US2840841A

US2840841A - Paint brush and method of making the same

Info

Publication number: US2840841A
Application number: US463710A
Authority: US
Inventors: Franklin C Maxwell
Original assignee: Elder & Jenks Inc
Current assignee: Elder & Jenks Inc
Priority date: 1954-10-21
Filing date: 1954-10-21
Publication date: 1958-07-01
Anticipated expiration: 1975-07-01

Description

July 1, 1958 F. c. MAXWELL 2,840,841

PAINT BRUSH AND METHOD OF MAKING THE SAME Filed Oct. 21. 1954 INVENTOR. 13 fiafil'iiizi/ifarmeil,

BY Fwd Pau A TTORNEYS.

United States Patent PAINT BRUSH AND METHOD OF MAKING THE SAME Franklin C. Maxwell, Philadelphia, Pa., assignor to Elder & Jenks, Inc., Philadelphia, Pa., a corporation of Penn- This invention relates generally to paint brush assemblies and more particularly to a paint brush structure which provides positive retention of the filaments in the direction of the brush handle.

Paint brushes in common use normally comprise filaments bonded together by a glutinous substance at one end, a tubular ferrule in which the filaments are inserted and a handle inserted in the ferrule at the end opposite to the filaments. The filaments in such brushes are held in place by the gripping action of the ferrule which is usually metallic, and this grip is augmented by rivets or pins driven through the ferrule and the bonded filaments. Brushes so constructed have a tendency to loosen where the ferrule grips the filaments or to break away in the bonding material because of the action of the rivets or 111118.

Accordingly it is a principal object of this invention to provide a paint brush in which the filaments are positively held in the deriction of the handle without damage to the bonding material which holds the filaments together.

It is another object of this invention to provide a paint n brush in which the bonded filaments are connected directly to the handle by a substantially rigid retaining membrane.

It is another object of this'invention to provide a method of marking paint brushes in which the brush is made up of independent units which are assembled without need of further treatment of the bonding material which holds the bonded filaments in the ferrule.

A paint brush in accordance with this invention includes a handle 11, a ferrule 12, a retaining element 14, a resinous capping layer 19, the filaments 13, andthe filament bonding material 18.

Fig. 1 is aperspective view partially cut away of a brush made according to the invention.

Fig. 2 is afragmentary side elevation of the handle and retaining element of a brush made according to the invention.

Figs. 3-6 are sectional side elevations showing the consecutive stages in the manufacture of a brush in accordance with the invention.

Fig. 7 is a perspective view of the retaining element made in accordance with the invention.

The term filament as hereinafter used includes natural pig bristle, nylon, horse hair and any other material normally used in the working portion of a brush.

The filaments 13 may be any one of the types normally used in paint brush manufacture including natural and synthetic materials. They are gathered together and are then bonded together at one end by a suitable bonding material 18. Such material may be a natural rubber or synthetic resin or a mixture of both. Where natural pig bristles are used, the bonding material will preferably be pure crude rubber; where nylon filaments are employed a suitable mixture of natural rubber and synthetic resin is preferred since the synthetic resin provides a better bond to the nylon filaments, whereas the pure rubber adheres better to the metal ferrule. Pure crude rubber is 2,840,841 Patented July 1, 1958 substance which is not subject to attack by the paintingmaterials to be employed with the brush or to boiling water.

The bonding material 18 is applied to the filaments 13 when the filaments 13 are inserted in the ferrule 12 as shown in Fig. 3. The quantity of bonding material applied is determined by the depth of penetration around the filaments desired and by the viscosity of the bonding material itself. When natural rubber is used the bonding material isvulcanized directly in the ferrule; otherwise it is permitted to harden in place.

When the bonded filaments 13 are in place in the ferrule 12 a layer of capping material 19 is poured into the ferrule 12 over the ends of'the bonded filaments 13. This material 19 is characterized by its capacity to harden Without the application of further heat or pressure. When the capping material 19 is poured into the ferrule 12 there is a limited mechanical combination with the bonding material 18 used to bind the filaments 13, and also a certain adhesion to the ferrule 12. The capping material 19 thus becomes a separate layer attached both to the filament bonding material 18 and the ferrule 12.

The handle of the brush 11, according to this invention, is of the normal type except that a T-shaped slot 20 is formed in the bottom end thereof, as shown in the drawings. This slot 20 continues across the full width of the handle 11 and is shaped to accommodate the upper flange 15 of the retaining element 14. The retaining element 14 is a substantially rigid structure having an I-beam crosssection in which the upper flange 15 is somewhat narrower than the lower flange 16. The lower flange 16 is provided with a plurality of perforations 17. The upper flange 15 of the retaining element 14 is inserted in the T-slot 20 in the handle 11 as shown in Fig. 2. The handle 11 is then inserted in the ferrule 12 sufficiently far to place the lower flange 16 in the fluid capping material. Due to the self-hardening nature of the capping material 19 no further action is needed to complete the construction of the brush other than to nail the ferrule 12 to the handle 11 by means of the nails 10. When the capping material 19 is hardened it will be seen that a positive directional pull is maintained on the filaments 13 through the bonding material 18, the hardened capping material 19, the metallic retaining element 14 and the handle 11. Thus the nails 10 may be eliminated.

It will be appreciated that many diflFerent types'of slot designs may be used to accommodate the upper portion ,of the retaining element 14, and that a corresponding number of different shapes may be employed in the retaining element itself. The preferred embodiment shown in the drawings has been found satisfactory in that the T-slot 20 is easily formed and the i-beam structure can be simply made from a single sheet of flat material. It is essential that the retaining element be firmly held by the handle and that the lower portion be sufficiently broad to provide low stress concentration in the capping material 19. As shown in Fig. 7 the lower flange 16 is pro vided with a number of holes 17 which allow the capping material 19 to flow around the flange 16.

It has been pointed out above that any self-hardening glutinous substance may satisfactorily serve as the capping material 19 in this invention. It is preferred, however, in the manufacture of a brush according to this invention, that the capping material 19 be capable of self-hardening at a relatively rapid rate without being a an instant-setting material which would prevent the pouring of the capping material during continuous manufacturing operations. It has been found desirable for manufacturing purposes, to employ a capping material which will completely harden within two hours after application but which will retain working fluidity for a minimum period of about thirty-five minutes. determined that the preferred, materials for, thispurpose are the two-part, self-setting reactive resins. In practice the epoxyresins having viscosities inthe range between 100 and 100,000 centipoises havebeen found to besatisfactory when used with a suitable propriety amine catalyst such as 8% by weight of diethylene triamine. Also satisfactory is a resorcinol resin basewith a suitable aldehyde catalyst such as 25% by weight of commercial 37% formaldehyde solution. A third material 'isbased upon the well-known phenolic resinoids. Therpreferred catalyst in this case is 7% by weight of hypophosphorus acid. It should be noted that the base resin employed in the latter capping material isnot stable alone at room temperature. It is of course essential that the catalyst employed in each case be well distributed throughout the base material to insure proper setting.

An important feature of my invention is the method of making the brush. The handle unit, Fig. 2, is assembled as one function; the upper flange 15 of the retaining clement14 is inserted in the T-slot 20. Since the T-slot 20 runs the full length of the bottom of the handle 11, the retaining element 14 is simply slid longitudinally along the slot into the posit-ion shown in Fig. l. The assembled filaments 13 are inserted in the bottom of the ferrule 12 and the desired bonding material 18 is poured is as shown in Fig. 3. Where the bonding material 18 is natural rubber, it is vulcanized directly in the ferrule 12. The capping material is then poured into the ferrule 12 over the filaments 13 and bonding material 18 to form a capping layer 19 of suificientdepth to encompass the lower flange 16 of the retaining element 14. The handle 11 and the connected retaining element 14 are then inserted in the ferrule 12. The height of the retaining element 14, the height of the ferrule 12 and the depth of the capping layer 19 are predetermined to place the lower flange 16 of the retaining element 14 in the capping material 19 substantially as shown in Fig. 5. Due to the self-hardening characteristics of the capping material 19 no further operation is needed on it to complete the brush other than to nail the ferrule 12 to the handle 11 where necessary. The ferrule 12 may be designed to grip the handle 11 in any known manner.

Many alternative forms and materials willbe apparent as substitutes for those shown. Thus it is of course not intended to limit the invention to brushes which are hand operated. Any type of head element may be employed for the handle 11. Likewise the invention could be entirely operative without the presence of the ferrule 12 as It has been.

astructural element, since directional strength is obtained from the retaining element 14.

It will be appreciated that the above description covers only a preferred embodiment of the invent-ion and that one skilled in the art may readily make various changes and modification therein without detracting from the invention as hereinafter claimed.

Having thus described my invention I claim:

1. A brush comprising a handle having a slot recessed along the bottom face thereof, a plurality of painting filaments grouped together at one end, a resinous bonding material disposed about and above the said end of said filaments, a separate layer of self-hardenable resinous plastic material disposed across said bonding material and mechanically attached thereto, and retaining means having one end inserted in said recessed slot and held in position by said handle, and the other end horizontally inserted in said separate layer of self-hardenable resinous material.

2. A method .of making a brush comprising inserting a plurality of filaments in one open end of a ferrule, applying a glutinous bonding material to the ends of the filaments in said ferrule, setting the bonding material, recessing a T-shaped slot in the lower part of a handle member and inserting therein the upper flange of an I- shaped elongated retaining member, placing a mass of self-hardening resin in said ferrule across and above said filaments, and inserting the handle and retaining element in said ferrule while said self-hardening resin is still plastic and immersing the lower flange of said retaining member in the self-hardening resin.

3. A paint brush comprising a handle having a T- shaped slot recessed along the bottom face thereof, a plurality of painting filaments bonded together at one end by a mixture of synthetic resin and natural rubber, a separate capping layer of a two-part self-setting'reactive resin disposed across said bonding material and above the ends of the filaments, an elongated retaining element of I- shaped cross section having a narrow upperflange inserted in said T-slot and having a broad lower flange substantially perforate disposed in said separate capping layer, and rigidly retained therein when said two-part resin has hardened. I

References Cited in the file of this patent UNITED STATES PATENTS 720,051 Moss Feb. 10, 1903 957,331 Hascy May 10, 1910 1,420,925 Inghram June 27, 1922 2,274,002 Saltzman Feb. 24, 1942 2,512,997 Bixler June 27, 1950 2,562,716 Hervey July 31, 1951