P/00/009 Regulation 3.2B AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION FOR AN INNOVATION PATENT Invention Title: DRINKING CUP LID The invention is described in the following statement together with the best method of performing it known to us: Our Reference: 106008 -2 DRINKING CUP LID The present invention relates to disposable beverage cups and, more particular to plastic sealing lids for such 5 cups. BACKGROUND Unitary or one piece plastic lids for wound paper or polystyrene cups for take-away tea and coffee, typically 10 include a sealing rim for the press-fitting of the lid to an upper lip of the cup, and a drinking orifice or spout provided in a raised rim. Typically also, the raised rim encloses a circular depressed region, sized so as to accept the insertion of the base of a second cup, is The most critical issues to Barristas when they are selecting takeaway beverage cup lids, are firstly ease of application and, secondly how well the lid seals and stays on. In the "morning rush" at coffee shops, time is money.. If the lid is too hard to put on, too much time is wasted 20 fitting lids, and if the lid leaks or comes off, the customer may go elsewhere next time. All such lids have an undercut, (annular hook) of an annular seal which must be stretched and 'snapped' over the edge of the cup, As well as preventing the lid from falling 25 off, this annular seal must provide a consistent interference fit with the rim or upper lip of the cup, so as to seal the edge of the cup when the cup is tilted for drinking from the lid orifice. This interference fit is primarily provided by the undercut of the annular seal being slightly smaller in 5 diameter than the upper lip of the cup, placing the annular seal of the lid in radial tension against the rim. The lid and the annular seal thus acts as a tight 'band' around the rim of the cup. Problems arise however when the cup rim varies in 10 diameter. Lids are moulded in plastic to tight tolerances. Most disposable cups however are now manufactured from paper and the upper lip of these cups can vary significantly. While most cup lids fit and seal using this 'band' principle, consistency of retention force is a major 15 problem. The most common failure occurs when the lid actually comes off the cup when the cup is squeezed or accidentally bumped. A known way of adjusting for this variation in upper lip diameter is to have a 'C' section profile included in 20 the annular sealing rim which, in most cases, effectively clamps around the whole circumference of the cup rim. If such a 'C' section is incorporated in the annular seal of the lid, the relationship between the cup rim diameters and the lid diameters is not as critical. Two problems with the 25 'C' section arrangement however, are firstly, that it is harder to attach the lid to the cup and secondly, the - 4 actual detail of the lid takes up more space, increasing the diameter of the lid. This in effect forces the drinking orifice provided in the raised projecting rim of the lid further from the lip of the cup. The further the drinking 5 orifice is from the cup lip, the less 'natural' the lid feels to drink from. The main reason that a 'C' section seal lid is harder to fit to a cup is that it is difficult to apply the even direct downward pressure required due to the flexibility of the section. 10 It is an object of the present invention to address or at least ameliorate some of the above disadvantages. Notes 1. The term "comprising" (and grammatical variations 15 thereof) is used in this specification in the inclusive sense of "having" or "including", and not in the exclusive sense of "consisting only of". 2. The above discussion of the prior art in the Background of the invention, is not an admission that any 20 information discussed therein is citable prior art or part of the common general knowledge of persons skilled in the art in any country. BRIEF DESCRIPTION OF INVENTION 25 Accordingly, in a first broad form of the invention, there is provided a drinking cup lid adapted for press- - 5 fitting to the upper lip of a disposable drinking cup; said lid including an annular sealing rim for engagement with said upper lip and a raised section projecting above said sealing rim; said drinking cup lid characterised in that at 5 least a part of said raised section is eccentric to said sealing rim. Preferably, The lid of claim 1 wherein a profile of said annular sealing rim is a non-uniform profile; said non uniform profile including a first profile segment in which 10 an extent of profile contact with said upper lip is less than corresponding profile contact of a second profile segment. Preferably, profile contact of said first profile segment substantially extends only from an uppermost portion of 15 said upper lip around to at least an outermost portion of said upper lip; profile contact of said second profile segment of said annular sealing rim substantially extending from at least an inward portion of said upper lip around to a point beyond said outermost portion of said upper lip; 20 said first and second profile segments being symmetric about a diameter of said lid passing through the centre of a drinking orifice. Preferably, an enclosing rim of said raised section encloses a substantially circular depressed region; said 25 enclosing rim sloping upwardly in both clockwise and anticlockwise direction from a minimum projecting height - 6 above said sealing rim at a point opposite said drinking orifice, to a maximum projecting height at said drinking orifice; an inner wall of said enclosing rim sweeping upwardly and outwardly from said substantially circular 5 depressed region, to said drinking orifice. In another broad form of the invention, there is provided a method of sealing in, and dispensing of, a liquid from a disposable cup; said method including the steps of applying a plastic lid as a press-fit to an upper lip of said 10 disposable cup; wherein a second profile segment of a non symmetric profile annular sealing rim of said lid is firstly engaged to a portion of said upper lip; a first profile segment of said non-symmetric sealing rim then applied to a remaining portion of said upper lip; said 15 second profile segment having a greater extent of profile contact with said upper tim than said first profile segment; said lid including a raised section; at least a part of said raised section eccentric to said sealing rim so as to place a drinking orifice radially proximate to 20 said upper lip of said disposable cup. In still another broad form of the invention, there is provided a lid for a disposable drinking cup; said lid formed as a unitary article, including a sealing rim for engaging with an upper lip of said disposable drinking cup 25 and a raised section projecting above said sealing rim; said lid further including a dispensing spout portion - 7 adapted for the lips of a user; said lid characterized in being formed of a biodegradable polymer; said polymer being digestible by a species of bacteria; said lid further characterised in that at least a part of said raised 5 section is eccentric to said sealing rim. Preferably, said disposable drinking cup is a paper cup; said paper cup provided with an upper lip; a profile of said upper lip generally forming a part of a circle. Preferably, said sealing rim includes a first profile and 10 a second profile; said first profile extending around a segment of said sealing rim; said segment disposed symmetrically about said dispensing spout; outer 'regions of said first profile forming merging portions leading into respective outer regions of said second profile. 15 Preferably, said first profile of said sealing rim is in contact around a lesser portion of a profile of said upper lip than is contacted by said second profile of said sealing rim. Preferably, said lesser portion of said profile of said 20 upper lip contacted by said first profile of said sealing rim extends approximately from an uppermost portion of said profile of said upper lip around to at least an outermost portion of said profile of said upper lip, Preferably, said portion contacted by said second profile 25 of said sealing rim contacts said profile of said upper lip from a point inward of said uppermost portion around to a - 8 point beyond said outermost portion of said profile of said upper lip. BRIEF DESCRIPTION OF DRAWINGS 5 Embodiments of the present invention will now be described with reference to the accompanying drawings wherein: Figure 1 is a perspective view of a drinking cup lid according to the invention fitted to a disposable beverage 10 cup, Figure 2 is an orthogonal plan view of the top of the drinking cup lid of Figure 1, Figure 3 is a cross section view of the drinking cup lid and cup of Figure 1 taken along a diameter passing 15 through the drinking orifice of the lid, Figure 4 is an enlarged sectioned view of the drinking cup upper lip and an annular sealing rim of the lid adjacent the drinking orifice, Figure 5 is an enlarged sectioned view of the drinking 20 cup upper lip and the annular sealing rim of the lid at a point on the upper lip diametrically opposite the drinking orifice. 25 DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS - 9 With reference to Figures 1 to 3, a one piece plastic drinking cup lid 10 for sealing engagement with a disposable drinking cup 12, according to the invention, is provided with an annular sealing rim 14 and a raised 5 section 16 projecting up from the level of the sealing rim 14. Raised section 16 comprises an enclosing rim 18 around a generally circular depressed region 20. Circular depressed region 16 is adapted to accept the base of another disposable drinking cup for stacking two or more 10 cups one on the other. Located in a raised portion of the enclosing rim 18 is a drinking orifice 22 or spout, adapted for the lips of a user (not shown) . An air compensating or breather hole 23 is located diametrically opposite the drinking orifice 22. 15 All these described features are common to this type of drinking cup lid. In the lid 10 of the invention however, and as best seen in Figure 2, the raised section 16 forming the enclosing rim 18, is only partially concentric with the annular sealing rim 14. In contrast to 20 known drinking cup lids, a portion of the enclosing rim 18 around the region of the drinking orifice 22 is eccentric to the sealing rim 14, being displaced outwardly, with the maximum displacement being adjacent to the drinking orifice 22. 25 This eccentricity of the raised portion 16 can also be discerned in the cross section view of Figure 3. Also - 10 visible in Figure 3 is the manner in which a portion of the internal wall 24 of the enclosing rim 18 proximate the drinking orifice 22, sweeps upwardly and outwardly, from the surface 26 of the substantially circular depressed 5 section 20, up to the drinking orifice 22. Preferably, the internal wall 24 of the enclosing rim 18 at the region of the drinking orifice 22 is slightly convex. Preferably also, the depressed region 20 further includes a concavely sculpted region 28 opposite the drinking orifice 22 10 providing improved space for a user's nose when tilting the cup and lid for drinking. The eccentricity of the raised section 16 and the enclosing rim 18 at the drinking orifice 22, has the effect of placing the drinking orifice 22 as close as possible 15 radially to the upper lip 30 of the drinking cup 12. This outward displacement of the drinking orifice 22 is made possible by a non-uniform profile of the annular sealing rim 14 of the lid 10 of the invention, as best seen in Figures 4 and 5. The non-uniform profile of the annular 20 sealing rim 14 includes a first profile segment 32 and a second profile segment 34. As best seen in the plan view of Figure 2, the first profile segment 32 extends a short distance symmetrically about a diameter of the lid passing through the centre of 25 the drinking orifice 22, with the second profile segment 34, also symmetric relative this diameter, extending around - 11 the remaining and major part of the periphery of the enclosing rim 18. The end regions of the first profile segment 32 merge with respective outer end regions of the second profile segment 34, Thus the non-uniform profile of 5 the annular sealing rim 14 of the lid 10 changes gradually, in both clockwise and anticlockwise directions, from that of the first profile segment 32 shown in Figure 4, to that of the second profile segment 34 shown in Figure 5. As can be seen from a comparison of Figures 4 and 5, 10 the extent of contact of the profile 36 of the first profile segment 32 around the part circular profile of the upper lip 30 of the cup 12, is less than the extent of contact of the profile 38 the second profile segment 34 around the profile of the upper lip 30. The profile 38 of 15 the second profile segment 34 is similar to the known 'C' section profiles commonly found in existing drinking cup lide, with contact between the sealing rim profile 38 and cup upper lip 30 profile extending from an inward portion 40 of the upper lip 30, around to a point 42 beyond the 20 outermost portion 44 of the upper lip 30. In contrast, the profile 36 of the first profile segment 32, contacts the profile of the upper lip 30 only from the uppermost portion 50 of the lip around to at least the outermost portion 44, and preferably to the same point 42 beyond the outermost 25 portion 44, - 12 This restricted extent of contact of the profile 36 of the first profile segment 32 with the lip 30 of the cup 12, allows the outer wall 52 of the enclosing rim 18 to be substantially coincident with the upper lip 30, and brings 5 the drinking orifice 22 into an optimum position, as can be seen from the cross section of Figures 3 and 4. As can best be seen from Figures 1 and 3, the enclosing rim 18 slopes upwardly in both clockwise and anticlockwise directions from a minimum projecting height 10 above the annular sealing rim 14 at a point 54 opposite the drinking orifice 22, to a maximum projecting height at the drinking orifice 22. The enclosing rim 18 is preferably generally higher than is common in these types of lids, allowing the substantially circular depressed region 20 to 15 be deeper. This higher enclosing rim 18 feature, combined with the concavely sculpted region 28, and the shape of the inner wall 24 at the drinking orifice 22, as well as the eccentric outward displacement of the drinking orifice 22, allows the contents of the cup to be consumed with a 20 reduced, and more comfortable, tilting angle. In at least one preferred embodiment, the lid 10 of the invention is formed from a biodegradable polymer, able to be digested by bacteria of a species commonly found in landfill waste disposal sites. 25 In Use - 13 Apart from aiding the placement of the drinking orifice 22 radially as close as possible to the upper lip 30 of the drinking cup 12, the particular non-symmetric profile of the sealing rim 14 of the invention allows for s greater dimensional variations of the upper lip diameter and more convenient placement of the lid 10 onto the upper lip 30 of a disposable drinking cup 12. To attach the lid 10 to a drinking cup 12, the second profile segment 34 is first brought into engagement with the upper lip 30 of the 10 cup. The lid is then pressed home on the upper lip at the region of the first profile segment 32, The above describes only some embodiments of the present invention and modifications, obvious to those skilled in the art, can be made thereto without departing 15 from the scope of the present invention.