"DISPENSING MEANS" This invention relates to thread dispensing means. This invention has particular reference to dispensing mea for dispensing dental floss and for illustrative purpos particular reference will be made hereinafter to su application. However it is to be understood that th invention can be used for dispensing other forms of threads a filaments such as, for example, fuse wire or sewing, binding whipping thread, tie wire or fishing line. Many advances have been made iri recent years in dent health and hygiene. These have ranged from treatment reticulated water supplies with fluoride to considerably redu incidence of cavities in the teeth of the population, to n materials for repair of damaged teeth, and new methods diagnosis and treatment for all problems of the teeth a mouth. A plethora of devices ranging from the traditiona tooth brush, geometric tooth brushes, rotating head toot brushes, water jet tooth brushes, tooth picks, flosses an floss/tooth pick combinations supplement the above advances i dental health, making a high level of oral hygiene possible.

Many companies around the world manufacture dental flos dispensers. Typically such floss dispensers are formed a rectangular packages about 20 mm thick, 40-60 mm wide, and 55 70 mm high. However, while the advantages of using denta floss after each meal are well recognised, the presen inconvenience of use resulting from the relatively bulk packages deters such use.

This invention aims to alleviate at least one of th abovementioned disadvantages and to provide thread dispensin means which will be reliable and efficient in use. Othe advantages of this ^' invention will hereinafter become apparent.

With the foregoing and other objects in view, thi invention in one aspect resides broadly in thread dispensin means including:- a supporting wall assembly; a thread guide in the supporting wall assembly;

a spool of thread from which the lead-out portion of thread may be dispensed to a fixed location without pass across the spool, said spool being fixedly supported by s wall assembly with said thread passing to said thread gui and said thread guide being disposed whereby said lead- portion of the thread may feed thereto without passing acr the spool.

The spool of thread may be a coil of thread and the le out portion of the thread may lead from the inner end of spool whereby it may be dispensed to a fixed location wit the centre of the spool without passing across the spo

Alternatively, the spool may be of the type in which the thr is built up in a concertina or fan-folded arrangement and lead-out portion of the thread may lead from one end of spool whereby it may be dispensed to a fixed location at side of said lead-out portion remote from the spool and with passing across the spool.

Suitably the thread guide is arranged in a wall portion the wall assembly which is recessed below the adjacent face the spool. The recessed wall portion may also suppo severing means for severing thread dispensed through the thre guide.

In a preferred embodiment of the invention the dispensi means is adapted as a dental floss dispenser and the spool dental floss is formed as a very narrow spool whereby t thickness of the dispensing means may be minimised. Suitab the dispensing means is thin and has major face dimensio similar to a credit card whereby it may be supported in wallet.

In a further aspect this invention resides broadly dental floss dispensing means including:- a supporting wall assembly having exterior dimensio similar to a credit card whereby the dental floss dispensi means may be supported in a wallet; a spool of floss supported within said supporting wa

assembly; a floss guide in the supporting wall assembly throu which the lead-out portion of the floss may be dispensed, and severing means for severing floss dispensed through t thread guide.

Preferably the floss guide and the severing means a arranged in a wall portion of the wall assembly which recessed below the adjacent face of the floss spool. The spo may be rotatably supported in the wall assembly to facilita dispensing of floss therefrom. Preferably however the floss non-rotatably supported within the wall assembly, the spool in the form of a coil of floss from which the lead-out porti leads from the inner end of the coil and the recessed wa portion extends into the open centre portion of the coil. Preferably the spool of thread or floss is wound on suitable former, preferably using waxed or other coated thre or floss whereby the thread or floss has the ability to coher thus giving adequate inherent structural strength whereby may be removed from the former, and fixedly supported betwe thin shell-like walls spaced apart by the thickness of t spool. For example a plastisol or other plastic coating, su as is used in unwaxed dental floss may be used. Impregnation the yarn with wax or other suitable material, which undergo phase change or solidification after the spool is woun imparts structural strength to the spool.

Suitably the spool of thread or floss is formed as a th formerless ovoid shaped spool whereby a longitudinal depressi may be formed in the wall assembly extending into the cent portion of the spool so as to accommodate the thread guide one end and the- severing means at the other end, leavi sufficient space therebetween to enable a user to gain fing access to the thread extending between the thread guide and t severing means. Preferably the thread guide at one end of t recess is disposed at a lower level than the severing means a the other end whereby floss may be pulled from the thread gui and engaged with the severing means without having t

manipulate the thread intermediate the thread guide and severing means. It is also preferred that the thread gui the severing means aperture and the thread extendi therebetween all lie below the top or outer major face of t supporting wall assembly and between the opposed major faces the wall assembly.

The spool may be formed by winding on a shaped forme held between two plates spaced appropriately to control t thickness of the spool of floss or thread or filament or t like and hereinafter collectively referred- to as floss. Duri winding, application of heat may be useful to melt or soft the wax or other coating on the floss and this coupled with t tension of the thread or floss causes the spool to fuse in the integral formerless spool required. The flat spool of floss with an elongated hole in t centre provides for a minimum thickness package which further assisted by forming the recess for the guide means, t severing means and for the floss to pass therebetween, a within the spool centre cavity. Thus all major elements l substantially within the same plane. As the guide means a cutter are within the centre of the spool of floss, when t floss is drawn from the dispensing means it is drawn from t inside of the spool. Thus the floss can unwind without t spool rotating or moving and also with a minimum of twisting Thus the floss as it comes out is substantially straigh because the inner circumference of the spool at all times, i relatively large compared to conventional spools of flos packages. For example in a credit card size dispensing mean the minimum inner circumference of the spool is in the order o 110 millimeters and increases as the floss is used. Thus th undesirable tendency that conventional flosses have of twistin after cutting may be reduced.

Alternatively the floss may be wound as a cylinder havin a circumference slightly less than one half of the majo dimensions of the final package, and the length of the cylinde being slightly less than the other major dimension of th

package. After winding, the cylinder is then flattened form a rectangle. The floss may also be wound flat directl Each final dimension would be less than the internal dimensi of the housing to allow for clearance between the floss and t housing. This clearance can be minimal, as the spool may fixedly mounted in the housing. The thickness of the cylind would be one half the thickness of the required floss packa (say 1.3 millimeters) so that on flattening the cylinder, package of the required thickness (say 2.6 millimeters n including wall thickness) would be produced.

It is also preferred that the lead-out portion of t floss which remains in the package is retained by the severi means. This may be achieved by forming the cutting member the severing means with a cutting edge distant from the gui means and a retaining edge adjacent the guide mean Furthermore with the floss guide means and the severing mea recessed in the centre of.the side wall face, the floss li may be maintained below the adjacent major surface of t housing, even when cutting. Thus the floss will tend to st cleaner. Also, the cutter of the severing means will not prone to catch on clothes or to injure, as its top surface ne not protrude beyond the adjacent major surface of the housin In order to prevent the spool from collapsing when t last few coils of floss remain, the outer surface of the spoo is bonded into the housing so that it is supported agains collapse even when just a little floss remains.

Accordingly in another aspect, this invention resides in method of supporting a spool of thread to be dispensed in housing including:- inserting the -spool into the housing, and encapsulating the spool within the housing with a suitabl medium which does not prevent withdrawal of the thread from th spool. Preferably the medium is wax. This may be introduce by clamping the spool between a side wall of the housing and false back wall so as to form an airtight chamber containin the spool. Molten wax is drawn into this airtight chambe

through one hole in the false back wall, connected to a sup of molten wax, by applying a vacuum to another hole in false back. Typically these holes would be at opposite ends the chamber, and the hole to which the vacuum is applied co be elevated relative to the other hole, so that a "ble effect ensures that all air bubbles are removed. The wax be circulated through both holes in normal operation, injecting the wax, and short circuited through the controlli valve when not operating. This will ensure that the remains molten at all times. Continuous circulation wi prevent "freezing" of the wax in the valve rendering the val inoperable during the production process.

In order that this invention may be more readi understood and put into practical effect, reference will now made to the accompanying drawings which illustrate preferr embodiments of this invention and wherein:-

FIG. 1 is a perspective view of a preferred form of dent floss dispenser;

FIG. 2 is a diagrammatic plan view illustrating the layo of the dispenser illustrated in FIG. 1;

FIG. 3 is a sectional view through the longitudin centreline of the dispenser;

FIGS. 4 and 5 are respective transverse sectional vie through the floss lead out guide and the floss severi means _r and

FIGS. 6, 7 and 8 illustrate a further embodiment of t invention.

The dental floss dispenser 10 illustrated in Fig. 1 is substantially credit card size, which is an acceptable siz for consumers, being able to fit easily and unobtrusively int a standard wallet or pocket. The external housing 11 is forme of a plastics material and has major face dimensions of 86 mm 54 mm and a thickness of approximately 3.6 mm. The housing 1 contains approximately 50 metres of dental floss store internal thereof in a oval shaped spool 12 as can be seen fro Fig. 2. The spool 12 is relatively thin and is formed with

relatively large open centre 13 which is elongated.

An elongated recess 14 is formed in one side wall 15 of t housing 11 and supports, at one end, a lead out aperture through which the floss 17 is dispensed from the interior the spool 12. The recessed side wall 15 is disposed parall to the major faces of the spool and the recess 14 extends in the large open centre 13 of the spool 12 and terminates spaced relationship with the opposite planar side wall 15 The recess 14 is relatively deep adjacent the aperture 16 a continues along at this depth to its opposite end at which t thread cutter/holder 18 is disposed above the base of t recess 14. The cutter/ holder or severing means 18 is form from stainless steel and includes a raised tongue portion struck from the thread cutter 18. The tongue 20 is rais slightly and extends substantially in the same plane as t planar portion of the side wall 15. The tongue 20 forms cutting edge 19 adjacent the end of the recess 14. The cutti edge is formed with an inwardly sloping chamfer 22 in order minimise risk of personal injury. A lead of floss 21 stretches from the aperture 16 to t raised tongue 20 at which it is held. The lead of flo extends along the recess 14, below the level of the plan portion of the side wall 15 and above the base of the rece whereby it spans between the aperture 16 and the tongue 20 free space making it easily accessible for grasping.

The floss spool 12 unwinds from the inside of the spo whereby the lead-out floss 21 passes from the inner face of t spool and out through the aperture 16 to the recess 14

Sufficient spacing exists between the aperture 16 and th cutter 18 to allow a user's finger to grasp the lead of flos

21 and to draw it through the aperture 16. Floss draw therefrom unwinds from the inside of the spool, while the bod of the spool remains fixed and stationary within the housing.

In a typical use, the floss dispenser 10 is hel horizontally by its long sides between the thumb and forefinge of the left hand. The user, after grasping the lead of flos

21 and pulling out the required amount of floss then wipes t floss along the edge 23 of the housing 11 adjacent the thre cutter 18. The location of the floss exit aperture 16 in t base of the recess 14 causes such wiping action to initial engage the floss under the tongue 20 for clamping thereby a as the user draws the floss further along the edge 23 the flo will be severed by the cutting edge 19. After cutting, the e of the floss remains attached to the spool inside the housi 11 and is retained under the tongue 20 providing a new lead floss 21 ready for further dispensing. The cutting acti occurs even though the cutting edge 19 is entirely below t top surface of the housing because of the relatively low location of the aperture 16.

The above arrangement ensures maximum safety and al obviates the need for a safety cover. This safety is furth enhanced by the chamfered configuration of the cutting edge which prevents the skin being caught under the cutting ed 19, thereby preventing injury. This safety design alleviat damage to clothing and the like. The spool 12 is secured within the housing 11 solidified wax, 24 or other suitable material. This body wax fixes the spool within the housing, and prevents collaps of the spool when only a few threads remain. A back plate 2 forms the back surface of the housing 11 and is joined at 2 to the front wall assembly 27 by suitable means such a ultrasonic welding or solvent welding, or by adhesive bonding.

The above arrangement is very efficacious to use. A advantage of the particular arrangement is that the oppose flat surfaces of the housing 11 can be used for product o company information, advertising or other promotiona information, reproduction of paintings or photographs information such as dentist's appointment reminders and contac details, or user and community medical information such a blood group, allergies and/or other special medical conditions whether organ donations are permitted, etc.

This design is also relatively rigid for a thin assembly.

The strength is a result of the physical arrangement of elements which is that of an entirely closed rectangular pr with only one aperture near the centre and recess, the locat and shape of which acts as a spacer to keep the walls ap under bending or torsion, maintaining its strength.

A preferred method for assembling the dental fl dispenser 10 is as follows. An appropriate floss fibre selected which is coated with wax or with another suita material. The floss is then heated to melt the coating, and then wound on a mandrel which has a suitably shaped core produce the required elongated hole in the centre of finished spool. The circumference of the core may requir relief angle e.g. 45 degrees to facilitate release of the sp from the mandrel. When the mandrel is undamped, the tens within the spool, and the stretch of the floss will cause spool to slide down the 45 degree slope, automatica releasing itself from the. core and one side, to remain loos attached to the other side which is flat.

The core is located in the mandrel between a pair parallel plates which are spaced apart by an amount equal the thickness required for the finished spool. Typically, t thickness, or the distance between the plates, will established by the thickness of the core. In operation, lead-out end of the floss is secured between the core and of the side plates, and the entire assembly is placed sufficient axial compression to prevent the plates moving ap as the floss builds up, and the total tension in the sp increases. This compression may be provided by a bolt and or by a clamping mechanism. The floss is passed through a bath, and/or tensioning devices as required. It may be t passed through a hot air blast which melts the wax on the flo and controls the temperature of the floss as it is wound. T mandrel may be preheated or precooled, if necessary, accordi to the coating material and other characteristics of t materials used. It is considered that preheating shou maintain the desirable wax coating on the floss where w

coating is utilised. The mandrel is rotated at an appropria speed and the floss is wound on. As the wax cools, it fus together imparting solidity to the spool. After cooling, t spool is released from the mandrel. The cutter is inserted into the housing and secure preferably by clinching. The housing is then placed on t assembly table. Alternatively, the cutter may be inserted injection of the plastic of the housing around the cutter whi has been previously placed in the injection mould. When t housing is placed on the assembly table, a vacuum, ducte through the table, may be used to clamp the housing onto th table. The spool is then placed into the housing. Th vacuum may then be used to suck the lead-in end of the flos through the thread guide or thread exit hole. When the spool is correctly located, a false back whic consists of a flat piece of rigid material, preferabl transparent, and which has a thickness of a soft material suc as polyurethane or silicone rubber, preferably als transparent, is placed on top of the housing and spool. Th soft material produces a good seal, and the clamping pressur of the vacuum means that it also protrudes into the cavity ensuring that the wax cast has a concave top surface. Thi facilitates the attachment of the backplate by maintaining th wax clear of the weld area ensuring good bonds. The vacuu holding the housing to the assembly table is then transferred, via the floss exit hole, to the centre of the false back. Th vacuum then clamps the false back to the housing. The fals back seals a cavity between itself, the outside of the spool, and the inside of the housing. A pair of holes in the false back provide access to diametrically opposite points of the cavity. A vacuum is applied to one of these holes, and the other hole is connected to a supply of molten wax. The wax is then sucked into one hole and then passes out via the other hole. Alternatively, molten wax or other material can be pumped in via one hole and bled out via the other hole, in a similar manner. The valve controlling the flow of wax will

ideally continually circulate the hot wax when not "injectin to prevent the wax from freezing.

After an appropriate time, i.e. when the air is bled ou and the heat of the molten wax has created a good bond to t spool and to the housing, the vacuum or wax supply is cut o and the assembly is allowed to cool. When the wax h solidified, the vacuum is released, and the false back removed and the back plate is placed on the housing. T backplate may also be secured by vacuum which may be different level of vacuum to that used for securing the ba plate. The back plate is welded to the housing by ultrasonic welder, or by solvent welding or adhesive bondin Assembly is now completed and the product can be released fr the assembly table, by terminating the vacuum. The floss dispenser 30 illustrated in Figs. 6 to 8 utilis a fan-folded spool of floss 31 of rectangular configurati from which the floss is . dispensed from one end through aperture 32 in the dished top end 33 of the housing 34. T lead-out floss 35 extends accessibly in free space across t dished end 33 to a metal cutter assembly 36 mounted at t remote end of the dished end 33. The cutter assembly incorporates a cutting tongue 37 against which the floss may severed and beneath which the lead-out floss 35 is retained.

It will of course be understood that the above has be given by way of illustrated example only and all su modification and variations thereto as would be apparent persons skilled in the art are deemed to fall within the bro scope and ambit of the present invention as defined in t appended claims.