This invention relates to dental-floss holders and dispensers .

According to one aspect of the invention there is provided a dental-floss holder wherein an element of dental floss extends between two spaced arms of the holder, the element of dental floss being attached at its two ends to respective plugs that are for entry into individual sockets of the two arms respectively, and wherein the sockets have resilience for releasable retention of the plugs entered therein.

Each of the plugs may be of a generally-cylindrical form and may have one or more part-circumferential shoulders for engagement within one or more recesses of the respective socket for establishing the releasable retention of the plug within the socket.

The dental-floss holder of the invention may be combined with a dispenser for dispensing onto the holder a dental- floss cartridge that comprises an element of dental floss that is attached at its two ends to two plugs respectively. In these circumstance, operation of the dispenser may dispense the cartridge onto the holder by forcing the two plugs of the cartridge into the two sockets respectively.

According to an additional aspect of the invention there is provided a method of re-loading a dental-floss holder wherein a first element of dental floss that is attached at its two ends to respective first plugs entered in releasable retention in individual spaced sockets of the holder, is replaced by a second element of dental-floss,

the second element being attached at its two ends to respective second plugs that are adapted for releasable retention in the sockets respectively, and wherein replacement is carried out by pressing the second plugs onto the first plugs to force the first plugs from the sockets and enter the second plugs therein in their place for resilient retention therein.

More especially, and according to another aspect of the invention there is provided a dental-floss dispenser for loading a dental-floss holder with one of a reserve of cartridges, each cartridge comprising an element of dental floss that is attached at its two ends to two plugs respectively for releasable retention within spaced sockets of the holder, and wherein the dispenser has a mouth for receiving entry into that mouth of the dental- floss holder, and is selectively operable to force the two plugs of said one cartridge into respective sockets of the entered holder for releasable retention therein.

A form of dental-floss holder and dispensers for loading it with dental floss, all in accordance with the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows the dental-floss holder according to the invention;

Figure 2 is illustrative to an enlarged scale, of a dental-floss cartridge for use in the dental-floss holder of Figure 1; Figure 3 is illustrative to enlarged scale of part of the holder of Figure 1 as loaded with the dental-floss cartridge of Figure 2;

Figure 4 is an enlarged view of one of two plug- retention sockets that form part of the dental-floss holder of Figure 1;

Figure 5 is sectional detail of the loaded, dental- floss holder of Figure 3, to which reference is made by way of explanation;

Figure 6 is a partially exploded perspective view of a dental-floss dispenser according to the invention for use in loading the dental-floss holder of Figure 1 with the dental-floss cartridge of Figure 2;

Figure 7 is a plan view from below of the dental- floss dispenser of Figure 6 with a bottom cover removed; Figures 8 and 9 are perspective views of the dental- floss dispenser of Figure 6 during successive stages of loading the dental-floss holder of Figure 1 with the dental-floss cartridge of Figure 2;

Figure 10 is a sectional elevation of the dental- floss dispenser of Figure 6 during loading of the dental- floss holder of Figure 1 with the dental-floss cartridge of Figure 2;

Figures 11 and 12 are sectional representations of detail of the loaded, dental-floss holder of Figure 3, during successive stages of replacing a used dental-floss cartridge, in the dental-floss dispenser of Figure 6.

Figure 13 is a partially exploded perspective view of an alternative form of dental-floss dispenser according to the invention; Figure 14 is a perspective view of the alternative form of dental-floss dispenser of Figure 13 with a dental-floss holder in accordance with the invention;

Figures 15 (a) and 15 (b) are illustrative of successive stages of loading the alternative dental-floss dispenser of Figure 13 with dental-floss cartridges;

Figure 16 is a perspective view of the alternative dental-floss dispenser of Figure 13 during loading of the dental-floss holder of Figure 14 with a dental-floss cartridge; and Figures 17 (a) and 17 (b) are illustrative of successive stages in loading the dental-floss holder with

a dental-floss cartridge within the alternative dental- floss dispenser of Figure 13.

Referring to Figure 1, the dental floss holder 1 to be described is a plastics-moulding of Y-configuration that incorporates an elongate handle-portion 2 for the user to grip when flossing. The handle-portion 2 splays out into two arms 3 which are topped by respective sockets 4 that are used for loading the holder 1 with floss.

In the latter respect, floss is loaded onto the holder 1 in the form of individual, disposable cartridges 5. Each cartridge 5, as illustrated in Figure 2, comprises two generally-cylindrical plugs 6 with a floss-strand element 7 attached at either end to them, and is loaded into the holder 1 as illustrated in Figure 3, with the two plugs 6 plugged into the two sockets 4 respectively and the element 7 taut between them. The degree of stretch to which the element 7 is subjected is determined fundamentally by the length of the element 7 in relation to the spacing between the sockets 4, but also by the overall resilience within the holder 1 between its arms 3, and the local resilience between each arm 3 and its socket 4.

Each socket 4, as illustrated more clearly in Figure 4, is of a generally-cylindrical form of C-shape cross- section with the gap between the opposed "jaws" 9 of the section facing inwardly so as to allow the floss element 7 to extend freely from the plug 6 in its respective socket 4, to the other plug 6. The gap between the jaws 9, however, also introduces resilience in the socket 4 to enable it to receive and retain the plug 6 within it. The manner in which the plug 6 is received and resiliently retained within the socket 4 will now be described.

Referring now also to Figure 5, each plug 6 has two diametrically-opposed shoulders 10 located midway along its length for resilient retention within conformal, central recesses 11 of the receiving socket 4. The plug 6 is entered in the socket 4 by pushing it lengthwise into the socket 4 to splay the jaws 9 open initially to admit the plug 6, and then with further pushing to allow them to return as the shoulders 10 snaps resiliently home into the recesses 11. With the shoulders 10 nested within the recesses 11, the plug 6 is retained resiliently within the holder 1 to an extent that it is not disturbed from its socket 6 during use of the holder 1 for dental flossing.

The loading of the holder 1 with a cartridge 5 is carried out most easily using a dispenser of the form illustrated in Figures 6 and 7

Referring to Figures 6 to 7, the dispenser 20 in this case has a loading-head 21 with an elongate body 22 extending rearwardly from it. The body 22, as illustrated in Figure 6, has two mutually-spaced runners 23 that extend the length of the body 22 and into the head 21 through respective, interconnected apertures 24. A pack of reserve cartridges 25 each having the form of the cartridge 5 described with reference to Figure 2, is loaded into the dispenser 20, each with its two plugs 6 either side of the runners 23 and the floss element 7 taut between them across the intervening space. The cartridges 25, which are loaded onto the runners 23 in abutment with one another, are covered by a lid 26 (shown In Figure 6 as transparent) of the body 22, and are retained together in the pack by stops 27.

The stops 27, which are interconnected via a bar 28 shown in Figure 7, are moveable together along the runners 23 under selective operation of a ratchet mechanism. The

ratchet mechanism involves outwardly-sprung finger-tabs 29 that are engaged with respective saw-tooth tracks 30 running lengthwise of the body 22. This engagement allows the bar 28 together with the stops 27 interconnected by it, to be moved stepwise in the direction towards the head 21, but precludes them from movement in the reverse direction until the tabs 29 are depressed towards one another. Thus, although the stops 27 can be advanced to press onto a pack of cartridges 25 already loaded in the dispenser 20, they can only be withdrawn to enable a pack to be loaded, while the tabs 29 are held depressed.

When a pack of reserve cartridges 25 has been loaded in the dispenser 20, the user exerts finger pressure on the bar 28 to urge the stops 27 into abutment with the rear of the pack. The stops 27 are pressed onto the pack in this way to step the leading cartridge 25 of the pack into the head 21 through the apertures 24, ready for loading into the user's holder 1. In this regard, and as illustrated in Figure 8, the user's holder 1 is brought to the dispenser 20 for entry of the arms 3 into a mouth 31 of the head 21. The arms 3 are entered in the mouth 31, as illustrated in Figure 9, to engage dimples 32 (Figures 1, 3 and 4) located behind the sockets 4 of the holder 1, with sprung detent-catches (not shown) within the mouth 31. This engagement serves to locate the holder 1 correctly with its sockets 4 in register beneath the plugs 6 of the leading, reserve cartridge 25 ready for loading. Loading is carried out by the user depressing a push-button 33 of the head 21 against a spring bias. This presses down on the plugs 6 of the leading, reserve cartridge 25 to force them fully home within the sockets 4 of the holder 1.

When the cartridge 25 loaded in the holder 1 is to be replaced, discharge of the used cartridge 25 from the

holder 1 and its replacement with a fresh cartridge 25 is readily carried out in a single operation of the dispenser 20. Before such operation, however, the stops 27 are stepped forward to the extent necessary to ensure that the next leading cartridge 25 of the pack is located within the head 21 ready to be loaded in the holder 1 as the replacement. With the replacement cartridge 25r in this location, and the holder 1 (still carrying the used cartridge 25u) entered in the mouth 31 as illustrated in Figure 10, depression of the push-button 33 acts on the plugs βr of the replacement cartridge 25r forcing the replacement cartridge 25r down into engagement with the entered holder 1. More particularly, the plugs βr of the cartridge 25r bear on the plugs βu of the used cartridge 25u (as illustrated by Figure 11) and push the plugs βu down out of the sockets 4 of the holder 1 as the plugs 6r are pushed home in loading the holder 1 with the replacement cartridge 25r (as illustrated by Figure 12) . The used cartridge 25u falls through the bottom of the head 21 for disposal, and the holder 1 loaded with the replacement cartridge 25r can then be withdrawn from the mouth 31 and put to use.

The body 25 of the dispenser 20 extends generally horizontally and whereas this may be found convenient for some in holding it in the hand while loading the holder 1 with a replacement cartridge 25, there are circumstances in which it would be advantageous and more convenient for the dispenser to have a vertical orientation for holding or mounting and during loading. An example of an alternative form of dispenser adapted for use in a vertical orientation is illustrated in Figures 13 to 17 and will now be described.

Referring initially to Figures 13 and 14, the alternative dispenser 40 has a body 41 which is designed to stand and be operated vertically. A plunger 42 extends down

through a top opening 43 of the body 41 and is coupled to the body 41 via a ratchet mechanism (not shown) . The ratchet mechanism allows the plunger 42 to be pushed down stepwise into an internal cavity 44 of the body 41, but to be drawn slidingly upwards out of it. The cavity 44 is accessible through an opening 45 in the front wall 46 of the body 41, and it is through this opening 45, that a cartridge cassette 47 is entered into the cavity 44 to clip resiliently to the body 41 and close the opening 45 as shown in Figure 14.

The cartridge cassette 47, as illustrated in Figure 15 (a) , holds a reserve-pack of cartridges 48 (each identical to cartridge 5 of Figure 2) stacked one upon the other for dispensing one at a time from the bottom 49 of the cassette 47. In this respect, the plugs (corresponding to plugs 6 of Figure 2) of each cartridge 48 of the stack are loaded in respective vertical channels 50 (see Figure 13) of the cassette 47, with their interconnecting floss-strand element (corresponding to the element 7 of Figure 2) horizontal between them across an intervening channel 51. The plunger 42 is withdrawn upwardly to its fullest extent as shown in Figure 15 (a), to enable the cartridge cassette 47 loaded with the stacked cartridges 48, to be entered laterally into the cavity 44 for clipped engagement therein with its bottom 49 standing on a cross-wall 53.

Referring especially to Figure 13, the wall 53 divides the cavity 44 from a lateral, dispensing mouth 54 of the body 41, and the channels 50 and 51 of the engaged cassette 47 align with an aperture 55 through the wall 53 that is configured appropriately to permit cartridges 48 discharged from the cassette 47 to pass into the dispensing mouth 54, without obstruction. However, as illustrated in Figure 15 (b) , a tray 56 located in the mouth 54 is spring-biased to block the aperture 55 and

thereby preclude dispensing of cartridges 48 from the cassette 47.

When a dental floss holder 57 as illustrated in Figure 14 and having the same essential construction as the holder 1 described with reference to Figure 1, is to be loaded with a cartridge 48, it is brought to the dispenser 40 for entry of its arms 58 into the mouth 54. Entry of the arms 58 to engage them in the mouth 54 as illustrated in Figures 16 and 17 (a) deflects the tray 56 backwardly against its spring bias, unblocking the aperture 55 and placing its sockets 59 (corresponding to the sockets 4 of Figure 1) in register with the channels 50 of the cassette 47 above. The plunger 42 is now pressed down onto the top cartridge 48 in the cassette 47, advancing it one ratchet-step so as to discharge the bottom cartridge 48 of the stack through the aperture 55 and forcing it into engagement with the entered holder 57. More particularly, the plugs of this cartridge 48 are pushed home into the sockets 59 of the holder 57 to load it with the cartridge 48 ready for use when withdrawn from the mouth 54.

In the event that the holder 57 is carrying a used cartridge when the plunger 42 is operated, this cartridge 48u will be pushed out of the holder 57 into an underlying chamber 60 of the body 41, as illustrated in Figure 17 (b) , by the action of loading the holder 57 with the replacement cartridge 48. The used cartridge 48u can be discharged from the chamber 60 via an aperture 61, by tipping the body 41, but until then it blocks the possibility of more than one cartridge 48 being dispensed in the one operation.

Withdrawal of the holder 57 from the mouth 54 allows the tray 56 to return under its spring bias to block further discharge of cartridges 48 from the cassette 47 until the

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holder 57 is returned to the mouth 54. Each time the holder 57 is re-engaged in the mouth 54, it is necessary only to push the plunger 42 down one step of its ratchet mechanism to carry out the combined step of loading the holder 57 with a fresh cartridge 48 from the bottom 52 of the cassette 47, and discharging the used cartridge.

When all the cartridges 48 in the cassette 47 have been dispensed, the plunger 42 will have been pushed down in successive ratchet-steps to the bottom 52 of the cassette 47 as the cartridges are in turn dispensed. The plunger 42 will need to be lifted up to withdraw it from the cassette 47 so that it can be withdrawn, once the cassette 48 has been undipped from the body 41, for replacement by the same or other cassette loaded with replacement cartridges 48.