US 2303470 A
Description (OCR text may contain errors)
Dec. 1, 1942. JQBST 7 2,303,470
BRUSH Filed Jan. 26, 1942 FIG I.
CONRAD JOBST BY WW /W@M ATTORNEYS Patented Dec. 1, 1942 UNITED. STATE BRUSH Conrad Jobst, Toledo, Ohio, assignor to -Th Toledo Automatic Brush Machine Company, Toledo, Ohio, a corporation of Ohio Application January 26,1942, Serial No. 428,289
In the manufacture of brushes employing bristle tufts, it is the common practice to form these tufts bybending the bristles double about a transversely extending anchor and to then simultaneously drive the anchor and bristles into a bored back to set the tuft. Anchors have been made of various materials, but to secure permanency and to avoid discoloration, it has been the practice to employ a non-corrodible metal such, for instance, as stainless steel. This will form an anchor which, where the brush is used for the purpose for which it is designed, will remain unchanged throughout its life.
An essential element of stainless steel, as well as other non-corrodible alloys, is the metal chromium. This has heretofore been available, but under present conditions within the United States; its use may be restricted to such industries as are engaged in the preparedness program. Under such conditions, it may be diflicult or impossible for brush manufacturers to obtain non-corrodible metal for forming tuft anchors.
It is the object of the invention to-obtain a satisfactory tuft anchor which does not require the use of stainless steel or other noncorrodible metal.
It is a further object to obtain an anchor which has additional advantageous characteristics for In the drawing:
Fig. 1 is an enlarged plan view of a portion of a toothbrush of my improved construction, viewed from the back;
Fig. 2 is a side elevation thereof;
Fig. 3 is an enlarged cross section of a round enameled wire;
Fig. 4 is an enlarged cross section of the wire after flattening the same preparatory to forming the anchors thereof; and
Fig. 5 is an enlarged cross section through a portion of a bored back, showing a tuft set therein.
In the present state of the art, wire formed of certain copper alloys has been provided with an enamel coating, primarily designed for electrical insulation. This wire is usuallyfof circular cross section. and the enamel completely envelopsits outer surface. I have discovered that such enameled wire can be flattened by suitable means as by rolls. and without injury to its enamel 608-171 ing, this being sufliciently elastic to compensate I have for the increased length of perimeter. also discovered that such flattened enameled wire may be substituted for the stainless steel or other non-corrodible metal heretofore used in tuft forming and setting mechanisms; further, that the anchors severed from the wire, when driven into the brush back, will be protected from corrosion. This is for the reason that the only por- 'tions of the anchor that are not covered by the enamel are the opposite ends, and these being embedded in the brush back, are protected thereby.
During recent years, certain synthetic materials have been used for forming brush backs, and some of these are transparent, so that the tufts and anchors are visible therethrough. With my improved construction of anchor, the enameled surface may be formed of any desired color and will give a distinctive appearance to the brush.
While the greater portion of the anchor is enveloped by the bristles of the tuft, the latter are also frequently formed of synthetic-transparent material, and consequently the color of the enamel will bevisible through the back.
tact and completely covering the surface. D is the brush back, E is the tuft set in a bore in said back, and F is the anchor cut from the wire C and having ,its opposite end embedded in the walls of the bore. As shown'in Figs. 1 and 2, the portions G of the-anchor which project be- 'yond the bristles of the tuft are clearly visible 40 through the transparent back and to a lesser extent the portions H which are covered by the bristles. This'would impart to the brush a distinctive appearance due to the color of the enamel.
ing of the wire is not essential to'my invention, provided that it possesses the necessary ductility to stretch over the increased perimeter of the cross section. I have found, however, that. or-
ganic coating material'such as described in Patents No. 2,085,995 to W. I. Patnode et al., July 6,
- 1937; and No. 2,191,581 to P. Nowak et al., Feb-.
As specifically illustrated, A is a metallic wire 7 The specific composition of the enamel 'coat- ,ibi'ush back of synthetic material, the enamel coating will weld to the synthetic material of the back, thereby insuring complete coverage and also increasing the strength of the bond. This welding effect is doubtless due to the fact that in brush machines thelanchors are driven into the brush backs at an extremely high rate of will weld to each other.
What I claim as my invention is:
1. The combination with a brush back provided with a tuft receiving bore, of a tuft set in said bore, and an anchor for said tuft having all but the ends of its surface coated with enamel, said ends being embedded in the back to protect the same from corrosion.
2.' In a method of forming brushes, the steps of rolling a metallic wire provided with a nonmetallic insulating elastic coating to flatten the same into an oblong cross section, thereby stretching the coating to completely cover the perimeter, severing the flattened wire into anchor lengths, and driving each anchor with a tuft into a bored brush back, thereby embedding the uncoated ends of the anchor in said back.
3. In a brush, a back formed of synthetic material, a tuft set in said back, and an anchorfor said tuft having a protective non-metallic coating surrounding the same, the opposite ends of said coating being welded to the material of said back.
' CONRAD JOBST.