IES940299A2 - A dental floss device - Google Patents

Abstract

A dental floss device comprises a handle 21 and a bifurcated part 31 rotatable one relative to the other. The bifurcated part 31 has a hollow base defining a housing containing a reel of dental floss. With the reel loose in the housing a continuous length of dental 10 floss 72 may be drawn from the housing, passed across the arms 40, 41 of the bifurcation and the leading end thereof returned to the housing through a slot 36. Upon rotation of the handle 21 relative to the bifurcated part 31 the leading end of the floss 72 15 becomes trapped in the housing and the trailing end of the floss is withdrawn back into the housing to tension the floss across the bifurcation arms 40, 41.

Description

—-——— This invention relates to a dental floss device.

The use of dental floss for oral hygiene is well known. Dental floss is a soft and flexible material which is usually manually inserted between teeth and worked toward the gum by a back and forth motion. It helps remove plaque and other debris and thus helps in cleaning the teeth.

Dental floss is usually dispensed manually from a container, the container usually having means for enabling a length of floss to be cut for use. Having cut a length of floss, the user then winds the ends of the length of the floss around, usually, the index fingers of the hands so as to provide a taut shorter length of floss which is used to clean the teeth. A difficulty with this technique, which is difficult to use, is the tightness of the floss as it is wrapped around the fingers which can be painful.

Various devices for enabling flossing to be carried out have been produced. For example, there is known a disposable device having a handle one end of which terminates in a u-shape the ends of which are connected by a length of floss. A difficulty with such device is that, apart from being relatively high in cost due to its disposability, the tautness of the floss is usually insufficient or is quickly lost. s 9 4 0 2 9 9 Another device comprises a handle having a bifurcation. The handle includes a button around which one end of a previously cut length of floss is wrapped. The floss is passed over respective slots in each furcation of the bifurcated end, the furcations are gently moved towards each other against a bias which tends to move the furcations apart and the ends of the floss are wrapped around the button. Upon release of the furcations, which now tend to move apart, tautness is created in the length of floss between the furcations which length of floss is used to clean the teeth. A difficulty with such a known device is the need to pre-cut a length of floss each time a floss piece is required and to manipulate the length of floss as described.

A further development of the device referred to above is the provision of a housing in the handle of the device having a means for storing a supply of floss. The floss exits the housing, passes over the furcations and may be collected in a means also housed in the handle for storing the used floss or, as in the previous example, is wrapped around a button on the handle.

A difficulty with all of these devices is their inability to provide a means for enabling sufficient tension or tautness of the floss between the furcations.

It is an object of the present invention to overcome these problems.

The invention, therefore, provides a dental floss device comprising two parts rotatable one relative to - * 4 s 9 4 0 2 9 9 the other one of the parts comprising a handle and the other part (the bifurcated part”) having an external bifurcation and a hollow region defining a housing, the device further including dispensing means in the housing from which a continuous length of dental floss may be drawn, passed across the bifurcation and the leading end thereof returned to the housing, and means for effecting that upon rotation of the handle relative to the bifurcated part the leading end of the floss becomes trapped in the housing and the trailing end of the floss is withdrawn back into the housing to tension the floss across the bifurcation.

The invention will be understood in greater detail from the following description of a preferred embodiment thereof given by way of example only and with reference to the accompanying drawings in which: FIGURE 1 is as perspective view of a floss device according to the invention; FIGURE 2 is a first side elevation of the device of Figure 1 of the drawings; FIGURE 3 is a second side elevation of the device of Figure 1 of the drawings; FIGURE 4 is an exploded view of the device of Figure 1 of the drawings; FIGURE 5 is an enlarged view of part of the device of Figure 2 of the drawings; and S 9 4 0 2 9 9 FIGURE 6 is a side elevation of a second embodiment of a device according to the invention.

Referring now to the drawings and in particular to Figures 1-5, there is shown a floss device 10 according to the invention of two-part construction, and a bobbin or reel 12 for storing a supply of floss 13. One part of the construction comprises a cylindrical handle 21 and the other part is a bifurcated part 31 . The handle 21 has a shaft 22 extending coaxially therefrom which is threaded for at least a portion of the free end 23 thereof.

At its forward end the bifurcated part 31 has an external bifurcation defined by arms 40, 41 and at its rear end the bifurcated part 31 has a hollow region forming a cylindrical housing 32 for the reel 12. The housing 32 has one end wall formed by an internal surface 33 of the bifurcated part 31, and a cylindrical sidewall 34. The surface 33 is shown in dashed lines and is substantially normal to the axis of the housing 32.

The bifurcated part 31 further has a screw-threaded bore (not shown) extending forwardly from the centre of the surface 33, the bore being substantially coaxial with the axis of the housing 32. The bore is in screw-threaded engagement with the screw-threaded end 23 of the shaft 22 such that the shaft 22 extends substantially co-axially through the housing 32 and the annular surface 71 of the handle 21 extends slightly into and hence closes the open end 72 of the housing 32. 8940299 - 5 The surface 71 is substantially parallel to the surface 33. Accordingly, the surface 71 of the handle forms an end wall of the housing 32 opposite to the end wall formed by the surface 33, and the distance apart of these surfaces 33 and 71 depends upon the degree of screw-threaded engagement of the handle 21 and bifurcated part 31.

In use the reel 12 is rotatably mounted on the shaft 22 and, accordingly, its axis of rotation is substantially coaxial with the axis of the shaft. With the handle 21 and bifurcated part 31 in screw-threaded engagement as described above the surfaces 33 and 71 may be adjusted from being sufficiently far apart to permit the reel 12 to rotate freely on the shaft 22 to being sufficiently close together to come to bear on the opposite ends of the reel 12. In this embodiment the handle 21 is rotated clockwise relative to the bifurcated part 31 as viewed in the direction of the arrow 70 in Figure 4 to reduce the distance apart of the surfaces 33 and 71.

The side wall 34 has a first slot 35 running from the mouth or open end 71 of the housing 32 to the surface 33. The first opening 35 provides communication between the outside of the housing 32 and internally thereof and is substantially parallel to the axis of the shaft 22.

A second slot 36 is provided in the side wall 34.

The second slot 36, which also provides communication between the outside of the housing 32 and internally S 94 0299 - 6 thereof, is not contiguous with or in direct communication with the first slot 35. Rather, the second slot 36 is located on the opposite side of the side wall 34 to the slot 35 and extends around approximately one-half the circumference of the side wall 34. In addition, one of the edges of the second slot 36 is aligned with the surface 33. The second slot 36 has diametrically opposite ends 37 and 38.

An integral guide member in the form of a pip 60 is provided on the outside of the bifurcated part 31 adjacent the trailing end 37 of the slot 36.

The free end of each bifurcation arm 40, 41 itself has a respective bifurcation 42, 43 and 44, 45. Each of the bifurcations 42, 43 and 44, 45 provides a respective opening 46, 47 which enables a length of floss to bridge the gap between the bifurcation arms 40, 41.

On the external wall of the bifurcated part 31 there is provided a groove 48 which is contiguous with the first slot 35 and is also contiguous with the opening 47 generated by the bifurcation 44, 45.

A floss cutting device 50 is provided on the external wall of the bifurcated part 31 adjacent the leading end 38. The reel 12 comprises a hub 15 terminated at opposite ends by a respective first flange 16 and a second flange 17. The outer rim 19 of the second flange 17 is sloped towards the axis of the housing 32 in the direction towards the surface 33, i.e. in the direction from left to right as viewed in Figure 5 of the drawings. The hub 15 has a relatively long S 94 0 2 9 9 continuous length of floss 13 wound therearound. The reel 12 with the floss 13 thereon is mounted on the shaft 22 so that upon dispensation of the floss 13 from the reel 12, the reel 12 rotates in an anti-clockwise direction when viewed in the direction of the arrow 70, i.e. opposite to the direction of rotation of the shaft 22 when engaging with the bifurcated part 31.

A washer or O-ring 18 is provided on the shaft 22 between the first flange 16 and the surface 71 of the handle 21 .

In use of the device, with the reel 12 initially freely rotatable in the housing 32, a length of floss 72 is pulled from the reel 12 via the first slot 35. The length is passed along the groove 48, threaded across the arms 40, 41 between the openings 47, 46, engaged with the pip 60, and the leading end thereof is then threaded through the second slot 36 so as to enter the housing 32 at the end 37 of the slot 36, pass between the surface 33 and the flange 17 of the reel 12, and exit the housing at the end 38 of the slot 36. The slope of the rim 19 assists in guiding the floss 72 between the surface 33 and the flange 17.

While the floss 13 is being pulled, the reel 12 is free to rotate about the shaft 22. The handle 21 is now screwed further into the bifurcated part 31 so that the surface 33 comes to bear against the flange 17 to sandwich or trap the leading end of the floss 72 between them. Simultaneously, the surface 71 of the handle 21 comes to bear upon the flange 16 via the o-ring 18 therebetween. The o-ring 18 is made of a substance which provides a higher coefficient of friction between the surface 71 and the flange 16 than the coefficient of friction between the flange 17 and the surface 33 with the floss 72 therebetween. This results in the reel 12 being constrained to rotate in unison with the handle 21 relative to the bifurcated portion 31. Continued rotation of the handle 21 after the point at which the surfaces 33 and 71 come to bear upon the flanges 17 and 16 respectively will therefore cause the reel 12 to rotate relative to the bifurcated portion 31 in such a direction as to cause the trailing end of the floss 72 to be withdrawn into the housing 32 and wound back on to the reel 12. However, as the leading end of the floss 72 is sandwiched between the flange 17 and the surface 33, tension develops in the floss 72 between the reel 12 and the leading end of the floss 72 trapped between the flange 17 and the surface 33 which tension is, of course, present in that part of the floss 72 bridging the bifurcation arms 41, 42. The device can now be used for flossing.

When it is desired to allow a clean portion of floss 72 to bridge the gap between the bifurcation arms 41, 42, the handle 21 and the bifurcated part 31 are unscrewed slightly so as to enable the reel 12 to once again rotate freely in the housing 32 thereby allowing floss 72 to be further released by pulling at the leading end thereof and when sufficient floss 72 has been dispensed, the handle 21 and the bifurcated part 31 are re-tightened as before. Excess floss 72 may be cut by the floss cutting device 50.

In order for the tension to be applied to the floss - 9 72, it is essential that following the trapping of the leading end of the floss 72 between the flange 17 and the surface 33, the handle 21 and the reel 12 are constrained to rotate in unison. This is achieved by ensuring that the coefficient of friction between the flange 16 and the handle 21 is greater than the coefficient of friction between the flange 17 and the housing 32. In the present embodiment, this effect is achieved by the provision of the O-ring 18 which could be made of a suitable material such as rubber, neoprene or the like. In essence, the relationship between the flange 16 and the handle 21 is that of friction clutch engaging surfaces. Such frictional difference could, however, be achieved in other ways of which one would be by way of a freewheeling clutch in which the handle 21 has a ratchet surface thereon as does the flange 16 thereby permitting relative rotation of the handle 21 and the flange 16 in a first condition of use but uponinterengagement and rotation in a second condition of use, they rotate in unison.

When the floss 72 is exiting the housing 32 via the slot 35, there is a danger that in certain circumstances, the floss may wind around the shaft 22 thus leading to entanglement of the floss 72. To obviate this possibility, and with particular reference to Figure 6 of the drawings, there is shown a second embodiment of a floss device 100 which is substantially the same as that described with reference to the device 10 of Figures 1-5 of the drawings except as follows.

As will be seen from Figure 5 of the drawings and with reference to the device 10, the first slot 35 S 9 4 0 2 9 9 - 10 extends the height of the housing 32 terminating at the surface 33 where it is contiguous with the groove 48.

To avoid the possibility of the floss 72 from being wound around the shaft 22, in the embodiment of Figure 6 the first slot 35 stops short of the surface 33 so that the floss 72 must exit the housing 32 within the confines of the flanges 16, 17. In those circumstances, the part of the housing 32 delineated by the lines 101 and 102 has a groove 148 which is contiguous with the slot 35 and the groove 48. Otherwise, the device 100 functions in a manner similar to the device 10.

With reference to Figures 1-6 of the drawings and in order to provide a disposable device 10 according to the invention, access to the reel 12 should be denied.

This can be achieved by extending the housing 32 such that it reaches beyond the handle 21 and is then capped permanently with a disc of diameter equal to the internal diameter of the housing 32. Segments cut from the extended housing 32 permit finger contact directly with handle 21 for use. However, the permanent cap at the end ensures the handle cannot be removed and as such the reel cannot be accessed to re-load it.

A device with such a configuration would be disposed of when the contents of floss have been used up.

The invention is not limited by or to the specific embodiment described which can undergo considerable variation without departing from the scope of the invention.

Claims (5)

CLAIMS:

1. A dental floss device comprising two parts rotatable one relative to the other, one of the parts comprising a handle and the other part (the bifurcated part) having an external bifurcation and a hollow region defining a housing, the device further including dispensing means in the housing from which a continuous length of dental floss may be drawn, passed across the bifurcation and the leading end thereof returned to the housing, and means for effecting that upon rotation of the handle relative to the bifurcated part the leading end of the floss becomes trapped in the housing and the trailing end of the floss is withdrawn back into the housing to tension the floss across the bifurcation.

2. A device as claimed in claim 1, wherein the handle and bifurcated part are in screw-threaded engagement, wherein the dispensing means comprises a reel within the housing which depending upon the degree to which the handle and bifurcated part are screwed together is freely rotatable within the housing or constrained to rotate with the handle, the reel having wound thereon a continuous length of dental floss, and wherein aperture means is provided in the wall of the housing by which the dental floss may be drawn from the reel when the reel is freely rotatable in the housing, the arrangement being such that when the handle and bifurcated part are screwed together sufficiently to constrain the reel to rotate with the handle the leading end of the dental floss becomes trapped in the housing and upon further screwing together of the - 12 handle and bifurcated part rotation of the reel within the housing causes the trailing end of the dental floss to be withdrawn back into the housing.

3. A device as claimed in claim 2, wherein the housing has opposite ends disposed along the axis of rotation of the handle and bifurcated part which ends are constituted respectively by an internal surface of the bifurcated part and a surface of the handle such that the distance apart of the two surfaces depends upon the degree of screw-threaded engagement of the handle and bifurcated part, wherein the reel is accommodated in the housing with its axis at least approximately coaxial with the axis of rotation of the handle and bifurcated part, and wherein means are provided such that when the handle and bifurcated parts are screwed together sufficiently for the opposite ends of the housing to bear upon the opposite ends of the reel respectively there is a frictional force between the internal surface of the bifurcated part and the reel which is less than the force between the surface of the handle and the reel so that further screwing together of the handle and bifurcated parts causes the reel to rotate with the handle, the aperture means permitting the leading end of the floss to be returned to the housing between the internal surface of the bifurcated part and the respective end of the reel so as to be trapped therebetween when the handle and bifurcated part are screwed together.

4. A device as claimed in claim 3, wherein the handle and bifurcated part are screw-threaded together by one - 13 of the handle and bifurcated part having a screw-threaded shaft which engages in a screw-threaded aperture in the other of the handle and bifurcated part, the shaft passing through the housing and the reel being rotatably mounted thereon.

5. A device substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.