US3915203A

US3915203A - Plastic-jacketed article and method of making the same

Info

Publication number: US3915203A
Application number: US215227A
Authority: US
Inventors: Nathan L Solomon
Original assignee: Solo Products Corp
Current assignee: Solo Products Corp
Priority date: 1970-11-23
Filing date: 1972-01-03
Publication date: 1975-10-28
Anticipated expiration: 1992-10-28

Abstract

A flexible article, such as a hair clip, is made of metal with a thin, continuous, uniform jacket of tough rigid plastic bonded to the metal. The plastic jacket is extruded about the metal prior to the forming and cutting operations. The formed, jacketed article is heated to temper the metal without harming the plastic jacket.

Description

United States Patent Solomon 5] *Oct. 28, 1975 PLASTIC-JACKETED ARTICLE AND [58] Field of Search 140/87, 82

METHOD OF MAKING THE SAME [75] Inventor: Nathan L. Solomon, Englewood, [56] References Clted Nj UNITED STATES PATENTS 2,589,518 3/1952 Taplinger 140/87 [731 Asslgnee' 3,073,355 1/1963 Grinnell 140/82 3,540,491 11/1970 Solomon 140/87 Notice: The portion of the term of this patent Subsequent to N 17 1987 Primary ExaminerLowell A. Larson h been i 1 Attorney, Ag'en't, or Firml-1oward C. Miskin [21] Appl. No.: 215,227 A flexible article, such as a hair clip, is made of metal R l t d A with a thin, continuous, uniform jacket of tough rigid 6O e a 8 pp Data plastic bonded to the metal. The plastic jacket is ex- 1 r' g f N 2 truded about the metal prior to the forming and cuts gg g22 ?gg3% ting operations. The formed, jacketed article is heated to temper the metal without harming the plastic 52 us. (:1. 140/87 Jack [51] Int. Cl. 321G 7/04 3 Claims, 4 Drawing Figures PLASTIC-JACKETED ARTICLE AND METHOD OF MAKING THE SAME This is a division, of application Ser. No. 92,264 filed Nov..23, I970, now abandoned, which was a continuation-in-part of application No. 531,264 entitled Plas tic Jacketed Hair Clip filed Mar. 2, 1966 now Pat. No. 3,540,491.

This invention relates to a plastic coated article, such as a hair clip, clasp for the hair, clothes hanger or spring and more particularly relates to an article having a uniform thin plastic jacket completely encasing a metal strand and a method of encasing and hermetically scaling in plastic an elongated wire or similar strand of any cross-sectional contour and to shape it and temper it into a finished article, such as a hair clip, a bobby pin, clothes hanger or spring without damaging or marring the plastic jacket.

It is common practice to form articles, such as bobby pins, hangers, springs, or the like from a metal strand or wire by bending, crimping or corrugating the wire, trimming the wire to form workpieces, shaping the wire about a forming tool and then coating the formed wire pieces with paint, enamel or lacquer, such as by spraying, dipping or the like. A recognized disadvantage of these methods is that these coatings are not flexible or durable and chip easily during the flexing while using, and further do not completely cover the metal. For example, in painting or spraying the formed hair accessory article, there is a bare spot of metal normally on the inside of the bent portion of the bobby pin or hair pin, which is the contact point of a bar or arm, which keeps the bobby pin open while the paint, enamel or lacquer is applied by spraying or coating. The wavesetting solutions widely used to form curls today are often corrosive to the metals used in the hair accessory items. Similarly, the cosmetic material and hair dye used in various sprays and treating solutions for the hair, often adversely react with the metal of these hair clips causing discoloration of the metal and the hair.

Also, during use, the constant flexing and spreading of the arms of the bobby pin or other hair pin loosens the paint or enamel from the metal core and cause flaking of the covering material, thereby exposing additional metal to the corrosive action of the various hair sprays and hair waving lotions. Enamel is often worn away where the arms of the bobby pin come in contact when not in use. The flaking of the paint or lacquer and the powder from the wearing off of the enamel left on the hair detracts from the appearance of the user and results in bobby pins having a short life span.

Molded plastic hair pins have been used with limited success. While these all plastic hair devices overcome many of the problems discussed above, they lacked springiness, flexibility and durability. To provide adequate strength, the molded plastic hair devices are made thicker and bulkier than the equivalent metal structure.

Attempts at coating metal articles, such as bobby pins and springs with plastic have not been satisfactory, since the plastic coating did not adhere to the metal sufficiently to remain bonded during the forming operations. The rigid plastic materials could not be applied to the hair items after forming, because of the corrugations and serpentine shape of most of the finished pieces. The plastic coating on the metal became marred during the forming operation, so as to detract from the appearance and snag hair. Further, variations in the thickness of the plastic resulted in uneven tempering which made the metal too brittle or too soft.

Therefore, it is an object of the present invention to provide a resilient one-piece formed strand of wire completely jacketed with a tough plastic material,

which will be long-wearing and will not flake, chip or wear away during long use, always be attractive.

A further object of the present invention is to provide a simple and effective resilient clasp for the hair, such as a bobby pin, which is completely encased and hermetically sealed in plastic, so that the metal base will not rust or discolor regardless of the hair sprays and waving solutions used, and which finish will not chip or flake off even after long use and severe flexing.

Another object of the present invention is to provide a method of uniformly jacketing with plastic an elongated untempered wire or similar strand of material, having any cross-sectional contour, shaping the jacketed strand into a finished article and heat-treating the jacketed strand to give the article its desired resilient properties.

A still further object of the present invention is to provide an article having a plastic jacket securely bonded to a metal core, which could be given a variety of permanent colors, including white, requiring no additional steps during the processing, which will not discolor during later heating and forming operations.

Still another object of the present invention is to provide a method of manufacturing a hermetically sealed, resilient bobby pin having a permanently bonded thin plastic jacket which will not discolor or be adversely effected by the acids, hydroxides, chemicals or dyes, such as used in hair waving solutions and hair sprays.

Another object of the present invention is to provide a plastic jacketed article that accomplishes all of the above and yet is inexpensive to fabricate, durable in use, pleasing to the eyes, reliable in operation, having permanent colors and a long life.

Other objects and features of the invention will be apparent when the following description is considered in connection with the annexed drawings in which:

FIG. I is a diagrammatic side-elevational view of an apparatus suitable for carrying out the method of the invention;

FIG. 2 is a diagrammatic side-elevational view of an apparatus for conveying the formed articles through various operations;

FIG. 3 is an enlarged front-elevational view of a bobby pin, produced according to the invention; and

FIG. 4 is a transverse cross-sectional view taken along line 4-4 of FIG. 3.

In accordance with the present invention, a thin uniform plastic jacket is applied to a wire strand. If the plastic jacket is too thick or is uneven in thickness, it will not form properly during the forming operations, or provide the finished article with a satisfactory appearance to the purchaser. During the crimping and bending operations a thick plastic layer will be marred by these forming operations and form an uneven unattractive surface on the article. Additionally, too thick of a jacket prevents good adhesion of the plastic to the metal strand, as well as being costly. Also, a thick coating results in uneven tempering of the strand by reason of the plastic coating reducing the heat transmitted to the metal through the plastic as the jacketed strand passes through a heating section.

As used herein, a thin coating refers to a layer of plastic on a side of metal strand in the range of about 0.0011 to 0.0055 inches. The layer must be uniform within the range of plus or minus 0.001 of an inch. A jacketed strand that provides good results has a metal strip of about 0.022 inch thickness and the jacketed strand has an outside measurement of about 0.0275 inches.

Broadly stated, the new method comprises feeding an endless strand of filament through a cleaning station, passing the treated filament through an extrusion die, through which is continuously forced a plastic material, so that the plastic material is formed about the filament. The jacket is cooled and the jacketed filament is formed, cut to a predetermined length and bent into shape, its ends are coated and the formed wire is heated to a predetermined degree for tempering the metal strand. The finished product could be packaged or collected in any conventional manner.

The following description of the invention is illustrated in connection with producing a hair accessory item, such as a bobby pin.

The schematic diagram of FIG. 1 illustrates the general arrangement of the various mechanisms and apparatus for producing a wire form item coated with a uniform thin coating of plastic and formed into a hair clip 11 illustrated in FIG. 3. As is shown, a continuous wire element is fed from a source of wire 12. Source 12 is shown as a payout reel rotatably mounted about a shaft 14. Wire 10 has any desired cross-sectional configuration. Advantageously, wire 10 is straightened and shaped to the size desired by any suitable mechanism, such as rollers or dies, indicated at 15. Wire 10 passes through a chemical bath 16 which removes dirt, oil, grease, scale or oxidation on the wire 10. After leaving bath 16, wire 10 passes through a heating station 17, which raises the temperature of the wire to fall within the range of about 300F to about 350F, which heats and further cleans the wire. From the heating station 17 the cleaned wire is fed into an extruder 18 having a suitable die 20, shaped to provide the desired finished size of the arms of the hair pins. The inlet of extruder 18 into which wire 10 is fed is coaxial with the extruder head 19, which contains the extruder orifice. A hard plastic material, such as nylon, is formed from the barrel of the extruder 18 under pressure through die orifice 20 longitudinally about wire 10 at the outlet end of extruder head 19. In die orifice 20 the plastic is formed about wire 10 as a covering or a jacket 24, having uniform outer dimensions. The outer dimensions of die orifice 20 are smaller than the outer dimensions of the coated wire. The speed of travel of wire 10 from die orifice 20 allows the coating 24 to enlarge in size a controlled amount after passing from die orifice 20, which provides a dimensionally constant thickness of the coating.

As the coated filament 10 leaves die orifice 20, the hot plastic coating is cooled prior to further handling to avoid distortion or disturbing the coating. As shown, the hot plastic coating 24 is cooled by passing through a cooling station 26, which has cooling fluid therein, which would be either water or air. The plastic coated wire upon leaving cooling station 26 is safe to handle and be worked. As shown, the coated wire leaving cooling station 26 is driven or moved forward by a pair of driving wheels 28 rotating in the direction as shown. If desired, a capstan may also be used.

The plastic coated wire, indicated at 29, passes from driving wheels 28 into a forming operation. As shown, wire 29 is fed into a crimping apparatus 30 for forming in the wire the proper corrugations, or multiple wave 31, shown in bobby pin 11 in FIG. 3. After a portion of the wire is properly corrugated, a cut-off tool trims the wire to a predetermined length and kicks up one end. Advantageously, the crimping, cut-off and kick-up is formed in one operation, shown as mechanism 30. The formed wire forms, shown as 32, are fed from apparatus 30 into the final bending and forming unit 33 directly above a forming pin 34. Arranged beneath pin 34 is a carrier or band 35. Forming unit 33 bends wire form 32 about pin 34 and strips form 32 from pin 34 onto band 35, which conveys forms 32 onto the following operation. By varying the speed of band 35, the spacing of forms 32 thereon can be varied. The bending of form 32 is accomplished by a pair of arms 38 moving towards each other and forcing the ends of form 32 towards each other. Pin 34 aids in maintaining its corresponding wire form 32 against displacement. After the bending operation, arms 38 return to their initial position ready to receive their next workpiece. As indicated, the crimping, cut-off and bending operations result in a bobby pin 11, described above. This operation is continued to repeat the forming operations.

As the wire forms are formed into bobby pins, they are positioned on band 35 and conveyed or carried through a dipping process, indicated at 40, for coating or covering their exposed ends. The ends have metal exposed due to the trimming operation. The ends can be covered by spraying with a plastic, if desired. Advantageously, the end-covering material is a plastisol, which is compatible with the plastic used for the coating, so as to form a complete plastic jacket. The jacketed bobby pins are then conveyed through a heater 42 where the coated ends are cured and the metal core is tempered to provide the resiliency and spring necessary for the bobby pin to operate properly. If the plastic coating on the bobby pin were not uniform, the metal strand would not have a uniform temper, so that portions with a thicker plastic coating would be less resilient than those portions of the metal having a thinner coating. However, if the steel is hardened too much by the coating being too thin, the metal would be too brit tle and would snap in use, when expanded or stretched for inserting hair. Upon the hair clips leaving the heating station 42, the formed and jacketed hair pins are assembled in groups having a predetermined number of pins by mechanism 43, which bunches the pins in groups of ten, as shown. Mechanism 43 moves towards band 35 to hold the pins 11 thereon until a predetermined number are bunched, then moves away, so as to allow bunched pins 11 to move on. The band 35 continues its forward movement all of this time. These uniform groups of pins are conveyed to a carding operation, or packed in some manner, not shown.

Bobby pin 11 made in accordance with the present invention is shown in FIG. 3 having a pair of

arms

48 and 50 with corrugations 31 along one arm 50, and being bent about portion 52.

Arms

48 and 50 can be flexed many times with no harm to, or separation of, the coating 24 on the metal strand. The end of arm 50 has a kick-up 54, which aids in receiving hair between

arms

48 and 50. The free ends of

arms

48 and 50 are coated, as at 56 and 58, respectively.

Any plastic material for applying coating 24 may be used, which forms a tough, resilient, formable coating, and which has high resistance to deformation and chemicals, and has good properties of aging, light fastness and weathering. Some examples are nylons, polycarbonates, fluorocarbons and acetal resins.

The speed of the forming and bending apparatus and 33 is synchronized to the lineal speed of the coated filament l0 delivered from extruder 18 by feed wheels 28. The uniform spacing of the formed pin on band 35 is controlled by the relative speeds of band 35 and the speed of pins leaving bending apparatus 33.

While a continuous coating and fabricating operation is shown in FIGS. 1 and 2, if desired, it can be done in several operations, namely taking up the coated wire on spools and retransferring the wire onto either larger or smaller spools for feeding through the forming and tempering operations. Also, the plastic when fed into the extruder can have various additional ingredients added for providing various colors and effects.

Employing the method and apparatus of the present invention. provides a uniform thin coating on a metal strand, which falls within the range of about 0.001 to about 0.0055 inches on a side and controls closely the outer dimensions of the jacketed wire of any crosssectional configuration. This thin coating can be mechanically formed, such as by corrugating and bending, without breaking or separating the coating, or marring its smooth surface, and the metal strand then tempered within its jacket to provide the desired degree of springiness and flexibility. No metal is exposed to the chemicals used in hair sprays, or touches the scalp or hair of the user.

While the description of the invention showed the production of a hair accessory item, it is not intended to be so limited. It is evident that other forming steps can replace its bending and crimping steps described.

While preferred embodiments have been described, it would be understood that many variations thereof will be readily apparent to those skilled in the art without departing from the spirit thereof. Therefore, it is intended that the foregoing description shall be deemed illustrative only and not construed in a limiting sense, the present invention being defined solely by the appended claims.

What I claim is:

1. The method of making a plastic jacketed bobby pin which comprises cleaning a strip of metal, applying a tough rigid plastic continuously about said strip, passing said strip with said plastic through a die to form a thin, continuous, uniform plastic coat about said metal strip, cooling said plastic coating, crimping a portion of said coated metal strip to form multiple waves, trimming said strip to a predetermined length including said crimped portion, bending said length into a substantially U-shaped form having a pair of arms, and coating the free end of each of said arms with a plastic material compatible with said first-mentioned plastic for hermetically sealing the entire metal strip.

2. The method of making a bobby pin in accordance with claim 1, further including heating said strip of metal prior to applying said plastic about said strip.

3. The method of making a bobby pin in accordance with claim 1, wherein said plastic material is a polyamide resin.