HK1033251B - Leak-proof cup with flow control - Google Patents

Description

FIELD OF THE INVENTION

The present invention relates generally to an improved leak-proof cup. More particularly, the present invention relates to a cup assembly having a cap bearing a drinking spout at one side and an air vent spaced from the drinking spout, with a flow control element frictionally engaged in the vicinity of the drinking spout and air vent to allow passage of liquid out and air in during use, while preventing significant leakage through the spout and vent when not in use.

BACKGROUND OF THE INVENTION

Enclosed cups having drinking spouts and separate air vents, which allow the user to drink from the spout without creating excessive vacuum in the cup, are known in the art. However, drinking spouts and air vents are liable to leak liquid stored in the cup between feedings, or if dropped during use. Accordingly, certain cups have been developed that use valving mechanisms at the spout and at the air vent. These valves respond to suction generated during feeding to open and allow liquid to pass through the spout and to allow air to enter the air vent when a vacuum is developed in the interior of the cup.

Two patents disclosing such valves are U.S. Patent No. 5,079,013 to Belanger and U.S. Patent No. 5,542,670 to Morano , both commonly assigned or licensed to the assignee of the present application. Applicant hereby incorporates the disclosure of those two patents herein by reference. Applicant has on the market a cup that employs a valve assembly similar to that shown in U.S. Patent No 5,079,013 that is secured to sleeves in the underside of the cup's top, but in which the valves are mounted on a single base element. Applicant is also aware of a competitive product having a flow control element of the configuration in Figure 1, sold as part of the Tumble Mates Spill Proof Cup by the First Years.

US-A-5 706 973 discloses a flow control element according to the preamble of claim 1 as well as a drinking cup assembly according to the preamble of claim 12

Despite the effectiveness of these cup mechanisms, applicant has discovered an improved flow control element and corresponding valve configuration that provides improved fluid flow rates without sacrificing the valve's resistance to spills or the valve's durability.

SUMMARY OF THE INVENTION

Thus, it is an object of the present invention to provide an improved valve mechanism for a cup assembly that is substantially leak-proof even when upended, dropped or shaken.

It is a further object of the present invention to provide an improved valve mechanism for a leak-proof cup that gives higher fluid flow rates at normal suction forces without sacrificing durability or resistance to spills.

It is a further object of the present invention to provide an improved valve mechanism, cap and cup that are easy to clean and easy to assemble.

Accordingly, the present invention provides flow control element according to claim 1 as well as a drinking cup assembly according to claim 12.

BRIEF DESCRIPTION OF THE DRAWINGS

• Figure 1 is a perspective view of a prior art valve mechanism;
• Figure 2 is a perspective view of a cup, cap and valve assembly according to the present invention;
• Figure 2 is a perspective view of a cup, cap and valve assembly according to the present invention;
• Figure 3 is a section diagram taken along the lines 3-3' in Figure 2; Figure 4 is a side view of the valve of Figure 3; and
• Figure 5 is a top view of the valve of Figure 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the figures and, in particular, Figures 2 through 4, the cup, cap and valve assembly of the present invention is generally referred to by reference numeral 10. The assembly 10 includes a cup 12, a cap 14 and a flow control valve 20. Cap 14 is adapted to seal cup 12, with the exception of the apertures in the spout 16 and air vent 18 formed in its surface. Flow control valve 20 is adapted to communicate with spout 16 and air vent 18, to form the substantially spill-proof assembly 10.

Cap 14 is formed with mating surfaces, preferably adjacent to or incorporated into spout 16 and air vent 18, to frictionally engage flow control valve 20 and place the flow control valve in fluid communication with spout 16 and air vent 18. In the embodiment depicted in Figure 2, cap 14 is formed with cylindrical recesses 17 within spout 16 and below air vent 18. These recesses 17 are configured to accept flow control valve 20.

In the embodiment shown in Figures 3 through 5, flow control valve 20 includes two stacks 24. Stacks 24 include lower portions 26, upper portions 28 and valve faces 30 bearing slits 32. Each valve face 30 preferably is concave, that is, it curves inwardly toward its stack 24.

These stacks 24 are adapted to be pressed into recesses 17 to friction fit flow control valve 20 into cap 14. Accordingly, when recesses 17 have a lower cylindrical portion, as preferred, lower portions 26 of stacks 24 are also preferably substantially cylindrical in shape.

As also shown in Figures 3 and 4, each stack 24 is elongated. In addition, each stack 24 is of significant diameter and of substantially equal height. The elongated shape of stacks 24 enables them to place valve faces 30 and slits 32 (see Figure 5) in close proximity to the apertures in spout 16 and air vent 18. The diameter of stacks 24 permits significant, relatively unconstrained fluid flow to the area of slits 32. It has been found that this arrangement provides optimal balancing of suction needed to open slits 32 and the fluid flow through the slits. Similarly, its substantial cylindrical diameter and resulting inner contour presents a simple, wide opening and tube to enable thorough cleaning of the stacks 24 after use and to minimize the number of corners and niches in which dried or congealed liquid can be deposited. It is preferred that the outer contour of stacks 24 be stepped, as shown in Figures 3 and 4, but that the inner contour of the stacks be a constant diameter or of constantly diminishing diameter, thus presenting a smooth, unstepped inner face. Thus, the smooth inner face is preferably either cylindrical, frustoconical, or a combination of the two. This smooth inner face further enhances free fluid flow and promotes easy cleaning of stacks 24. The fact that this preferred flow control valve 20 is easy to clean is very important both to the proper and sanitary functioning of the assembly 10, and also to consumer acceptance of the valve.

It has also been discovered that the preferred concave shape of valve faces 30, in conjunction with the attendant curved shape of slits 32, provides superior fluid flow rate through slits 32 than existing valve configurations. This makes the assembly 10 easier to drink from and less frustrating and tiring to use. Furthermore, it has been found that elongated single slits 32 are preferred to cross-cuts or other types of apertures through valve faces 30. It is also preferred that slits 32 extend substantially from edge to edge of concave valve faces 30.

Most preferably, the radius of curvature of the valve face 30 that is aligned with spout 16 is 7 mm (0.267 inches). The most preferred radius of curvature of the valve face 30 that is aligned with air vent 18 is also 7 mm (0.26 inches). The most preferred length of slit 32 that is aligned with spout 16 is 6 mm (0.235 inches). The most preferred length of slit 32 that is aligned with air vent 18 is 4 mm (0.170 inches). The most preferred inner diameter of the stack 24 that is aligned with spout 16 is from 8 mm 0.301 inches) to 9 mm (0.368 inches), ideally a frustoconical shape having the foregoing as minimum and maximum diameters. The most preferred inner diameter of the stack 24 that is aligned with air vent 18 is from 6 mm (0.252 inches) to 9 mm (0.368 inches,) ideally a frustoconical shape having the foregoing as minimum and maximum diameters. The most preferred height of the stack 24 that is aligned with spout 16 is 20 mm (0.803 inches) from top to bottom, and 13 mm (0.521 inches) from indentation to bottom. The most preferred height of the stack 24 that is aligned with air vent 18 is 19 mm (0.730 inches from top to bottom, and 14 mm (0.550 inches) in from indentation to bottom. The two stacks 24 are preferably 41 mm (1.60 inches) on center. The preferred outer diameter of the lower portion 26 of the stack 24 that is aligned with spout 16 is 13 mm (0.522 inches.) The preferred outer diameter of the lower portion 26 of the stack 24 that is aligned with air vent 18 is 12 mm (0.457 inches.) These dimensions provide an interference fit with a cup lid having cylindrical recesses 17 having preferred inner diameters of 13 mm (0.499 inches) and 11 mm (0.439 inches), respectively. All of the foregoing measurements are subject to a preferred tolerance of plus or minus 0,12 mm (0.005 inches.) In addition, a further dimension that is most preferred is the thickness of valve face 30. It is most preferably 0,58 mm (0.023 inches) thick, with a preferred tolerance of only about plus or minus 0,05 mm (0.002 inches). This dimension has been found to be very important in providing proper flexion of the valve faces 30 and opening of slits 32 under suction during use.

It is preferred that the flow control valve 20 be formed from a single piece of elastomeric material to facilitate easy insertion Into and removal from recesses 17. However, flow control valve 20 can be formed of two separate valving elements, each adapted to be inserted into recesses 17 or otherwise engage cap 14. The elastomeric material used is most preferably silicone, but TPE (thermoplastic elastomer), natural rubber, and synthetic rubber (e.g., isoprene) are also preferred.

The following data demonstrate the improved flow rates of a flow control valve 20 according to the present invention. Six samples of a flow control valve as depicted in Figure 3 (Valve A) were tested against six samples of a flow control valve as depicted in Figure 1 (Valve B) and against ten samples of a flow control valve as disclosed in U.S. Patent No. 5,079,013 to Belanger (Valve C).

Sample Number	kPa	Suction to Start Flow (psi)	kPa	Suction for Continuous Flow (psi)	Time to Evacuate 100 ml water (sec.)
1	8.6	1.23	15.5	2.21	49
2	10.3	1.47	15,5	2.21	37
3	10.3	1.47	17.2	2.46	51
4	10.3	1.47	16.3	2.33	44
5	8.6	1.23	16.3	2.33	56
6	8.6	1.23	15.5	2.21	50
Avg.	9.5	1.35	16.0	2.29	48

Sample Number	kPa	Suction to Start Flow (psi)	kPa	Suction for Continuous flow (psi)	Time to Evacuate 100 ml water (sec.)
1	6.8	0.98	19.7	2.82	58
2	6.8	0.98	20.7	2.95	41
3	12.0	1.72	17.2	2.46	44
4	12.0	1.72	18.9	2.70	57
5	10.3	1.47	18.9	2.70	63
6	8.6	1.23	17.2	2.46	75
Avg.	9.5	1.35	18.8	2.68	56

Sample Number	kPa	Suction to Start Flow (psi)	kPa	Suction for Continuous Flow (psi)	Time to Evacuate 100 ml Waters [s]
1	17.2	2.46	30.9	4.42	36
2	20.7	2.95	31.8	4.54	27
3	20.7	2.95	30.9	4.42	76
4	17.2	2.46	27.5	3.93	24
5	20.7	2.95	30.9	4.42	38
6	22.3	3.19	29.2	4.17	33
7	17.2	2.46	27.5	3.93	78
8	22.3	3.19	30.9	4.42	29
9	17.2	2.46	27.5	3.93	40
10	20.7	2.95	2.75	3.93	26
Avg.	19.6	2.80	29.5	4.21	40.7

These data show that the Valve A, a valve according to the present invention, requires lower suction to generate a continuous flow than the prior art valves, and requires less time to evacuate 100 ml of water than the prior art elastomeric valve, Valve B. Moreover, this Valve A is more consistent from sample to sample than the controls. This provides a more acceptable product.

Various modifications may be made to the foregoing disclosure as will be apparent to those skilled in the art. Thus, it will be obvious to one of ordinary skill in the art that the foregoing description and drawings are merely illustrative of certain preferred embodiments of the present invention, and that various obvious modifications can be made to these embodiments within the scope of the appended claims.

Claims (36)

1. A flow control element for use in a spill-proof cup assembly (10) that includes a lid with a drinking spout (16) and an air vent (18), said flow control element comprising two stacks (24) adapted to engage the drinking spout (16) and air vent (18), respectively, wherein each of said stacks (24) has a top portion and said concave valve faces are at said top portions of said stacks (24), characterized in that each of said two stacks having a concave valve face that curves inwardly toward its said stack (24).
2. The flow control element of claim 1, wherein each of said two stacks has an upper portion (28) and a lower portion (26), and said lower portion (26) has an outer diameter that is larger than the outer diameter of said upper portion (28)
3. The flow control element of claim 1, wherein each of said two stacks (24) as an upper portion (28) and a lower portion (26), and said concave valve faces extend substantially across said upper portion (28).
4. The flow control element of claim 2 or 3, wherein the lid includes mating surfaces in communication with the spout (16) and the vent (18), and only said lower portions of said stacks are dimensioned to engage the mating surfaces.
5. The flow control element of claim 4, wherein the mating surfaces comprise depending recesses and said lower portions of said stacks are adapted to engage the depending recesses.
6. The flow control element of any of claims 2 through 5, wherein said lower portions of said stacks have frustoconical outer contours.
7. The flow control element of any of claims 1 through 6, wherein each said concave valve face has a single valve slit (32) extending therethrough.
8. The flow control element of claim 7, wherein said single valve slits extend substantially completely across said concave valve faces.
9. The flow control element of claim 1, wherein each of said concave valve faces has a peripheral edge and said single valve slits (32) extend substantially from edge to edge of said concave valve faces.
10. The flow control element of any of claims 1 through 9, wherein said flow control element is formed of a single piece of elastomeric material.
11. The flow control element of any of claims 1 through 10, wherein said flow control element comprises two separate pieces, each of which bears one of said two stacks (24).
12. A drinking cup assembly comprising:

    a cup having an open end;

    a cap adapted to enclose said open end, said cap including a drinking spout, an air vent (18) and mating surfaces adjacent or incorporated into said drinking spout (16) and said air vent (18); and

    a flow control valve (20) including two stacks (24) adapted to engage said mating surfaces,

    each of said stacks (24) has a top portion (28) and said concave valve faces (30) are at said top portions (28) of said stacks (24),

    characterized in that each of said two stacks (24) having a concave valve face that curves inwardly toward its said stacks (24).
13. The drinking cup assembly of claim 12, wherein said cap includes an inside surface, said mating surfaces are in communication with said inside surface, one of said mating surfaces is located adjacent or incorporated into said drinking spout (16) and another of said mating surfaces is located adjacent or incorporated into said air vent (18), each of said two stacks (24) being adapted to engage a separate one of said mating surfaces and thereby place said flow control valve (20) in fluid communication with said spout and said vent.
14. The drinking cup assembly of claim 12 or 13, wherein each of said stacks (24) has an upper portion (28) and said concave valve faces are in said upper portions (28) of said stacks (24)
15. The drinking cup assembly of claim 14, wherein said concave valve faces (30) extend substantially completely across said top portions (28) of said stacks (24).
16. The drinking cup assembly of any of claims 11 through 15, wherein each of said concave valve faces (30) has a single valve slit (32) therethrough.
17. The drinking cup assembly of claim 16, wherein said single valve slits (32) extend substantially completely across said concave valve faces (30).
18. The drinking cup assembly of any of claims 12 through 16, wherein each of said concave valve faces (30) has a penpheral edge and said single valve slits (32) extend substantially from edge to edge of said concave valve faces (30).
19. The drinking cup assembly of claim 12 or 13, wherein said two stacks (24) are of substantially equal height.
20. The drinking cup assembly of claim 12 or 13, wherein said stacks (24) have a stepped outer contour.
21. The drinking cup assembly of claim 12 or 13, wherein each of said two tacks (24) has a hollow interior with a smooth inner contour.
22. The drinking cup assembly of claim 21, where said smooth inner contour is selected from the shape consisting of cylindrical, frustoconical, and a combination thereof.
23. The drinking cup assembly of claim 22, wherein said smooth inner contour is frustoconical.
24. The drinking cup assembly of claim 23, wherein said smooth frustoconical inner contour extends substantially to said single valve slit (32)
25. The drinking cup assembly of any of claims 12 through 24, wherein said flow control element is formed of a single piece of elastomeric material.
26. The drinking cup assembly of any of claims 12 through 24, wherein said flow control valve comprises two separate pieces, each of which bears one of said two stacks (24)
27. The drinking cup assembly of claim 26 wherein said mating surfaces comprise cylindrical recesses.
28. The drinking cup assembly of any of claims 12 through 27, wherein each of said concave valve faces (30) is 0,58 mm (0.023 inches) thick.
29. The drinking cup assembly of claim 12 or 13, wherein each of said two stack (24) has an upper portion (28) and a lower portion (26), and said lower portion (26) has an outer diameter that is larger than the outer diameter of said upper portion (28).
30. The drinking cup assembly of claim 12 or 13, wherein each of said two stacks (24) has an outer surface contour that includes a step that is located between and is in communication with said upper and lower portions of said stack (24).
31. The flow control element of claim 12 or 13, wherein said lower portions (26) of said stacks (24) have frustoconical outer contours.
32. The flow control element of claim 29, wherein said mating surfaces comprise depending recesses and only said lower portions of said stacks (24) are adapted to engage said depending recesses.
33. The drinking cup assembly of claim 12 or 13, wherein each of said mating surfaces comprises a wall.
34. The drinking cup assembly of claim 33, wherein said walls define recesses (17).
35. The drinking cup assembly of claim or 33 or 34, wherein said upper portions (28) of said stacks (24) are formed of an elastomeric material and there is a gap between said walls of said mating surfaces and said upper portions of said stacks.
36. The drinking cup assembly of claim 33 or 34, wherein said upper portions (28) of said stacks (24) are formed of an elastomeric material and there is a gap between said walls of said mating surfaces and said top portions of said stacks.