BRUSH INCLUDING SPRING-MOUNTED BRISTLE HOLDERS

Abstract: A brush including spring-mounted bristle holders in which the springs are formed from a planar strip of elastic material stamped with a plurality of spirally-extending slits at spaced locations underlying each of the bristle holders, to define a spirally-extending element integrally formed with the strip and in the same plane as the strip. Each of the spirally-extending elements is pressed out of the plane of the strip to produce a helically-extending spring element underlying each of the bristle holders and decreasing in diameter from the strip to the bristle holder.

Description: BRUSH INCLUDING SPRING-MOUNTED BRISTLE HOLDERS The present invention relates to a brush including spring-mounted bristle holders. The invention is particularly useful in toothbrushes, and is therefore described below with respect to this application. The advantages of providing spring-mounted bristle holders in brushes generally, and toothbrushes specifically, have long been recognized, and a number of patents describe various brush constructions for this purpose. For example, brush constructions including various types of spring-mounted bristle holder are described in US Patents 2,882,544, 2,935,755, 3,082,457, 3,386,118, 3,683,442, 4,240,451, 4,240,452, 4,633,542 and 4,694,844. However, insofar as I am aware, none of these constructions has found widespread commercial use, presumbly because of the limited bristle holder displacements permitted by the brush construction, the short useful life of the brush construction, and/or the relatively large expense required to produce the brush construction. An object of the present invention is to provide a novel brush construction including spring- mounted bristle holders having advantages in one or more of the above respects. According to the present invention, there is provided a brush including a handle at one end and a brush head at the opposite end, the brush head including a plurality of bristle holders and spring means normally urging the bristle holders outwardly but permitting their inward movement during use of the brush head; characterized in that the spring means comprises: a planar strip of elastic material stamped with a plurality of spirally-extending slits at spaced locations of the planar strip underlying each of the bristle holders, to define a spirally-extending element integrally formed with the strip at each of the locations and in the same plane as the strip; each of the spirally-extending elements being pressed out of the plane of the strip to produce a helically-extending spring element underlying each of the bristle holders and decreasing in diameter from the strip to the bristle holder. Brushes, and particularly toothbrushes, constructed in accordance with the foregoing features provide a number of advantages over the prior-known devices. Thus, they permit large displacements and high density of the bristle holders, thereby increasing the efficiency of the brushing action; they provide a relatively long useful life; and they are inexpensive to produce in volume and at low cost. Further features and advantages of the invention will be apparent from the description below. The invention is herein described by way of example only, with reference to the accompanying drawings, wherein: Fig. 1 is a fragmentary sectional view illustrating one form of toothbrush constructed in accordance with the present invention; Fig. 2 is an exploded view more particularly illustrating the construction of the toothbrush of Fig. 1; Fig. 3 is a top plan view illustrating the spring member included in the brush of Figs. 1 and 2; and Fig. 4 is a fragmentary view illustrating a variation in the construction of the toothbrush. The toothbrush illustrated in Figs. 1-3 comprises a handle 2 at one end, and a brush head 4 at the opposite end. The brush head 4 is formed with a plurality of sockets 6 each receiving a plurality of bristles 8 mounted within bristle holders 10 slidable within their respective sockets 6 so as to permit the bristle holders 10 to be individually moved either to an extended position, as illustrated in Fig. 1, or to a retracted position within their respective sockets. The illustrated brush head further includes a spring mounting cooperable with all the bristle holders 10 normally urging all the bristle holders outwardly to their extended positions in order to press the bristles 8 against the surface being brushed, but permit each bristle holder to be individually moved to its retracted position within its respective socket 6, according to the pressure applied by the respective bristles 8 to the surface being brushed. By thus spring-mounting the bristle holders 10 for individual movement, the bristles more effectively penetrate into all the crevices of the teeth and between the teeth, thereby producing an efficient brushing action. In addition, when the bristle holders are pressed inwardly during a brushing action, they stiffen the bristles, thereby further enhancing the brushing action. The spring mounting for the bristle holders 10 comprises a planar strip 12 of elastic material stamped with a plurality of spirally-extending slits 14 (Fig. 3) at spaced locations of the strip to underlie each of the bristle holders 10. The spiral-slits 14 thus define a plurality of spirally-extending elements 16 integrally formed with the strip 12 and in the same plane as the strip. After the strip is so formed, each of the spirally-extending elements 16 is pressed out of the plane of the strip 12, such that the spirally- extending elements 16 now becomes helically-extending spring elements, as shown at 16' in Fig. 2, decreasing in diameter from the strip 12 to its outer end to engage its respective bristle holder 10, as more particularly shown in Fig. 1. The brush head 4 is preferably made of suitable plastic material, as by injection molding, and is formed with a plurality of openings 18, one for each of the sockets 6 and communicating with the upper end of its respective socket. The opposite side of the brush head 4 is closed by a cover plate 20 formed with a drain opening 22 for each socket 6. Preferably, the strip 12 is made of hard springy material, such as stainless steel, although it is contemplated that hard plastic material, such as hard nylon, may also be used. The helically-extending spring elements 16' permit a very large displacement of the bristle holders 10 for any given thickness of brush head 4 since the spring elements may be deformed back into the plane of the elastic strip 12, thereby avoiding any "dead space" within their respective sockets 6. In addition, such a construction enables a relatively high density of bristles and provides a relatively long useful life for the brush head. Moreover, since the spring elements 16' are produced by merely stamping the strip 12 and pressing the elements outwardly, such a construction can be produced in volume and at low cost. Fig. 4 illustrates a variation in the construction of the toothbrush, also including a handle 102 and a brush head 104 having three rows of bristle holders. In this case, however, each bristle holder 110 in the middle row is urged outwardly by a spring 112, whereas the bristle holders 108 in the two outer rows are fixed to the brush head 104. While the invention has been described with respect to two preferred embodiments, it will be appreciated that these are set forth merely for purposes of example. Thus, there may be a different number of rows of bristle holders, some or all of which may be spring-mounted. Also, the springs used in some rows may be lighter than those used in other rows. Further, the invention could be included in other types of bristles. Many other variations, modifications and applications of the invention wil be apparent.

Claims: WHAT IS CLAIMED IS: 1. A brush including a handle at one end and a brush head at the opposite end, said brush head including a plurality of bristle holders and spring means normally urging the bristle holders outwardly but permitting their inward movement during use of the brush head; characterized in that said spring means comprises: a planar strip of elastic material stamped with a plurality of spirally-extending slits at spaced locations of the planar strip underlying each of said bristle holders, to define a spirally-extending element integrally formed with said strip at each of said locations and in the same plane as said strip; each of said spirally-extending elements being pressed out of the plane of said strip to produce a helically- extending spring element underlying each of said bristle holders and decreasing in diameter from said strip to the bristle holder. 2. The brush according to Claim 1 , wherein said brush head is formed with a plurality of sockets each receiving one of said bristle holders, which bristle holders are urged outwardly of their respective sockets by their underlying helically-extending spring elements. 3. The brush according to Claim 1 , wherein said brush head includes at least two rows of bristle holders spring-urged outwardly by said spring means and separated by a row of bristle holders fixed to the brush head. 4. The brush according to any one of Claims 1-3 / wherein said strip of elastic material is of stainless steel.

Inventors: HOLLAND NETTA
Applicants: NATHANSON DAN, PAZ OHAD
Application year: 1991
Main classification: A46B7
IPC codes: A46B7