SLIDER FOR SECURING A STICK OF PASTE, MECHANISM FOR RETRACTING OF THIS STICK INTEGRATED WITH SAID SLIDER, AND CORRESPONDING COSMETIC APPLICATION DEVICE

Abstract: The present invention includes a slider (10) for a stick of paste which is to be retracted, some means capable of gripping the paste, limiting the appearance of mechanical tension within the paste. The slider for securing a stick of paste, one end of which is applied by spreading as it is consumed, has a flexible part (3,30) formed in the body of the slider for absorbing the pressures exerted on the holding zone (20) formed by an end part (2) of the slider. The end part (2) comprises a rim of constant height in the form of a ring (50), interrupted at least once by an opening in order to form at least one securing element (51), imparting sufficient flexibility for anchoring the paste and limiting the mechanical stresses connected with shrinkage. The ring is comprised of T-shaped tangential securing elements.

Description: SLIDER FOR SECURING A STICK OF PASTE, MECHANISM FOR RETRACTING OF THIS STICK INTEGRATED WITH SAID SLIDER, AND CORRESPONDING COSMETIC APPLICATION DEVICE Background of the Invention The present invention relates to a slider for securing a stick of paste, particularly of the cosmetic type, to a mechanism that makes possible the retraction of this stick integrated with said slider, as well as cosmetic application devices equipped with said mechanism. The present invention also relates to a dampening slider for a paste stick. The present invention is applicable to the field of cosmetics and is applicable to any device for application of a paste-like material in a form of a stick to the body, for example foundation stick, lipstick, lip protector, deodorant stick, "blush" (rouge), make-up stick, lip or eye liner and so forth. The present invention also relates to other fields that use sticks of paste-like or friable materials that are to be applied to a surface and whose height decreases as they are consumed, for example, the paper trade, sticks of glue or gum, seals and so forth. In order to allow the necessary paste to be used during application without altering the condition of the remaining product, the stick is conventionally protected in a case which only exposes for consumption one end of the stick of a small constant thickness as the product is eliminated with use. For this purpose, the stick is arranged in a mechanism which makes it possible, on the one hand, to adjust the thickness of paste exposed for use, and on the other hand, to retract all of the paste into the protective case during storage or transport. This mechanism has two parts, one of which is manually movable in translation with respect to the other. One of these parts respectively constitutes the barrel, or protective case, and the other part the support for the stick, hereafter called the slider. Depending upon the application, each part is made up of one or more pieces of metal or plastic material. The translational movement is generated by the rotation of an intermediate helical system which mechanically couples the two parts together. In order to simplify the description, the protective cast part shall be considered stationary and the slider part, movable. A number of solutions have been developed for producing mechanisms which are more particularly suited to the dimensions and/or to the physicochemical nature of the paste molded in the form of a stick. For instance, in one solution, the slider is of the "elevator" type with a smooth and cylindrical surface, from which diametrically opposing pins project radially in order to be engaged in a spiral guiding groove laid flat against the internal surface of the sheath, and a rotating intermediate envelope with a longitudinal groove allows movement of the pins in the spiral and therefore the slider moves according to a helical movement. In another solution, the slider is of a screw-nut type, with a cylindrical external surface on which several ribs or grooves form threads which rest on a transverse rim of the envelope in order to advance according to a helical movement in the envelope, when the operator exerts torque to the end of the slider. There are also mechanisms such as direct translation thrustors, plungers, lever mechanisms and so forth. These mechanisms have major disadvantages. In effect, in the course of time, the stick shrinks and/or its seating is not mounted sufficiently in the slider, which causes detachment or breaking of the stick. Shrinkage comes from evaporation of certain components of the formula constituting the paste or of the solvent, water, silicone, solvent, and so forth, because of the incomplete sealing of the system, while the holding of the stick, ensured by a cylindrical seating possibly reinforced by fins, is not stable. Furthermore, these mechanisms, in connection with their structure, engender different defects during positioning of the paste in the package. This positioning is done by casting in the liquid phase, for example, between 60 and 90 degrees Centigrade, in order to shape the stick and to present it in its package. There are several casting modes which have the following disadvantages: Direct casting in the upper part situated on the side of the closing cap, called "from the top". In this case, the slider has a closed bottom in order to avoid leaks. While solidifying, the stick shrinks slightly and generates a small peripheral space which allows it to move with respect to the case. The major disadvantage of this process is that it requires an operation of leveling the upper surface of the stick. Moreover, adhering of the stick to the walls of the protective case occurs during solidification. The action exerted on the mechanism during its first use then causes breakage of the stick by shearing or tearing. Direct casting in the package in an overturned position, is called "from the bottom". In this case, the slider has a central opening making the filling possible, and the rest of the stick which forms the exposed part is closed off by a metal mold, possibly cooled, or by a cap or plug made of plastic material, or by a molding part integrated with the cap. The problem comes from the maximum shrinkage of the part of the stick in the slider, with respect to the rest of the stick, which makes this part fragile. Furthermore, the adhering of the stick to the walls of the case is also possible. Casting a mold, then placing the stick in the mechanism after solidification, is a process called "inserting". This process, the traditional method for lipsticks, requires numerous operations which can be automated. However, this process produces a relatively mediocre securing of the stick in the slider for small diameter products, a small surface area for securing, as well as for large diameter products, heavy weight of the stick. In order to remedy the disadvantages of the process of casting from the bottom and the inserting process, a proposal has been made in the past to produce ribs in the slider, arranged radially, possibly inclined or in helical form, in order to increase the adherence of the paste. This solution only provides mediocre holding ability because the adherence of the paste to the ribs varies considerably depending upon the composition of the stick and the surrounding temperature. The pigments and coloring agents used in cosmetics also have a great influence on the holding of the stick by adherence. A proposal has been made to reinforce the holding of the stick by holes made in the slider. This solution also is not satisfactory because the paste trapped in the holes is easily sheared off during the application of tensile force on the stick. Description of the Drawings Figure 1 is a perspective view of an example of a slider with a screw-nut mechanism of the present invention. Figure 2 is a perspective view of an embodiment of a slider with an "elevator" mechanism of the present invention. Figures 3a-3c illustrate other examples of forms of slider rings according to the present invention. Figure 4 illustrates a view in perspective of an example of a dampening slider with two turns for a screw-nut mechanism of the present invention. Figure 5 illustrates a view in perspective of an example of a dampening slider for an "elevator" mechanism, according to the present invention. Figures 6a to 6c illustrate examples of shapes of rings of a dampening slider, according to the present invention. Summary of the Invention One embodiment of the present invention includes a slider for securing a stick of paste. One end of the paste is applied by spreading as the stick of paste is consumed. The slider and stick are arranged in a protective case. The slider comprises an end part. The end part comprises a rim of substantially constant height in a form of a ring. The ring terminates in an end that is interrupted at least once by an opening. The ring allows for sufficient flexibility for anchoring the stick of paste and limiting the mechanical stresses connected with shrinkage. Another embodiment of the present invention comprises a dampening slider for holding a paste stick whose end is applied by spreading as it is consumed, the slider and the stick being arranged in a mobile carrying case. A flexible part is formed in the body of the slider for absorbing the pressures exerted on a holding zone for the stick at the edge of the slider. In one embodiment, a flexible part is formed by a spring which has at least one turn arranged in the vicinity of the holding zone for the stick, the turns having variable pitches and /or diameters, or formed by a leaf spring. Other flexible means can be used, such as an elastic washer or joint made of rubber or elastomer. Detailed Description The present invention includes a slider mechanism capable of gripping a stick of pasty material without causing an appearance of mechanical tension within the paste. More precisely, the present invention comprises a slider for securing a stick of paste, one end of which is applied by spreading as it is consumed, the slider and the stick being arranged in a movable carrying case, where an end part has a rim of constant height in the form of a ring, interrupted at least once by an opening and allowing sufficient flexibility for anchoring the paste and for limiting the mechanical stresses connected with shrinkage. In one embodiment, the rim of the slider is notched with at least one securing element having the general form of a "T", where it is possible for the number of securing elements to range up to 6 or 7 or even more, depending on the diameter of the stick. According to some more particular embodiments, the securing elements, of the same thickness as the slider, are arranged tangentially, inclined and/or radially with respect to the cylindrical surface of the hollow screw, the top of the "T" is symmetrical or asymmetrical, the securing elements are of identical size or at least of two different sizes. Depending upon the symmetry or asymmetry of the securing elements, the removal of the slider from the mold during its production is made correspondingly easier and simpler, as compared to unmolding by force. According to some embodiments, the slider is one of the elements of a mechanism for retracting a stick of paste, this mechanism being chosen from elevator mechanisms and screw-nut mechanisms. The securing elements have a form chosen from the trefoil, petal, and spear shapes. According to other characteristics, the slider is produced by molding a plastic material such as polyoxymethylene (POM), polyethylene terephthalate (PET), polypropylene, or a polymer of the styrene family. The slider of the present invention allows one to proceed with any type of filling of the sheath without the aforementioned disadvantages. Its shape varies from cylindrical, oval or flattened. One slider is compatible with all types of mechanisms, such as elevator, screw-nut, and so one. In Figure 1 , the slider comprises a support screw 10 with double external threads, the threads only beginning a distance from the first end part 1 of the slider, while at the other end 2 of the screw, notched ring 50 is formed. This ring 50 is comprised of four securing elements 51, arranged peripherally, in the extension of the cylindrical screw body. Each securing element 51 has the form of a "T". The radial thickness of the "T" is considerably less than that of the screw, and the lateral outgrowths 51a and 51b form the top of the "T", symmetrically with respect to central shaft 51c of the "T". The slider is produced out of polyoxymethylene (POM) by molding in a suitable mold under the conditions known to the expert in the field. In Figure 1, the slider also has support ring 5, arranged radially at the base of notched ring 50. This ring allows seating of the paste which is mounted in securing elements 51. In order to obtain a paste which is well anchored in the securing elements of the slider based on the invention, the casting of the paste is done in the liquid phase in the slider arranged in the protective casting. This casting is done while the paste is hot, at approximately 80 degrees, in one example of the casting of a foundation stick. In order to carry out this casting, the case and the slider are held towards the bottom, with the ring arranged in low position and the opening arranged in the upper position. The paste flows into the case which is plugged by a seal and is then cooled to room temperature. In Figure 2, slider 11 is of the elevator type. It is formed by the ring with four securing elements 51 which are extended by cylindrical body 3 equipped with two diametrically opposed pins 31 formed by molding. Figures 3a -3c show different forms of securing elements constituting the ring: trefoil shape 41 (Figure 3 a), petal shape 42 (Figure 3b) and spear shape 43 (Figure 3c). Other embodiments of the present invention relate to the domain of cosmetics and apply to any product for application of a pasty material in a stick form to the body, for example, foundation stick, lipstick, lip protector, deodorant stick, "blush" (rouge), make-up stick, lip or eyelid pencil, and so on. The present invention also relates to other domains in which sticks of pasty or friable materials are used that are to be applied by spreading on a surface, and whose height decreases as they are consumed, for example, stationary uses (sticks of glue or gum), odd jobs (seals) and so on. In order to make possible the use of necessary paste during application without altering the state of the remaining product, the stick is conventionally protected in a case which only exposes for consumption an end of the stick over a small constant thickness. The exposed end is eliminated during its use. For this purpose, the stick is arranged in a mechanism that allows one, on one hand, to adjust the thickness of paste exposed for its use, and on the other hand, to retract all of the paste into a protective case during storage or transport. This mechanism has two parts, one of which can be manually moved with respect to the other by translation. One of these parts, respectively, constitutes a sheath or protective case, and the other part, the support for the stick, hereafter called the "slider." Depending upon the execution, each part can be made up of one or more pieces, made of metal or plastic material. The translational movement is generated by rotation of an intermediate helical system which mechanically couples the two parts together. To simplify, the protective case is considered partly stationary and the slider, partly mobile. A number of procedures have been developed for executing mechanisms more particularly suited to the dimensions and/or to the physicochemical nature of the paste poured in the form of a stick. The slider can be of the "elevator" type with a smooth and cylindrical surface, from which diametrically opposed studs project radially and engage in a spiral guide groove lying against the internal surface of the sheath. An intermediate turning envelope with a longitudinal groove makes it possible to move the studs in the spiral and therefore the slider by a helical movement. The slider can be of the screw-nut type, with a cylindrical external surface on which one or more ribs or grooves form a thread which resets upon a transverse edge of the envelope in order to progress by a helical movement of the envelope when the operator exerts torque at the end of the slider. There are also direct translation push mechanisms, lever mechanisms, and so forth. However, the mechanisms have major disadvantages. The use of the stick takes place by direct transmission of the application force on the part of the body to be coated with no flexibility or gradualness of the pressure exerted. One embodiment of the present invention comprises a mechanism for dampening forces exerted on the paste stick transmitted by its slider. The mechanism comprises a dampening slider for holding a paste stick whose end is applied by spreading as it is consumed, the slider and the stick being arranged in a mobile carrying case, and in which a flexible part is formed in the body of the slider for absorbing the pressures exerted on a holding zone for the stick at the edge of the slider. For some embodiments, the flexible part is formed by a spring which has at least one turn arranged in the vicinity of the holding zone for the stick, the turns having variable pitches and/or diameters, or formed by a leaf spring. Other flexible mechanisms are usable, such as an elastic washer or joint made of rubber or elastomer. The slider enables one to obtain sensorial pleasure during use of the product. A gradualness in contact is felt by the user, the reactive pressure first very flexible, increases gradually for the same force exerted. Furthermore, positioning of the paste in the package is done by pouring in a liquid phase, for example, between 60 and 90 degrees Centigrade, in order to shape the stick and to present it in its package. The present invention comprises several modes of pouring. The modes comprise direct pouring into an upper part situated on the closing cap side, called "from the top". In this case, the slider has a bottom which is closed off in order to prevent leaks. In solidifying, the stick retracts slightly and generates a small peripheral space which allows it to move with respect to the case. This process requires an operation of smoothing of the upper surface of the stick. Moreover, sticking the stick against the walls of the protective case can occur during solidification. The action exerted on the mechanism during its first use can then cause breaking of the stick by shearing or tearing. Another mode comprises direct pouring into the package in an overturned position, called "from the bottom". In this case, the slider has a central opening to allow filling, and the rest of the stick which forms the exposed part is closed off by a metallic mold, possibly cooled, by a cap or plug made of plastic material, or by a molding part integrated in the cap. Sticking of the stick against the walls of the case can also occur. Another mode comprises pouring into a mold, then depositing of the stick in the mechanism after solidification, a process called "insertion." This process, traditional for lipsticks, requires numerous operations which can be automated. The pouring process induces defects due to sticking of material which can generate stick ruptures during application of axial or angular forces on the mechanism or because of vibrations or impacts. The slider, according to the invention, enables one to compensate for the effects of the causes of rupture. The slider, according to the invention, in particular, makes it possible to promote pouring from the bottom which is more economical than the other methods, considerably reducing the risks of breaking of the stick associated with its fragility and /or sticking of the paste. In effect, when the helical system begins to be actuated while the stick is stuck to the walls of the case, the flexible mechanism of the slider, according to the invention, deforms by torsion to the point of bringing about by advance of the screwing part, an axial thrust of the stick, making a clean detachment possible. The slider, according to the invention, can also be used with other filling processes. Moreover, it can be suited to a stick of varied shape. Besides, circular, this cross-section can be oval, polygonal, or flattened. According to one embodiment, the slider also has a holding zone for the paste in the form of a ring that is capable of resisting disconnection, which results from the contraction of material occurring during solidification based upon different pouring processes. Combined with the flexible mechanism, this holding ring makes it possible to keep a lasting mounting of the stick in the slider. Preferably, the ring has a constant height, interrupted at least once by an opening, and allows sufficient flexibility to anchor the paste and limit the mechanical stresses connected with contraction. In an advantageous form of execution, the edge of the slider is notched with at least one hooking element with a general shape in the form of a T. The number of hooking elements can range up to 6 or 7, or even more, depending upon the diameter of the stick. According to more particular embodiments, the hooking elements of the same thickness as the slider are arranged tangentially, slantwise, and/or radially with respect to the cylindrical surface of the hollow screw, the bar of the T is symmetrical or asymmetrical, the hooking elements are of identical size, or at least of two different sizes. According to other characteristics, the slider is made out of plastic material such as polyoxymethylene (POM), polyethylene terephthalate (PET), polypropylene, or a polymer of the styrene family by molding or injection. Such a slider is compatible with all types of mechanisms such as elevator, screw-nut and so forth. The invention also includes a retraction mechanism of any type integrating the slider as one of the elements of said mechanism. In Figure 4, the slider comprises support screw 10 with a double external threading, the threads begin only a distance from a first end part 1 of the slider, while at the other end part 2 of the screw, holding zone 20 is formed. The slider also has support ring 5, arranged radially at the base of holding zone 20. This ring allows one to seat the paste held in zone 20. In the vicinity of this holding zone, the slider has spring 3 with one turn for dampening produced in the body of the slider 10. The slider is produced out of polyoxymethylene (POM) by molding in a suitable mold under conditions which are known to an expert in the field. In Figure 4, slider 11 is of the elevator type. It is formed by a holding zone of the preceding type 20, extended by cylindrical body 4 equipped with two studs 41 molded in one piece and diametrically opposed. Dampening spring 30 is formed by several spirals 3c with differing pitch and diameter in order to improve the gradualness of contact of the stick. Figures 6a to 6c illustrate different shapes of ring 50 formed in the edge of the stick holding zone. In Figure 6a, this ring 50 is comprised of four hooking elements 51 arranged peripherally in the extension of the body of the cylindrical screw. Each hooking element has the shape of a T. The radial thickness of the T is appreciably less than that of the screw, and lateral protuberances 51a and 51b form the bar of the T symmetrically with respect to central rod 51c of the T. In order to obtain a paste which is well-anchored in the hooking elements of the slider, the pouring of the paste is done in a liquid phase in the slider arranged in the protective case, at the bottom of which an opening has been made in order to receive the pouring. This pouring is done hot, at approximately 80 degrees Centigrade, as an example of the pouring of a foundation. The hooking elements constituting the rig can also have the shape of a trefoil 52 (Figure 6b) or a spear 53 (Figure 6c). Other shapes are possible, petal shaped, hump shaped, or combinations of these different shapes. The invention is not limited to the embodiment examples described and illustrated. The securing elements can in effect assume shapes which are at least in part rounded. The height of the securing elements is preferably small with respect to the diameter of the case, for example, 1/10, in order to maintain sufficiently rigid holding. Certain securing elements can have a certain shape and a certain position, whereas other elements can assume a different shape and position.

Claims: IN THE CLAIMS What is claimed is: 1. A slider for securing a stick of paste, one end of the paste being applied by spreading as it is consumed, the slider and the stick being arranged in a protective case, the slider comprising an end part (2), the end part comprising a rim of substantially constant height in a form of a ring (50), interrupted at least once by an opening, and allowing sufficient flexibility for anchoring the stick of paste and limiting the mechanical stresses connected with shrinkage. 2. The slider according to claim 1, in which ring (50) has at least one securing element (51). 3. The slider according to claim 2, in which each securing element has a general form selected from "T" (51), trefoil (41), petal (42) and spear (43) shapes. 4. The slider according to claim 2 or 3, in which securing elements (51, 41, 42, 43) are arranged tangentially, inclined and/or radially with respect to the surface of the slider (10). 5. The slider according to claim 3, in which the top of the "T" of securing elements (51) is symmetrical. 6. The slider according to claim 3, in which the top of the "T" of the securing elements is asymmetrical. 7. The slider according to any one of claims 3-5, in which all the securing elements are of identical size. 8. The slider according to any one of claims 3-5, in which the securing elements are of at least two different sizes. 9. A retracting mechanism for a stick of paste, characterized by a slider according to any one of the preceding claims. 10. A cosmetic application device, characterized by a mechanism according to claim 10. 11. The slider of claim 1 , comprising a polymeric material. 12. The slider of claim 11 wherein the polymeric material is selected from the group consisting of polyoxymethylene, polyethylene terephthalate, polypropylene or a polymer of styrene. 13. A slider comprising : a screw with threads; a ring positioned on one end of the screw; and at least one securing element extending outwardly from the ring. 14. The slider of claim 13 wherein the slider comprises four securing elements. 15. The slider of claim 13 wherein the securing element has a "T" shape. 16. A dampening slider for holding a paste stick whose end is applied by spreading as it is consumed, the slider and the stick being arranged in a protective case, characterized by a flexible part (3, 3c, 30) formed in a body (4) of slider (10,11) for absorbing the pressures exerted on holding zone (20) for the stick at the edge of the slider. 17. The dampening slider of claim 16, in which the flexible part is formed by a spring which has at least one turn (3, 3c, 30) arranged in the vicinity of holding zone (20) for the stick. 18. The dampening slider of claim 17, in which turns (3c) have variable pitches and/or diameters. 19. The dampening slider of claim 18, in which the holding zone is in the form of ring (50) which is capable of resisting disconnection. 20. The dampening slider of claim 18, in which ring (50) has a constant height, interrupted at least once by an opening allowing sufficient flexibility to anchor the paste and limit the mechanical stresses connected with contraction. 21. The dampening slider of claim 20, in which the edge of the slider is notched with at least one hooking element (51, 52, 53). 22. The dampening slider of claim 21, in which the hooking element has a general shape chosen from a shape in the form of a T (51 a, 51 b, 51 c), a shape in the form of a trefoil (52) and a shape in the form of a spear (53). 23. The dampening slider of claim 22, in which the hooking elements are arranged tangentially, slantwise and/or radially with respect to the cylindrical surface of the holding zone. 24. A mechanism for retraction of a stick of paste integrating the slider according to any of the preceding claims, in which the slider is an element for holding the stick of paste of said mechanism. 25. A cosmetic application device, characterized by the mechanism of claim 24.

Inventors: MATHIEZ JEAN-LOUIS, MATHIEZ, JEAN-LOUIS
Applicants: COTY S A, MATHIEZ JEAN LOUIS, COTY S.A., MATHIEZ, JEAN-LOUIS
Application year: 2000
Main classification: A45D40
IPC codes: A45D40