CA1326744C

CA1326744C - Toothbrush

Info

Publication number: CA1326744C
Application number: CA000607420A
Authority: CA
Inventors: Ronald William Klinkhammer
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-01-19
Filing date: 1989-08-03
Publication date: 1994-02-08
Anticipated expiration: 2011-02-08
Also published as: AU4054989A; WO1990001281A2; EP0434701A1; EP0434701A4; WO1990001281A3

Abstract

TOOTHBRUSH
Abstract The brush has sets of relatively reciprocably displaceable bristle which are straddled about a row of teeth, transverse thereof, and applied to the opposing faces of the teeth by means of a pair of paddle-headed tweezer-like rods 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. As they are applied to the faces of the teeth, the bristle may also be translated along the length of the row; and is so, the bristle may be equipped with a pair of picks, which are used to locate the gum lines of the teeth and steer the bristle while raking the gum lines themselves.
Moreover, in such a case, the picks may have thin flanges extending relatively toward one another, to provide fillet-like gussets with which to stab-ilize the picks against splay when they are traced along the gum lines. The brush lends itself to being packaged and shelved in compact form, and if desired as a disposable brush, that is, as one to be put to use a time or two and then thrown away.
For example, it can be fabricated as a thin, flat item which has a cross hinge so that it can be reentrantly folded onto itself, longitudinally thereof, for compactness.

Description

-` 1 3267~4 1 6~456-36 TOOTH BRUSH
Technlcal Field This lnventlon relates to a tooth brush, and in parti-cular to a straddle-type tooth brush.
Backqround Art In USP 2,807,820 to Dlnhofer, the straddle-type tooth brush dlsclosed therein comprises an elongated rod-like device whlch comes ln two parts, but when assembled, the devlce comprlses a pair of elongated arms having outboard end portions and adapted for lnsertion in the mouth of the person whose teeth are to be cleaned, a tookh brushlng lmplement that is connected with the arms for cleanlng the teeth, and a handle that is operable to support the arms adiacent a row of teeth while the implement is applled thereto. The arms pro~ect from the distal end of the handle ln generally spaced parallel relationship to one another, with an elongated slot extendlng therebetween, and are rlgldly interconnected with the han~le so as to ~orm rela~lvely rigid extensions of the same, longitudlnally thereof. The implement comprises a foldable brush-formlng head which is separate from the devlce, but operatively connected with the arms to straddle the slot at the outboard end portions of the arms on an axls of the lmplement e~tending from arm to arm crosswise the length of the slot. The brush-formlng head has three sections in the body thereof comprislng a pair of spaced wings, and A midsection ln the space therebetween, whlch are serially interconnected with one another alony the aforesaid axls of the lmplement. The head also has bru~h-formlng means on correspondlng sides of the wlngs, and . ~

when the head is folded and put to use, it ls operatlvely arranged on the arms so that the wlngs are reentrantly folded about the mldsection transverse the axls of the implement, wlth the brush-forming sides thereof folded relatively toward one another, but spaced apart from one another by a gap havin~ a mouth opposlte the mldsection of the head for the introduction of the teeth to the ~ap. Addltlonally, the brush-formlng head has added portlons thereof, ln the form of channeled sections, which are interposed between the respective wings and the midsection thereof, axially of the implement, to be used in mountlng the implement on the arms when the wings have been reentrantly folded about the mldsectlon as lndicated.
Disclosure of the Invention The present inventlon relates to a simllar straddle-type tooth brush, but one which ls lmproved over Dlnhofer's brush ln that the rod-like devlce of the present invention is a monolith of a semi-rlgid but resiliently fle~lble plastlc materlal, and ls molded or otherwlse fa~rlcated ln two halves that are transversely foldable between a relatively flat condltlon ln whlch the devlce can be packaged, stored and sold in compact form, and a reentrant-ly folded condition in which the head of the device i5 adapted for use as a straddle-type tooth cleaning head that has all of the Eeatures and advantages of the head disclosed ln appllcant's U.S.
Patent 5,137,039. This ls to say that when the handle of the device ls reentrantly folded into the operatlve conditlon and then held in one hsnd llke a ~aton while the head of the device is straddled about a row of teeth and drlven forward with the handle B

3 ~8456-36 to translate lt along the length of the row, the head will remain engaged with the inside and outside faces of the teeth, and wlll rake the yum lines of the teeth in lts own right, wlthout manlpu-lation on the part of the user's hand, because of these features and advantages. Whlle so engaged, moreover, and while raking the gum llnes of the teeth, the head wlll ad~ust comfortably to the ~arying dlameters of the teeth ln the row.
When ln the relatively flat condltion, the hal~es o~ the devlce may also be foldable longitudinally thereof, so that it can be packaged in even more compact form when desired.
Often, the devlce ls constructed as a disposable ltem.
That ls, it ls constructed as one whlch can be put to use but a slngle tlme or two, and then thrown away because of its low prlce.
In partlcular, the device may be molded from inexpenslve polymeric material, and then packaged, marketed and prlced in such lnexpen-slve form, that the user wlll not hesitate to discard it after a slngle use or two. Hospltals, nursin~ homes and other health care faclllties in particular, are in need of such a device to use on patlents within their care.
Accordlng to the lnvention, the handle of the devlce comprlses a palr of elongated handle-forming members whlch are dlscrete from one another, but are arranged ln generally spaced parallel relatlonshlp to one another and hlngedly lnterconnected wlth one another at the space therebetween so that they are rota- -table ln relatlon to one another abou-t axes of rotatlon whlch extend between the members substantlally parallel to the mu-tually ad~acent sldes thereof, and lle ln a plane that substantlally 4 68~56-36 colncides with the hinged connectlon between the members. The arms of the device pro~ect from the dlstal ends o~ the handle-Eormlng members ln generall~ spaced parallel relatlonshlp to one another, wlth the slot extendln~ therebetween, and are sufflclent-ly rlgldly lnterconnected wlth the handle-forming members to form relatlvely rlgld extenslons of the same, longltudlnally thereof, whlch are con~olntly rotatable wlth the handle-formlng members about the aforesald axes of rotation extendlng therebetween.
Meanwhlle, blasing means extendlng crosswise of the hinged connec-tion between the handle--formlng members, operate to blas the mem-bers to rotate ln flrst angularly opposlng dlrectlons about the axes therebetween, relatlvely toward flrst posltlons in which the members assume relatively low angles of lncldence with the plane of the hlnged connection therebetween, i.e., angles ln which they tend toward a coplanar or flattened conditlon. The wlngs in the head of the devlce are connected with the outboard end portions of the arms so as to pro~ect laterally outwardly therefrom and rotate ln con~unction wlth the arms about the axes of rotatlon extendlny between the members, includlng ln the dlrectlons of the aforesald 2~ flrst posltlons ln which the memhers tend toward a coplanar or flattened condltlon. But the blaslng means are reslllently yleld-able to counterblaslng ~orces that are applled to the members ln second axlally opposlng dlrectlons opposed ~o the aforesald ~lrst dlrectlons about the axes between the members. And the mldsectlon and added portlons o~ the head of the devlce are disposed ln the slot between the arms, and are flexibly lnterconnected wlth one another and wlth the arms so that when the counterblaslng force B

684~6-36 are applled to the members ln the second dlrectlons about the axes therebetween, and the members are rotated ln the second directions to second posltions ln whlch the wlngs of the head are reentrantly folded about the mldsectlon to such relatlvely hlgh angles of lncldence wlth the plane of the hinged connectlon that the user must relatlvely forclbly wedge the tops of the teeth between the tooth cleanlng sldes of the wings to straddle the head about a row of teeth, the mldsectlon and added portlons of the head form an artlculated ~olnt between the arms whlch ls operable to preserve the counter blas of the forces on the wlngs axlally of the lmple-ment, yet allow the head to ad~ust to the varylng dlameters of the teeth axlally of the lmplement, when the head, after belng strad-dled about a row of teeth, ls translated along the length of the row ln engagement wlth the opposlng inslde and outslde faces of the teeth.
In many of the presently preferred embodlments of the lnvention, the mldsection of the head of the devlce takes the form of a web-llke member whlch ls lnterposed ln the slot between the arms, a tooth in wldth, and hlngedly lnterconnected wlth the respectlve arms by the added portlons of the head to form an articulated ~olnt therebetween whlch ls operable to preserve the counterblas of the forces on the wlngs axlally of the lmplement as lndicated. In some embodlments, the slot extends ketween the handle-formlng members as well, and the axes of rotation of the handle~formlng members are spaced apart from one another at the opposlng sldes of the slot, and the hlnged connectlon between the handle-forming members takes the form of a web-llke member whlch B

1 3267~4 6 6845~-36 ls interposed ln the slot between the handle-forming members and hlngedly interconnected with the respective handle-forming members at the axes. In fact, in certaln embodiments, the device has a slngle web-like member extend.tng the length thereof, in the slot, which is hinge~ly interconnected with the respective handle-formlng members at the axes to form the hinged connection there-between, and hingedly interconnected with the respective arms by the added portions of the head to form the aforesaid articulated ~oint therebetween. In some of these, moreover, the added por-t~ons of the head are coextenslve with the web-like member the full length of the slot, to form hlnged connections between the web-like member and the handle-formlng members as well.
In one group of the latter embodiments, the device has a pair of hinge formlng grooves extendlng along the axes of rotatlon to subdlvide the device into three hingedly lnterconnected sec-tions, the edge forming sections of whlch, transversely of the axes, are inherently biased to assume the aforesaid flrst posl-tlons when the devlce ls in the relaxed condition thereof. The wlngs of the head, meanwhile, pro~ect laterally outwardly from the edge forming sections of the ~evice at the distal end portions of the edge forming sectlons, and the brush formlng means are dls-posed on those sldes of the wings which oppose one another when the edge forming sections of the device are rotated in the second directlons about the axes.
Preferably, the brush further comprises means operative-ly interconnectable wlth the handle-forMing members of the devlce to retain the members ln the aforesald second posltions thereof ` 1~3 7 68~6-36 when the counterbiasing forces are released therefrom. ~n certain of the presently preferred embodiments of the invention, for e~am-ple, the retention means are separate from the device and ta~e the form of an elongated tube which is slidably engageable about the palr oE handle-forming members to retain the members in the aEore-sald second posl-tions thereof.
Preferably too, the handleforming members of the device, and the hinged connection therebetween, have a hln~e-forming groove extendlng thereacross, transverse the axes of rotation, to enable the relatively proximal and distal end portions of the handle-formin~ members to be reentrantly folded over onto one another, lon~itudinal].y of the device.
Typically, the brush forming means take the form of operatively mutually opposing ~irst and second sets of bristle on the operatively opposlng sides of the wings, which have a ~ap therebetween that coincides with a plane e~tending normal to the plane of the hinged connection and parallel to the axes of rota-tion. Moreover, the midsection of the head commonly has a thlrd set of bristle thereon, opposite the mouth of the gap, as well as a fourth set of bristle thereon at the relatlvely outer periphery o~ the head.
Brlef Descrlption of the Drawin~s These features and advanta~es will be better understood by reEerence to the accompanyin~ drawings whlch lllustrate two straddle-type brushes, the second of which has a head that oper-ates in accordance with the dictates of applicant's U.S. Patent 5,137,039, and is preferred.

B

1 3~6744 In the drawlngs:
FIGURE l ls a top perspective vlew of a brush whlch has a slngle hlnye-forming groove along the top thereof;
FIGURE 2 ls a top p].an vlew of the brush;
FIGURF 3 ls a plan vlew of the brush from the dorsal side thereof;
FIGURE 4 ls an end elevatlonal vlew o~ the brush at the dlstal end thereof;
FIGUR~ 5 is an enlarged plan vlew of the head of the brush from the dorsal slde thereof;
FIGURE 6 ls a part cross sectlonal vlew of a molded brush at the time lt ls taken from the mold;
FlGURE 7 ls a part cross sectlonal vlew of the molded brush after lt has undergone foldlng at the hlnge thereof;
FIGURE ~ ls a top perspective view of a brush havlng a palr of spaced parallel hlnge formlng grooves ln the top thereof, wlth a web therebetween;
FIGURE 9 is a top plan vlew of the brush ln Flgure 8;
FIGURE 10 ls a plan view of the brush ln Flgures 8 and 9 from the dorsal slde thereof;
FIGURE 11 ls an end elevatlonal vlew of the brush in Flgures 8-10 at the distal end thereo~;
FIGURE 12 ls a top perspectlve vlew of the brush ln Flgures 8-11 when lt has been equlpped wlth a telescoplng sheath to retaln the handle-forrnlng members in the rotated posltlons thereof when the counter-blaslng forces are released from the members;
FIGURE 13 is a cross sectlon of Flgure 12 along the llne '' ~3 g 68456-36 13 - 13 thereof;
FIGURE 14 ls a part cross sectlonal view of the head of the brush ln Figures 1-7 when lt has been modified to include gusseted sty:Lus means in the opposing sets of bristle thereon;
~ IGURE 15 is a plan view of the modifled head when seen along the line 15 - 15 of Figure 14f, and FIGURE 16 ls a part slde elevational view of the brush ln Figures ~-11, when it has been reentrantly folde~, longltudln-ally thereof, to give lt a more compact form.
Best Mode for Carryinq Out the Invention Referring to the drawings, it wlll be seen that the rod-llke device 2 whlch forms the hasic element o the too-th brush in Figures 1 - 7, is constructed from semi-rigid but resillently flexlble plastic material, and is monollthic in character. It also has halves 12 which are transversely foldable between a rela-tively flat condltion ~Figure 6) ln which the brush can be packag-ed, stored and sold ln compact forrn, and a reentrantly folded con-dltlon (Figure 7) in whlch the brush is adapted for use as a straddle-type tooth cleaning device, but not a device of the type disclosed by Dinhofer, nor a device of thls type whlch in addl-tion, has all of the features and advantages of the device dis-closed in the aforementloned now USP 5,137,03g.
More specifically, the device 2 has an elongated body 16 of the aforesaid material, and a hinge-formlng groove 1~ runnlng down the length of the body, at the center thereof, which leaves lt blfurcated into halves 12. The halves operate as a palr of elongated handle-forming members 28 whlch are dlscrete from one another, but are arranged ln generally spaced parallel relation-B

ship to one another and hlngedly lnterconnected to one another at the groove 14 so that they can be rotated ln relation to one another about axes 18 ~ormed at the opposiny sldes 45 of the groove. Moreover, because of the character of the plastlc materi-al and the manner in whlch lt ls :Eabricated, the members 28 are inherently biased in the angularly opposing upward dlrections about the axes 18, to assume relatlvely low angles of lncldence to the plane of the groove 14 therebetween, that ls, to assume posl-tlons ln whlch the devlce 2 ls relatlvely flat. Compare Flgures 6 and 7. However, when the devlce ls held ln one hand ln the manner o~ a baton, the blas on the members 28 ls reslllently yieldable to the counterblaslng forces of the user's thumb and flngers ln the angularly opposlng downward dlrectlons (Flgure 7), to enable the members to be rotated to posltlons of relatively hlgher angles of incldence to the plane of the groove, so that the user can put the devlce to use as a toothbrush, though not one wlth as deslreable a head as that in Flgures 8 - 11, as shall be explalned.
The groove 14 extends the full length of the devlce, from the proxlmal 56 to the dlstal ends 38 of the members 28, and at the dlstal end portlons 26 of the members 28, the devlce has an ovate head 4 thereon whlch ln turn has paddle-llke wlngs 30 pro-~ectlng laterally outwardly from the members ! wlth phalanxes 6 of tooth brushlng brlstle 8 on those sldes 32 of the wlngs 30 whlch oppose one another when the members are rotated ln the downward dlrectlons about the axes 18. In the respectlve phalanxes 6, the bristle 8 have varylng lengths, moreover, so that the two pha-lanxes 6 have oppositely lncllned proflles at the tlps thereof, 1l1 3 2 6 7 4 4 68456-36 relative to the dlmenslonal planes of the wlngs 30. The lnclina-tlon of the profiles is relatlvely downward into the ~ap or clear-ance 66 between the phalanxes, furthermore, so that the two pha-lanxes approach one another at an angle at approxlmately 90 degrees when the members 28 are rotated downward agalnst the bias thereon to the posltlons of Figure 4. This in turn inclines the respectlve sets of brlstle 8 at approxlmately 45 degrees to the gum lines of a row of teeth, when the head 4 of the brush is straddled about the row and translated along the length of the row. The head 4 does not provlde the actlon called for ln Appllcatlon Serlal No. 145,771, however, as shall be explalned.
Commonly, the devlce 2 ls molded from polymerlc materlal which has an lnherently resillently yleldable blas across the groove 14 of the same when molded, so that the members 28 tend to assume a generally coplanar condltion with one another as ln Flgure 6. Preferably, however, the members 28 do not remaln ln a coplanar condltlon wlth one another when removed ~rom the mold, so that when the uaer plcks up the devlce 2 ln one hand, he wlll flnd that the members are already somewhat opposed to hls thumb and ~lngers, and can be readlly "pinched" lnto operatlve condltlon wlthout the necesslty for bendlng them out of the coplanar condl-tlon flrst.
Preferably, too, the members 28 have reinforclng ribs 52 on the outer perlpher~es thereof to assure that the wlngs 30 are con~olntly rotatable wlth the membQrs about the axes 18. In fact, the rlbs 52 commence on the dlstal end portlons 26 of the members 28, and then taper lnward along the lengths of the members to B

1 32674~

points ad~acent the proxlmal ends 56 thereof. The ribs 5~ may also taper sldewlse toward the relatlvely remote edges 58 of the members, to asslst the user ln grlpplng the devlce wlth hls thumb and fingers.
Turning now to the embodiment shown in Flgures 8 ~
it will be seen that the handle-formlng members 34 of the devlce 2' now have a much wlder slot 50 extending therebetween, for the full length of the device, and the hinged connectlon between the handle-formlng members 34 takes the form of a web-like member 4~
which ls lnterposed ln the slot 50, a tooth in width, and hingedly lnterconnected with the respective handle-forming members at axes of rotation 18' on the opposing sl~es of the slot~ Once agaln, the device 2' is a monolith of a seml-rigid but reslllently flex-ible plastic material, as in Figures 1 - 7, and the members 34 are inherently biased in the angularly opposing upward dlrections to assume relatlvely low angles of lncldence to the plane of the web 48 therebetween. Moreover, once agaln, the bias on the members is reslllently ~leldable to the counterblaslng forces of the user's thumb and flngers to enable the members 34 to be rotated ln angu-larly opposlng downward directions to positlons in which thedevice 2' can be put to use as a tooth brush. However, ln those positlons, the devlce ls more typlcal of the type shown ln the aforementioned ~pplicatlon Serial No. 145,771, in that, flrstly, the distal end portions 40 of the handle-formlng members 34 form a pair of elongated arms whlch pro~ect from the same ln generally spaced parallel relatlonshlp to one another wlth the slot 50 extendlng therebetween, and wlth the head 74 of the device ~,~

connected wlth the pair of arms 40 so as to straddl0 the slot 50 at the outboard end portions 38' of the arms on an axis 20 ex-tending from arm to arm crosswlse the length of the slot 50. See Figure 11. Addltionally, the head 74 IIOW has three sections in the body thereo~ comprislng a pair of spaced wings 30', and a mid-section 48 in the space therebetween, whlch are serially inter-connected with one another along the axis 20. The head 74 also has phalanxes 6' of tooth brushing bristle 8 on corresponding sides of the wings, and when it ls folded, it ls operatlvely arranged on the arms so that the wlngs 30' reentrantly fold about the full wldth of the mldsection, transverse the axls 20 of the head, rather than about the sldes 45 of a narrow groove 14, as in Flgures 1 - 7. This means that when the tooth cleanlng sldes 6' of the wings approach one another ln foldlng, they are not only spaced apart from one another by a deeper and more widely recessed tooth-slzed gap 66' than was provlded in Fl~ures 1 - 7, havlng a mouth 53 opposlte the midsectlon 48 for the lntroductlon of the teeth to the ga~, but ln ad~ltlon, the head 74 of the device oper-atively assumes a taco shell-shaped configuratlon ln which the midsectlon 48 and the grooved hlnge portlons 46 of the head be-tween the mldsectlon 48 and the wlngs 30', are dlsposed in the slot 50 and flexibly lnterconnected wlth one another and wlth the arms 40 so that when the counterblaslng forces applled to the members 34 ln the downward dlrectlons about the axes 13', reen-trantly fold the wlngs 30' about the mldsection 48 to such relative].y hlgh angles of lncidence wlth the plane of the mld-section ~See Figure 13~, that the user must relatively forcibly 1~ 68456-36 wedge the tops of the teeth between the tooth brushing sides 6' of the wlngs in the manner of the aforementloned Applicatlon, to straddle the head 7~ about a row of teeth, the mldsection 48 and hinge portlons 46 of the head form an artlculated ~oint 4G, 48 between the arms which is operable to preserve the counterbias on the wings axially of the head, yet allow the head 74 to ad~ust to the varying dlameters of the teeth, when the head, after being straddled about the row of teeth, ls translated along the length of the row ln enyagement wlth the opposlng lnslde and outslde faces of the teeth.
The device 2' in Figures ~ - 11, also has substantially collinear hinge formlng ~rooves 84 thereacross, transverse the axes 18', and on the dorsal sldes of the respectlve sectlons 34, 48, 34, wherehy one end portlon of the devlce can be folded over on the other, ln the manner of Flgure 16, to render the devlce more compact longltudlnally thereof, when the devlce ls out of use.
Additionally, the head 74 of the devlce ls e~uipped wlth an addltlonal set 72 of brlstle 8 on the inner periphery of the mldsectlon 48, and a further set 70 of bristle 8 on the outer per-iphery of the midsectlon, whlch is directly opposed to that 72 on the lnner periphery of the web.
As ln ~ppllcation 1~5,771, the wlngs of the head may be equlpped wlth stylus-like means 76 that upstand wlthln the sets 6' of brlstle on the wlngs, and are sufflciently rlgld and appropri-ately located on the inner perlpheral faces 32' (Figure 141 of the wlngs, to perform as picks that trace along the gum lines of a row B

of teeth to be cleaned, when the head 74' of the devlce (Flgures 14 and 15) is straddled about the row and translated along the length of the row opposite the faces of the teeth, as explalned in the co-pending Appllcatlon.
Preferably, the plcks 76 are arranged in parallel rows on the opposlte sldes of the gap 66' !Figure 15), and there are thin flanges 78 whlch extend relatlvely lnwardly toward the gap from corresponding plcks, and termlnate at the gap, as seen in Flgures 14 and 15. The flarlges 78 provide flllet-like reinforcing gussets wlth whlch to stabllize the plcks against splay when they are employed ln raklng the gum llnes of the teeth to be cleaned.
Commonly, the flanges 78 are recessed below the proflles 80 of the sets of brlstle 8 so that they do not lnterfere wlth the actlon of the bristle in the center reglon of the head as they provide the relnforcement indlcated. In addltlon, when the picks 76 are arranged ln two or more palrs of the same, the pairs are commonly spaced apart from one another in the center region of the head, and the spaces 82 between the respectlve pairs of flanges are freed of bristle on the opposing sides of the gap, as shown in Figure 15.
When elther devlce 2 or 2' ls put to use, the user may choose to use further means such as the tube 60 seen ln Flgures 12 and 13, to retaln the members 28 or 34 ln the reentrantly folded posltions thereof. That is, before the user releases the members from the reentrantly folded condition thereof, he may telescopl-cally engage the tube 60 about the members to provlde a means for retalnlng the members in their respectlve posltlons when the 16 6~456-36 counterblasing forces of hls thumb and foreflngers are removed.
The tube ls shown as circular, but one wlth a more oblong cross sectlon ~not shown) may be employed, for example, for the embodl-ment of Flgures 1 - 7.

B

Claims

1. In a straddle-type tooth brush which comprises:
an elongated rod-like device which in turn comprises a pair of elongated arms having outboard end portions and adapted for insertion in the mouth of the person whose teeth are to be cleaned, a tooth brushing implement that is connected with the arms for cleaning the teeth, and a handle that is operable to support the arms adjacent a row of teeth while the tooth brushing implement is applied thereto, the arms projecting from the distal end of the handle in generally spaced parallel relationship to one another, with an elongated slot extending therebetween, and the arms being rigidly inter-connected with the handle so as to form relative-ly rigid extensions of the same, longitudinally thereof, the tooth brushing implement comprising a brush-forming head which is connected with the arms and straddles the slot at the outboard end portions of the arms on an axis of the tooth brushing implement extending from arm to arm crosswise the length of the slot, the brush-forming head having three sections in the body thereof comprising a pair of spaced wings, and a midsection in the space therebetween, which are serially interconnected with one another along the aforesaid axis of the tooth brushing implement, the head also having brush-forming means on cor-responding sides of the wings and being arranged on the arms so that the wings are reentrantly folded about the midsection transverse the axis of the tooth brushing implement, with the brush-forming sides thereof folded relatively toward one another, but spaced apart from one another by a gap having a mouth opposite the midsection of the head for the introduction of the teeth to the gap, and the brush-forming head having added portions thereof which are interposed between the respective wings and the midsection thereof, axially of the tooth brushing implement, the improvement wherein:
the rod-like device is a monolith of a semi-rigid but resiliently flexible plastic material, the handle of the device comprises a pair of elon-gated handle-forming members which are discrete from one another, but are arranged in generally spaced parallel relationship to one another and hingedly interconnected with one another at the space therebetween so that they are rotatable in relation to one another about axes of rotation which extend between the handle forming members substantially parallel to the mutually adjacent sides thereof, and lie in a plane that substan-tially coincides with the hinged connection between the members, the arms of the device project from the distal ends of the handle-forming members in generally spaced parallel relationship to one another, with the slot extending therebetween, and are suffi-ciently rigidly interconnected with the handle forming members to form relatively rigid exten-sions of the same, longitudinally thereof, which are conjointly rotatable with the handle forming members about the aforesaid axes of rotation extending therebetween, biasing means extending crosswise of the hinged connection between the handle forming members, operate to bias the members to rotate in first angularly opposing directions about the axes therebetween, relatively toward first positions in which the members assume relatively low angles of incidence with the plane of the hinged connec-tion therebetween, the wings in the head of the device are connected with the outboard end portions of the arms so as to project laterally outwardly therefrom and rotate in conjunction with the arms about the axes of rotation extending between the handle forming members, the biasing means are resiliently yieldable to counterbiasing forces that are applied to the handle forming members in second axially opposing directions opposed to the aforesaid first directions about the axes between the members, and the midsection and added portions of the head of the device are disposed in the slot between the arms, and are flexibly interconnected with one another and with the arms so that when the counterbiasing forces are applied to the handle forming members in the second directions about the axes therebetween, and the members are rotated in the second directions to second positions in which the wings of the head are reentrantly folded about the midsection to such relatively high angles of incidence with the plane of the hinged connection that the user must relatively forcibly wedge the tops of the teeth between the tooth cleaning sides of the wings to straddle the head about a row of teeth, the midsection and added portions of the head form an articulated joint between the arms which is operable to preserve the counterbias of the forces on the wings axially of the tooth brushing implement, yet allow the head to adjust to the varying diameters of the teeth axially of the tooth brushing implement, when the head, after being straddled about a row of teeth, is trans-lated along the length of the row in engagement with the opposing inside and outside faces of the teeth.

2. The straddle-type tooth brush according to Claim 1 wherein the midsection of the head of the device takes the form of a web-like member which is interposed in the slot between the arms, a tooth in width, and hingedly interconnected with the respective arms by the added portions of the head to form an articulated joint there-between which is operable to preserve the counterbias of the forces on the wings axially of the tooth brushing implement as indicated.

3. The straddle-type tooth brush according to Claim 2 wherein the slot extends between the handle-forming members as well, and the axes of rotation of the handle-forming members are spaced apart from one another at the opposing sides of the slot, and the hinged connection between the handle-forming members takes the form of a web-like member which is interposed in the slot between the handle-forming members and hingedly interconnected with the respective handle-forming members at the axes.

4. The straddle-type tooth brush according to Claim 3 wherein the device has a single web-like member extending the length thereof, in the slot, which is hingedly interconnected with the respective handle-forming members at the axes to form the hinged connection therebetween, and hingedly interconnected with the respective arms by the added portions of the head to form the aforesaid articulated joint therebetween.

5. The straddle-type tooth brush according to Claim 4 wherein the added portions of the head are coextensive with the web-like member the full length of the slot, to form hinged connections between the web-like member and the handle-forming members as well.

6. The straddle-type tooth brush according to Claim 1 wherein the device has a pair of hinge-forming grooves extending along the axes of rotation to subdivide the device into three hingedly interconnected sections, the edge-forming sections of which, transversely of the axes, are inherently biased to assume the aforesaid first positions when the device is in the relaxed condition thereof, the wings of the head projecting laterally outwardly from the edge-forming sections of the device at the distal end portions of the edge-forming sections, and the brush forming means being disposed on those sides of the wings which oppose one another when the edge-forming sections of the device are rotated in the second direct-ions about the axes.

7. The straddle-type tooth brush according to Claim 1 further comprising means operatively interconnectable with the handle-forming members of the device to retain the handle forming members in the aforesaid second positions thereof when the counterbiasing forces are released therefrom.

8. The straddle-type tooth brush according to Claim 7 wherein the retention means are separate from the device and take the form of an elongated tube which is slideably engageable about the pair of handle-forming members to retain the members in the aforesaid second positions thereof.

9. The straddle-type tooth brush according to Claim 1 wherein the handle-forming members of the device, and the hinged connection therebetween, have a hinge-forming groove thereacross, transverse the axes of rotation, to enable the relatively proximal and distal end portions of the handle-forming members to be reentrantly folded over onto one another, longitudinally of the device.

10. The straddle-type tooth brush according to Claim 1 wherein the brush forming means take the form of operatively mutually opposing first and second sets of bristle on the operatively opposing sides of the wings, which have a gap therebetween which coincides with a plane extending normal to the plane of the hinged connec-tion and parallel to the axes of rotation.

11. The straddle-type tooth brush according to Claim 1 wherein the midsection of the head has a third set of bristle thereon, opposite the mouth of the gap.

12. The straddle type toothbrush according to Claim 1 wherein in the first positions of the handle forming members, the monolith is foldable about an axis extending crosswise the axes of rotation of the handle forming members so that the monolith can be reduced to a more compact form.

13. The straddle type toothbrush according to Claim 12 wherein the monolith has a body and the crosswise axis extends within the body of the monolith so that the relatively proximal and distal end portions of the respective handle forming members can be folded over onto one another longitudinally of the device.