Patent Grant
7685685
The present invention is directed to a child seatbelt assembly with a child resistant buckle and, in particular, to an improvement in the type of buckle commonly used in many children's safety seats, strollers, baby carriages, shopping cart seat belts, etc. A prior art buckle for use with a seatbelt assembly is made, for example, by Illinois Tool Works (ITW) and others and is well known. Referring to
Others have attempted to provide a child resistant buckle for use with a seatbelt assembly. For example, see Gallbreath, U.S. Pat. No. 5,991,985 which provides a third fastening element and includes a depressable button to allow the third fastening element to be undone. This buckle is cumbersome because it requires that the user learn an additional motion in order to undo the buckle, i.e., the user must at the same time depress the side latches and the center button to undo the buckle and release the seatbelt strap.
Retainer strap seatbelt assemblies with conventional buckles are disclosed in U.S. Pat. Nos. 6,101,687 and 6,101,690, which are incorporated herein by reference in their entireties. These seatbelt assemblies are typically used in shopping carts to help restrain children in the carts and prevent injury. However, the buckles in these seatbelt assemblies are not designed to be child resistant to any certain extent.
Indeed, no readily adoptable standard for child resistant buckles is presently available. However, because of the importance of providing a child resistant buckle, it would be desirable to provide a buckle that is not easily opened by children under a certain age, for example 4 years old, but is readily opened by adults or older minors, for example, of 16 years of age or older.
An example of a child resistant buckle in a seatbelt assembly is found in U.S. patent application Ser. No. 10/081,353, the entire disclosure of which is hereby incorporated into the present application by reference. The buckle includes a number of features to increase the child resistant properties of the buckle. However, there is no readily available data that suggests one design is more appropriate for providing child resistant properties than another design.
Moreover, when the types of buckles and straps described above are used in an environment where the buckles are typically subjected to high impact and compression forces, the buckle can be damaged. A typical application for the buckles and straps are on child safety restraints, or seatbelts, used on grocery shopping carts. When carts are nested together with one another for storing large numbers of carts easily, for example, the buckles can be caught between the carts and can be subjected to high impact and compressive forces. Impact forces like these tend to cause the buckle to crack or even shatter. Compressive forces can deform the buckle beyond a point of elastic resilience, resulting in an unworkable buckle. In addition, if it is desired that the buckle exhibit certain features, such as child resistance, the forces applied to the buckle should not disrupt the desired features.
In addition, the seatbelt assembly is sometimes misused in connecting grocery carts together, for example, to tow a number of carts together. These occasions of misuse can produce high tensile strain on the buckle, causing the buckle to fail and resulting in damage to buckle components.
It is an object of the present invention to overcome the drawbacks associated with the prior art.
It is a further object of the present invention to provide a seatbelt assembly with a child resistant buckle while maintaining design and operating features similar to those provided in the prior art and simplicity of operation.
It is a further object of the present invention to provide a seatbelt assembly that is resistant to high tensile, impact and compressive forces.
Briefly stated, according to the present invention there is provided a seatbelt assembly with a buckle with male and female mating parts, in which the male and female parts include features to prevent disengagement operation by a child. The child resistant features include added ribs, webbing in the form of flanges or struts, or barbs or prongs that increase the difficulty for disengaging the buckle. The force to disengage the buckle is set at a threshold level that is above a force level that a child can exert on the buckle. The buckle can be operated easily by an adult, while remaining secure from disengagement by a typical child. The female part has an arcuate outer profile to improve the structural integrity of the overall buckle. Both the male and female parts can have thickened portions to permit the seatbelt assembly to be child resistant, while improving resistance to tensile, impact and compressive forces. A gap between the male and female buckle parts serves to enhance the child resistant characteristics of the buckle.
a is a plan view of a conventional male and female mating connector;
b is an end side view of a conventional female connector;
The present invention provides a simple child resistant buckle with design and operating features that are substantially the same as the prior art buckle made by ITW and others for use with seatbelt assemblies so that no new operating procedure need be learned. The buckle is resistant to tensile, impact and compressive forces, and is operated conventionally to undo the buckle and is thus more easily used by consumers. In contrast to the prior art ITW buckle, however, the amount of force required to undo the buckle is increased, thereby preventing young children from undoing the buckle. Referring to
Referring now to
Strap retainers 16 and 16′ permit strap portions 120, 140 to be fastened to a shopping cart without the use of tools. Any type of retainer mechanism including clasps, rings and loops can be used. The retainer mechanism should not be considered to be so limited, however, and need only function to attach strap portions 120, 140 to an object. For example, the retainers can be permanently attached to strap portions 120, 140, or can be removably attached. Also, the retainers can be produced separately from assembly 110, and provided with straps 120, 140 to be assembled on site, for example. Assembly 110 can be adjusted with a known belt adjuster 33.
Referring now to
While conventional buckles have a wall thickness of less than about 0.07 inches, the buckle according to the present invention preferably has a wall thickness range of from about 0.07 inches to about 0.14 inches. The additional wall thickness provides significant increases in resistance to stress and external forces. Accordingly, the design of connector part 62 also resists deformation that can occur with applied compressive forces. Because of the greater resistance to external forces exhibited by connector part 62, a more substantial male connector part can be used. Use of more substantial male connector can increase overall resistance of the buckle to external tensile, impact and compression forces. A more substantial male connector can also further assist the child-safety feature of the present invention and provide a more robust and longer lasting seatbelt assembly.
It should be clear that the embodiment shown in
While
Each of the above described features for increasing the compressive force resistance of the prongs on male connector 20 all have the same goal of providing a child resistant buckle. Each of the above described features accomplish this goal in different ways, however, the overall affect is to increase the pressing force applied to the prongs of male connector 20 to disengage the buckle. One of the factors that becomes important in adopting a buckle design to increase an applied force sufficient to disengage the buckle is repeatability under stress. That is, the design should be able to provide a threshold pressing force on a consistent basis, even when subjected to compressive and impact forces that are somewhat typical of buckles in an ordinary shopping cart environment, for example.
Accordingly, the improvements to the connector 30 serve to preserve the tolerances of the buckle associated with aspects of the child-resistant feature. That is, by making female connector 30 more robust and resistant to impact and compressive forces, the buckle is less likely to experience tolerance changes that may affect the child resistant feature.
A pressing force threshold level for disengaging the buckle is believed to be an effective child resistant measure that can be verified through empirical data and field studies. Provided that the threshold level is set high enough, children in a certain age range should typically be unable to open the buckle, while adults or responsible minors can easily open the same buckle.
The child resistant buckle must also be easily opened by adult individuals with typically less pressing strength. For example, an individual of age 60 or greater typically has less of an ability to apply a pressing force to disengage the buckle, than does an individual of age 30 when all other factors are balanced and taken into account. Accordingly, a child resistant buckle based on a threshold level for a pressing force must be high enough to be inoperable for a child of a given age, but still easily operable for individuals of a given age range.
In a survey conducted by Mathiowetz et al. in 1985, 310 males ages 20-94 and 318 females ages 20-94 were tested to determine pinch force ability between a thumb and index finger. The results were aggregated to obtain an average pinch force for both the male and female sample populations. The results of the survey indicated that the males exert an average pinch or pressing force of 16.93 pounds with a standard deviation of 0.918, while females exert an average pinch or pressing force of 11.36 pounds with a standard deviation of 0.582. A child resistant buckle is thus preferably openable with 10.78 pounds of force or less, provided the force is great enough to be child resistant.
In conducting an extensive and exhaustive study of the amount of pressing force able to be exerted by a child aged 4½ and younger, it was found that a certain pressing force threshold will prevent nearly all instances of undesirable operation of the buckle by a child in the above-mentioned age range. A study was conducted by Owings in 1977 to determine average maximum pinching strength of children in the age range of 3½ to 4½. The study concluded that the average maximum pinching strength for the children tested was about 5.7 pounds over a distance of about 2 cm. Over a distance of about 5 cm, the resulting strength applicable was 6.39 pounds. Accordingly, a threshold level for a 3 cm wide buckle with increased resistance to pressing force for children aged 4½ and younger should be approximately 5.93 pounds of force. Below this level, children aged 4½ and younger are increasingly able to operate the buckle as the force diminishes. Above this level, children aged 4½ and younger are typically unable to operate the buckle. With regard to adult operation, the preferable maximum amount of force to open a buckle is less than about 10.78 pounds average minimum−standard deviation), as described above. Accordingly, it would be desirable to provide a buckle with an opening force that is greater than approximately 5.93 pounds, but less than approximately 10.78 pounds.
An extensive study of available buckles has been conducted to determine whether any known buckle meets this criteria. At the end of this exhaustive study, it was determined that only one buckle met the desired criteria of child resistance with a simple and intuitive construction and operation, the buckle constructed according to the present invention. The results of the study and evaluation of pressing force to open compression fit type buckles is tabulated below in Table I.
The data in Table I is for the minimum force applied that will open the tested buckle. This number is used to gauge child resistant characteristics of the tested buckle with the view that a child would be able to apply the least amount of pressure needed to open the buckle. As can be seen from the data provided in Table I above, there is a wide range of pressing force applied to the prongs of a male member that can disengage a buckle. However, the pressing forces fall below the threshold value of approximately 5.5 pounds of force with little variation, with the exception of buckle ID SS2, a buckle made according to the present invention. Variations in the opening force among various samples of the different buckles is typically attributable to variations in manufacturing processes that produce variations in the tolerance of the buckle components. Nevertheless, the buckle according to the present invention with buckle ID SS2 consistently tests above 5.5 pounds of force for opening operation.
Accordingly, by providing a buckle that has a consistent opening force equal to or greater than approximately 5.5 pounds, the present invention is able to achieve child resistant results unmatched by any other buckle. When the buckle according to the present invention is constructed to consistently have greater than 6.0 pounds of pressing force to permit opening, the buckle should exceed the ratings at which children under the age of 4½ are able to open the buckle. As can be seen by the sample date, the force for buckle ID SS2 meets this criteria. Thus, the buckle according to the present invention is consistently child resistant, where other buckles are unable to provide such a feature.
In studies to validate the child resistance of the buckle according to the present invention, in which a pressing force of approximately 5.5 pounds or greater would disengage the buckle, only about 4% of children under the age of 4½ years were able to successfully operate the buckle. As an example, the buckles were found to be 96% child resistant to children ages 48 months and younger in a group of 50 children. The buckle design according to the present invention is, however, easily openable by adults who are typically easily able to exert a force of about 10 pounds to disengage the buckle. The applied force is developed as a pinching force against the two prongs so that both prongs are disengaged from the female member.
Another child resistant feature for the compression fit type buckles discussed herein is obtained by varying a width of the buckle in conjunction with pressing force. That is, it is more difficult for a child to pinch the prongs of a narrow buckle with enough leverage to exert pressure sufficient to open the buckle than it is for a wide buckle. Accordingly, as the width of the buckle decreases, the force threshold to make the buckle child resistant also decreases, making the buckle easier to operate for adults, while still being child resistant. Conversely, as the buckle width increases, the force threshold for child resistance increases. Several prior art buckles have typically greater widths than the buckle according to the present invention, however, pressing force des not increase with width in these prior art buckles. Accordingly, not only are the wider prior art buckles more susceptible to being opened by a child, they do not meet the threshold for child resistance according to the present invention. As an example, one buckle measures 4.0 cm, and has an average minimum opening force of 5.6 pounds. The greater width and opening force combine to decrease the child resistance available in the buckle design.
Referring now to
In conventional buckles, gaps 102 do not exist, or are insufficiently large enough to accommodate a child's finger. Accordingly, a child pinching a set of conventional barbs is able to exert greater pressure on the barbs, even if the child's fingers slide towards ends of the barbs, because the child's fingers do not come to rest at a disabling portion of the clasped buckle. Rather, in the conventional buckle, the child will find support for their fingers in the sloped side wall of the female member that is close enough to the barbs to permit the child to exert leverage on both the sloped side wall and the prongs to achieve an opening force sufficient to unclasp the buckle.
The embodiment shown in
When a child attempts to pinch barbs 14 together to unclasp the buckle, and the child's fingers slide into gaps 102, the child still may be able to exert a force near pointed portions 104 in an attempt to displace barbs 14 to unclasp the buckle. However, because barbs 14 move in an arcuate path, even if the child is successful in displacing barbs 14 towards each other with a pinching force, because the force is applied in proximity to gap floors 206 of gaps 102, the arcuate path of barbs 14 causes pointed portions 104 to move closer to each other at a greater displacement than catches 210 on barbs 14. Accordingly, even thought the child can compress pointed portions 104 together, catches 210 remain securely positioned on shoulders 112 of female connector 30. In contrast, an adult is easily able to compress barbs 14 together by applying pressure at a location away from pointed portions 104 to sufficiently displace barbs 14 so that catches 210 are disengaged from shoulders 112, and the buckle is released. Even if an adult's fingers slides down slopes 108, and into gap 102, the pressing force exerted by the adult is capable of displacing barbs 14 sufficiently to open the buckle. In addition, an adult's fingers are typically larger in diameter than a child's fingers, permitting the adult to provide a greater displacement on barbs 14, even when the adult's fingers are in gaps 102.
Referring now to
With respect to finger size, even though both child and adult fingers 124, 126 substantially slide into gaps 102, child finger 124 is totally within a nonfunctional zone 122, as indicated with dashed divider line 128. Adult finger 126, however, overlaps barb 14 to lie within a functional zone 220. Because adult finger 126 is able to move barb 14 in functional zone 220 because of an appropriate sizing, an adult can open the buckle, where a child cannot. In addition, child finger 124 is prone to landing in gap 102, which is completely in non-functional zone 122, through the action of slopes 108. A child is thus unable to get a good grip on barb 14 due to lack of a stable landing or footing for child finger 124 on barb 14. Furthermore, slot walls 106 tend to help an adult secure a footing in pressing barbs 14, since adult finger 126 is large enough to abut slot wall 106 while remaining at least partially in functional zone 220.
It should be apparent that non-functional zone 122 can be tailored to a given application. For example, gaps 102 can be eliminated but non-functional zone 122 can remain the same. That is, a child may depress barb 14 in non-functional zone 122 when there is no gap 102 provided, however, that barb 14 will not displace sufficiently for the buckle to open.
Gap 102 can be created a number of ways, for example by extending female connector 30, or shortening male connector 20. Slot openings 202 on either side of female connector 30 can be made deeper or shallower, or have a contour to assist in disabling the buckle for child fingers. For example, slot openings 202 can be shallower in nonfunctional zone 122, while deeper in functional zone 220 to further enhance the child resistant functions and features.
The invention thus provides a simpler, more intuitive way of providing a child resistant buckle for a seatbelt assembly that utilizes the same releasing actions as in the prior art buckle so that consumers will be accustomed to its use the first time it is used. The buckle only requires that a greater force be applied to undo it and release the seatbelt assembly. The force required should be enough so that the buckle is incapable of being undone by a typical child but can be operated by the children's parents or guardians or other adult supervisors.
The female connector of the present invention can absorb greater external forces, and results in a more robust design overall. With a stronger female connector according to the present invention, a stronger male connector can also be used, effectively improving child-resistancy of the seatbelt assembly without adding further complexity. The arcuate shape of the female connector part surfaces achieves greater strength while avoiding a large increase in the amount of material needed.
Although ribs, struts, webs, flanges and enlarged barbs are shown for the male connector, other embodiments can be developed which are in accordance with the concepts disclosed herein. Although arcuate surfaces are shown for the female connector, other embodiments including those described hereinabove, can be developed and applied that are in accordance with the concepts disclosed herein. Further, combinations of the above embodiments can be provided. Further, the enlarged prongs or barbs of
When the buckle is composed of ST801 in formulations of 50% or greater, the buckle tends to be easier to operate, i.e., less pressing force is needed to open the buckle. Accordingly, the buckle design is modified to increase pressure force to open the buckle when ST801 in formations of 50% or greater is used as the buckle material.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.
This application is a Continuation-In-Part of application Ser. No. 09/952,070, filed Sep. 13, 2001 now U.S. Pat. No. 6,604,265, entitled CHILD RESISTANT BUCKLE, and is based upon and claims benefit of Application No. 60/232,546, filed Sep. 14, 2000, entitled CHILD RESISTANT BUCKLE, and is based upon and claims benefit of application No. 60/421,532, filed Oct. 28, 2002, to each of which a claim of priority is hereby made.
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| Number | Date | Country | |
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| Parent | 09952070 | Sep 2001 | US |
| Child | 10639964 | US |
