HK1110565A - Reclosable cup lid - Google Patents

Description

Cup cover capable of being covered again

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application No.11/402,426 filed on 12.4.2006, U.S. patent application No.11/402,426 is itself a continuation of U.S. patent application No.11/244,133 filed on 5.10.2005, and U.S. patent application No.11/244,133 is itself a priority application of U.S. provisional patent application No.60/617,123 filed on 8.10.2004. The disclosure of each of the above applications is incorporated by reference into this application in its entirety.

Technical Field

The present invention relates generally to cup lids and, more particularly, to a thermoformed disposable cup lid having a drinking aperture and a closure plate disposed generally radially between an open position in which the aperture communicates with the interior of the lid and a closed position in which the closure plate covers the aperture to reduce or substantially prevent spillage during use.

Background

The following patent applications describe the basic changes commonly known in the construction of reclosable lids: leggett, U.S. patent No.581,293 entitled "can lid or the like; U.S. patent No.949,974 entitled "closure for can" to cibulk a; U.S. patent No.1,433,544 entitled "sieve tank" to j.c. gibbs; U.S. patent No.1,765,284 entitled "ink reservoir closure" to l.b. pronsanitz; U.S. patent No.1,888,363 entitled "ink reservoir" to c.e. tannewitz; U.S. patent No.2,492,846 entitled "dispensing container with sliding closure" to style et al; U.S. patent No.4,170,724 to Waterbury entitled "saleable reclosable beverage container"; U.S. Pat. Nos. 4,201,320 entitled "measurement Dispenser" to Eppenbach; U.S. patent No.4,434,906 to Florczyk et al entitled "container with resealable opening device"; lyon's U.S. Pat. No.5,025,945 entitled "beverage Container"; U.S. patent No.5,086,941 to English et al entitled "dispenser closure assembly"; U.S. patent No.5,462,189 to Pierce entitled "resealable, refillable container system"; U.S. patent No.6,354,454 entitled "bottle cap" to Wrong; U.S. patent No.6,439,442 entitled "cap with slidable dispensing spout" to Markert et al. The disclosures of the above applications are incorporated herein by reference in their entirety.

U.S. patent No.4,749,099 to Davis et al entitled "beverage reservoir"; hambleton et al, U.S. Pat. No.5,470,817 entitled "slidable reclosable Plastic lid"; and U.S. patent No.4,127,212 to Waterbury entitled "salable reclosable beverage container" shows a reclosable beverage lid or container. The disclosures of the above applications are incorporated herein by reference in their entirety. In the Davis et al application, the push-in tabs are interconnected with the closure panels within tracks formed in the metal top of the container. The push-in tab is manipulated downwardly into the top portion to puncture the score line portion for exposing the opening to enable the closure panel to be moved over the opening to protect unused items in the container. In Hambleton et al, the plastic container lid includes a main lid member and a slide member. The main cover element has support rails between which the sliding element is arranged, the support rails being chamfered with respect to the plane of the main cover element in order to hold the sliding element on the cover. The main cover is provided with a hole therein and the sliding member can cover the hole. The slide element includes a finger engaging portion. Waterbury discloses a reclosable beverage container and provides a sliding closure that fits over the upper end of the container for movement over the opening of the lid. The cap cannot be removed from the lid.

The above products are generally not suitable for the disposable lid/cup market where cost, storage, ease of manufacture, etc. are paramount.

For disposable lids, the closure panel is typically integral with the upper wall of the plastic lid, defined by indicia to facilitate removal of the closure panel from the adjacent portion of the lid along the indicia and then folding back to open the drinking aperture of the lid; selectively secured to the upwardly projecting projection in its open position; and then folded to the edge to close the lid. Proper operation of these lids is difficult and often results in substantial spillage (especially troublesome for hot beverages), but enjoys great commercial success in part because they meet the cost criteria required by the disposable product market.

Hemispherical heated cup lids, while not reclosable, often place flat trough lids with fold-shaped closure panels because they are preferred by users and can substantially control some spillage due to their increased "splash height" above the contained beverage. Lids commonly known in the art include a hemispherical shape formed of a thermoplastic polymeric material and have an opening for drinking a beverage when the lid is placed on a cup. The lid, the opening, and the closure formed therein have various shapes.

U.S. patent No.6,732,875 to Smith et al entitled "reclosable container lid" and U.S. patent No. d489,260 to Smith et al entitled "reclosable container lid" disclose reclosable hemispherical lids. The cover includes a cover component and a rotating disk component that fits within the cover of the cover. The post is located on the periphery of the lid to rotate the disc below the drinking aperture between the open and closed positions. Since the disc/lid geometry and lid/disc combination requires redundant construction of the cover, i.e. two layers over the entire top wall, it is clearly necessary to incorporate features such as drain holes. Moreover, the proposed cover member prevents efficient nesting, increased storage, packaging and shipping costs. The disclosed embodiments also prevent stacking in cups on the lid structure when the consumer purchases multiple beverages; the disadvantage of increased spillage can be eliminated by closing the drinking hole.

Another embodiment of a reclosable cup lid is shown in U.S. Pat. No.6,824,003, the disclosure of which is incorporated herein by reference in its entirety for the purpose of disclosing a disposable and reclosable thermoformed lid. The cover has a C-shaped guide track into which a reclosable panel is inserted. The guide rails are tapered so as to be embedded in the guide rails. It is believed that it is difficult, if not impossible, to manufacture such a lid in a thermoforming process because of the sharp angled edges formed in the C-shaped rails. Also, it is believed that the covers cannot be stacked in an efficient manner.

Despite the many options, existing and proposed disposable lids suffer from one or more of the following disadvantages: difficult to operate and ineffective resealing; invalid overflow control; high material costs; excessive storage, packaging and shipping costs; not stackable in cups on a lid structure, etc. By the present invention, these deficiencies of the prior art are overcome and a reclosable lid is provided that is durable and reclosable, easy to use, stackable, effective in preventing splatter and spillage, easily made of thermoplastic material using existing machinery, and low cost.

Disclosure of Invention

The present invention provides a disposable and reclosable cup lid made of thermoplastic polymeric material including a lid component and a closure panel. The thermoformed cover component may be provided with side walls and a top wall having upper and lower surfaces and a drinking aperture at the periphery of the top wall. The drinking aperture communicates with the interior of the cup when the lid is engaged with the cup to close the beverage therein. The top wall also defines a pair of skirt-like lace engaging tracks depending from the lower surface of the top wall and the post apertures of the closure panel. To provide a reclosable disposable lid, a thermoformed closure panel is inserted into the engaging track of the skirt by applying a bending force on the engaging track of the skirt to widen the distance between the engaging tracks of the skirt. The posts of the closure plate will extend above the top surface of the cover member which will cause the closure plate to slide within the engagement tracks of the skirted lace. Moreover, the lid component and the closure panel are configured to minimize dripping of the beverage onto the user's skin or clothing during use experienced by the user by including a reservoir within the closure panel. The reservoir may also have a drain hole within its boundaries to facilitate draining of the reservoir when in use. Furthermore, the closure plate may have locking profiles or detents thereon adapted to cooperate with corresponding locking profiles in the cover member. The assembled lids are stackable to minimize space requirements. Methods of making such caps are also provided in this application.

Other features and advantages of the present invention will become apparent from the following discussion and the accompanying drawings.

Drawings

The present invention will hereinafter be described in detail with reference to the appended drawings, wherein like reference numerals denote like elements, and wherein:

fig. 1 is a side view of a reclosable cap having features of the present invention.

FIG. 2 is a bottom view showing one embodiment of the lid of the present invention wherein the lid has a pair of scalloped engagement tracks.

Fig. 3 is a cross-sectional view of the slide rail of fig. 1 at the maximum inward projection.

FIG. 4 is a perspective view of a closure plate having a substantially chamfered edge.

Fig. 5 is a partial end view of the closure panel of fig. 4.

Fig. 6 is a detailed sectional view showing a joining rail of the skirt lace of the present invention.

FIG. 7 is a top view of one form of the closure panel of the present invention having a reservoir with a discharge aperture therein, and a locking profile and a drinking aperture profile.

Fig. 8 is a detailed sectional view showing the closing plate of fig. 7.

Figure 9 is a cross-sectional view showing the configuration of the elevated drinking aperture region of one form of the cap of the present invention.

Detailed Description

The following detailed description is intended to be merely illustrative and explanatory of the invention. Modifications within the scope of the invention as set forth in the appended claims will be readily apparent to those skilled in the art. As used in this application, technical terms are intended to have their ordinary meaning unless a specific definition is given or indicated by context.

"aspect ratio" refers to the ratio of the length of an object to the width of the object, for example the ratio of the length of a closure panel to the width of the same closure panel.

"substantially radially" refers to a direction substantially parallel to or substantially along a diameter of the article.

"undercut depth" refers to the distance below (or above) a side projection of the same thermoformed part along the side to define a recess of the side groove within that part. The undercut is described by the so-called "negative draft" discussed below. If there is no undercut, the part or feature has a positive draft angle. When used in conjunction with undercuts of different depths, such as the undercut of a scalloped edge, the "undercut depth" refers to the undercut depth at the maximum lateral depth of the undercut. The undercut depth defines an "undercut groove" that is substantially coextensive with the engagement track of the scallops.

The "direction of the scallops" refers to a direction in the form of a continuous series or circular elements or angular projections that form a boundary. Element 158 in fig. 2 shows an example where the direction of the scallops is not limited.

"disposable" means that the object is intended to be discarded after use by one or a maximum of several people.

By "substantially sealed" is meant that there is no or substantially no spillage from the closure panel in the closed position.

Containers with resealable lids, i.e., cups, for example, for holding hot beverages such as coffee and tea, are generally not suitable for disposal after use by one person, taking into account the cost of their components. Such prior art containers are typically intended for multiple uses and are made of injection molded plastic material. In such prior art reclosable lids made of injection molded plastic, the tracks are typically defined by rails formed in the lid. However, as will be appreciated by those skilled in the art, it is virtually impossible to form sharp edges in a thermoforming process, such as to produce the reclosable lid of the present invention by a thermoforming process. It is not easy to make sharp corners in thermoforming. Moreover, the workpiece must be designed to be substantially non-deforming (e.g., bending or twisting) when removed from the mold, which deformation adversely affects the structural integrity of the workpiece. As a result, it is difficult to manufacture the sharp-angled edges of the joining rail described in U.S. patent No.6,824,003 by a hot forming process.

The inventors of the present invention have found that the shape of the engagement track (which is defined by the undercut groove and the overall distance of the engagement track) is important in order to properly manufacture and assemble the thermoformed reclosable cup lid. If the design of the tracks is not maintained within certain parameters, it has been found that the thermoformed lid cannot be removed from the mold to form a reclosable lid without deforming the engagement tracks to such an extent that the closure panel cannot be inserted into the tracks. That is, if the cap must be deformed sufficiently to be removed from the mold, the plastic material from which the engagement tracks are made will be stretched, torn, or deformed such that the engagement tracks do not have structural integrity. This loss of structural integrity causes the closure plate to no longer reliably engage the engagement track and/or causes liquid to leak from the cap in use. Furthermore, the inventors have found that it is difficult to assemble the cover members and closure panels if the joining rail is made of a fixed length of material, as opposed to less than the entire rail length.

Accordingly, the inventors of the present invention have determined that a thermoformed reclosable cup lid can be properly manufactured and assembled, requiring a large adjustment to the engagement track area as compared to a proper design for preparing an injection molded reclosable cup lid. In particular, it may be determined that a measurable amount of material must be removed from the region of the engagement track. Thus, as proposed by the present invention, the joining rail in the cover part of the present invention is scalloped (strained).

The scalloped engagement track of the present invention includes an undercut depth that defines an undercut groove, which in turn substantially defines the scalloped engagement track. The undercut depth can be from at least about 0.020 to about 0.060 inches or from at least about 0.025 to about 0.050 inches. The inventors of the present invention have found that when the undercut groove is too deep, the engaging track of the skirt-like lace will deform when the lid is removed from the mold. It is believed that because of the simple placement, the cap will be inserted therein when the recess of the mold is too deep, and thus in order to remove the cap from the mold, it is necessary to bend or twist the cap at, for example, recess 160 in fig. 3.

The inventors of the present invention have also found that the extent of the undercut depth is related to the engagement track defining the skirt, the undercut depth being sufficiently deep that the closure panel is securely retained in the engagement track of the skirt. The undercut depth in the present invention ensures that the slide does not become dislodged from the track and fall into the beverage in use, while allowing the lid component to be properly removed from the mould.

It is important to manufacture the reclosable cup lid of the present invention to be able to insert the closure panel into the engagement track of the skirt without causing substantial deformation of the engagement track of the skirt while also maintaining the integrity of the engagement track of the skirt to ensure a good fit of the closure panel in the engagement track. During high speed assembly, the closure panel must be quickly and easily inserted into the mating rail without deforming the rail so that the closure panel will remain in the rail during use. These features for high speed assembly are described in detail below.

To accomplish this, the inventors of the present invention have found that the scalloped (or recessed) design provides a lid structure that is particularly well suited for the reclosable lid of the present invention. For example, fig. 2 shows the direction of the skirt lace. The radius from the scalloped end to the end can range from about 0.125 to about 0.3 inches. Because the entire number of scallops determines the length of the engagement track of the scallops, there are more scallops when the radius is smaller; when the radius is larger, there are fewer scallops. The engaging tracks of the skirt-like lace are spaced apart by a distance. The engaging tracks of the skirts are substantially parallel to each other. The undercut depth and the scallops cooperate to provide an engagement track in which the closure panel travels.

It has been found that insertion and mating of the closure panels can be improved by rounding and/or chamfering the extended edges of the closure panels. For example, by bevelling the edges so that the edges of the closure panel point away from the lower surface of the cover member, less force is required to insert the closure panel into the engagement track. Moreover, the chamfered edges allow the closure panel to slide into the engagement tracks without requiring too much force to be applied to the closure panel itself or the engagement tracks. These angles will be discussed further herein.

In some aspects, the arms of the engagement track in which the skirted lace of the closure panel is provided are not tapered at the free ends. Also, the engagement track does not include a pair of C-shaped rails. U.S. Pat. No.6,824,003 discloses such a C-shaped guide rail. The' 003 patent discloses that the closure member is easily inserted into the lid portion when the C-shaped rail is tapered at the free end. The inventors of the present invention believe that the design of the '003 patent results in a significant distortion of the structure of the C-shaped guide rails when the closure plate is inserted into the cap of the' 003 patent, even when tapered ends are also included. Thus, the inventors believe that the design described in the' 003 patent will result in a loose fit of the closure panels therein.

Moreover, it is believed that the use of thermoforming techniques to make the lid illustrated in the' 003 patent is particularly difficult due to the sharp edges in the design. As mentioned above, such sharp-angled edges cannot be used reasonably for manufacturing, because it is difficult to remove the workpiece from the mold after hot forming. In contrast to the joining rail design disclosed in the' 003 patent, the scalloped design of the joining rail of the present invention allows the cover component to be easily removed from the mold after thermoforming with little or no distortion of the joining rail.

Moreover, in the present invention, the configuration of the skirt of the engagement track is such that the closure plate is securely retained in the engagement track of the skirt to provide a reclosable seal in the finished cup lid. The chamfered outer edge on the closure plate also improves the ability to assemble the lid to provide a reliable seal in a two-piece reclosable disposable cup lid. It has been found that the corners of the closure panel are radiused to provide improved fit of the closure panel into the engagement tracks of the skirting lace.

In one form, the invention provides a reclosable disposable lid for a cup, the lid being made of a polymeric material and comprising a thermoformed lid component having a side wall and a top wall, the top wall having an upper surface, a lower surface and a drinking aperture at the periphery of the top wall, wherein the drinking aperture communicates with the interior of the cup when the lid is engaged with the cup. The top wall also defines a pair of engaging tracks for a skirt depending from the underside of the top wall of the lid member. The cover member also has a closure plate post aperture. The lid also includes a thermoformed closure plate having opposed and chamfered engagement edges along its length and/or radial corners. The closure plate also includes an upper surface provided with posts projecting upwardly therefrom. When the lid is assembled, the closure panel posts project through the closure panel apertures. The lid also includes a drinking aperture area which is sealable by a sliding engagement portion of the closure panel within the engagement track of the skirt.

As mentioned above, the closure plate is substantially planar along a central portion and is chamfered or radiused at respective opposite joining edges. The opposite outer edges of the plate are chamfered as shown in fig. 4 and 5. The opposite engagement edges of the closure panel are substantially the same thickness as the closure panel and engage the generally parallel engagement tracks of the scallops. The opposite engaging edges of the closure panel have a substantially chamfered profile and the undercut groove of the engaging track of the skirt-like lace has an S-shaped or modified S-shaped profile (as shown, for example, in fig. 6) adapted to receive the opposite chamfered outer edges of the closure panel. The closure plate has chamfered longitudinal edges to provide a mounting angle that has been found to be particularly suitable for high speed assembly processes in which the closure plate is adapted to fit into the engagement track of the scallops. It has been found that suitable chamfer angles for the closure plate are from about 5 to about 15 degrees, or from about 8 to about 12 degrees.

The length of the closure plate can be from about 1/2 to about 3/4 of the diameter length of the lid member; the length of the closure plate can be about 2/3 times the length of the diameter of the closure plate; the area of the closure panel is from about 5 to about 25% of the area of the top wall. The area of the closure panel is typically no greater than about 25 to about 35% of the area of the top wall of the lid component. The aspect ratio of the closing plate (as defined herein) is at least about 1.5 or at least about 2.0 or at least about 3.0.

In an important aspect, the closure plate includes a liquid reservoir thermoformed therein. The inventors of the present invention have found that this reservoir greatly reduces the likelihood of liquid collecting in the vicinity of the closure plate or on the top of the lid component, typically in or around the drinking aperture area. That is, in use, the beverage will splash in the cup. Because there is no tight seal between the closure panel and the engaging track of the skirt, some liquid will typically leak into the closure panel. In order to prevent liquid from splashing onto the user's clothing when drinking beverages, it has been found that at least one form of reservoir according to the invention is important.

The depth of the closure plate reservoir is not considered critical, however, there should be sufficient volume to properly store excess liquid remaining between the closure plate and the engaging track of the skirt lace. In non-limiting examples, the closure panel memory is from about 0.40 to about 0.80 inches in the closure panel width direction, or from about 0.50 to about 0.70 inches in the closure panel width direction. The depth of the reservoir is from about 0.030 to about 0.080 inches as measured from the top surface of the closure plate. Details of the memory are discussed further herein in connection with the discussion below regarding fig. 7 and 8.

The possibility of beverage remaining between the closure plate and the engaging track of the skirted lace and then dripping onto the clothes is an important issue for the manufacturer of cups and lids used for drinking hot beverages. It has been found that incorporating a liquid reservoir within the closure panel surface can accommodate excess liquid remaining in the lid (as opposed to on the lid surface) and substantially prevent liquid from spilling out of the lid when the user sucks on the lid any further. Furthermore, if the closure plate incorporates an exit aperture in the reservoir, any retained liquid that passes through the exit aperture of the closure plate (which, as described herein, is configured by piercing the lid in the direction of the inner surface of the assembled container) can flow back into the container, thereby facilitating the draining of retained beverage from the reservoir into the container.

The closure plate may also include a ridge on the upper surface of the closure plate that acts as a locking mechanism or detent when the assembled lid is in the closed position. The locking mechanism should be of a suitable height to prevent the closure panel from inadvertently opening during use and causing beverage to spill from the drinking aperture. However, the degree of locking must also be balanced with the needs of the user in order to be able to easily open the closure panel when the user wishes to inject a beverage into the container. More suitably, the locking mechanism should be suitable for one-handed operation. The height of the locking mechanism is from 0.020 to 0.040 inches, or from about 0.024 to 0.032 inches. The locking mechanism in the closure panel matches the associated and complementary profile in the cover member. The coupling of the locking profiles in the cover member and the closure panel cooperate to lock the closure panel so as not to inadvertently open the closure panel during use.

Importantly, the reclosable cup lid of the present invention can be easily opened by a user with one hand. This is a significant improvement over prior art reclosable cup lids that have tabs or bumps on the outer upper lid surface or sliding locks. Such designs require the sliding portion of the reclosable cup lid to be pushed over the lid rim or engaged by mating over the rim or upper surface of the cup periphery in the event of a rupture of the flap lid. In such designs, the user is required to push the nub down or slide it off of the locked position-each motion requiring two hands to operate. In contrast, the locking member of the present closure provides a lock to prevent inadvertent opening of the closure while being suitable for one-handed operation. This one-handed operation allows the user to actuate or perform other tasks while opening and closing the lid in use.

The closure panel may also include a drinking aperture contour that is substantially aligned with the drinking aperture of the lid member. It has been found that this profile provides an improved friction fit between the closure member and the drinking aperture. In particular, when the closure plate comprises a profile that substantially matches the drinking aperture opening, the closure plate will better seal in use. As presently desired, the contour includes a notch in the upper surface of the closure panel in which the corresponding edge of the drinking aperture contour is located when the closure panel is in the closed position. In order to ensure that the closure panel can be opened and closed properly in use, the profile of the closure panel should be sufficiently narrow so as not to cause the edges of the drinking aperture to lock into the profile of the closure panel and to be difficult for a user to open.

As provided by the present invention, the lids are stackable. Such stackability is important because the covers must be shipped and stored in a convenient form. Also, the cup lid can be configured such that the cup bottom can be stacked on the lid. Such a configuration is beneficial to improve the ability of a user to safely transport multiple filled containers.

The closing plate is suitably provided with a discharge device, wherein such a discharge device comprises one or more discharge holes. In such a form, the discharge aperture is positioned so that the post aperture communicates with the interior of the lid member when the closure panel is in the open position, thereby to open the interior in the open position for drinking.

In an important form, the evacuation means comprises one or more bores in the closure plate and one or more bores in the cover member. The discharge hole has a diameter of from about 0.040 to about 0.080 inches, or from about 0.050 to about 0.070 inches.

The apertures in the closure plate and the cover member are not suitably each in substantial alignment where the evacuation means is included to facilitate direct passage between the cover member and the closure plate. In one aspect, it is important that the discharge means comprise a discharge aperture that is not substantially aligned in the closure panel and the top wall of the lid component when the lid is in the closed position. For the sake of clarity, these ejectors are referred to as "asymmetric ejectors".

In this asymmetric drain arrangement, each drain hole is positioned so that when the closure panel is in the closed position, the holes in the lid component are located at a suitable distance to minimize the possibility of hot beverage spilling through the drain hole during transport of the beverage container when the closure component is in the closed position. In one form, the bore in the cover member is offset, or substantially offset, from the centre line of the cover member. The respective discharge hole of the closure member is located at a position in the reservoir which allows the container beverage to be properly discharged while properly preventing splashing.

Asymmetrical discharge means have been found to be particularly suitable for use with the reclosable cup lid of the present invention. It is known that the presence of a discharge hole in the lid assists in dispensing the beverage from the container by reducing the negative pressure differential within the container. The inventors of the present invention have found that an asymmetric drain having one of the drain holes disposed in the reservoir not only reduces the positive pressure differential when the lid is in the open position for drinking, but also effectively draws off excess beverage collected in the area of the closure panel during transport or storage of the beverage. In particular, the two-piece design of the present invention makes it suitable for beverage access in the area of the closure plate, resulting in a capillary action between the closure plate and the underside of the lid part. The arrangement of the discharge orifice preferably reduces the transport flow entrainment of liquid from the interior of the container to the closure plate and then to the plane of the top central closure plate of the reclosable cup lid by capillary action.

Whether or not an asymmetrical evacuation device is used, it is advantageous to provide a bore in each of the cover member and the closure plate in a particular direction. In particular, the inventors of the present invention have found that the bore in the cover member should pass through the bottom wall of the cover member so that any barbs created by the bore are located on the upper surface of the cover member. When the discharge holes are arranged in this direction, the inventors have found that the closing member is less likely to be clogged by the barbs formed in the plastic cover due to the drilling process. In particular, it has been found that the closure member can become clogged if the bore is made through the top wall of the cover member because the plastic barb is formed as a result of the drilling process.

Likewise, it has been found that when the drilling motion is directed through the top side of the closure member at the bottom of the reservoir, the closure member is more likely to allow free flow of the collected liquid so that the resulting plastic barbs are directed from the top of the closure member through to the bottom of the closure member. When the closure member is drilled in this manner, the closure member is more likely to allow the collected liquid to flow freely back to the container. Furthermore, it has been found to be more advantageous to drill from the bottom to the top of the lid member and from the top to the bottom of the closure member and to include the lid member and the closure member with these features in the finished container lid. Briefly, it has been found that the lid member weep hole barb should be oriented toward the top surface of the lid member and the closure plate weep hole barb should be oriented toward the bottom surface of the lid member.

In an important form, the drinking aperture of the lid of the present invention is elevated from the top surface of the lid component in the assembled lid. In particular, it has been found that the enhancement of the drinking aperture provides a comfortable drinking experience for the user. The drinking aperture should be high enough to provide a comfortable drinking experience while not being so high from the top surface of the lid as to resemble a child's "drinking cup" which has been found unsuitable for use by adults. In one aspect, the drinking aperture is elevated from about 0.20 to about 0.30 inches from the top surface of the lid. The shape of the drinking aperture is generally a flattened oval shape when viewed from the top of the lid surface. Although other suitable shapes can be used, it has been shown that a flat oval shape provides a comfortable drinking experience.

The special structure of the cap of the present invention comprises: a) a single lid component having a sidewall and a top wall, i) the sidewall having a fitting groove at a lower portion thereof, the fitting groove configured to engage and form a seal with the rim of the cup; ii) the top wall also having an upper surface and a lower surface, and a raised drinking aperture at the periphery of the top wall, the periphery having a sealing ridge formed therearound that projects downwardly from the upper surface and the locking profile, the top wall further defining a pair of substantially parallel scalloped engagement tracks defined by substantially parallel undercut grooves between the lower surface of the top wall and a lower portion of the scalloped engagement tracks, the top wall further having a post aperture disposed inwardly with respect to the raised drinking aperture; b) a thermoformed closure panel having an upper surface configured with a post projecting upwardly from the upper surface, and a reservoir in the closure panel and a discharge aperture located in the reservoir to facilitate leakage of beverage from the reservoir, a sealing groove formed around the sealing region and a locking profile thereon and an engaging edge of opposed skirted laces along the length thereof; c) a cover member and a closing plate configured such that a longitudinal engaging edge of the closing plate is slidably fitted in an engaging track of the skirt-like lace on a lower surface of a top wall of the cover member when the closing plate slides along the engaging track of the skirt-like lace; d) wherein when the closure panel is mounted in the engagement track of the skirt, the post of the closure panel projects upwardly through the post aperture, the post aperture and the post thereabout cooperating to limit displacement of the closure panel relative to the cover member; e) the sealing position of the closure plate is characterized in that the sealing edge is around the elevated drinking hole seat in the sealing groove of the closure plate; and f) the closure panel further comprises a locking profile on the closure panel configured to cooperate with an associated locking profile on the lid component.

In one form, the lid of the present invention is formed by heating. Generally, thermoforming is the pressing and/or stretching of a heated deformable material into a final shape. In the most basic aspect, thermoforming is the covering of a flexible sheet over a forming mold. In a more detailed aspect, thermoforming is the automated high speed positioning of a heated sheet with a properly controlled temperature onto a pneumatically driven forming station, whereby the shape of the article is determined from the mold, followed by trimming and regrinding the material (collection) as known in the art. Forming techniques other than conventional thermoforming may also be suitable for making the articles described herein. These include variations such as pre-softening the extruded sheet to a temperature below the final melting temperature, skiving off flat portions (i.e., billets) from the sheet, conveying the billets by gravity or mechanical means into a matching mold, whereby the billets are formed into articles by heat and pressure. Other alternatives include the use of hot sheet drapes, vacuum, pressure, mold-less manual blowing, matched mold, corrugated hot sheet drapes, snap-back vacuum, corrugated vacuum, plug-assisted (plug assist) vacuum, reverse drawing with plug assist, pressure bubble immersion, trapped (trapped) sheet, paper sheet (slip), membrane, two-layer cut sheet, double-layer roll forming, and suitable combinations of the foregoing. A book of j.l.throne published by coulhard in 1987, thermoformed, provides details. Pages 21 to 29 of the book are incorporated herein by reference. Suitable alternatives also include a pillow (pillow) forming technique that creates positive air pressure between two heated soft sheets to expand them against a clamped male/female die system to create a hollow product. The metal mold type is etched with a pattern ranging from fine to coarse in order to simulate a natural or granular structure profile. The trimming can be selectively reused by consistently trimming the appropriately shaped article using a cut-off die. Other solutions for increasing throughput include simultaneously forming multiple articles using multiple molds in order to maximize throughput and minimize waste.

The thermoplastic material desirably includes a material suitable for a thermoplastic mold of the hot cup lid. A suitable material for the lid is a styrene polymer composition, which may be filled or unfilled. The composition has sufficient color to provide opacity or near opacity. Other suitable materials include polyolefins such as polyethylene, polypropylene and blends thereof, polyesters, polyamides, polyacrylates, polysulfones, polyether ketones, polycarbonates, acrylics, polyphenylene sulfides, acetates, celluloses, polyetherimides, polyphenylene ethers/oxides, styrene-maleic anhydride copolymers, styrene acrylonitrile copolymers, polyvinyl chloride and resinous derivatives thereof. These materials may be filled or unfilled as well. The filler for any polymeric material may be any conventional material, as is well known to those of ordinary skill in the art.

The cover (cover member and closure panel) can be thermoformed from a sheet of thermoplastic material. Typically, the thermoplastic sheet from which the closure is made has a thickness of from about 10 to about 20 mils (thousandths of an inch), or from about 14 to about 19 mils. The sheets cut into blanks can be collected from the recyclables. Also, the sheet material that has been cut into blanks may be made from a starting material. Also, sheets that have been cut into blanks may be made from a mixture of virgin and recycled material.

The thermoformed article should be designed so that there is no undue interference with the surface of the article to allow the mold sections to be freely demolded from the molded article. The surface of such articles typically includes a so-called positive "draft" with respect to a direction in which the mold sections are moved during demolding to ensure little or no interference between the molded article and the inner surface of the mold section during demolding. The interference between the article and the mold is commonly referred to as "negative draft". Draft can be considered as the difference between the upper transverse span of the mold cavity and the span below it. Positive draft allows the sample to be completely pulled out of the mold; however, undercuts inherently have negative draft angles.

In the present invention, the undercut depth and distance required to secure the closure plate to the domed portion of the cap is generally minimized in order to reduce manufacturing difficulties associated with negative draft angles. In particular, the engagement track of the skirt has an undercut groove defined by its inner wall and an outer wall of negative draft, wherein the outer wall of the engagement track of the skirt has an arcuate cross-section.

The inventors of the present invention have found that in order to make the reclosable cup lid of the present invention, the manufacturability of the lid portion and the need to retain the closure panel in the engaging track of the skirt-like lace must be balanced. That is, to function as a resealable closure for the beverage, the closure panel must easily slide from the open position to the closed position when inserted into the engaging track of the skirt. As mentioned above, the barbs formed on the cover and the attendant jamming of the closure panel during use can be reduced by drilling the cover member so as to keep the barbs away from the path of operation of the closure panel during use.

The reclosable lid of the present invention is assembled by applying a bending force to the lid so as to widen the distance between the engaging tracks of the substantially parallel skirted laces. The widening allows the beveled and/or chamfered closure panel to slidingly fit within the engaging track of the skirt lace to provide an assembled reclosable thermoformed cup lid. The closure panel posts are oriented to project upwardly through the post apertures toward the top surface of the cover member.

In contrast to the previously discussed' 003 patent, the closure panel does not have an engagement track embedded in the skirt of the lid of the present invention. Also, the cover member itself is bent to insert the closure plate into the engagement rail of the skirt lace in the present invention, whereas in the' 003 patent, the engagement rail, that is, the C-shaped rail itself, is bent to fit the plate into position.

The present invention also provides a method of making a reclosable disposable lid for a cup, the method comprising: providing a lid component made of a thermoformable material, wherein the lid component comprises: providing a thermoformed closure plate having a post projecting upwardly from a chamfered and/or radiused closure plate, wherein the chamfered and/or radiused closure plate is configured to slidingly fit within the engagement track of the skirt lace, applying a bending force to the cover member to widen the distance between the engagement tracks of the skirt lace; inserting a chamfered and/or beveled closure panel into the engagement track of the skirt lace such that the post is disposed upwardly through the post aperture toward the top surface of the cover member, wherein the inserting is performed when the cover member is flexed; and releasing the bending force after inserting the closing plate into the engaging track of the skirt lace. The cover member includes: a sidewall adapted to engage a rim of a cup; the roof includes: a drinking aperture at the periphery of the top wall, a pair of substantially parallel spaced apart scalloped engagement rails disposed on a lower portion of the top wall portion, wherein each rail includes a scalloped configuration and an undercut depth, wherein the scalloped configuration and the undercut depth cooperate to provide the engagement rails; and a post hole provided toward the center of the cover member. When the closure plate includes a locking profile, the lid member has associated locking profiles adapted to cooperate to provide locking of the closure plate, thereby preventing or substantially preventing inadvertent opening of the closure plate when a beverage is received in a cup on which the reclosable cup lid is used.

In view of the manufacturability of the reclosable lid of the present invention, the mechanical stripping action of the stripper plate in the thermoforming apparatus must be precisely timed with the operation of the air jet. Activation of the stripper plate associated with the air jet stream too early or too late will tear the rail and deform the cover out of service.

The reclosable disposable cup lid of the present invention has a size that fits any cup on which the lid is typically used. The reclosable disposable cup lid of the present invention is particularly suitable for hot beverages.

Fig. 1 discloses a reclosable cup lid having features of the present invention. The top 24 of the sidewall 14 is specifically provided to prevent the stackable cup 100 with the rim 104 from sliding off the lid 10. In particular, the top 24 is of a height and size such that the bottom end (not shown) of the cup 100 is in abutting engagement with the inner wall surface 25 of the top 24. Moreover, the roof 24 has a height H that substantially corresponds to the height of the post 82, and because the post 82 is positioned away from the roof 24, when a known container and cup is stacked, the stacking of the cup 100 and lid 10 is unaffected by the post 82 because the post 82 fits within the open area (not shown) of the known container and cup.

The sidewall 14 also includes a generally annular skirt portion 26 depending therefrom. The skirt portion 26 includes an annular sealing groove 28 configured to sealingly engage the rim 104 of the cup 100. A sealing groove 28 is formed adjacent the end of sidewall 14 and a generally annular flared rim 30, which annular flared rim 30 depends from annular sealing groove 28. Annular sealing groove 28 is configured to engage and form a seal with rim 104 of cup 100. Thus, the annular sealing groove 28 provides a means for preventing leakage of the contents of the cup when the lid 10 is secured to the cup 100. The flared rim 30, which is generally annular, provides a gripping surface for a user to remove or place the lid 10 onto the cup 100.

The sidewall 14 also includes a stacking recess 32 formed in the sidewall 14 and the roof 24. The stacking recess 32 facilitates stacking of each lid 10 on top of each other and prevents the lids 10 from stacking together when not stacked.

The engagement track 48 is positioned in fig. 1 so as to span the aligned drink aperture 36 and post aperture 82 a distance sufficient to define a shoulder region 50 therebetween. Shoulder region 50 is visually distinguishable from the remainder of the top wall (not shown) and is therefore adapted to receive indicia or the like thereon. The engagement track 48 is formed such that the substantially planar outer surface 22 includes a smooth arcuate transition surface 52 at the outer wall of the track terminating in a flat bottom surface 54, the flat bottom surface 54 having a channel 56 opposite the transition surface 52. The channel 56 is bounded by a substantially vertical wall 58 terminating at the shoulder region 50. Thus, when viewed from outer surface 22, engagement track 48 appears to have a channel 56 hidden under the longitudinal undercut edge of shoulder region 50 in top wall 16. The height of the post 82 is only slightly greater than the height of the roof 24 above the surface 22. This feature is suitable for cup stacking on lids as described above and lid stacking as further described herein. The crown 24 is rounded at its top to facilitate improved ergonomics of the hemispherical member 12 and to make contact with the user's lips more comfortable. For example, a radius R1 of about 0.050 inches could be used for the crown 24. The post 82 has opposite longitudinal engaging edges 76.

Referring to fig. 2, a cover 150 constructed in accordance with the present invention is shown. The lid 150 has a closure plate 152 and a dome 154 with a pair of opposed scalloped engagement tracks 156, 158. The scalloped engagement rails 156 and 158 have undercut grooves along the longitudinal scalloped geometry. As discussed herein, the scallops facilitate the release of the product from the mold and may have a radius of curvature of from about 0.125 to about 0.30 inches or from about 0.15 to about 0.25 inches. The scalloped geometry also facilitates a deeper undercut groove as shown in fig. 2, which is a partial cross-sectional view of the area along line 13-13 where the dome projects most inwardly.

As shown in fig. 3, undercut groove 160 has an undercut depth 162 of about 30 to about 50 mils or so; the maximum depth is discontinuous with the lesser depth. Other possible configurations for undercut depth are presented herein.

Referring to fig. 4 and 5, the closeout plate 190 is shown with chamfered edges 192, 194, the chamfered edges 192, 194 being more readily understood by reference to fig. 5, which is a partial end view of the plate 190.

Plate 190 has an upper central surface 196 that changes direction downwardly at a chamfer angle 198, which may be any suitable angle, such as about 10 degrees or a suitable angle.

Fig. 6 shows another embodiment of the invention in which the undercut groove of the engaging track of the scallops is shaped like a modified "S" having a generally squared off corner at 202. As with other figures discussed herein, 200 is an undercut groove that substantially defines an engagement track and 202 is an undercut depth.

FIG. 7 illustrates a closure plate 204 having features of the present invention. The closure plate 204 includes post apertures 140. The reservoir 206 includes a drain hole 208 that drains any beverage (not shown) remaining in the closure plate 204 by leaking through an engagement track (not shown) of the skirt-like lace of a corresponding lid component (not shown). The closure plate 204 also includes lock tabs 210 that mate with corresponding lock tab engagement portions 212 (shown in FIG. 9). The closure panel 204 also includes a drink aperture sealing contour 214 having an outer region 216, the outer region 216 corresponding to the contour of a drink aperture (not shown) of an associated lid member (not shown).

Fig. 8 shows a side cross-section of the closure plate 204 of fig. 7.

Fig. 9 shows a lid component according to the invention with a raised drinking aperture 214. The drinking aperture 214 is open to the container (not shown) to facilitate drinking of a beverage (not shown) contained therein when the corresponding closure panel (not shown) is in the open position.

Although the invention has been described in conjunction with a number of features, variations to these examples within the scope of the invention will be apparent to those of skill in the art. In view of the foregoing description, the relevant knowledge in the art, and the above-mentioned references and detailed description in connection with the background art, the disclosures of which are incorporated herein by reference, further description is not necessary.

Claims (11)

1. A reclosable, disposable lid for a cup comprising:

a) a thermoformed cover member having a sidewall adapted to engage the rim of a cup, the cover member comprising:

i) a sidewall adapted to engage a rim of a cup; and

ii) a top wall having an upper side and a lower side, wherein the top wall comprises:

1. a drinking aperture in the periphery of the top wall; and

2. a pair of spaced apart, substantially parallel engagement tracks, wherein the tracks are longitudinally disposed on an underside of the top wall, each track comprising a scalloped configuration and an undercut depth that cooperate to provide a scalloped engagement track; and

3. a column hole opening at an end of the cover member in a direction opposite to the drinking hole;

b) a thermoformed closure panel having a post and a top surface and a bottom surface, wherein the closure panel is insertable into the engagement track of the skirt by applying a bending force to the lid member adapted to widen the distance between the tracks such that the closure panel is inserted into the engagement track of the skirt such that the post projects upwardly through the post aperture opening, wherein at least one discharge aperture is provided in one or both of the lid member and the closure panel, the closure panel comprising a reservoir adapted to collect beverage that leaks into the area of the engagement track of the skirt from a container engaged with the reclosable cup lid, thereby providing a reclosable disposable lid.

2. The lid of claim 1, wherein the engagement track of the skirt does not include a C-shaped rail.

3. The lid of claim 1, wherein the first ejection aperture is located within a boundary of the reservoir on the closure plate, the first ejection aperture including a barb directed toward the bottom surface of the closure plate.

4. The lid of claim 1, wherein the lid component and the closure panel each include at least one discharge aperture, the discharge aperture of the lid component including a barb directed toward a top surface of the lid component, the closure panel including a barb directed toward a bottom surface of the closure panel.

5. The lid of claim 1, wherein the closure panel includes a panel locking profile at a location forward of the post aperture, and the lid component includes a lid component locking profile, the panel and lid component locking profiles being configured to cooperate with each other, whereby a locking mechanism is provided in the lid to substantially prevent the closure panel from being opened and disengaged by a user.

6. The lid of claim 5, wherein the locking profile of the closure member has a height of from about 0.020 to about 0.040 inches.

7. The lid of claim 1, wherein the reservoir includes a drain hole within the confines of the closure plate.

8. A reclosable, disposable lid for a cup comprising:

a) a thermoformed cover member having a sidewall adapted to engage the rim of a cup, the cover member comprising:

i. a sidewall adapted to engage a rim of a cup; and

a top wall having an upper side and a lower side, wherein the top wall comprises:

1. a drinking aperture in the periphery of the top wall;

2. opening the column hole;

3. a top wall locking profile; and

4. a first discharge orifice including a first barb directed toward an outer surface of the cover component;

b) a thermoformed closure panel comprising:

i. a post projecting upwardly from the closure plate, wherein the post is configured to project upwardly through a post aperture opening;

a reservoir adapted to collect liquid contained within the container, where the liquid is retained in the region of the closure panel by splashing out of the container during transport or consumption of the beverage;

a second vent comprising a second barb directed toward the underside of the closure plate, wherein the vent is optionally located within the confines of the reservoir; and

a closure panel locking profile configured to interfit with the top wall locking profile;

wherein the locking profiles cooperate to provide locking of the closure panel components to substantially prevent the closure panel from being opened without operation by a user, wherein the locking mechanism allows the user to operate the closure panel substantially with one hand, the discharge aperture in the reclosable cup lid being substantially misaligned when the lid is in the open or closed position.

9. The lid of claim 1, wherein the engagement track of the skirt does not include a C-shaped rail.

10. The lid of claim 5, wherein the locking profile of the closure member has a height of from about 0.020 to about 0.040 inches.

11. The lid of claim 1, wherein the vent hole is located in the reservoir.