TOOTHBRUSH Technical Field

This invention relates to a hand-held toothbrush, and in particular, to the type which has bristle carrier means thereon that are equipped with sets of relatively recipro- cably displaceable bristle adapted to be straddled about a row of teeth, transverse thereof, and applied to the opposing faces of the teeth as the carrier means are translated along the length of the row. Related Application Brushes of this type are disclosed in my co-pending Application Serial No. 145,771 filed on January 19, 1988 and entitled Tooth Cleaning Device and Method, of which the present Application is a continuation-in-part. Background Art In U.S.P. 4,486,914 and 4,498,209, each patentee discloses a hand-held toothbrush which has bristle carrier means thereon that take the form of a pair of jaws which are supported at the ends of a pair of elongated resilien- tly flexibly interconnected tong-like members. The tong- like members are held in unison as a handle and manipu¬ lated, so to speak, like chopsticks, to straddle the jaws about a row of teeth and then apply the bristle to the opposing faces of a tooth. Thereafter, when the jaws are to be translated from that tooth to the next, the user must first relax the handle, and then relocate the jaws at the next tooth before adjusting the clamping action or ^•■ grip*' of the jaws to apply the bristle to the faces of that second tooth. Disclosure of the Invention The present invention also relates to a hand-held toothbrush which has bristle carrier means thereon that are equipped with sets of relatively reciprocably dis-

placeable bristle and accompanied by elongated positioning means for straddling the sets of bristle about a row of teeth, transverse thereof, and applying the bristle to the opposing faces of the teeth. However, the elongated positioning means of the present invention comprise a pair of collateral staff-like members which are semi-rigid and discrete from one another, but hingedly interconnected with one another so that they can be held in unison as a handle while being rotated in relation to one another about an axis extending substantially parallel to the mutually adjacent sides thereof. In this way, the brush lends itself to being given a programmed "grip" with which to apply the bristle to the faces of the teeth, as well as being given means with which to locate and steer the bristle along the row of teeth in the manner described in the aforementioned co-pending Application. More impor¬ tantly, the brush also lends itself to being fabricated as a relatively flat item which can be packaged and shelved in compact form, and in addition, if desired, cheaply constructed as a so-called "disposable brush", that is, as one which can be put to use a single time or two and then thrown away because of its cheapness. In particular, the brush can be molded from inexpensive polymeric material or the like, and can be mass produced, packaged, marketed and priced in such inexpensive form that the user will not hesitate to discard it after a single use or two. Hospitals, nursing homes and other health care facilities are particularly in need of such a brush to use on patients within their care.

In addition to the staff-like members themselves, there are stop means between the members which limit their relative rotation in one set of angularly opposing directions about the axis; as well as resiliently yield- able biasing means across the hinge between the members,

which tend to rotate the members in the aforesaid one set of angular directions about the axis when the handle is disposed in the relaxed condition thereof. Meanwhile, rotary transmission means are interposed between the handle and the bristle carrier means to vary the displace¬ ment of the sets of bristle relatively toward and away from one another when the staff-like members are rotated about the axis in the angular directions opposed to the bias of the biasing means.

In many of the presently preferred embodiments of the invention, the staff-like members are elongated in the directions of the axis and the rotary transmission means comprise tong-like extensions of the same which project boom-like from the distal ends of the members substantial¬ ly parallel to the axis so that they are rotatable in conjunction with the members about the axis. The bristle carrier means comprise a pair of jaws which are connected with the tong-like extensions of the members, adjacent the distal ends thereof, so as to be rotatable in conjunction with the extensions when they are rotated by the members. The sets of bristle are fixedly positioned on the jaws, meanwhile, to assume a counter disposition to one another when the jaws are rotated against the bias of the biasing means. However, the bias effectively limits the counter disposition of the sets of bristle to a condition in which they assume a predetermined angle to one another, such as an angle of no less than approximately 90° , when the staff-like members are rotated to the maximum. This assures that the respective sets of bristle will, in turn, assume angles of approximately 45° to the gum line of the user's teeth when the jaws are straddled about a row of the same and translated along the length of the row, as explained in the aforementioned co-pending Application. In certain of the presently preferred embodiments of the

invention, the jaws themselves are also hingedly intercon¬ nected with one another about the axis, as are the tongue¬ like extensions of the handle. In fact, the respective hinges between the members, the extensions, and the jaws, are interconnected end-to-end of one another so that the brush has a unitary construction in which the jaws, members and extensions form opposing paddleheaded tweezer- like elements which have a co-extensive hinge between the mutually adjacent sides thereof, opposing sets of bristle on the heads thereof, and a resiliently yieldable bias across the hinge between the sides thereof, for substan¬ tially the entire length thereof. The tweezer-like elements are commonly fabricated as a single monolithic body which has an ovate head for the bristle and an elongated stem for a handle. A groove extends the length of the body on a parallel to the center line thereof, and forms a flexible hinge for the body, as well as stop means for limiting the relative rotation of the elements about the hinge in the aforesaid one set of angular directions about the axis.

In one group of embodiments, the body has a pair of spaced parallel hinge-forming grooves between the elements thereof, which extend along parallels to the center line of the brush, symmetrically thereof, and have a connecting web therebetween.

In some embodiments, the body is molded from polymeric material which has an inherent resiliently yieldable bias across the hinge of the same when taken from the mold. Moreover, the body is molded in a condition in which the elements and hinge are co-planar with one another.

In many of the presently preferred embodiments, moreover, the tweezer-like elements comprise relatively thin, tongue-like rods which have reinforcing ribs upstanding on the outer peripheries thereof, to provide

the rigidity with which the rotary action generated in the handle will be transmitted in full to the jaws. In fact, the ribs commonly commence on the jaws, and then feather out along the lengths of the handle members to points adjacent the proximal ends of the same.

In some embodiments of the invention, the brush further comprises annular retainer means which can be telescoped about the handle of the brush to fix the relative displacement between the staff-like members. For those embodiments wherein the body of the brush has a pair of spaced parallel hinge-forming grooves therein, the retainer means are circular in cross-section; and in many such embodiments of the invention, the retainer means take the form of a tubular sheath.

In one group of presently preferred embodiments of the invention, the staff members are elongated in the direc¬ tion of the axis and have substantially co-linear hinges thereacross, transverse the axis, so that the relatively forward and rearward end portions of the handle can be reentrantly folded onto one another, longitudinally thereof. In this way, the toothbrush can be given a more compact form, for example, when it is to be packaged for sale. In certain embodiments of the invention, the sets of bristle upstand from the bristle carrier means in the form of mutually parallel phalanxes of bristle having a slot¬ like clearance therebetween that coincides with the hinge between the staff-like members of the handle. In some embodiments, the bristle have varying lengths so that the sets of the same have oppositely inclined profiles at the tips thereof, relative to the dimensional planes of the carrier means from which they upstand. The inclination is relatively downward into the clearance between the sets, moreover, so that the sets can approach one another at an

angle of approximately 90° when the staff-like members are rotated in full against the bias of the biasing means.

When the body of the brush is equipped with a pair of spaced parallel hinge-forming grooves therein, with a web therebetween, the brush may also have an additional set of bristle on the inner periphery of the web, between the first mentioned sets of bristle. Furthermore, there may be a fourth set of bristle on the outer periphery of the web, which is directly opposed to that on the inner periphery of the web. In addition, the bristle carrier means may also be equipped with stylus-like means which upstand within the sets of bristle as in the co-pending Application. Once again, the stylus-like means are sufficiently rigid to perform as picks, and are located so that they operatively trace along the gum line of a row of teeth, when the sets of bristle are straddled about the row, transverse thereof, and translated along the row opposite the faces of the teeth, as explained in the co- pending Application. Preferably, the picks are arranged in parallel rows on the opposite sides of the clearance; and in certain embodiments of the invention, there are thin flanges extending relatively toward one another from corresponding picks, which terminate at the clearance between the sets of bristle. The flanges provide fillet¬ like reinforcing gussets with which to stabilize the picks against splay when they are employed in raking the gum lines of the user's teeth. Brief Description of the Drawings These features will be better understood by reference to the accompanying drawings which illustrate several presently preferred embodiments of the invention. In the drawings:

FIGURE 1 is a top perspective view of a brush which has a single hinge-forming groove along the top thereof;

FIGURE 2 is a top plan view of the brush; FIGURE 3 is a plan view of the brush from the dorsal side thereof; FIGURE 4 is an end elevational view of the brush at the distal end thereof;

FIGURE 5 is an enlarged plan view of the head of the brush from the dorsal side thereof;

FIGURE 6 is a part cross sectional view of a molded brush at the time it is taken from the mold;

FIGURE 7 is a part cross sectional view of the molded brush after it has undergone folding at the hinge thereof;

FIGURE 8 is a top perspective view of a brush having a pair of spaced parallel hinge-forming grooves in the top thereof, with a web therebetween;

FIGURE 9 is a top plan view of the brush in Figure 8; FIGURE 10 is a plan view of the brush in Figures 8 and 9 from the dorsal side thereof;

FIGURE 11 is an end elevational view of the brush in Figures 8-10 at the distal end thereof;

FIGURE 12 is a top perspective view of the brush in Figures 8-11 when it has been equipped with a telescoping sheath to fix the relative displacement between the staff¬ like members thereof; FIGURE 13 is a cross section of Figure 12 along the line 13 - 13 thereof;

FIGURE 14 is a part cross sectional view of the head of the brush in Figures 1-7 when it has been modified to include gusseted stylus means in the opposing sets of bristle thereon;

FIGURE 15 is a plan view of the modified head when seen along the line 15 - 15 of Figure 14 , and

FIGURE 16 is a part side elevational view of the brush in Figures 8-11, when it has been reentrantly folded, longitudinally thereof, to give it a more compact form.

Best Mode for Carrying Out the Invention

Referring to the drawings, it will be seen that the toothbrush 2 in Figures 1-7 has bristle carrier means 4 thereon that are equipped with sets 6 of relatively reciprocably displaceable bristle 8 and accompanied by elongated positioning means 10 for straddling the sets of bristle about a row of teeth (not shown) , transverse thereof, and applying the bristle 8 to the opposing faces of the teeth. The elongated positioning means 10 comprise a pair of collateral staff-like members 12 which are semi¬ rigid and discrete from one another, but hingedly inter¬ connected with one another at 14 so that they can be held in unison as a handle 16 while being rotated in relation to one another about an axis 18 extending substantially parallel to the mutually adjacent sides 20 thereof. There are stop means 14 between members, however, which limit their relative rotation in one set of angularly opposing directions about the axis, i.e., the directions angularly upward of the members in Figure 1. There are also resiliently yieldable biasing means 24 across the hinge 14 between the members, which tend to rotate the members in the aforesaid one set of angular directions about the axis when the handle is disposed in the relaxed condition thereof. Meanwhile, rotary transmission means 22 are interposed between the handle 16 and the bristle carrier means 4 to vary the displacement of the sets 6 of bristle relatively toward and away from one another when the staff-like members 12 are rotated about the axis 18 in the angular directions opposed to the bias of the biasing means 24.

More particularly, the staff-like members 12 are elongated in the direction of the axis 18 and the rotary transmission means 22 comprise tong-like extensions 26 of the same which project boom-like from the distal ends 28

of the members 12 substantially parallel to the axis 18 so that they are rotatable in conjunction with the members about the axis. The bristle carrier means 4 comprise a pair of jaws 30 which are connected with the tong-like extensions 26 of the members, adjacent the distal ends thereof, so as to be rotatable in conjunction with the extensions when they are rotated by the members. The sets 6 of bristle 8 are fixedly positioned on the inner peripheral faces 32 of the jaws 30, meanwhile, to assume a counter disposition to one another when the jaws are rotated against the bias of the biasing means 24. See Figure 4. However, the bias effectively limits the counter disposition of the sets of bristle to a condition in which they assume a predetermined angle to one another, such as an angle of no less than approximately 90° , when the staff-like members 12 are rotated to the maximum. Again see Figure 4. This assures that the respective sets of bristle 8 will, in turn, assume angles of approximately 45° to the gum line of the user's teeth when the jaws are straddled about a row of the same and translated along the length of the row, as explained in the aforementioned co- pending Application.

Commonly, as shown, the jaws 30 themselves are also hingedly interconnected with one another about the axis 18, as are the tongue-like extensions 26 of the handle. In fact, as seen, the respective hinges 14', 14" and 14"' between the members 12, the extensions 26, and the jaws 30, are interconnected end-to-end of one another so that the brush has a unitary construction in which the jaws, members and extensions form opposing paddle-headed tweezer-like elements 34, which have a coextensive hinge 14 between the mutually adjacent sides 20 thereof, and a resiliently yieldable bias 24 across the hinge 14 between the sides 20 thereof, for substantially the entire length

thereof. The tweezer-like elements 34 are commonly fabricated as a single monolithic body 36 which has an ovate head 38 for the bristle 8, and an elongated stem 40 for a handle. A groove 42 extends the length of the body 36, on a parallel to the centerline thereof, and forms a flexible hinge 44 for the body, as well as stop means 45 for limiting the relative rotation of the elements 34 about the hinge 44 in the aforesaid one set of angular directions about the axis 18.

Alternatively, and as seen in Figures 8-11, the body 36' of the tweezer-like elements 34' of the brush 2' may have a pair of spaced parallel hinge-forming grooves 46 between the elements 34' thereof, which extend along parallels to the centerline of the brush, symmetrically thereof, and have a connecting web 48 therebetween.

Preferably, the bodies 36 or 36' of the brushes 2 and 2' are molded from polymeric material which has an inherent resiliently yieldable bias 24 across the hinge 14 or 46,48,46 of the same when taken from the mold. Moreover, the bodies are molded in a condition in which the elements and hinge are co-planar with one another. See Figure 6. However, when the elements are rotated against the bias of the hinge, they will tend to assume a bat-like, dropped wing configuration, such as the inverted V-shaped configuration of Figure 7, or the inverted U- shaped configuration of Figure 11. Thereafter, when the rotational forces on the elements are relaxed, the elements will tend to resume the co-planar condition of Figure 6, but preferably, the elements will not fully resume that condition. If not, then the user will find the elements somewhat opposed to his thumb and fingers when he picks up the brush again, and this in turn, will enable him to put the brush to immediate use without the necessity for first rotating the elements to the dropped-

wing configuration of Figure 7 or 11 before he can easily grasp the brush for use.

In the embodiment of Figures 1-7, the tweezer-like elements 12 comprise relatively thin, tongue-like rods 50 which have reinforcing ribs 52 upstanding on the outer peripheries 54 thereof, to provide the rigidity with which the rotary action generated in the handle 16 will be transmitted in full to the jaws 30. The ribs 52 commence on the jaws 30 and then feather out along the lengths of the handle members 12 to points adjacent the proximal ends 56 of the same. However, in the embodiment of Figures 8- 11, the tweezer-like elements 34' or rods 50' have sufficient rigidity, when coupled with a web 48 therebe- tween, to assure that the rotary action generated in the handle 40' will be transmitted in full to the jaws 30' of the head 38' .

The bodies of the ribs 52 preferably taper toward the respective ends thereof and have a longer, shallower inclination at the proximal end portions thereof, than at the distal end portions thereof. They may also taper sidewise toward the relatively remote edges thereof, to assist the user in gripping the brush with his thumb and fingers. In the embodiment of Figures 8-11, the brush is also adapted to be reentrantly folded onto itself, for example, for purposes of reducing it to more compact form, such as when it is to be packaged for sale. Referring again to Figures 8-11, and Figure 16 in addition, it will be seen that the rods 50' and the web 48 therebetween, have substantially co-linear hinge-forming grooves 84 there- across, transverse the axis 18, and at the dorsal sides thereof, so that the relatively forward and rearward end portions of the handle 40' can be reentrantly folded upwardly over onto one another, longitudinally thereof, as

in Figure 16.

When putting either brush to use, the user grips the handle 40 or 40' of the same in the manner of a baton, using his thumb on one rod 50 or 50' and his fingers on the other, so that he can press or pinch the rods rela¬ tively towards one another against the bias of the biasing means 24. Due to the semi-rigid nature of the rods, lengthwise thereof, the rotary action of his thumb and fingers will be transmitted to the jaws 30 or 30', and they in turn, will transmit the action to the sets 6 or 6' of bristle 8 to vary the relative displacement between the same, as well as the angle between them. This can be done prior to the insertion of the head 38 or 38' of the brush in the user's mouth, and/or prior to positioning it adjacent a row of teeth. Or it can be done at the time the bristle are applied to the faces of the teeth. Moreover, if desired, a tubular sheath 60 can be tele¬ scoped about the handle 40' of the brush to fix the relative displacement between the rods, and the angle between the sets 6' of bristle, as seen in Figures 12 and 13. The sheath 60 serves as retainer means for preserving the relative displacement of the rods, so that each time the user employs the brush, he can do so without the necessity for flexing the rods during the brushing operation.

Preferably, a circular sheath 60 is employed about the embodiment of Figures 8-11, and one with a more oblong cross-section (not shown) is employed about the embodiment of Figures 1-7.

As seen in Figures 4 and 11, the sets 6 and 6' of bristle upstand from the bristle carrier means 38 or 38' in the form of mutually parallel phalanxes 64 of bristle 8 having a slot-like corridor or clearance 66 therebetween that coincides with the hinge 14 or 46,48,46 between the

staff-like members 50 or 50' of the handle. In Figure 4, moreover, the bristle 8 have varying lengths so that the sets of the same have oppositely inclined profiles 68 at the tips 70 thereof, relative to the dimensional planes of the carrier means 30 from which they upstand. The inclination is relatively downward into the clearance 66 between the sets, moreover, so that the sets can approach one another at an angle of approximately 90° when the staff-like members are rotated in full against the bias of the biasing means 24.

In Figures 8 - 11, the body 36' of the brush is equipped with an additional set 72 of bristle 8 on the inner periphery of the web 48 between the first mentioned sets 6' of bristle. Furthermore, there is a fourth set 74 of bristle 8 on the outer periphery of the web, which is directly opposed to that 72 on the inner periphery of the web.

The bristle carrier means 38" (Figures 14 and 15) may also be equipped with stylus-like means 76 which upstand within the sets 6" of bristle as in the co-pending Application. Once again, the stylus-like means 76 are sufficiently rigid to perform as picks, and are located on the inner peripheral faces 32' of the jaws 30" so that they operatively trace along the gum line of a row of teeth when the jaws are straddled about the row, trans¬ verse thereof, and translated along the row opposite the faces of the teeth, as explained in the co-pending Application. Preferably, the picks 76 are arranged in parallel rows on the opposite sides of the clearance 66', and there are thin flanges 78 extending relatively toward one another from corresponding picks, which terminate at the clearance 66' between the sets 6" of bristle. The flanges 78 provide fillet-like reinforcing gussets with which to

stabilize the picks against splay when they are employed in raking the gum lines of the user's teeth.

Commonly, the flanges 78 are recessed below the profiles 80 of the sets 6" of bristle, so that they do not interfere with the action of the bristle 8 in the center region of the head 38" yet provide the reinforcement indicated. Often, moreover, when the picks 76 are arranged as two or more pairs of the same, the pairs are spaced apart from one another in the center region of the head, and the spaces 82 between the respective pairs of flanges are freed of bristle on the opposing sides of the clearance as shown in Figure 15.