[0001] This invention relates to a flow restrictor for minimizing accidental spilling of
               liquid from a drinking cup, a cap with such a flow restrictor, and a drinking cup
               incorporating such a cap. Such an invention finds special, though not exclusive, application
               in providing spill-proof cups for babies and toddlers.
 
            Background of the Invention
[0002] There are in existence conventional drinking cups which are designed to be easily
               handled by babies and toddlers. As babies and toddlers are prone to mishandle cups
               whilst drinking, such cups are usually provided with some spill-proof mechanism for
               preventing accidental spilling of the content. Such spill-proof mechanism are usually
               sophisticated in structure, difficult to manufacture, and thus costly. Some such mechanisms
               employ movable parts, which may break down or be damaged on repeated use. In addition,
               in order to ensure the spill proof effect, most such mechanisms are permanently secured
               to the cap and/or body of the cup, thus making it very difficult to clean.
 
            [0003] It is thus an object of the present invention to provide a flow restrictor and a
               drinking cup incorporating such a flow restrictor, in which the aforesaid shortcomings
               are mitigated, or at least to provide a useful alternative to the public.
 
            [0004] It is a further object of the present invention to provide a flow restrictor with
               a simple structure and no movable parts, and is thus easy and relatively cheap to
               manufacture.
 
            [0005] It is a yet further object of the present invention to provide a flow restrictor
               which is removable from the cap, thus allowing easy cleaning of both the flow restrictor
               and the cap.
 
            [0006] Such and other objects of the present invention will be made apparent in the ensuing
               description, with the aid of the accompanying drawings.
 
            Summary of the Invention
[0007] According to a first aspect of the present invention, there is provided a flow restrictor
               for a liquid, said restrictor having a first end; a second end; and a path with an
               inlet at said first end and all outlet at said second end, said path allowing the
               passing of said liquid from said inlet to said outlet, wherein said path has a first
               portion and a second portion, said first portion being upstream of said second portion,
               and wherein the distance between said first portion and said second end is shorter
               than the distance between said second portion and said second end.
 
            [0008] According to a second aspect of the present invention, there is provided a cap for
               a drinking cup, said cap including a drinking spout and a flow restrictor in a liquid
               communicable relationship with said drinking spout, said restrictor having a first
               end, a second end, and a path with an inlet at said first end and an outlet at said
               second end, said path allowing the passing of a liquid from said inlet to said outlet,
               wherein said path has a first portion and a second portion, said first portion being
               upstream of said second portion, and wherein the distance between said first portion
               and said second end is shorter than the distance between said second portion and said
               second end.
 
            [0009] According to a third aspect of the present invention, there is provided a drinking
               cup including a container with an open end and a space adapted to contain a liquid;
               a cap releasably engaged with said container, said cap including a drinking spout;
               a flow restrictor releasably engaged with said cap, said restrictor being in a liquid
               communicable relationship with said space of said container and said drinking spout
               of said cap; wherein said flow restrictor has a first end, a second end, and a path
               with an inlet at said first end and leading to said space of said container, and an
               outlet at said second end and leading to said drinking spout of said cap, said path
               allowing the passing of said liquid from said inlet to said outlet, wherein said path
               has a first portion and a second portion, said first portion being upstream of said
               second portion, and wherein the distance between said first portion and said second
               end is shorter than the distance between said second portion and said second end.
 
            Brief Description of the Drawings
[0010] An embodiment of the present invention will now be described, by way of an example
               only, with reference to the accompanying drawings, in which:
               
               
Fig. 1 is a perspective exploded view of a drinking cup according to the present invention;
               Fig. 2A is a top perspective view of a base part forming part of the flow restrictor
                  shown in Fig. 1;
               Fig. 2B is a top view of the base part shown in Fig. 2A;
               Fig. 2C is a side view of the base part shown in Fig. 2A;
               Fig. 2D is a bottom view of the base part shown in Fig. 2A;
               Fig. 2E is a sectional view of the base part taken along the line A-A in Fig. 2D;
               Fig. 3A is a bottom perspective view of an outer part of the flow restrictor shown
                  in Fig. 1;
               Fig. 3B shows in two dimension a trough on the outer surface of the outer part shown
                  in Fig. 3A;
               Fig. 3C is a top view of the outer part shown in Fig. 3A;
               Fig. 3D is a sectional view of the outer part taken along the line B-B in Fig. 3C;
               Fig. 3E is a side view of the outer part shown in Fig. 3A;
               Fig. 3F is a sectional view of the outer part taken along the line C-C in Fig. 3E;
               Fig. 4A is a side view of the flow restrictor shown in Fig. 1;
               Fig. 4B is a front view of the flow restrictor shown in Fig. 4B;
               Fig. 4C is a bottom view of the flow restrictor shown in Fig. 4B;
               Fig. 4D is an enlarged bottom perspective view of the flow restrictor shown in Fig.
                  4B; and
               Fig. 5 is a sectional view of the cap of the drinking cup shown in Fig. 1, in an upside
                  down orientation.
 
            Detailed Description of the Preferred Embodiment
[0011] As shown in Fig. 1, a drinking cup according to the present invention is shown and
               generally designated as 10. The cup 10 includes a base 12 with a space for containing
               liquid, e.g. water or milk. The base 12 is threadedly engageable with a cap 14 for
               covering the base 12. The cap 14 has a drinking spout 16 through which the content
               in the base 12 may be drawn out by a sucking force. The drinking spout 16 has a generally
               cylindrical portion 18 extending downwardly from a generally planar surface 20 of
               the cap 14. The cylindrical portion 18 has a space 22 receiving a flow restrictor
               24, to be discussed further below.
 
            [0012] The flow restrictor 24 has a base part, generally designated as 26, and as shown
               in Figs. 2A to 2E, and an outer part to be discussed below. The base part 26 is made
               of a thermoplastic material, e.g. polypropylene. As can be seen in Figs. 2A to 2E,
               the base part 26 of the flow restrictor 24 includes a base plate 28, from which a
               post 30 extends, said post 30 being perpendicular to a major surface of the base plate
               28. The top end 31 of the post 30 is of a larger diameter than that of the body of
               the post 30. Around the part where the post 30 joins the plate 28 is a raised ring
               portion 32 distributed with a number of holes 34.
 
            [0013] Various views of an outer part 36 of the flow restrictor 24 is shown in Fig. 3A,
               and 3C to 3F. The outer part 36 is made of a thermoplastic elastomer. As can be seen,
               the outer part 36 is generally cylindrical in shape, with a continuous trough 40 on
               its outer surface joining an upper end 42 and an opposite lower end 44. The trough
               40 is of a rectangular cross-section. A number of pins 38, which are formed integrally
               with the outer part 36, extend from the lower end 44 of the outer part 36. These pins
               38 are numbered, sized and configured to be each fitted within a respective hole 34
               in the ring portion 32 of the base part 26, for properly aligning the outer part 36
               with the base part 26 for forming the flow restrictor 24. In particular, the outer
               part 36 is over-molded onto the base part 26, so that the outer part 36 and the base
               part 26, once assembled, cannot be separated.
 
            [0014] Turning to Fig. 3B, such shows a two-dimensional view of the surface contour of the
               outer part 36 of the flow restrictor 24, with the pins 38 removed for clarity purpose.
               The trough 40 has an inlet S at the lower end 44 of the outer part 36, first leading
               towards the upper end 42 of the outer part 36 and parallel to the longitudinal axis
               L-L of the outer part 36. The trough 40 then turns 90° into a path M which is parallel
               to both the upper end 42 and the lower end 44 of the outer part 36. The trough 40
               then makes two 180° turns, at P and Q respectively, and subsequently leads into a
               path N which is parallel to both the upper end 42 and the lower end 44 of the outer
               part 36. The trough 40 then turns 90°, heading towards and eventually reaching the
               upper end 42 of the outer part 36, and exits at the outlet T. It can be seen that
               the path M is upstream of the path N, and the distance m between the path M to the
               upper end 42 is small than the distance n between the path N and the upper end 42.
 
            [0015] Turning now to Figs. 4A to 4D, such show various views of the flow restrictor 24,
               formed of over-molding of the outer part 36 onto the base part 26. The outer circumferential
               surface of the outer part 36 are exposed for frictional engagement with an inner surface
               35 of the cylindrical portion 18 of the drinking spout 16. Because of the resilient
               nature of the thermoplastic elastomer with which the outer part 36 is made, there
               is effectively no space between the inner surface 35 of the cylindrical portion 18
               of the drinking spout 16 and the outer part 36 except the channel formed between the
               trough 40 and the inner surface 35. Liquid contained in the base 12 can thus only
               exit the cup 10 
via the drinking spout 16 by travelling through the channel.
 
            [0016] Because of the shape and structure of the trough 40 and the channel formed thereby,
               the liquid can exit the cup 10 only if it is drawn by a sucking pressure applied at
               the outlet T. It was found in experiments that the amount of water drawn from such
               a cup 10 incorporated with a flow restrictor 24 with a trough 40 of a length of 127
               mm and a cross-sectional area of 3.4 mm
2, at a sucking pressure of 4 inch of mercury (i.e. the equivalence of 13,545.5 Pa)
               and for 10 seconds, was 43.3 g (in a first experiment), 53.7 g (in a second experiment)
               and 48 g (in a third experiment), all within the range of 15 g to 100 g. Experiments
               also showed that no waterleaked from the cup 10 when it was held upside down for 3
               minutes. The following Table 1 shows the results of experiments conducted on the amount
               of water exiting from the cup 10 incorporated with the flow restrictor 24, again with
               a trough 40 of a length of 127 mm and a cross-sectional area of 3.4 mm
2, when it was allowed to free fall:
               

 
            [0017] It can be seen that the above arrangement effectively prevents or at least significantly
               reduces accidental spilling of the liquid content in the cup 10. The flow restrictor
               24 is easy to manufacture, and does not contain any movable part which is prone to
               wear and tear. The flow restrictor 24 may also be removed from the cap 14 so as to
               enable both the cap 14 and the restrictor 24 to be thoroughly cleaned.
 
            [0018] To enhance the spill-proof function of the drinking cup 10, and as shown in Fig.
               5, a tube 40 is integrally formed with the cap 14 and leading into the space 22 of
               the cap 14. The tube 40 has a central channel 44 leading from the space 22 of the
               cap 14 to the outside environment. It can be seen that if and when the drinking cup
               10 is upside down, the cap 14 will assume the orientation as shown in Fig. 5. a reservoir
               46 will be formed between the outer surface of the tube 40 and the inner surface 35
               of the of the cylindrical portion 18 of the drinking spout. By way of such an arrangement,
               any content that may leak from the interior of the base 12 through the flow restrictor
               24 will be captured in this reservoir 46, and prevented from being spilled out of
               the cup 10 to the outside environment. Table 2 below shows the results of experiments
               conducted on the amount of water which exited from the cup 10 incorporated with the
               flow restrictor 24 (with a trough 40 of a length of 127 mm and a cross-sectional area
               of 3.4 mm
2) and the tube 40, when it was allowed to free fall:
               

 
            [0019] It should be understood that the above only illustrates an example whereby the present
               invention may be carried out, and that various modifications and/or alterations may
               be made thereto without departing from the spirit of the invention.
 
            [0020] It should also be understood that various features of the invention which are, for
               brevity, described here in the context of a single embodiment, may be provided separately
               or in any appropriate sub-combinations.
 
          
         
            
            1. A flow restrictor for a liquid, said restrictor having:
               
               
a first end;
               
               a second end; and
               
               a path with an inlet at said first end and an outlet at said second end, said path
                  allowing the passing of said liquid from said inlet to said outlet,
 wherein said path has a first portion and a second portion, said first portion being
               upstream of said second portion, and wherein the distance between said first portion
               and said second end is shorter than the distance between said second portion and said
               second end. 
 
            2. A flow restrictor according to Claim 1 wherein said path has at least one turn of
               substantially 180°.
 
            3. A flow restrictor according to Claim 2 wherein said path has at least two turns of
               substantially 180°.
 
            4. A flow restrictor according to Claim 1 wherein said path has at least one turn of
               substantially 90°.
 
            5. A flow restrictor according to Claim 4 wherein said path has at least two turns of
               substantially 90°.
 
            6. A flow restrictor according to Claim 1 wherein said restrictor includes an outer part
               over-molded onto a base part.
 
            7. A flow restrictor according to Claim 6 wherein said base part is made at least principally
               of a thermoplastic material.
 
            8. A flow restrictor according to Claim 7 wherein said base part is made at least principally
               of polypropylene.
 
            9. A flow restrictor according to Claim 6 wherein said outer part is made at least principally
               of a thermoplastic elastomer.
 
            10. A flow restrictor according to Claim 9 wherein said path is provided on said outer
               part of said restrictor.
 
            11. A flow restrictor according to Claim 1 wherein said path is provided on an outer circumferential
               surface of said restrictor.
 
            12. A flow restrictor according to Claim 1 wherein said first end is opposite to said
               second end.
 
            13. A flow restrictor according to Claim 1 wherein said first portion of said path is
               substantially parallel to said first end.
 
            14. A flow restrictor according to Claim 1 wherein said second portion of said path is
               substantially parallel to said second end.
 
            15. A flow restrictor according to Claim 1 wherein said path is of a substantially rectangular
               cross section.
 
            16. A cap for a drinking cup, said cap including a drinking spout and a flow restrictor
               in a liquid communicable relationship with said drinking spout, said restrictor having
               a first end, a second end, and a path with an inlet at said first end and an outlet
               at said second end, said path allowing the passing of a liquid from said inlet to
               said outlet, wherein said path has a first portion and a second portion, said first
               portion being upstream of said second portion, and wherein the distance between said
               first portion and said second end is shorter than the distance between said second
               portion and said second end.
 
            17. A cap according to Claim 16 wherein said flow restrictor is releasably engaged with
               said cap.
 
            18. A cap according to Claim 16 wherein said flow restrictor is frictionally engaged with
               an inside surface of said drinking spout.
 
            19. A cap according to Claim 16 wherein said flow restrictor combines with said inside
               surface of said drinking spout to form a channel allowing said liquid to pass through.
 
            20. A cap according to Claim 16 further including a tube integrally formed with said drinking
               spout, said tube leading into an interior of said drinking spout.
 
            21. A cap according to Claim 20 wherein an outer surface of said tube and an inner surface
               of said drink spout combine to define a cavity adapted to contain said liquid when
               said cap is disposed upside down.
 
            22. A drinking cup including:
               
               
a container with an open end and a space adapted to contain a liquid;
               
               a cap releasably engaged with said container, said cap including a drinking spout;
               
               a flow restrictor releasably engaged with said cap, said restrictor being in a liquid
                  communicable relationship with said space of said container and said drinking spout
                  of said cap;
 wherein said flow restrictor has a first end, a second end, and a path with an inlet
               at said first end and leading to said space of said container, and an outlet at said
               second end and leading to said drinking spout of said cap, said path allowing the
               passing of said liquid from said inlet to said outlet, wherein said path has a first
               portion and a second portion, said first portion being upstream of said second portion,
               and wherein the distance between said first portion and said second end is shorter
               than the distance between said second portion and said second end. 
 
            23. A drinking cup according to Claim 22 wherein said flow restrictor is frictionally
               engaged with an inside surface of said drinking spout.
 
            24. A drinking cup according to Claim 23 wherein said path of said flow restrictor combines
               with said inside surface of said drinking spout to form a channel allowing said liquid
               to pass through.
 
            25. A drinking cup according to Claim 22 wherein said flow restrictor includes an outer
               part over-molded onto a base part.
 
            26. A drinking cup according to Claim 25 wherein said inside surface of said drinking
               spout is frictionally engaged with said outer part of said flow restrictor.
 
            27. A drinking cup according to Claim 26 wherein said outer part of said flow restrictor
               is made at least principally of a thermoplastic elastomer.