials.
If a thermoplastic material is used then it may include a cross-linking agent. Preferably,
the wiper device is formed of a thermoplastic material or of a blend comprising a
thermoplastic material. Wiper devices formed from thermoplastics materials or blends
comprising a substantial proportion of thermoplastics materials have advantages, for
example, relatively low cost compared with rubber materials. They do, however, have
disadvantages, such as loss of resilience and the possibility of material failure
as discussed above. The applicator and rod of the present invention are especially
advantageous when used with a wiper device formed from thermoplastic material or a
blend comprising thermoplastic material as those problems are at least partially alleviated.
Preferred materials are 100% low density polyethylene and 100% thermoplastic elastomeric
material (TPE), for example, a thermoplastic elastomeric material having a shore hardness
in the range of from D40 to D60. Thermoplastic elastomeric materials are more resilient
than materials such as polyethylene.
[0037] A preferred wiper device suitable for use with the rod and applicator of the invention
and in the cosmetics applicator assembly of the invention comprises an elongate hollow
resilient body having a substantially circular orifice, and positioned around and
extending directly from the periphery of the orifice a plurality of elongate resilient
members (the resilient fingers), each having a free, distal, end portion, each member
extending inward toward the axis of the orifice and away from the body, each member
being at an angle within the range of from 90° to 120° to the axis and tapering toward
the distal end, the members being radially spaced apart at least at their distal ends,
and preferably occupying at most 55%, most preferably 50%, of the area of the orifice
as viewed axially. More especially, the wiper is one having four elongate resilient
members, at an angle of at least about 100° to the axis, the distance between a pair
of opposed distal ends being at most 10% of the diameter of the orifice. Wiper devices
of that type are described in EP-A-900 534. It will be appreciated that when the rod
is of narrow diameter, for example 3.5 mm, engineering considerations may not allow
such a close approach, the minimum practical spacing being about 0.4 mm. Accordingly
this spacing may then represent up to 15 or 20% of the orifice diameter.
[0038] It will be appreciated that the orientation of the members defined above is that
adopted when the wiper device is in its relaxed or equilibrium configuration, i.e.,
in the absence of deformation by, for example, the rod of a cosmetics material applicator.
When the wiper is in position about a rod not having a groove at the rest position,
the members will extend along the rod, bearing resiliently against it.
[0039] In operation, accordingly, as the applicator rod is withdrawn from a container in
which such a wiper is fitted, with the end of the wiper carrying the members facing
away from the container opening, the edge or face of the wiper orifice will remove
viscous material from the rod and control the quantity of material remaining on the
applicator, the elongate members bearing resiliently against the rod as it passes
by until the constriction or stop member is reached, whereupon the ends of the elongate
members are turned back on themselves to an inward position. When the applicator begins
to pass the members the ends remain turned inward and the members may also be drawn
backward into the brush by the action of the fibres. As the free end of the applicator
passes, the members spring out, removing at least part of the drop of material from
the end of the applicator.
[0040] It will be appreciated that where the applicator is a brush the elongate members
will recover toward their equilibrium configuration by intermingling with the brush
fibres to a greater or lesser extent as the brush passes them, the extent depending
on the flexibility of the members and the nature of the brush, which advantageously
is one having radially extending bristles.
[0041] To achieve the desired wiping effect the tips of the resilient fingers of the wiper
should penetrate into the brush as far as possible. Their tips should be as close
to the central core of the brush, usually a twisted wire, as possible. Fingers that
are turned inward as they meet the brush, as in the present case, penetrate the brush
better and get closer to the wire than wiper fingers that have not been turned back
on themselves. As the brush is drawn through the wiper the bristles do not usually
exert enough pressure on the fingers to keep them turned completely turned back on
themselves so the ends do unfold. There is sufficient pressure, however to stop the
fingers from returning to their equilibrium positions. They are generally allowed
to unfold until the fingers are approximately perpendicular to the core of the brush.
The force exerted by the passing bristles is then sufficient to maintain them in that
position and it is that position that achieves the desired wiping of the brush.
[0042] A typical twisted wire brush for use with mascara or similar viscous cosmetic material
has from 40 to 400, more usually 170 to 300, bristles or fibres per cm, with bristles
or fibre thickness being in the range 0.06 to 0.25 mm, the number of twists in the
wire typically being from 4 to 7 per cm. (The fibre count is half the number of bristle
ends.)
[0043] It has been found that optimum interaction between the fibres and the wiper, ensuring
that the wiper fingers are turned inward as they meet the brush, is achieved when
the fibre count is toward the lower end of the typical range while the fibre thickness
and hence stiffness is toward the upper end of the typical range. Preferably, the
brush has from 160 to 200 fibres per cm, the fibres being of diameter in the range
0.125 to 0.2 mm. The relatively low fibre count, in combination with a relatively
stiff fibre, allows easy combing of the brush through eyelashes.
[0044] In another preferred embodiment, the fibres for the first 3 to 6 mm length of brush
at the proximal end, i.e., the end first encountered by the wiper, are about 0.25
mm diameter, while the remainder of the brush, typically 20 to 25 mm in length, beyond
the first two to four twists, uses more flexible fibres, for example of about half
that, e.g., about 0.125 mm, to allow easy combing in use. More preferably, the fibre
density is from 160 to 200 per cm.
[0045] Using a preferred brush as described above, the resilient fingers of the wiper are
reliably turned inward even if there has been some set during storage, despite the
provision of a groove in the rod. Brush manufacturing equipment may be adjusted as
required to pick up the desired density of fibres from the supply. The number of fibres
per unit length may be varied by adjusting, for example, the spacing of the transfer
means, usually teeth. For the embodiment where there are fibres of two different thicknesses
the number of fibres in the strand or rope feed may be varied.
[0046] In all cases, whatever stiffness and density of bristles are used, the ends of the
resilient fingers will tend to return toward their equilibrium configurations as the
applicator end approaches, and will "flick" or snap back as this stage of withdrawal,
assisting in removing the final drop from the applicator. Providing the applicator
with a tapered free end will usually make drop removal even more effective.
[0047] Advantageously, the wiper device is preferably provided with from three to five,
preferably four, fingers. The spacing between the fingers or members advantageously
increases from their proximal to distal ends, i.e., the free end of each member will
subtend a smaller angle viewed along the axis of the orifice than does the proximal
end, and if desired the extremities of the proximal ends of the members may merge
to be in contact. Advantageously, however, the proximal ends are spaced apart, and
may occupy at most 55%, more especially 50%, of the circumferential length of the
orifice. Advantageously, the distal ends of the members taper, i.e., are roughly triangular.
The wider proximal portions provide an enhanced resistance to deformation set or twist
while the tapering distal end portions are flexible so as to allow them to be turned
inward and to enhance removal from the free end of the applicator (which is normally
tapered) of any adherent blob of material as it is withdrawn past them but do not
remove significant quantities of the material from the length of the applicator, for
example, from the bristles if the applicator is a brush, as it is withdrawn.
[0048] Advantageously, when the wiper is viewed along the axis in its relaxed configuration,
the fingers or elongate members occupy at most 55%, preferably, 50%, more preferably
from 40 to 50% and, most preferably about 45%, of the area of the wiper orifice. Also,
advantageously, the distance between a pair of opposed distal ends is at most 25%
of the diameter of the orifice, preferably at most 20%, and more preferably at most
10%. In principle, the distal ends of the members may be in contact but such a construction
is not readily achieved by the presently preferred manufacturing process.
[0049] However, advantageously the lengths of the wiper members, relative to the size of
the wiper orifice, and their rest angle are such that as they spring out they touch,
maximizing the proportion of the drop that is removed. Such a result is achieved,
for example, with an angle of from 100° to 120° and a separation in the rest position
of less than 10%.
[0050] Referring again to the fingers or elongate members in their relaxed configuration,
each advantageously comprises a proximal portion that tapers toward the distal end
either as seen along the axis of the aperture, or as seen transverse to the axis,
or, preferably, as seen in both such directions. Advantageously, the proximal portion
of the member itself is of rectangular cross-section. The distal portion of each member
advantageously tapers toward the distal end as seen along the axis of the aperture,
or as seen transverse to the axis or, preferably, as seen in both such directions.
Advantageously, the distal portion of the member is of rectangular cross-section,
except for the distal end itself, which is advantageously triangular, as will be described
in more detail with reference to the drawings. The member advantageously tapers regularly
from one end to the other. Each member is advantageously generally straight in its
undeformed configuration.
[0051] A wiper device also suitable for use with the present invention may comprise a resilient
body having a substantially circular orifice, and spaced apart around the periphery
of the orifice a plurality of elongate resilient members (the fingers), each having
an end portion proximal to the body and a free, distal end portion, the proximal end
portion extending from the body in a direction having at least a substantial component
parallel to the axis of the circular orifice, the free distal end portions of the
members extending inward toward the axis and the distal ends being at or close to
the axis. Such wiper devices are described in GB-A-2312617.
[0052] In a preferred embodiment, the applicator assembly is suitable for use for applying
a viscous material, the assembly comprising a container for the viscous material,
a closure member, an applicator and rod, and a wiper device located within the container
through which, in use, the rod and applicator may be drawn, the wiper device comprising
an elongate hollow resilient body having a substantially circular orifice, and positioned
around and extending directly from the periphery of the orifice a plurality of elongate
resilient members, each having a free, distal, end portion, each member extending
inward toward the axis of the orifice and away from the body, each member being at
an angle within the range of from 90° to 120° to the axis and tapering toward the
distal end, the members being radially spaced apart at least at their distal ends,
and occupying at most 55%, preferably at most 50%, of the area of the orifice as viewed
axially, and the rod comprising a proximal end attached to the closure member and
a distal end attached to the applicator and comprising near to or at the distal end
a constriction, the cross-sectional area of the rod between the part of the constriction
having the smallest cross-sectional area and the distal end being less than that of
the rod the proximal side of the constriction and the cross-sectional area of that
part of the rod forming the distal side of the constriction being greater than the
smallest cross-sectional area of the constriction, the rod further comprising a groove
at the point of contact, in the closed position of the assembly, of the elongate members
of the wiper device.
[0053] Two forms of applicator, rod and assembly device constructed in accordance with the
invention and several suitable wiper devices will now be described in greater detail,
by way of example only, with reference to the accompanying drawing(s) in which:
Fig. 1 shows a longitudinal section through an applicator assembly, in a closed position,
constructed in accordance with the invention,
Fig. 2 shows a longitudinal section through the applicator assembly of Fig. 1 as the
applicator rod is being drawn through the wiper device,
Fig. 3 shows a longitudinal section through the applicator assembly of Fig. 1 as the
applicator is about to be drawn through the wiper device,
Fig. 4 shows a longitudinal section through a first wiper device which may be used
in the assembly of the invention,
Fig. 5 shows a plan view of the device of Fig. 4,
Fig. 6 shows a part of Fig. 4 enlarged to show details of the resilient members,
Fig. 7 shows a longitudinal section through a second wiper device which may be used
in the assembly of the invention;
Fig. 8 shows a plan view of the device of Fig. 7;
Fig. 9 shows a longitudinal section through a third wiper device which may be used
in the assembly of the invention;
Fig. 10 shows a plan view of the device of Fig. 9;
Figs. 11 and 12 show longitudinal sections through second and third applicator assemblies,
in a closed position, constructed in accordance with the invention.
[0054] Referring to Figure 1, an applicator assembly, in particular a mascara unit or hair
dye unit, is shown. The unit comprises a thermoplastics container indicated generally
by the reference numeral 1 having a neck portion 3 with an external thread 4 joined
to the body of the container by a shoulder 2.
[0055] A cap 8, the closure device, with an internal thread 9 is fitted onto the external
thread 4 of the neck 3, an outside cover 10 being held in position over the cap 8
by a heat-setting adhesive layer 11, or simply by a force fit. Extending from the
cap 8 into the interior of the container 1 is a rod 12, to the lower end 13 of which
is attached an applicator brush 14. A wiper device indicated generally by the reference
numeral 6 having a rim 15 is located in the neck 3, the rim 15 providing a seal 5
between the container 1 and the cap 8.
[0056] The wiper device 6, discussed in greater detail below, is located in the neck 3.
When the assembly is closed, as shown in Figure 1, the rod 12 extends from the cap
8 through the wiper device 6 and the wiping surface 18 is in contact with the rod
12. Fingers 22 of the wiper extend downwards into the container 1 and rest on the
rod. In preferred embodiments a groove 7 is provided in the rod 12 and the fingers
22 rest in the groove. In the embodiment shown in Figure 1 the sides of the groove
slope relatively shallowly to allow the fingers to expand outwards gently as the rod
12 is removed from the container.
[0057] At the distal end of the rod 12, just before it is joined to the applicator brush
14, the rod narrows at the constriction 16 and then broadens sharply by means of a
surface or shoulder 20 provided by the circular face of a solid cup shaped part 25
(a frustum of a cone but with a bulbous rather than a strictly conical surface). The
diameter of the shoulder and of the remaining portion of the rod is, however, less
than the diameter of the rod at its widest part and is, preferably, less than the
relaxed diameter of the orifice of the wiper 6. The shoulder 20 subtends an angle
θ, to the axis of the rod 12. In Figure 1 θ is 90°.
[0058] As the rod 12 and applicator brush 14 are withdrawn from the container 1 as illustrated
in Figs. 1 and 2, the fingers 22 gently bear against the rod or rest on its surface
until they reach the narrowing section 16. As they pass the narrowing section 16 they
relax inwards towards their equilibrium state and then their ends are brought into
contact with the surface 20 as in Fig. 2. The movement of the surface 20 against the
end of the fingers 22 causes them to turn inwards so that they are turned back on
themselves as shown in Fig. 3. The ends remain turned in as the rest of the rod 12
and applicator 14 are withdrawn.
[0059] Referring now more especially to Figs. 4, 5 and 6, the wiper device 6 is shown in
more detail. As indicated above, it has at its upper end a rim 15 which, in addition
to providing a seal, forms a stop to locate the device 6 in the neck 3, and a bead
17 on the outside wall of the body just below the rim 15 serves to engage with a corresponding
recess in the inside wall of the neck 3 and assist in sealing and ensuring a secure
fit. The external and internal surfaces of the wall of the body of the device are
angled inwards so that the device tapers toward its lower end wall 19, the internal
wall surface terminating in a wiping surface 18 occupying 360° of arc. Extending from
the lower end wall 19 are four spaced apart wiping fingers 22 extending toward the
axis. As may be seen most clearly from Fig. 5, each finger 22 tapers toward the free,
distal, end 28. The fingers 22 are of rectangular cross-section, all faces of the
rectangle becoming smaller with approach to the free, distal, end 28. The angle between
the inner face 24 of each finger 22 and the wiping surface 18 (which is parallel to
the axis of the device 6) is about 100°. The outer face 30 and the inner face 32 of
the terminal section of the distal end 28 are pointed, the faces 30 and 32 being offset
to provide an edge 36 parallel to and slightly away from the axis of the device 6.
The four fingers occupy about 45% of the area of the orifice defined by the wiping
surface, when viewed axially, as seen in Fig. 5.
[0060] Typically, the diameter of a mascara applicator rod is within the range of 2.5 to
4.5 mm. For a 4.3 mm rod, the diameter of the wiping orifice may be about 4.2 mm,
the length of the fingers measured along the inner face being 2.0 to 2.2 mm, the edges
36 of diametrically opposed fingers being about 0.25 mm apart. As examples of materials
from which the wiper may be constructed, there may be mentioned a low density polyethylene,
a low density polyethylene/thermoplastic elastomer blend, for example in proportions
of about 1:2 by weight, a thermoplastic elastomer and wholly elastomeric materials,
for example a nitrile rubber, for example an elastomeric material with a Shore hardness
in the range of 70 to 80.
[0061] A suitable wiper of similar construction but having longer elongate members is shown
in Figures 7 and 8. Features corresponding to those of Figures 5 and 6 are given corresponding
reference numerals. The upper part of the device is as described above and tapers
at its lower end, the internal wall terminating in a wiping edge 18. Extending parallel
to the axis of the device from the lower end wall are four spaced apart elongate pillar
members 21, from each of which a wiping finger 22 extends toward the axis. The extremities
23 of the fingers 22 are rounded to enable them to approach the centre of the applicator
brush 14 as closely as possible on withdrawal of the brush. In order to minimize the
extent of the deformation of the pillars and fingers when the applicator rod 12 is
in its storage position, an annular groove 7 (see Fig. 1) may be formed in the rod
at the appropriate location.
[0062] The fingers 22 extend at an angle of about 100° to the pillar members 21.
[0063] Typically, the diameter of a mascara applicator rod is within the range of 2.5 to
4.5 mm. For a 4.3 mm rod, the diameter of the wiping orifice may be about 4.2 mm and
the length of the pillars about 3.6 mm, the fingers each extending about 2.0 mm from
the internal wall of the pillars.
[0064] Referring now to Figs. 9 and 10, in which features corresponding to those of Figs.
7 and 8 are given corresponding reference numerals, a third embodiment of a suitable
wiper device is shown, in which the body portions are like those of Figs. 7 and 8.
Extending from the lower end wall 19 of the body of the wiper device 6 are six spaced
apart members indicated generally by the reference numeral 30, the proximal portions
31 of each member extending parallel to the axis of the device and the distal end
portions 32 extending inward at an angle of about 130° to the axis, intermediate portions
33 providing a smooth curve between the end portions. As in the embodiment shown in
Figs. 7 and 8, the members extend as close to the axis as is consistent with their
being capable of being removed from a mould during manufacture. In both embodiments
shown in Figures 7 to 10, the material of which the devices are constructed is resilient,
and the proximal portions 21 and 31 of the members assist in inhibiting amnesia under
deformation.
[0065] Fig. 11 shows an applicator assembly identical in construction to that of Figs. 1
to 3 in all but the construction of the rod and applicator. Features corresponding
to those of Figs. 1 to 3 are given corresponding reference numerals.
[0066] The distal end 40 of the rod 12 tapers towards the applicator 14. Supported on the
end portion 42 of the applicator 14 is a stop member 44 which provides a shoulder
20. As the rod 12 and applicator brush 14 are withdrawn from container 1, the fingers
22 gently bear against the rod or rest on its surface until they reach the tapering
end 40 of the rod 12 and the end portion 42 of the applicator where they relax towards
their equilibrium state. Their ends are then brought into contact with surface 20
and the movement of surface 20 against their ends causes the fingers 22 to turn inwards
so that they are turned back on themselves.
[0067] The applicator brush 14 may, for example, comprise a helix of bristles supported
by a core comprising a twisted steel wire, in which case the end portion 42 may be
formed by the twisted steel wire.
[0068] Fig. 12 shows a further applicator assembly similar in construction to that of Fig.
1. In the Fig. 12 embodiment, however, only the portion 50 of the rod 12 within the
wiper device 6 when the container is closed is of a wider diameter, the remaining
portion 52 being of a uniform smaller diameter, a tapered portion 54 linking the portions
50 and 52 lying under the fingers 22 of the wiper 6 when the closure device 8 is screwed
onto the thread 4 on the neck 3 of the container 1. The taper 54 is ogee shaped in
this and the other embodiments and located so that the fingers 22 rest on the convex
portion. When withdrawal of the rod begins, the fingers move to the concave portion
with no tendency to invert at this stage. However, advantageously as the rod 12 and
the applicator brush 14 are withdrawn further, the fingers 22 will be inverted by
the shoulder 20 of the stop member 44.
1. An applicator and rod suitable for use in an applicator assembly for applying a viscous
material, the assembly comprising the applicator, the rod and a container, a closure
means and a wiper device located within the container through which, in use, the rod
and applicator may be drawn, the rod and the applicator each having a proximal end
and a distal end, the distal end of the rod carrying the applicator by the latter's
proximal end, and wherein (a) the rod has a constriction, the cross-sectional area
of the rod between the part of the constriction having the smallest cross-sectional
area and the distal end being less than that of the rod the proximal side of the constriction
and the cross-sectional area of that part of the rod forming the distal side of the
constriction being greater than the smallest cross-sectional area of the constriction
or (b) the distal end of the rod tapers toward the applicator, there being positioned
on the proximal end of the applicator a stop member, the cross-sectional area of the
stop member being less than that of the rod on the proximal side of the tapered part
but greater than the smallest cross-sectional area of the tapered part of the rod
and, if there is any part of the applicator between the distal end of the rod and
the stop member, greater than that part, or (c) the proximal end of the rod has a
greater cross-section than that of its distal end, the rod tapering from its greater
cross-section to its lesser cross-section at a region of the rod closer to the proximal
end than to the distal end, there being positioned on the proximal end of the applicator
a stop member, the cross-sectional area of the stop member being less than that of
the rod at the proximal end but greater than that of the rod on the distal side of
the taper and, if there is any part of the applicator between the distal end of the
rod and the stop member, greater than that part.
2. An applicator and rod as claimed in claim 1(a).
3. An applicator and rod as claimed in claim 2, wherein the constriction is at the distal
end of the rod.
4. An applicator and rod as claimed in claim 2 or claim 3 wherein the constriction is
formed by a narrowing of the rod and then a widening to form a shoulder and the line
of the shoulder subtends an angle greater than 70° to the axis of the rod.
5. An applicator and rod as claimed in claim 1(b) or 1(c) wherein the proximal face of
the stop member forms a shoulder subtending an angle greater than 70° to the axis
of the rod and the applicator.
6. An applicator and rod as claimed in claim 4 or claim 5, wherein the angle is greater
than 80°.
7. An applicator and rod as claimed in claim 4 or claim 5, wherein the shoulder is approximately
perpendicular to the axis of the rod, the shoulder advantageously forming the larger
circular face of a solid cup shape or the larger circular face of a solid frustrum
of a cone.
8. An applicator and rod as claimed in any one of claims 1 to 7, wherein the applicator
is a brush having bristles extending from a twisted wire core, the brush comprising
from 160 to 200 bristles per cm, the fibres being of diameter within the range 0.125
to 0.2 mm.
9. An applicator and rod as claimed in any one of claims 1 to 7, wherein the applicator
is a brush having bristles extending from a twisted wire core, the brush comprising
a proximal portion of length from 3 to 6 mm having bristles of about 0.25 mm diameter,
the remainder of the brush comprising bristles of about half the thickness of the
proximal end bristles, the bristle density advantageously being from 160 to 200 per
cm.
10. An applicator assembly suitable for use for applying a viscous material, which assembly
comprises an applicator and a rod as claimed in any one of claims 1 to 9.
11. An applicator assembly suitable for use for applying a viscous material, the assembly
comprising a container for the viscous material, a closure member, an applicator and
rod as claimed in any one of claims 1 to 9, the applicator being attached to the closure
member by the rod, and, located within the container, a wiper device comprising a
plurality of resilient fingers, the wiper device advantageously being formed from
a thermoplastic material especially a thermoplastic elastomeric material, or from
a blend comprising a thermoplastic material.
12. An applicator assembly as claimed in claim 11 comprising a wiper device comprising
an elongate hollow resilient body having a substantially circular orifice, and positioned
around and extending directly from the periphery of the orifice a plurality of elongate
resilient members, each having a free, distal, end portion, each member extending
inward toward the axis of the orifice and away from the body, each member being at
an angle within the range of from 90° to 120° to the axis and tapering toward the
distal end, the members being radially spaced apart at least at their distal ends,
and occupying at most 55% of the area of the orifice as viewed axially.
13. The assembly of claim 12, wherein there are four elongate resilient members, the members
are at an angle of at least about 100° to the axis and the distance between a pair
of their opposed distal ends is at most 10% of the diameter of the orifice.
14. An applicator assembly as claimed in any one of claims 10 to 13 wherein the rod comprises
a groove at the point of contact of the wiper's resilient fingers when the assembly
is in its closed position.
15. An applicator assembly as claimed in any one of claims 10 to 14 wherein the rod comprises
a constriction and it is nearer the distal end of the rod than the point of contact
of the resilient fingers when the assembly is in its closed position.
16. An applicator assembly as claimed in any one of claims 10 to 15 comprising a rod of
substantially circular cross-section and a wiper device comprising a hollow resilient
body having a substantially circular orifice wherein the diameter of the rod between
the constriction and the distal end or the diameter of the stop member is less than
or equal to that of the circular orifice of the wiper when in its equilibrium position
minus twice the thickness of one of the resilient fingers.
17. An applicator assembly suitable for use for applying a viscous material, the assembly
comprising a container for the viscous material, a closure member, an applicator and
rod, and a wiper device located within the container through which, in use, the rod
and applicator may be drawn, the wiper device comprising an elongate hollow resilient
body having a substantially circular orifice, and positioned around and extending
directly from the periphery of the orifice a plurality of elongate resilient members,
each having a free, distal, end portion, each member extending inward toward the axis
of the orifice and away from the body, each member being at an angle within the range
of from 90° to 120° to the axis and tapering toward the distal end, the members being
radially spaced apart at least at their distal ends, and occupying at most 55% of
the area of the orifice as viewed axially, and the rod comprising a proximal end attached
to the closure member and a distal end attached to the applicator and comprising near
to or at the distal end a constriction, the cross-sectional area of the rod between
the part of the constriction having the smallest cross-sectional area and the distal
end being less than that of the rod the proximal side of the constriction and the
cross-sectional area of that part of the rod forming the distal side of the constriction
being greater than the smallest cross-sectional area of the constriction, the rod
further comprising a groove at the point of contact, in the closed position of the
assembly, of the elongate members of the wiper device.
18. Use in a material applicator assembly comprising a wiper device comprising a plurality
of resilient fingers and a rod carrying an applicator, of (a) a constriction in the
rod to cause the resilient fingers of the wiper device to turn inward toward the rod
as the rod is drawn through the wiper device and a cross-sectional area of the rod
between the part of the constriction having the smallest cross-sectional area and
the applicator of less than that of the rod before the constriction to inhibit or
reduce failure of the material of the wiper device or of (b) tapering the rod carrying
the applicator in the direction of the end of the applicator and a stop member positioned
on the proximal end of the applicator to cause the resilient fingers of the wiper
device to turn inward toward the rod as the rod is drawn through the wiper device,
the cross-sectional area of the stop member being less than that of the rod before
the taper to inhibit or reduce failure of the material of the wiper device.