US3499686A - Method of making a brush - Google Patents

Description

March 10,1970 w, J, mm :m 3,499,686

us'mon or MAK NG A nmisn Filed Dec. 21,1967

bliu sq Mam/)7 A A/05V B m lmvaqw/wr AZTW W ORNE 5 INVENTO ohms? United States Patent 3,499,686 METHOD OF MAKING A BRUSH William James Landen, Cheshire, and Gunnar F. Lundquist, Kensington, Conn., assignors to The International Silver Company, Meriden, Conn., a corporation of Connecticut Filed Dec. 21, 1967, Ser. No. 692,416 Int. Cl. A46d 3/08 US. Cl. 30021 4 Claims ABSTRACT OF THE DISCLOSURE The invention contemplates securing a bundle of natural brush bristles in assembled relation to a tubular retaining ferrule having a bore open at both ends. The root ends of the bristles are assembled within the bore, with the tip ends projecting outwardly as the applicator end of the brush. A guided pin is inserted on the central axis of the bundle to radially outwardly further compact the bristles in the bore, and to serve a molding function as a thermosetting resin is cured to hardness; the root ends are thereby bonded to each other and to the ferrule, and a smooth central passage is defined for pomade supply.

BRUSH CONSTRUCTION AND METHOD This invention relates to internally fed brushes of natural bristle and, in particular, to such a brush construction and its method of manufacture.

Feed-through brushes of the character indicated find use in a variety of applications, including cosmetic applicators wherein a reservoir of pomade or the like supplies the brush bristles from the rear, being forced through spaces between bristles. In quality brushes, which employ natural bristle such as pony hair, squirrel or sable, the brush bundles have been assembled to a nose piece or ferrule, with the root ends of the hairs glued to each other and to the bore of the ferrule, the feed-through passage being generated by drilling the glued assembly from the pomade-supply end. This process necessarily destroys and breaks numerous individual bristles, thus inviting the annoyance of bristle fragments, as a contaminant of the applied pomade. Necessarily, a number of the original bristles are completely lost, so that the ability to lay down a uniform pomade application is impaired.

It is, accordingly, an object of the invention to provide an improved applicator brush of the character indicated, as well as an improved method of making the same.

It is a specific object to provide a natural-bristle applicator brush in which all bristle elements are continuous throughout, in which greater compacting of bristles is achieved within the retaining ferrule or nose piece, in which there is absolutely no waste or destruction of the natural bristle assembled in the ferrule, and in which the possibility of dispensing bristle or glue fragments with pomade or the like is reduced to an absolute minimum.

It is another object to achieve the foregoing objects with a structure and method which are inherently simple, inexpensive, and foolproof, lending the same to mass-production.

Other objects and further features of novelty and invention will be pointed out or will occur to those skilled in the art from a reading of the following specification, in conjunction with the accompanying drawings. In said drawings, which show, for illustrative purposes only, a preferred embodiment of the invention:

3,499,686 Patented Mar. 10, 1970 FIG. 1 is a view, in side elevation, of a pomade applicator incorporating a feed-through dispensing brush tip of the invention;

FIG. 2 is an enlarged side elevation of the nose piece of FIG. 1, the view being partly broken-away on a secends. The root ends of the bristles are assembled within the bore, with the tip ends projecting outwardly as the applicator end of the brush. A guided pin is inserted on the central axis of the bundle to radially outwardly further compact the bristles in the bore, and to serve a molding function as a thermosetting resin is cured to hardness; the root ends are thereby bonded to each other and to the ferrule, and a smooth central passage is defined for pomade supply.

Referring to FIG. 1 of the drawing, the invention is shown in application to a cosmetic pomade-dispensing applicator having a tubular body 10 which serves as the pomade reservoir. At one end, the nose piece or ferrule 11 is secured to body 10, preferably in connection with a resilient seal ring 12 which may also seal the nose end when a cupped closure cap (not shown) is replaced, after pomade use. Internally fed bristles 13 extend out beyond the tip of the pose piece; and a manual actuator 14 carried at the other end of the body is operable to advance piston means 15 within body 10, for controlled dispensing supply of pomade or the like from the reservoir to the brush bristles 13. The piston-actuating mechanism forms no part of the invention and is therefore not further described.

The completed nose assembly of the invention is shown in FIG. 2, wherein the ferrule 11 is seen as a single piece which may be die-cast or formed on a screw machine. The body of ferrule 11 surrounds a continuous bore, characterized by an inner reducing taper 16 of length T, between a larger cross-sectional area at the liquid-receiving end 17 and a smaller cross-sectional area at the brush-projecting end 18. The ferrule body expands, from a minimum radial thickness near the tip end 19, to a size at 20 consistent with that of body 10; a threaded projecting end 21 engages the 'body 10, enabling the seal ring 12 to be compressed and located against a shoulder 22.

As previously explained, the bristles 13 are of straight natural hair, oriented to outwardly project the tip ends, and to contain the root ends within the bore of ferrule 11. The root ends are shown near the base end of taper 16, and a region 23 with the bore is sectioned for plastic to show the employment of thermosetting resin to consolidate into a single unit a substantial length of all bristles within the bore and near the root ends. Preferably, this consolidated region terminates short of the smaller or tip end of the bore. Additionally, a smooth-bore central passage 24 is provided, free of bristles, and lined by continuous bristle and cured resin, throughout the region 33.

FIGS. 3 to 6 illustrate successive steps in the preferred method of making the structure of FIG. 2. FIG. 3 shows the ferrule 11, just prior to insertion of the bundle of bristles 13 at the tail end 17. The orientation is such that the smaller (tip) ends of the bristles are inserted first, with the base or root ends at the rear. The tapered region 16 is in the order of 10 included angle and is smoothly formed with the adjacent bore ends 17-18, so that smooth loading of the bundle 13 may proceed, using known techniques. The tip ends of bristles 13 are then drawn out the tip of the ferrule, until the root ends are at or near the base region of taper 16. Preferably, the compliment of bristles thus loaded into the ferrule is essentially the same as if the bristle density were to be uniform throughout the dispensing section, i.e., just as many bristles as if there were to be no passage 24.

Having thus loaded the bristles 13 into ferrule 11, this partial assembly is placed, inverted, in a locating aperture 26 of a support member or plate 27, allowing for free downwardly projecting suspension of bristles 13, as shown in FIG. 4. A second plate 28, having apertures as at 29, is then set against shoulder 22 to assure precise vertical orientation of the loaded ferrule. It will be appreciated that for quantity production, plural loaded ferrules may be similarly accommodated at registering further apertures (not shown) in plates 27-28. The assembly is now ready for molding.

Molding proceeds by first applying a predetermined quantity of liquid thermosetting resin (e.g., phenolformal dehyde) to the upwardly open end of the ferrule. This is suggested in FIG. 4 by the dashed outline 30 for the measured drop or drops of resin. A jig or guide member 31 (FIG. is then located against the open end of the ferrule so as to align its guide bore 32 with the bore of the ferrule. Jig 31 is shown with a reduced end located in the bore section 17 and with a shoulder seated on the upper exposed edge of ferrule 11. An elongated pin 33 is reciprocably guided at 32, with a sharply pointed tip 34 poised for clean entry into the root end of the bristles 13. Depression of pin 33 is suggested by an arrow, the full extent being limited by head 35 abutting the upper surface of jig 31.

At this juncture, the parts relationship is that shown in FIG. 6, wherein the pointed tip 34 extends beyond the ferrule but short of the bristle ends, and wherein the cylindrical body of the pin also extends beyond the ferrule. The rack 27-28 of ferrules 11 is then placed in an oven to cure the resin to final hardness. In the heating involved in curing, the resin 30 flows by gravity and by capillary action to permeate all interstices between bristles, for a longitudinal extent reflecting the controlled quantity injected at 30. As previously indicated this quantity, which must be determined by experiment for the particular conditions of bristle nature, bristle density, bore size, etc. is nevertheless chosen to accomplish bonding in region 23 to a longitudinal extent which is short of the ferrule-tip end. The nature of resin flow during curing will be understood to define a smooth continuous passage 24 within ferrule 11 and to bond the bristles to each other and to the bore of the ferrule.

After curing, plate 28 and jig 31 (with pin 33) are removed, and the finished sub-assembly (nose piece with bristles) is ready for use, as shown in FIG. 2. For certain precision uses, it may be desired to have all projecting bristles trimmed to the same projected length. The clearance between pin tip 34 and the bristle tips at X (FIG. 6) permits a suitable trimming cut to be taken, as on alignment 36, before plates 27-28 are disassembled.

In a highly satisfactory employment of this invention, a nose piece of As-inch diameter outer-end bore has been packed with sable bristle. The bristle length contained within the ferrule 11 has been substantially one-half inch, about one-half of which was anchored in the tapered region 16, which reduced the area of bore section by about 3 percent in a distance T (FIG. 3) of one-quarter inch. The diameter of pin 33 serves to further reduce, by substantially 4 percent, the cross-sectional area at 18, so that pin-insertion radially outwardly displaced and compressed the bristles (at 18) to that extent. To provide clean separation at the molded passage 24, pin 33 was pre-treated with a fluorocarbon releasing agent; a single such coating is found to serve repeated recycling of the molding operation on successive pieces. The guide bushing or jig 31 is also preferably similarly treated with a fluorocarbon releasing agent, to avoid bonding the bushing to the ferrule, should the resin spill or be carelessly applied. Curing of the resin to complete bonding and molding was accomplished at an oven temperature of 275 F. for four hours, following instructions given for the particular commercially available liquid resin which was employed. Upon removal from the oven, the entire unit was left to assume room temperature, over a period of hours. Clean pin removal, without damaging the brush or the passage 24, was then accomplished.

It will be seen that we have provided an improved brush of the character indicated, wherein a precision bore for pomade or the like may be molded on the brush axis without breakage or loss of bristles. Pomade or the like application, using such a brush, is found to be remarkably smooth, uniform, and free of contamination, either by bristle fragments or by resin fragments.

Although the invention has been described in detail for the preferred form and method, it will be understood that modifications may be made without departing from the scpoe of the invention as defined in the claims which follow.

What is claimed is:

1. The method of securing a bundle of brush bristles in assembled relation to a tubular retaining ferrule having a bore open at both ends, which comprises inserting the bundle within and in partial overlap with the bore so as to fill the bore section with corresponding ends of the bristles and to project the other ends out one end of the ferrule, inserting a central elongated pin via the other end of the bore and into said bundle to radially outwardly compress said corresponding ends against the adjacent bore surface, the pin being inserted into longitudinal overlap with the bristles at the compressed end of the bundle, thereby developing a central elongated passage from which previously centered bristles have been displaced by the outward compression, bonding said corresponding ends to each other while in radially outwardly displaced relation, and then removing said pin from the ferrule; whereby a finished hole, formed by said pin, is self-retained by the bonding action, with all bristles in continuous longitudinally aligned relation.

2. The method of securing a bundle of brush bristles in assembled relation to a tubular retaining ferrule having a bore open at both ends, one of said ends being a liquid receiving end of larger cross sectional bore area than the bore area at the opposite end, there being a reducing taper in the bore between the sections of larger to smaller area, said method comprising inserting the tip ends of elongated natural bristles via the liquidreceiving end of the ferrule in packed overlapping relation with each other, the tip ends of said bristles being projected out and beyond the opposite end to constitute a brush bundle available for liquid application, the root ends of said bristles being contained within the taper of said bore, inserting a central elongated pin through the larger bore end and into the bundle packed within the ferrule, thereby radially outwardly displacing the bristles in greater packed compression against the bore wall, bonding the packed bristle ends, and removing the pin from the ferrule; whereby a finished hole, formed by said pin, is self-retained by the bonding action, with all bristles in continuous longitduinally aligned relation.

3. The method according to claim 2, in which bonding is achieved by a thermosetting resin applied via the larger bore end with the ferrule oriented to upwardly face said larger bore end; whereby, under heat of curing, the liquid resin may flow by combined gravity and capillary action into substantial longitudinal contact with the packed bristle ends and the taper of the bore.

4. The method of claim 3, in which the resin is applied as a liquid to the packed bristle ends prior to pin insertion, the heat to produce bonding being applied after pin insertion.

References Cited UNITED STATES PATENTS 1,244,132 10/1917 Ring 300-21 1,741,700 12/1929 Hart et a1. 30021 6 2,610,896 9/1952 Marsh 300-21 3,155,998 11/1964 Hardman et a1. 30021 XR 3,300,808 1/1967 Karl 300-21 XR GRANVILLE Y. CUSTER, 111., Primary Examiner US. Cl. X.R. 40l288

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