Dental floss device

A dental floss device (1, 40, 50, 60, 70) comprises a handle (2) having a shank (3) terminating in a head piece (4). A disposable dental floss holder (5) comprises a base portion (10) and a pair of spaced-apart jaws (11, 12) with a length of dental floss (13) extending therebetween. The head piece (4) has a groove (20) in which the base portion (10) is securely retained when the device is used in all flossing directions. Snap-fit projections (15) extend inwardly from the jaws (11, 12) of the floss holder (5) and are retained behind marginal edges (25) of a floor (24) of the groove (20). When used, the floss holder (5) is removed and a new floss holder (5) is fitted.

The invention relates to a dental floss device of the type comprising a 
handle having a head piece, a disposable dental floss holder and 
releasable engagement means between the head piece and holder for fitting 
and disposal of the holder. 
A dental floss device of this type is described in U.S. Pat. No. 3,892,249. 
The device described in this prior specification comprises a handle having 
a curved head piece with in-turned Jaws which have formations which 
interengage with complementary formations on a dental floss holder. The 
holder is of flexible material and is bowed for fitting to the Jaws of the 
head piece and thumb pressure applied. 
One of the problems with known dental floss devices of this type is that 
the dental floss holder may be difficult to engage and disengage with the 
head piece. There is also a substantial risk of the dental floss holder 
becoming detached from the head piece in use in the mouth. 
This invention is directed towards providing a dental floss device which 
will overcome at least some of the problems with known devices. 
This invention is characterised in that the releasable engagement means on 
the head piece and holder is arranged to retain the holder securely in 
position on the head piece during movement of the holder in use in the 
mesio-distal, bucco-lingual and gingivo-incisal directions. 
The advantage of this arrangement is in ensuring that the device may be 
effectively and safely used in all directions of operation in use. The 
distal-medial direction refers to the direction across the face of a tooth 
in a substantially horizontal plane. The bucco-lingual direction refers to 
the movement interproximally in a substantially horizontal plane. The 
gingivo-incisal motion refers to the flossing motion in a vertical plane. 
In one embodiment of the invention the holder comprises a base portion and 
a pair of spaced-apart Jaws extending from the base portion to accommodate 
a length of dental floss therebetween and the releasable engagement means 
includes engagement means between the base of the head piece and the 
holder. This arrangement facilitates the flossing action in use and ease 
of manufacture. 
The length of floss may be integral with the Jaws or may be attached 
thereto by any suitable means such as adhesives or the like. 
In a preferred embodiment of the invention the releasable engagement means 
includes a transversely extending groove on the holder or head piece and a 
complementary tongue portion on the other of the holder or head piece 
which interengage an assembly. 
The provision of a transverse groove and tongue affords particular 
advantages of strength in use and ease .of attachment and disconnection of 
the holder. 
Preferably the releasable engagement means includes snap-fitting means 
between the holder and head piece. Snap-fitting engagement in addition to 
the tongue and groove arrangement provides for ease of attachment and 
disconnection while adding to the ability of the connection to resist the 
forces generated in use. 
In one case the snap-fitting means comprises snap-fit projection(s) on one 
of the holder or head piece which engage with corresponding recess(es) on 
the other of the head piece or holder. Preferably for ease of fitting and 
construction the snap-fit projections and corresponding recesses are 
provided on the Jaws of the holder and adjacent to the groove of the head 
piece. Typically the projections extend inwardly from the jaws of the 
holder to engage with corresponding recesses provided adjacent to the 
groove of the head piece. 
In a particularly preferred embodiment which is preferred for ease of 
fitting and strength in use the groove is of arcuate shape in longitudinal 
cross section for interengagement with a correspondingly shaped tongue 
portion. 
In another embodiment of the invention the snap-fit projections extend from 
one of the holder or head piece to engage a complementary recess in the 
other of the holder or head piece. Typically there are two spaced-apart 
and oppositely directed snap-fit projections for engagement with a recess 
provided by a slot. In one case for easeof construction and use the slot 
is provided in the holder and the snap projections extend from the head 
piece to snap-fittingly engage in the slot. 
According to a further embodiment of the invention the head piece includes 
an additional retaining means for movement between a released position for 
fitting and removal of the head piece to a locking position substantially 
enclosing the head piece in the holder. This arrangement leads to a 
particularly strong construction. 
For ease of construction and use the additional retaining means may be 
hingedly connected, for example, by means of a live hinge, to the head 
piece. 
For additional strength and ease of use the additional retaining means 
snap-fittingly engages, typically by snap-fit projections on the 
additional retaining means, with the head piece in the locking position. 
In another embodiment of the invention the releasable engagement means 
comprises a spigot extending from the head piece of the holder to engage 
with a complementary socket in the other of the holder or head piece. 
In a particularly preferred arrangement the socket is provided in the head 
piece and the spigot extends from the holder to engage the socket. 
Preferably the handle includes a shank portion which is inclined in the 
longitudinal direction at an angle of between 145.degree. and 180.degree. 
to the handle. 
Preferably also the handle includes a shank portion and the head-piece is 
inclined in the longitudinal direction at an angle of between 125.degree. 
and 180.degree. to the neck portion. 
The device is most preferably substantially of plastics material. The head 
piece may be of the same or different plastics material than that of the 
holder.

Referring to the drawings and initially to FIGS. 1 to 5 thereof there is 
illustrated a dental floss device according to the invention indicated 
generally by the reference numeral 1. The device 1 comprises a handle 2 
having a shank portion 3 terminating in a head piece 4. The dental floss 
device 1 also comprises a disposable dental floss holder 5, the holder 5 
and the head piece 4 having releasable engagement means for fitting and 
disposal of the holder 5. 
The holder 5 comprises a base portion 10 which in this case is of arcuate 
shape in longitudinal cross section and a pair of spaced-apart Jaws 11, 12 
extending from the base portion 10 to accommodate a length of dental floss 
13 therebetween. The dental floss 13 may be integrally moulded with the 
holder 5 or may-be attached by any suitable means to the holder such as by 
adhesive bonding. 
The releasable engagement means in this case include snap-fit projections 
15 which extend inwardly from the Jaws 11, 12 of the holder 5 as will be 
particularly apparent from FIGS. 4 and 2. 
The head piece 4 of the handle 2 includes a transversely extending groove 
20 defined between a pair of upstanding shoulders 21, 22 and a floor 24 of 
the head piece 4. The groove 20 is of similar shape and dimension to that 
of the base portion 10 of the holder 5 and the marginal edges 25 of the 
floor 24 of the groove 20 are rounded to accommodate the snap-fit 
projections 15 as they ride over the marginal edges 25 of the floor 24 of 
the groove. At least part of the base portion 10 of the floss holder 4 
defines a tongue portion which in use is securely retained within the 
groove 20. 
In use, the holder 5 is fitted to the head piece by first inserting the 
head piece 4 through the gap defined between the jaws 11, 12 of the holder 
5 and dropping the holder 5 into the groove 20. Light finger pressure is 
then applied to the base 10 of the holder 5 to push the snap-projections 
15 over the marginal edges 25 of the groove 20 until they engage with the 
floor 24 of the groove 20 as illustrated in FIG. 4. In this fitted 
position the holder 5 is positively restrained from movement or deflection 
in all positions and directions of use of the dental floss device 1. 
Referring particulary to FIG. 5 the various directions of use of the dental 
floss device are diagrammatically illustrated. The arrows X indicate the 
bucco-lingual direction in which the floss 13 is drawn interproximally 
forward and backwards in the gap between adjacent teeth. The arrows Z 
indicate the mesio-distal direction which is the movement of the floss 
across the face of the teeth. The arrows Y indicate the gingivo-incisal 
directions of the cleaning action in a vertical plane Z using the dental 
floss device. 
Referring particulary to FIG. 3 it will be appreciated that the handle of 
the device may be arranged at any suitable angle and may be of any desired 
shape. For ease of access in use in this case the shank 3 extends at an 
angle B to the handle 2 of between 145 .degree.and 180.degree.. The head 
piece 4 is inclined at an angle A to the shank 3 of between 125.degree. 
and 180.degree.. The particular angle and configuration presents a dental 
floss device which may be readily used with all teeth in the mouth with 
minimum discomfort to the user. It will be appreciated that in the other 
embodiments described below similar angular configurations may be 
utilised. 
The invention provides a dental floss device which is of simple 
construction and easy to use. It offers a dental device with holders for 
dental floss which can be readily fixed in position and replaced as 
desired. Because of this simplicity and ease of construction it is 
anticipated that the device will lead to far more widespread use of dental 
floss. Because the dental floss holder is easily replaceable and yet 
retained effectively in position in all directions of use it is easy and 
safe to use. 
Referring to FIGS. 6 to 8 there is illustrated another dental floss device 
according to the invention indicated generally by the reference numeral 
40. The device 40 is similar to the device described above with reference 
to FIGS. 1 to 4 and like parts are assigned the same reference numerals. 
In this case the base portion 10 of the dental floss holder 5 and the 
groove 20 of the head piece 4 are of generally horizontal rather than 
arcuate shape in longitudinal cross section. It is anticipated that this 
device according to this embodiment of the invention will be slightly 
cheaper due to less complex moulding requirements. 
Referring to FIGS. 9 to 11 there is illustrated another dental floss device 
50 according to the invention. The device 50 is again similar to the 
device illustrated in FIGS. 1 to 5 and like parts are assigned the same 
reference numerals. In this case the head piece comprises a channel member 
having a base 51, a first side web 52a extending from the shank 3 and a 
second side web 52b which are sized and shaped to receive the base portion 
10 of the dental floss holder 5. Additional retaining means 4 for 
retaining the holder in position is in this case provided by an extension 
plate 53 which extends from and is hingedly interconnected by a plastics 
hinge 55 to the side web 52b. The extension plate 53 has inwardly 
extending snap-fit projections 56 which engage over the shank 3 of the 
handle when the plate member 53 is hinged into the closed or locked 
position illustrated in FIGS. 9 and 11. In the locked position illustrated 
in FIGS. 9 and 11 it will be noted that the base portion 10 of the dental 
floss holder 5 is completely confined against movement in all directions 
in use leading to a particularly strong construction. It will be noted 
that the side web 52a is extended sidewardly to provide a shoulder to 
engage part of the jaws 11, 12 of the holder 5 to assist in retaining the 
holder securely in position. To replace the floss holder 5 the snap 
projections 56 are released from the shank 3 of the handle and the 
extension plate 53 is pushed into the release position illustrated in FIG. 
11 allowing the holder 5 to be removed and a fresh holder to be placed in 
position. For ease of fitting and removal of a holder 5 from the device 
the hinge 55 may be a live hinge which biases the snap projections 56 
towards the shank 3 and/or away from the shank 3 to facilitate insertion 
and removal of a floss holder 5. 
Referring to FIGS. 12 to 14 there is illustrated another dental floss 
holder according to the invention indicated generally by the reference 
numeral 60. The dental floss holder 60 is similar to the holder 
illustrated in FIGS. 7 to 9 and like parts are assigned the same reference 
numerals. In this case the groove 20 in the head piece 4 for receiving the 
floss holder 5 is defined by a base wall 61 and side webs 62a, 62b 
projecting from the base wall 61, the side webs having in-turned edges 63 
to facilitate snap-in of the holder in the head piece. One of the side 
webs 62 includes a generally L-shaped extension 65 which is hingedly 
connected to the web 62b by a plastics hinge 66 and has an inwardly 
extending projection 67 which, in the locked position illustrated in FIGS. 
10 and 12, enters the gap between the projections 63 to even more 
positively retain the holder 5 in position on the head piece 4. The device 
is operated in a similar manner to the device illustrated in FIGS. 9 to 
11. 
Referring to FIGS. 15 and 17 there is illustrated another dental floss 
device according to the invention indicated generally by the reference 
numeral 70 which is similar to the device described above with reference 
to FIGS. 1 to 5 and like parts are assigned the same reference numerals. 
In this case the releasable engagement means between the floss holder 5 
and head piece 4 comprises a pair of snap-fit projections 71 extending 
from the base portion 10 of the holder 5 to engage in a complementary 
socket 72 in the head piece 4. To release the holder 5 a user draws the 
snap-projections 71 towards each other allowing the projections to move 
freely through the socket 72. It will be noted that in this case the 
groove 20 is closed at both ends to securely retain the holder 5 in 
position in the head piece 4. 
An additional retaining means may be provided for retaining the snap 
projections 71 splayed in the locked position. The additional retaining 
means may comprise a spike-like member for insertion between the 
projections 71. The spike-like member may be attached to the head piece 4 
by a hinge arrangement. 
The dental floss device may be of any suitable material of construction. 
Preferably the device is of substantially plastics material. The head 
piece may be of the same or different plastics material than that of the 
holder. 
Many variations on the embodiments of the invention described will be 
readily apparent and accordingly the invention is not limited to the 
embodiments hereinbefore described which may be varied in both 
construction and detail.