US 2697239 A
Description (OCR text may contain errors)
Dec. 21, 11954 c. A. FUN K 2,697,239
TOOTHBRUSH Filed June 9, 1952 Charles A.Fzm]( INVENTOR.
A TTOHNEY United tates atent 2,697,239 Patented Dec. 21, 1954 ffice TOOTHBRUSH Charles A. Funk, Louisville, Ky. Application June 9, 1952, Serial No. 292,525 3 Claims. (Cl. 15167) The present invention relates to a tooth brush, and re lates in particular to a brush which can effectively reach the lingual surfaces of the teeth.
With the various types of tooth brushes available it is quite difficult to properly and effectively clean the lingual surfaces of the teeth. Such brushes make limited contact with the lingual surfaces during brushing, and it is entirely a matter of chance whether or not areas are omitted and escape brushing. Various shapes and styles of brushes for this purpose have been proposed, but so far as I am aware, none have been effective to reach an extended area According to the present invention, a brush is provided having bristles arranged in an arc and having the bristle ends arranged on a convex curve. The handle for the brush may extend from near the middle at the convex or brush back. By forming the back of the brush in a compound curve the bristle tufts may be of uniform length yet their ends will be arranged in a convex curve, and the rows of tufts will be arranged in an arc. However, the curved proper length. straight or pointed ends.
The invention will be described in greater detail in connection with the accompanying drawing showing a preferred embodiment of the invention by way of example, and wherein:
Figure 1 is a from the top;
Figure 2 is a perspective view as seen from the bottom;
Figure 3 is an end elevation view of Figure 1 as seen from the right;
Figure 4 is a bottom view of Figure 1;
Figure 5 is a section taken on line Figure 6 is a view teeth, and
Figure 7 is a view illustrating the brushing of the lower teet Referring to the drawing the brush back or holder is more or less lune or crescent shaped in plan and in end eleperspective view of the invention as seen 55 of Figure 4; illustrating the brushing of the upper offset with respect to the vation. Thus the edge 1 in plan appears as the convex border of the back, and edge 2 appears in plan as the parallel concave border of the back, with curved ends 3 and 4. As viewed in end elevation, the bottom 5 is of convex curvature, and the top 6 is concavely curved. Thus the entire brush back is formed about a warped curve which corresponds roughly to a curve of a sphere.
The bristle tufts 7 are embedded in the back in the usual manner, and are arranged in any desired number of rows; two being shown. As the bristles are of equal length the rows of tufts are arranged in an are parallel to edges 1 or tom face in substantially parallel relation to each other. The brush handle 9 is offset slightly and extends from the convex edge 1. The brush may be made by casting the back and handle of any suitable plastic material with the bristles embedded in the back.
In using the brush as shown in Figures 6 and 7, the brush is drawn back and forth in a rotary motion so that the bristles engage the lingual surfaces of the teeth while moving from the gums to the edge. Because of the curvature of the bristles in two planes practically all the bristle ends contact some part of the tooth surface on each stroke with a substantially uniform pressure, so that in making overlapped strokes no area of the teeth escapes cleaning.
I claim as my invention:
1. A brush for cleaning the lingual surfaces of the teeth comprising: a back member in the form of a narrow crescent as viewed in plan with the concave edge at the front and the convex edge at the rear, and having upwardly bowed ends providing a lower convex face, the crescent being of a length and curvature to enable it to fit in the front lingual arch in the mouth of the user; bristle tufts ing substantially to the front lingual arch of the teeth; and a long narrow handle extending rearwardly from the middie of the back member.
2. A brush as specified in claim 1 wherein: the back member has a concave upper face; and the handle extends from the middle of the upper face of the back member and is offset vertically upward from the lowest part of the upper surface at the middle of the back member.
3. The brush of claim 1 wherein: the bristles extend from the curved bottom face in substantially parallel relation to each other.
References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,520,730 Street Dec. 30, 1924 2,084,873 Strause June 22, 1937 FOREIGN PATENTS Number Country Date 259,458 Great Britain of 1926