MXPA00007867A - Method of manufacturing a razor - Google Patents

Abstract

A method of affixing a shaving aid element (38, 42) to a razor (10) is disclosed, which includes the step of extruding the shaving aid element to form a strand (50) of shaving aid material. The strand is then rolled onto a continuous spool (48) for storage. During assembly, the strand is fed to an ultrasonic welder/cutter (62) for cutting the strand into a predetermined length and for welding the shaving aid element to a razor. The strand may be cold worked using rollers (54A, 54B) to increase its ductility and to alter its shape prior to being cut and welded.

Description

METHOD FOR MANUFACTURING A SHAVING MACHINE FIELD OF THE INVENTION The present invention relates to a method for manufacturing a razor and more particularly to a method for manufacturing a razor having an auxiliary shaving element. BACKGROUND OF THE INVENTION Frequently, it is desired to incorporate an auxiliary razor into a disposable razor. U.S. Patent No. 4,170,821 ("'821" patent) discloses a razor cartridge with a water soluble solid shaving aid. The shaving aid can be a lubricant, a softener, a razor cleaner, a pharmacological agent, aloe vera, vitamin E, lanolin, and other ingredients or any combination of these ingredients. A typical composition of a shaving aid comprises a hydrophilic polymer and other soluble shaving aids such as those listed above integrated into a matrix of a hydrophobic polymer. Typically, polyethylene oxide is used as the hydrophilic polymer and polystyrene is used as the hydrophobic polymer. Other compositions can also be employed. Regardless of the exact chemical composition employed for the shaving aid, injection molding or extrusion may be employed to manufacture shaving aids in amounts necessary for mass production. In injection molding, the shaving aid is co-molded directly into the razor as shown in U.S. Patent No. 4,778,640. In the case of extrusion, the shaving aid is extruded into the desired shape and then typically cut to a size as shown in U.S. Patent No. 4,624,051 ("'051" patent). In addition, the placement of the pre-cut elements in the proper orientation and in the correct position for fixing on the razor complicates the manufacturing process. Methods for attaching the pre-cut shaving aid on the razor include mechanical means and adhesives. When a mechanical means is employed, the razor is manufactured with an internal cavity and the auxiliary shaving element is inserted into the cavity as illustrated in the '051 patent. A tongue or any similar member retains the auxiliary shaving element in the cavity. Disadvantages associated with this method include the need to accurately pre-cut the auxiliary shaving element within a narrow range of tolerances, as well as the cost and additional manufacturing time to produce the tabs or similar members. When an adhesive such as an acrylate adhesive is used, the shaving aid and the razor must be properly placed after the application of the adhesive and gag together for a certain period of time to allow the formation of a bond . Even when the curing time can be reduced by the application of energy such as ultraviolet radiation, this adds another manufacturing step and raises the cost of production. In addition, ultraviolet radiation can be absorbed or diverted by structural elements in the razor units, thus preventing a uniform curing of the adhesive. Either way, even an accelerated cure time decreases manufacturing efficiency. Other disadvantages with adhesives are the added expense of the adhesive and the difficulties associated with the handling of the adhesives. The application of ultrasonic energy to join plastic components has been used in many industries. In ultrasonic welding, a source of energy in the solid state transforms electrical energy into mechanical energy of 20 kHz or 40 kHz. A converter changes this electrical energy into ultrasonic mechanical vibratory energy. A speaker transmits the ultrasonic mechanical energy directly to the parts to be assembled. A combination of applied force, surface friction, as well as intermolecular friction on the contact surface between the parts to be joined raises the temperature until the melting point of the material is reached.

The force is maintained after the suspension of the vibrations and a molecular bond or welding is produced at the interface. A more complete presentation of ultrasonic welding is found in the following publications that are incorporated here by reference: "Ultrasonics &Microprocessors Team-up for Efficient Assembly", (Ultrasonic energy and microprocessors come together for efficient assembly), Assembly Engineering, November 1987, and Ultrasonics Plastics Assembly, 1979, published by Branson Ultrasonics Corporation. Ultrasonic welding has also been used in the shaving industry. For example, U.S. Patent No. 5,070,613 discloses a razor blade unit with a blade fastener secured by an attachment strap ultrasonically welded onto a lower portion of the razor blade unit. In addition, it is known to ultrasonically weld a head portion of a disposable razor on a handle portion. However, ultrasonic welding of a shaving aid has not been suggested or disclosed in the art. Accordingly, there is a need for a workable method in which a shaving aid is ultrasonically welded on a razor. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method for manufacturing a razor in which at least one auxiliary razor has been ultrasonically welded onto the razor. Another object of the invention is to optimize the manufacturing process of a razor having a shaving aid attached thereto. A further object of the invention is to extrude an auxiliary shaving element in the form of a continuous wire to facilitate storage and eventual fixing on the razor. It is also an object of the present invention to cold-work the wire until the desired shape is obtained before fixing the shaving aid on the razor. These and other objects of the invention are achieved through a method for fixing an auxiliary shaving element on a razor, comprising the steps of: extrude the shaving aid on a continuous wire, wind the wire on a spool, feeding the spool wire to a cutting machine, cutting the wire into predetermined segments of shaving aids; and fastening at least one auxiliary shaving element on a razor. Said method may also include the step of extruding the auxiliary shaving element into a continuous wire having a circular cross section, and the step of cold working the wire before the step of cutting the wire. In addition, said method may also include the step of ultrasonically welding the shaving aid onto the razor, directing the ultrasonic energy on the side walls of a channel in the razor adapted to receive the at least one auxiliary shaving element. . BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an enlarged perspective view illustrating a razor with shaving aids manufactured in accordance with the present invention; Figure 2 is a schematic of a manufacturing assembly employing the method according to the present invention for producing the razor; Figure 3 is an enlarged schematic view of a cold working portion of the manufacturing assembly; Figure 4 is an isometric view of a horn of an ultrasonic / cut welding machine; Figure 5 is a cross-sectional view of a razor cover having the shaving aids; and Figure 6 is a cross-sectional view of the razor cover illustrated in Figure 4 without the shaving aids. DESCRIPTION OF THE PREFERRED MODALITIES As shown in Figure 1, a razor comprises a leaf seat 10 with a seat portion 12 and a connection portion 14. The connection portion 14 makes contact with an arm 16 of the handle 18, only a part thereof is illustrated. The connecting portion 14 and the arm 16 are permanently fixed to each other by any suitable method such as an adhesive or by ultrasonic welding. Thus, the razor illustrated in Figure 1 is a disposable razor in which the entire unit is discarded when the blade has lost its edge. The present invention can also be used to manufacture a disposable cartridge adapted to be coupled and uncoupled from a reusable razor handle, and therefore, the present invention is not limited to a particular type of razor configurations. The seat portion 12 includes a rectangular opening 20 at each end and several circular holes 22 positioned therebetween. A seat portion 12 is configured and sized to receive at least one blade 24. The blade 24 has end slits 26 and several circular holes 24 therebetween. When a sheet 24 is properly seated in the seat portion 12, the slits 26 align with the openings 20 and the holes 22 align with the holes 28. Even when the razor is illustrated having only one blade, the method of Manufacture according to the present invention can also be used in the case of disposable razors or cartridges having several razor blades. With the extrusion of a cutting edge 30, a cover 32 covers the entire sheet 24. Rivets 33 (illustrated in Figure 5) and posts 34 extend from a rear side of the cover 32. A sheet 24 is fastened by rivets 33 inserted in holes 22 in the seat portion 12 through the holes 28 in the sheet 24, and by posts 34 inserted in rectangular openings 20 through end slots 26. The ends 35 of the rivets 33 are compressed to hold permanently the cover 32 and the sheet 24 on the sheet seat 10. The cover 32 has an upper channel 36 adapted to receive a first auxiliary shaving element 38 and a lower channel 40 for receiving a second auxiliary shaving element 42. The first element shaving aid 38 and second shaving aid 42 can be lubricants, softeners, razor cleaners, pharmacological agents, aloe vera, vitamin E, lanolin, or any combination ation of these. It is preferred that each of the shaving aids carries a different shaving aid. It is also important to note that the present invention can be used with any number of shaving aids. After assembly of the razor, a cover 44 covers the cutting edge 30 and offers protection until its use and between uses. In a preferred embodiment, an auxiliary shaving element is extruded in a continuous wire in a well known manner and cooled with air before being wound onto a storage reel. Methods for extruding shaving aids have been disclosed in the '821 patent and in the references mentioned herein, and are therefore incorporated herein by reference. U.S. Patent No. 4,182,582 also teaches a method for co-extruding different polymers including hydrophilic and hydrophobic materials and is incorporated herein by reference. The '051 patent also discloses that the hydrophobic polymer matrix can constitute up to 50% or more by volume of the shaving aid. The hydrophobic polymer can constitute from 20% to 80% by volume of the shaving aid. It is preferred that the matrix constitutes approximately 25% -35% by volume of the shaving aid and the matrix material is preferably polystyrene. The remaining volume of the shaving aid comprises the various water-soluble shaving aids. further, the preferred shape for the extruded shaving auxiliary wire is a circular cross section, since it is the optimum shape for storage on a reel. It is also preferred that environmental factors such as temperature and humidity be controlled during the extrusion process in order to minimize the absorption of water by the hydrophilic polymers contained in the shaving aid. The manner in which the shaving aid is fixed on the razor is shown in FIG. 2. A manufacturing assembly 46 employs a spool 48 containing an auxiliary shaving element in the form of a continuous wire 50 as discussed above. The wire 50 is fed from a spool 48 through tension elements 52 which pull the wire 50 tautly on the left roller 54A and on the right roller 54B to cut it to the predetermined length and to fix it on the wire winder. to shave. Thus, according to the present invention, the cutting of the auxiliary shaving element in pre-measured segments for storage and then orientation and positioning of the shaving auxiliary elements before their fixing on the razor in accordance with that illustrated in the patent. 051 were removed. The rollers 54A, 54B are adapted to pull a wire 50 from the spool 48 and feed the auxiliary shaving element from the wire 50 to the razor assembly unit. The rollers 54A and 54B can also cold-work the wire 50 in any desired profile of the shaving aids that can be co-wound including symmetrical cross sections such as circular, square, rectangular, triangular, and elliptical cross sections, as well as cross sections. transverse non-symmetrical. As best seen in Figure 3, left and right rollers 54A, 54B have contact surfaces 56A, 56B, respectively. The degree of cold working and the final profile of the shaving aids depend on the geometry and dimension of the contact surfaces 56A, 56B. It is not necessary for the contact surfaces 56A, 56B to be identical. For example, the contact surface 56A may be rectangular and the contact surface 56B may be round. It has been observed that cold working also offers a 50 wire with greater ductility. The increased ductility of the wire 50 offers greater flexibility in the manufacturing process. Alternatively, heat can be added to the rollers 54A and 54B in order to facilitate the process. With reference to Figures 2 and 3, the wire 50 is fed into a wheel 58 after the cold working step. The wheel 58 has several attachments 60. Each attachment 60 is configured and has a dimension suitable for receiving a cover 32 and any method for feeding the cover 32 on the attachment 60 can be employed. For example, the covers 32 can be fed into attachments 60. on a wheel 58 through a vibrating cup, such as vibrating cups available from Moorseed Corp. in Indianapolis, Indiana, United States of America. When a portion of wire 50 has been fed and aligned with the abutment 60, a predetermined length of wire 50 is cut and the auxiliary shaving element is fixed on the cover 32 in the upper channel 36 or in the lower channel 40. A machine ultrasonic welding / cutting machine 62 cuts a wire 50 in a predetermined length of shaving aid and carries out an ultrasonic welding of the shaving aid on the razor. The ultrasonic welding machine / cutting machine 62 includes an actuator that contains a converter, driver, horn, and pneumatic or servo controls. The actuator carries the horn 64 in contact with the abutment 60, applies the appropriate force during welding and cutting, and retracts the horn after the welding cycle. After ultrasonically welding the shaving aid on the cover 32, the cover 32 is transferred to a quality control unit 66 for inspection. For simplicity, FIG. 2 and FIG. 3 illustrate the attachment of only one auxiliary shaving element on the cover 32. To hold a second auxiliary shaving element, a second configuration of a spool, tension elements, and rollers would feed a second wire on the wheel 58. A second ultrasonic welding machine / cutting machine is used to cut and weld the second auxiliary shaving element on the cover 32. In another preferred embodiment of the invention, the ultrasonic energy coming from the speaker 64 is focused out of the bottom of channels 36, 40 and towards the side walls of these channels. As shown in Figure 4, a horn 64 has a tapered body 68 terminating in an energy transmitter 70. The geometry of the horn 64 controls the direction of the ultrasonic energy preferably toward the side walls 72A and 72B (FIGS. and 6) of the channels 36, 40. More specifically, an energy transmitter 70 comprises a circular portion 71 configured and of such dimensions that it fits over the shaving aid 38, 40. A circular portion 71 terminates at the corners 74A and 74B. The ultrasonic energy coming from the transmitter 70 preferably partially melts a portion of the side walls 72A and 72B, illustrated in Figure 6 to form a weld between the shaving aid and the side walls. As shown in Figure 5, the shaving aids are illustrated in the form of a splice with side walls 72A and 72B. After application of the ultrasonic energy, the splice areas are melted together to form two continuous welding lines between each shaving aid and channel 36, 40 to permanently hold the shaving aid on the razor cover. It is known that a strong ultrasonic welding can be produced if the parts to be joined are made of the same material or similar materials, therefore, if polystyrene is used, as the hydrophobic component of the shaving aid 38, 42, it is preferred that cover 32 is also made of polystyrene. However, the method according to the present invention can produce a bond of sufficient strength between different materials. Thus, a sufficient connection can be established between the auxiliary shaving element 38, 42 and the cover 32, even though these elements are made of different materials. While it is evident that the illustrative embodiments of the present invention disclosed herein meet the objectives set forth above, it will be noted that numerous modifications and other modalities may be designed by persons skilled in the art. Accordingly, it will be understood that the appended claims are intended to encompass all modifications and modalities that fall within the spirit and scope of the present invention.

Claims (1)

1. CLAIMS A method for fastening an auxiliary shaving element on a razor, comprising the steps of: extrude the shaving aid on a continuous wire; wind the wire on a spool; feeding the wire from the reel to a cutting machine; cutting the wire into predetermined segments of shaving aids; and fastening at least one auxiliary shaving element on a razor. The method according to claim 1, wherein the step of extruding the auxiliary shaving element includes the step of extruding the auxiliary shaving element into a continuous wire having a circular cross section. The method according to claim 1, further comprising the step of cold working the wire before the step of cutting the wire. The method according to claim 1, wherein the step of holding at least one auxiliary shaving element on the razor further includes the step of ultrasonically welding the shaving aid onto the razor. The method according to claim 4, wherein the step of ultrasonically welding further includes a step of directing the ultrasonic energy towards side walls of a channel in the razor adapted to receive at least one auxiliary shaving element. A method for manufacturing a disposable razor with at least one auxiliary shaving element comprising the steps of: ultrasonically welding the at least one auxiliary shaving element on the razor; seat at least one razor blade on a sheet seat; and fixing the at least one razor blade between the leaf seat and a cover. The method according to claim 6, further comprising the step of directing the ultrasonic energy towards side walls of at least one channel in the cover of a suitable size to receive the at least one auxiliary shaving element in such a way that the less an auxiliary shaving element and the lid are joined by welds formed between the side walls of the at least one auxiliary shaving element. The method according to claim 6, further comprising the step of extruding the auxiliary shaving element into a continuous wire. 9. The method according to claim 8, further comprising the step of storing the continuous wire on a reel until use. The method according to claim 8, further comprising the step of cold working on wire to produce a profile corresponding to a profile of the at least one channel in the lid. The method according to claim 10, further comprising the step of carrying out cold work by passing the wire between two rollers. 12. The method according to claim 8, further comprising the step of cutting the wire into a predetermined segment of the at least one auxiliary shaving element. The method according to claim 6, wherein the cover is made of polystyrene and the at least one auxiliary shaving element contains polystyrene. The method according to claim 13, wherein the at least one auxiliary shaving element contains 25% -35% polystyrene. 15. The method according to claim 8, further comprising the step of controlling ambient temperature and humidity to reduce the water absorption of the wire. 16. A disposable razor or cartridge comprising a blade seat, at least one razor blade, a cover, and at least one auxiliary razor; wherein the at least one auxiliary shaving element is ultrasonically joined to the razor or cartridge. . The razor or cartridge according to claim 16, wherein the joints are located between the at least one auxiliary shaving element and the cover. . The razor or cartridge according to claim 17, wherein the cover has at least one channel for receiving the at least one auxiliary shaving element. . The razor or cartridge according to claim 18, wherein the joints are located on side walls of the at least one channel. The razor or cartridge according to claim 16, wherein the cover is made of polystyrene and the at least one auxiliary shaving element contains polystyrene.