Patent Application
20090106945
The present invention relates generally to the field of holding devices intended for securing napkins, bibs and the like about a person's neck, particularly that of a dental patient. More specifically, the present invention pertains to an adjustable napkin clip assembly which is comfortable to wear, easy to use and constructed for either disposable or reposable use to maximize efficiency through savings of time, and to minimize the potential for the spread of bacteria.
The use of napkins or bibs to protect a person's clothing is widely known in both household and professional applications. Conventionally, it has been known to secure the napkin to the front of one's clothing by means of some sort of a napkin clip. In the field of dentistry, a ball and link neck chain with terminal metal napkin clips is commonly used to secure the napkin in place. The use of such napkin clip assemblies has been criticized, however, in that they can be a significant source for the development of bacteria and infectious disease. Dental detritus and other bacteria become easily lodged between the ball links of the chain and napkin clips, thus requiring time-consuming re-sterilization procedures between uses. This has become a growing concern for all dental care providers. In fact, OSHA regulations now require that contaminated napkin dental clips be disinfected immediately after each use so as to avoid the possible spread of bacteria.
The conventional napkin clip assembly with a ball and link neck chain is also uncomfortable and inconvenient to use. The metal chain and clips are cold to the touch upon a person's neck, and often become tangled with neck hair when applied or removed. This results in painful pulling and uprooting of the neck hair. Before re-sterilization of the assembly can even begin, the tangled hair must be removed, thus requiring additional costly staff time.
There is also no means for ready adjustment of the napkin around a patient's neck. Aside from tediously disengaging the ball and link chain from each napkin clip and reconnecting the same, the length of the chain extending around the patient's neck is basically incapable of adjustment. Therefore, depending on the size of the patient's neck, the conventional ball and link dental napkin clip assembly is oftentimes too tight or loose around the neck, thus adding to its discomfort and hindering its ability to properly cover the patient's clothing.
Attempts have previously been made to enhance the comfort and convenience of such dental napkin clip assemblies, but none have heretofore solved all of the above deficiencies. For instance, in one known assembly, the ball and link chain has been replaced with a flexible smooth tubular member that fits over the ends of each terminal napkin clip. While this increases the comfort level to the patient, the metal napkin clips still require sterilization between uses, and there is no means for adjustment by the dental care provider. In another device, described in U.S. Pat. No. 5,414,903 (Porteous), a single use, plastic disposable dental bib holder assembly is provided which eliminates the need for sterilization. Again, however, this device provides no means for adjusting the position of the napkin clips on the neck strap so as to properly position the napkin for patients having larger of smaller neck sizes.
From the foregoing, it is evident that there is a distinct need for a napkin clip assembly which provides comfort and ease of use to the user, is readily adjustable for proper positioning of the napkin, and which is durable and cost efficient to produce, thereby facilitating disposable or reposable use thereof. It is with these objects in mind that we have developed the present invention, which is described and claimed in detail hereafter.
In the present invention, an adjustable napkin clip assembly is provided which includes a pair of integrally formed one-piece napkin clips adjustably carried at opposite end portions of an elongated elastic cord that is intended to extend around the nape of a person's neck. Each napkin clip is integrally molded from a relatively rigid, yet flexible, resilient plastic material to form a pair of interacting jaws which are flexibly interconnected at a hinged joint to facilitate movement relative to one another between established open and closed positions.
In a preferred embodiment, each napkin clip is configured the same. The napkin clips are each generally oval-shaped (but may be of other general configurations) with opposite end portions located on their major axis and connecting side portions extending therebetween. One of the jaws of each napkin clip comprises an outer flexible frame which surrounds the other inner jaw of the clip. At one end portion of the napkin clip, the inner jaw is integrally molded to the outer surrounding jaw to form a flexible hinged connection therebetween. The inner jaw is molded at an angle relative to the outer jaw, thereby resiliently biasing the jaws in an open position relative to one another so as to facilitate easier/quicker insertion of the napkin therebetween. At the opposite end portion of the clip, the inner and outerjaws are constructed to cooperatively interlock upon closure to pinch and hold the napkin in place between the jaws.
Along the side portions of each napkin clip and between opposite end portions thereof, the frame of the outer jaw is slightly spaced from the inner jaw. This spacing between jaws permits the frame of the outer jaw to be squeezed inwardly, which causes a slight elongation of the outer jaw to assist in the disengagement of the interlocked j aws and consequent release of the napkin. The opposing side portions of each jaw also converge slightly inwardly toward one another to form a convenient location to grasp the clip with one's fingers. The converging portions of the outer surrounding jaw include a plurality of minor protrusions which aide in gripping the napkin clip between the user's thumb and fingers.
A fastening mechanism adapted to slidably receive and frictionally engage the elastic cord is integrally formed in the outer surface of the inner jaw of each napkin clip. In a preferred embodiment, this fastening mechanism is formed as an elongated channel member extending longitudinally between opposite end portions of the clip. The channel member has sidewalls which are designed to pinch and hold the elastic cord in place within the channel so as to facilitate sliding positional adjustment of the clip along the length of the cord. A portion of the channel sidewalls preferably include a plurality of inwardly protruding ribs designed to engage the elastic cord and further facilitate frictional engagement thereof.
The elastic cord of the napkin clip assembly may be comprised of an extruded solid or tubular member, formed of a flexible plastic material. Although the use of rubber and other various elastomers of suitable tensile strength are certainly contemplated, the elastic cord is preferably constructed of a material that will more readily facilitate slidable engagement within the fastening mechanism of each napkin clip. Materials such as flexible polyvinylchloride (PVC), vinyl or thermoplastic elastomer (TPE) are contemplated as being suitable for this purpose in that they are generally less sticky and have a lower coefficient of friction than rubber materials. Therefore, the napkin clips will slide more easily on the cord. Moreover, the smoother cord will reduce pulling of the neck hairs of the user.
In use, each terminal end of the elastic cord is simply pressed into the frictional fastening mechanism of a napkin clip with the jaws thereof opening toward the terminal end. The cord is then positioned about the nape of a person's neck in a conventional manner, and a napkin is inserted and pinched between the interlocking jaws of each clip. With relative ease, each clip may then be slidably adjusted on the cord for proper positioning of the napkin.
The present invention provides a low cost, durable and easy-to-use alternative to the costly conventional ball and link napkin clip assembly. Each of the napkin clips are integrally formed as one-piece disposable or reposable plastic units that are adjustably carried and readily removable from an equally low cost, disposable or reposable elastic neck cord. This not only facilitates ease of use, but also helps to prevent the accumulation of harmful and infectious bacteria, and provides enhanced comfort to the user.
These and other objects and advantages of the invention will more fully appear from the following description, made in connection with the accompanying drawings, wherein like reference characters refer to the same or similar parts throughout the several views, and in which:
With reference to
As shown and discussed herein, in a preferred embodiment of the invention, napkin clips 3 and 5 are configured and function identical to one another. Therefore, for ease of illustration, the following discussion will describe in detail the construction and function of napkin clip 3 only, it being understood that the construction and function of napkin clip 5 is intended to be the same. As shown in
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At end portion 35 of napkin clip 3, the inner and outerjaws 13 and 15 are constructed to be freely movable relative to one another but capable of cooperative interlocking engagement upon closure to pinch and hold the napkin 19 between jaws 13 and 15. As shown best in
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In the embodiment shown, napkin clip 3 be configured to be somewhat elongated and generally oval-shaped, having opposite curved end portions 21 and 35 located along its major axis, with connecting side sections 31 and 33 of the outerjaw 15 extending therebetween so as to define the outer confines of the napkin clip 3. In order to facilitate easier handling and operation of napkin clip 3, each of the side sections 27, 29 and 31, 33 of jaws 13 and 15, respectively, curve slightly inwardly so as to converge toward one another near their mid-section, thereby forming a convenient location to grasp the napkin clip 3 with one's fingers. The converging portions 55 and 57 of the outer surrounding jaw 15 include a plurality of minor protrusions 59 which further aide in gripping the napkin clip 3 between the user's thumb and fingers, as shown in
As noted previously, each napkin clip 3 and 5 are preferably integrally-molded as one-piece units from a relatively rigid, yet flexible, resilient plastic material to form interacting jaws 13 and 15. This helps to facilitate proper locking interengagement and disengagement of jaws 13 and 15, as described heretofore. In a preferred embodiment, it is contemplated that napkin clips 3 and 5 be formed of a thermoplastic material with high enough elongation at break (Tensile elongation corresponding to the point of rupture) to allow the material at the point of hinge 23 to deform without failure. Although 50% or greater elongation at break is deemed preferable, it could be less, provided the jaws 13 and 15 can be repeatedly worked without failure.
Additionally, the material utilized in the formation of the napkin clips 3 and 5 should also be resilient enough that it will not undergo mechanical yield failure when torque is applied to the hinged joint 23, since it is important that the jaws 13 and 15 of each napkin clip 3 and 5 rebound to about their initial position at rest when unsnapped and released from interengagement. Since movement of jaws 13 and 15 tend to cause the clips 3 and 5 to deform as torsion springs, it has been found that the clip material is best described in terms of its flexural modulus, which characterizes the material's ability to resist deflection under a bending load. While the use of a thermoplastic material having a flex modulus as low or lower than about 0.7 Gigapascal (GPa) is possible, for best results, it is contemplated that the napkin clip material preferably have a flex modulus of approximately 1.5 GPa, or greater, in order to achieve reliable engagement of jaws 13 and 15 during use, and the desired flexibility and resiliency thereof.
As shown in the drawings, the elastic cord 11 of the napkin clip assembly 1 is preferably comprised of an extruded solid or tubular member, having a tensile strength suitable to ensure its structural integrity and prevent breakage upon pulling the same through the channel member 45 of napkin clips 3 and 5. For purposes of the present invention, it is deemed preferable that the cord 11 be capable of supporting a ten pound (10 lb) load without failure, although it is certainly possible that a cord of lesser strength could still function adequately, provided it does not break upon pulling the same during use. By way of example, for a 0.07 inch diameter cord to support a 10 lb load, a tensile strength of at least 2600 PSI is preferred.
Although the elastic cord may be formed of rubber or other elastomeric materials of greater friction, in a preferred embodiment, it is deemed desirable that the elastic cord 11 be formed of a flexible plastic material that is readily slidable within the channel member 45 of napkin clips 3 and 5. Materials such as flexible polyvinylchloride (PVC), vinyl or thermoplastic elastomer (TPE) having the desired strength characteristics are contemplated as being suitable for this purpose in that they are generally smoother, less sticky and have a lower coefficient of friction than rubber materials. Consequently, the napkin clips 3 and 5 will slide more easily on cord 11, and the smoother cord 11 will reduce pulling of the neck hairs of the user.
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With relative ease, each napkin clip 3 and 5 may then be slidably adjusted on the cord 11 for proper positioning of the napkin 19. With reference to
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Disengagement of the napkin 19 from napkin clips 3 and 5 may also be accomplished with relative ease. As shown best in
Although the napkin clips 3 and 5, and the cord 11, are each constructed as one-piece, low-cost moldable units which may be readily disposed of after a single use, the entire napkin clip assembly 1 is also designed for reposable use, if desired. As is perhaps most evident from
It is evident from the above that the present invention provides a low cost, durable and easy-to-use alternative to the costly conventional ball and link napkin clip assembly. Each of the napkin clips 3 and 5 of the present invention are integrally formed as one-piece disposable or reposable plastic units that are adjustably carried and readily removable from an equally low cost, disposable or reposable elastic neck cord 11. The use of such a smooth elastic cord 11 not only facilitates easy slidable adjustment of the napkin clips 3 and 5, but also helps to prevent the accumulation of harmful and infectious bacteria, and provides enhanced comfort to the user.
It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the parts without departing from the scope of the invention which comprises the matter shown and described herein and set forth in the appended claims.
