Applicator for soft materials

An improved applicator for soft materials includes a cartridge section and a relatively rotatable body section, the soft material being contained within the cartridge section and a plunger being provided to advance the soft material. The improvement resides in providing an assembly within the applicator body to prevent the inadvertent separation of the cartridge section from the body section. In a preferred embodiment, this assembly comprises a clutch means between the rotatable body section and the plunger whereby rotation of the body is transmitted to the plunger to advance and retract the plunger and associated soft material, the clutch means being designed so as to disengage before the plunger is retracted to the point at which it would forcibly separate the cartridge from the body.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to an improvement to an applicator for soft, 
moldable materials as for example, soft cosmetics, crayons, marking pens, 
eye liners, eye shadows, lip sticks, lip liners and the like. In 
particular, it relates to an improvement to such applicators that 
overcomes potential inoperative conditions caused by improper user 
activation of such applicators. 
2. Description of the Prior Art 
The particular applicators to which this improvement is directed are of the 
type which include a cartridge containing the soft, moldable material 
within a longitudinal bore, a cap having a pointing insert therein and a 
body attached to the cartridge by a retention fitting and containing a 
rotatable plunger or follower rod means for expelling the material. The 
rod threadably engages the bore of the cartridge such that rotation 
thereof causes it to move linearly within the cartridge to express the 
soft material. Generally, clockwise rotation advances the rod and the 
material and counterclockwise rotation retracts the rod and material. An 
applicator of this general type is disclosed in Published PCT application 
No. 88/09267, published Dec. 1, 1988, the contents of which are 
incorporated herein by reference. 
In prior applicators of this type, it often occurs that a user may retract 
the plunger too far so that it bottoms out against the inner end of the 
applicator body. When this happens, before the threads of the rod become 
disengaged from the cartridge bore, the rearward force against the body 
overrides the retention fitting with the cartridge and causes the two 
pieces to separate thus rendering the item inoperative. The present 
invention overcomes this problem, effectively preventing excessive 
retraction of the rod and separation of the parts. 
It is an object of this invention to provide an applicator for soft 
moldable materials, that overcomes the problem of the prior art. 
It is a further object of this invention to provide an applicator that does 
not inadvertently disassemble. 
Other objects and advantages of this invention will be apparent from the 
accompanying drawings and the following description: 
SUMMARY OF THE INVENTION 
The applicator of this invention includes in combination an elongated 
cartridge having first and second open ends with a longitudinal bore 
running between them. Removably securable to the first or front end of the 
cartridge is a hollow cap which may have an interior, conical forming 
surface while a hollow body is attachable to the second or rear end of the 
cartridge. The hollow body has a first open end and a second closed end 
which are connected by an inner longitudinal bore, the forward end of 
which is adapted to receive the rear end of the cartridge. A charge of 
moldable soft material such as a cosmetic is inserted into the cartridge 
bore and forced by a piston or rod towards the closed end of the cap, 
preferably into the conical surface of the cap until a conical tip is 
formed. The cap may then be removed exposing a shaped point of soft 
material supported by the cartridge and available for use. The interior 
surfaces of the cartridge and the cap are sufficiently smooth and 
non-sticking so that the charge of moldable soft material is freely 
slidable within the cartridge and readily releasable from the cap. 
The forcing piston or rod is an elongated member that is inserted into the 
bore of the cartridge through the second end and is moveable by rotation 
to act on the charge of soft material. The rod has a first end that is 
flared to contact the soft material and a second end that extends out of 
the second end of the cartridge into the hollow body. Means are provided 
on the second end of the rod to engage the inner surface of the body such 
that rotation of the body causes the rod to rotate. A portion of the rod 
adjacent its second end is provided with threads that engage cooperating 
threads in the bore of the cartridge to convert rotation into linear 
movement. Preferably, clockwise rotation advances the rod into the 
cartridge and counterclockwise rotation retracts the rod from the 
cartridge into the body. The body attaches to the cartridge by means of a 
retention fitting, such as a cooperating annular detent and groove, to 
allow the body and cartridge to rotate relative to each other about a 
common longitudinal axis. 
To overcome the problem of the prior art, the length of the threads on the 
threaded portion of the rod is limited and a resilient means is introduced 
into the body to cushion and absorb the rearward force of the retracting 
rod. In this manner, the force is absorbed and redirected in a spring-like 
manner to keep the rod threads engaged with those of the cartridge, even 
though the rod is fully retracted. Furthermore, limiting the thread length 
causes the threads to disengage before the rearward force becomes 
sufficient to fully compress the resilient means and force the barrel out 
of retention with the cartridge. Alternatively, a clutch mechanism may be 
included at the driving means which will provide slippage upon achieving a 
particular level of force thereby preventing continued retraction of the 
rod and subsequent separation of the body and cartridge.

DETAILED DESCRIPTION OF THE INVENTION 
As shown in FIG. 1, the applicator comprises three sections, the cap 1, the 
cartridge 2, also shown in FIG. 7, and the body 3. Looking at FIGS. 2 and 
3, the cap 1 fits onto the forward end 7 of the cartridge 2 and contains a 
forming insert 4. Attachment of the cap 1 to the cartridge 2 is preferably 
by cooperating threads 5. The forming insert 4 is made separately from the 
cap 1 and inserted during assembly of the applicator. The insert 4 may be 
machined from an extruded rod of Teflon or, and more preferably, is 
injection molded from other suitable materials such as Celcon. The 
cartridge 2 has a longitudinal bore 19 therethrough in which is charged a 
mass of moldable, soft material, such as a cosmetic 6 which fills the 
forward end 7 of the cartridge 2 and is pressed against the forming insert 
4 of the cap 1 so as to mold the cosmetic 6 into a smooth tapering point 
8. The portion of the bore 19 in the rearward end 9 of the cartridge 2 has 
internal threads 21, the purpose of which is disclosed below. 
Attached to the rearward end 9 of the cartridge 2 is the applicator body 3, 
also shown in FIG. 6. A retention fitting 10 holds the two parts together, 
while allowing for relative rotation of each. This retention fitting 10 
preferably comprises an annular detent 22 on the rearward end 9 of the 
cartridge 2 and a cooperating annular groove 23 in the inner surface of 
the body 3. These features are shown in FIGS. 6 and 7. Preferably, the 
rearward portion of the inner cavity 24 of the body 3 has an internal 
surface 25 that is other than round. This internal surface 25 comprises a 
plurality of planes abutting along their long edges such that the internal 
surface 25 of the body 3 has a polygonal cross section. The forward 
portion of the inner cavity 24 is round to accommodate the rearward end 9 
of the cartridge 2. 
When the applicator is assembled as in FIG. 1, there is within the body 3 
and extending into the cartridge 2, plunger rod 12 (see FIGS. 3 and 5a). 
As shown in FIG. 5a, this part comprises a shaft 13 divided into a first 
threaded portion 14, a second non-threaded mid-shaft portion 15, 
preferably of smaller diameter than the first portion 14, and a flared 
pushing end 16. At the base of the threaded portion 14 is driving lug 17 
comprising an enlarged portion having a plurality of sides 18 that 
correspond to the shape of the internal surface 25 of the rearward portion 
of the body's inner cavity 24, the overall size of the lug 17 being 
slightly smaller than the inner cavity 24 to allow the plunger rod 12 to 
telescope therein. By forming the driving lug 17 and the rearward surface 
25 of the cavity 24 in the same shape, the plunger rod 12 can be made to 
rotate when the body 3 is rotated and because of the cooperative 
threading, 14a and 21, of the rod 12 and cartridge 2, the rotation of the 
rod 12 will be converted to linear travel within the body 3 and the 
cartridge 2. 
Alternatively, as shown in FIGS. 8 and 9, the inner cavity 24 of the body 3 
may be cylindrical throughout its length with the rearward surface 25 of 
slightly smaller diameter. This rearward surface 25 is provided with at 
least one longitudinal groove 29 along its length. On the rod 12" the lug 
17 corresponds to the shape of the rearward portion 25 of the inner cavity 
24 and has at least one lateral cooperating member, such as the two 
projections 30, that travel within the longitudinal groove 29. Preferably 
there will be two grooves 29 diametrically opposite in the body 3 and two 
projections 30 arranged to fit the grooves. Such a projection and groove 
combination will function like the shaped lug 17 and rear portion 25 of 
the preferred embodiment shown in FIGS. 5a and 6 to transfer rotation of 
the body 3 to the rod 12", the longitudinal nature of the groove 29 
allowing linear movement of the rod 12". 
The rearmost end of the body 3 may be solidly molded as shown in FIG. 8 or, 
if there is an aperture, closed with a plug 11 (see FIG. 6). 
When first assembled with the moldable material, preferably a cosmetic, 
such as eye shadow or lipstick, the driving lug 17 or 17' and most of the 
threaded portion 14 of the shaft 13 extend into the inner cavity 24 of the 
body 3. The rest of the plunger rod 12 or 12" extends into bore 19 of the 
cartridge 2 where the pushing end 16 engages the mass of cosmetic 6. This 
pushing end 16 is preferably flared to make a good but slidable fit with 
the bore 19 of the cartridge 2 so as to push the cosmetic 6 ahead of it. 
In applicators of the prior art, as shown in FIG. 2, the threads 14a on the 
threaded portion 14 of the plunger rod 12' extend along the shaft 13 from 
the driving lug 17 to the beginning of the mid-shaft 15. Such a prior art 
rod 12' is shown in FIG. 5b. Thus, when the applicator is assembled, the 
driving lug 17 is adjacent the bottom 20 of the inner cavity 24 of body 3 
with the threads 14a at the forward end of threaded portion 14 engaging 
the inner threads 21 at the rearward end 9 of cartridge 2. In this case, 
rotation of body 3 in a counterclockwise direction will cause rod 12' to 
attempt to retract further from the cartridge 2, thus pushing against the 
bottom 20 of inner cavity 24 of body 3. This causes body 3 and cartridge 2 
to separate at the retention fitting 10, rendering the applicator 
inoperative. 
The applicator of the present invention, as shown in FIG. 3, is similar to 
the prior art, but overcomes the above-described defect in the following 
manner. 
The plunger rod 12, as best seen in FIG. 5a, is modified so that the 
threads 14a extend along only part of the shaft portion 14. Thus, unlike 
the prior art of FIG. 5b, less than the full length of this portion 14 is 
threaded, for example 1/2 to 7/8, preferably 2/3 to 3/4, the length of 
portion 14 from driving lug 17 to the beginning 15' of the mid-shaft 15. 
By reducing the threaded length in this manner, plunger rod 12 is not 
bottomed out against bottom 20 when the applicator is assembled, since rod 
12 extends further into bore 19 of cartridge 2 before the respective 
threads 14a and 21 engage each other. The space between driving lug 17 and 
the bottom 20 of body 3 is sufficient such that threads 14a and 21 of 
plunger rod 12 and cartridge 2, respectively, will disengage before lug 17 
contacts the bottom 20, thus preventing the inadvertent separation of 
cartridge 2 and body 3. 
When rod threads 14a disengage from the cartridge threads 21, rod 12 falls 
to the bottom 20 of body 3. Therefore, to reengage threads 14a and 21 
without dismantling the applicator, the invention provides a means to 
reengage the threads 14a and 21 of rod 12 and cartridge 2 in the event rod 
12 is caused to retract too far into body 3 from cartridge 2. 
The reengaging means may comprise an insert 26 placed in body 3 between the 
bottom 20 thereof and the driving lug 17 of plunger rod 12, as shown in 
FIG. 3. The insert 26 may be made of a resiliently compressible, 
elastomeric material such as, for example, sponge rubber, neoprene or the 
like. 
FIG. 4 illustrates a preferred embodiment of insert 26 which is 
substantially cylindrical with slightly frusto-conical ends 27a and 27b. 
Having the ends in this shape facilitates introduction of the insert 26 
into inner cavity 24. Although insert 26 may be solid, it is preferred 
that it have a longitudinal bore 28 centrally located and continuous from 
one end 27a to the other end 27b. It is believed that provision of such a 
bore 28 improves the resiliency of the insert 26 providing better spring 
action between the bottom 20 of body 3 and lug 17 of plunger rod 12. 
When insert 26 is in place in the applicator of the invention, rotation of 
the body 3 relative to cartridge so as to retract the plunger rod 12 from 
the cartridge 2, will cause the driving lug 17 to press against the end of 
the insert 26. Because insert 26 is compressible, the rearward force of 
plunger rod 12 will be absorbed by insert as it is compressed between 
driving lug 17 and bottom 20 of the body 3, rather than that force being 
transferred to the body 3 and overcoming the retention fitting 10. 
Furthermore, the resilience of insert 26 is such that, when the plunger 
rod 12 is retracted sufficiently to disengage the threads 14a and 21, the 
insert functions as a spring to push the plunger rod 12 forward, thereby 
maintaining the respective threads in contact. Thus, rotation of body 3 in 
the opposite direction will once again advance rod 12 into the cartridge 
2. 
The foregoing is a preferred embodiment of the invention. Further 
embodiments within the scope of the following claims are deemed to be 
included herein. For example, in place of elastomeric material, the 
resilient, insert may be formed as a resiliently compressible metal or 
plastic spring-like member, e.g. a coiled or molded metal or plastic 
spring 26' such as shown in FIG. 3a, a molded spring 26'" of engineering 
plastic material such as shown in FIG. 3c, or a Belleville spring 26' of 
steel or plastic, such as shown in FIG. 3d. FIG. 3b shows a still further 
embodiment in which the resilient insert rather than being a compression 
device placed between lug 17 and the bottom 20 of the body 3, is a tension 
spring 26" secured between the rear end 9 of the cartridge 2 and lug 17 
and enclosing the rod 12 within the body 3. In this manner, excessive 
rotation of the body 3 so as to retract rod 12 beyond the point of 
engagement of the threads 14a and 21, places tension on spring 26" so that 
it will pull the rod forward to reengage the threads 14a and 21. This 
embodiment preferably employs the projection 30 and groove 29 means shown 
in FIGS. 8 and 9 to effect cooperation between the rod 12 and the body 3. 
In either case the springs, whether compression or tension springs, must 
have sufficient memory to fully return to their unstressed condition and 
may be tempered. Also, the shape of the forming insert 4 may be rounded 
rather than conical, or the forming insert may be entirely omitted. 
In a further embodiment, shown in FIGS. 10 and 11, a clutch mechanism 30 is 
employed at the end of the rod 12 to prevent the inadvertent separation of 
cartridge 2 from body 3. With this clutch mechanism 30, the extent of 
threads 14a along shaft portion 14 of rod 12 is not critical. Clutch 
mechanism 30 comprises two parts, an adapter 31 and a driver 32 each 
having cooperating detents whereby rotation of one part is imparted to the 
other part until a certain degree of rotational tension is reached at 
which point friction between the detents is overcome and the parts may 
rotate relative to each other. These parts are shown in FIGS. 14-17 and 
FIGS. 18-21 respectively. 
Referring to FIGS. 14-17, adapter 31 comprises two sections, a larger, 
cylindrical driver engaging section 33 and a smaller cylindrical rod 
engaging section 34. Rod engaging section 34 extends from a forward end 35 
of driver engaging section 33 along a common center line and preferably 
has an outside diameter which is smaller than that of driver engaging 
section 33. Adapter 31 is hollow, as shown in FIG. 17, each section 33 and 
34 having inside diameters whose relationships are commensurate with that 
of the outside diameters of the sections. Thus, the inside diameter of 
driver engaging section 33 is preferably larger than the inside diameter 
of rod engaging section 34. Turning now to FIGS. 18-21, driver 32 
comprises a driving lug portion 38 and an adapter engaging portion 39. 
Adapter engaging portion 39 is cylindrical and extends from the forward 
end of driving lug portion 38 along a common center line and has an 
outside diameter equal to or slightly smaller than the inside diameter of 
driver engaging section 33 of adapter 31. As shown in FIGS. 10 and 11, 
adapter engaging portion 39 of driver 32 fits into the hollow cylindrical 
interior 33a of driver engaging section 33 of adapter 31. By making the 
outside diameter of adapter engaging portion 39 the same as or slightly 
smaller than the inside diameter of driver engaging section 33, adapter 31 
and driver 32 will be able to rotate relating to each other. 
Driving lug portion 38 corresponds to driving lug 17 and, like lug 17, 
comprises an enlarged portion having a plurality of sides 40 and 
corresponds to the shape of the interior surface 25 of the rearward 
portion of the body's inner cavity 24, the overall size of driving lug 
portion 38 being slightly smaller than the inner cavity 24 to allow it to 
move longitudinally therein. As with the previous embodiments, forming 
driving lug portion 38 and the rearward surface 25 of the cavity 24 in the 
same shape will cause driver 32 to rotate when the body 3 is rotated. 
Driving lug portion 38 is further characterized by having an interior 
cavity 43 which is open at the rearward end of driving lug portion 38. 
Centrally located within cavity 43 and extending coaxially there within is 
a pin 44 which provides a means for mounting a compression spring 45 
within cavity 43. Spring 45 is preferably a coil spring having an inner 
diameter to fit over pin 44 and, as shown more clearly in FIG. 10, this 
spring 45 extends between driver 32 and bottom 20 of inner cavity 24 of 
body 3. In this manner spring 45 provides sufficient tension against 
driver 32 to maintain driver 32 and adapter 31 in operative contact. 
As shown in FIGS. 10 and 11, adapter 31 fits on the rearward end of rod 12 
and adapter engaging rod 39 of driver 32 fits into driver engaging portion 
33 of adapter 31 to form a complete rod and driving mechanism. Toward this 
end, rod 12 instead of having driving lug 17 on its rearward end is 
modified as shown in FIG. 12 to have an attachment pin 37 of reduced 
diameter. Pin 37 fits into the hollow center of rod engaging section 34 
and is affixed therein by friction or a suitable adhesive or cement. Since 
it is intended that adapter 31 and rod 12 rotate together, pin 37 and the 
interior 34a of rod engaging section 34 may be formed so as to have 
cooperating cross sections that are other than circular. Cooperating 
hexagonal configurations are preferred as shown in FIGS. 13 and 15. In 
contrast, adapter 31 and driver 32 must be free to rotate separately of 
each other when necessary; accordingly, the interior 33a of driver 
engaging section 33 has a circular cross section as shown in FIG. 16. 
Adapter 31 and driver 32 cooperate in a clutch fashion to provide driving 
motion to rod 12 for extension and retraction thereof while having the 
ability to release from each other during retraction upon reaching a 
particular level of rotational tension. This is accomplished by the 
cooperating detents which allow slippage of the driver 32 relative to 
adapter 31 in one direction upon reaching the particular tension level 
while providing positive connection in the opposite direction. Such 
cooperating detents preferably take the form of circular arrays of 
cooperating teeth 41 and 42 on the adapter 31 and driver 32 respectively. 
The teeth 41 of adapter 31 are cut into the end 36 of driver engaging 
section 33 while the teeth 42 of driver 32 are located on the forward face 
38a of driving lug portion 38 and form a ring around the base of adapter 
engaging portion 39. Preferably both sets of teeth 41 and 42 comprise 
eight equally spaced teeth with each tooth comprising an acute and an 
obtuse surface, 41a and 41b for adapter teeth 41 and 42a and 42b for 
driver teeth 42. Preferably the acute surfaces 41a and 42a have an angle 
of 15.degree. relative to the tooth apex, and the obtuse surfaces 41b and 
42b have an angle of 75.degree. relative to the apex, thus each tooth has 
one short face 41a and 42a and one long face 41b and 42b. The arrangement 
of the teeth 41 on adapter 31 and teeth 42 on driver 32 are such that 
clockwise rotation of driver 32 will cause short faces 42a of driver teeth 
42 to butt against short faces 41a of adapter teeth 41 thereby 
transferring rotation to adapter 31 and rod 12. Such clockwise rotation 
will preferably cause extension of rod 12. Conversely, counter clockwise 
rotation of driver 32 will cause long faces 42b of driver teeth 42 to butt 
against long faces 41b of adapter teeth 41 and, under normal conditions, 
transfer rotation to adapter 31 and rod 12 thereby causing retraction of 
rod 12. Under normal retraction there is sufficient friction between the 
long faces 41b and 42b to permit transference of rotation. However, the 
angular relationship of these faces is such that this engagement will slip 
upon reaching a certain level of rotational tension such as when spring 45 
reaches nearly full compression on retraction of rod 12. When this occurs, 
the angle of long faces 41b and 42b is such that the relative friction 
between those faces is overcome and driver teeth 42 are able to ride over 
adapter teeth 41 upon continued rotation of driver 32. At this point there 
is preferably sufficient free play between the parts of the apparatus to 
allow the necessary longitudinal displacement of driver 32 and adapter 31 
so that driver teeth 42 may ride over adapter teeth 41. Alternatively, 
adapter 31 and driver 32 may be made of a material which allows partial 
compression of their respective teeth 41 and 42. This may be combined with 
an alternative design of teeth 41 and 42 wherein short faces 41a and 42a 
are undercut to facilitate compression from force applied to long faces 
41b and 42b. 
Such relative slippage of the clutch parts, adapter 31 and driver 32, upon 
full retraction of rod 12 functions to prevent the inadvertent separation 
of cartridge 2 and body 3 at retention fitting 10 by allowing the parts 31 
and 32 to slip relative to each other rather than continue to retract rod 
12 which would force cartridge 2 and body 3 apart. While the foregoing is 
a preferred embodiment of a clutch mechanism to be employed in such 
applicators, other embodiments within the scope of the following claims 
are deemed to be included herein. For example, driver 32 and adapter 31 
may be made from materials having particular coefficients of friction that 
allow cooperative frictional engagement therebetween to be overcome at a 
particular rotational tension level whereby adapter 31 and driver 32 will 
slip relating to each other. Alternatively, the cooperative detents 
exemplified by teeth 41 and 42 may have different forms such as 
cooperating bumps or bumps and depressions on the contacting faces 36 and 
38a of adapter 31 and driver 32 respectively. 
Still other embodiments and modifications within the spirit and scope of 
the foregoing description and appended claims will become apparent to 
those of skill in the art after reviewing this application.