Buckle with safety latch

The plastic snap buckle is provided with a safety latch slidably mounted to an elongated bar of the male plug of the buckle. The latch member is generally rectangular shape having a length equal to the distance between two arcuate portions formed in the free end portion of two flexible arms of the male plug. The latch member may be slidably to locate between the arcuate portion of the flexible arm so as to prevent the flexible arms to be operated inadvertently or forcefully to release the engagement between the male plug and the female receptacle.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to plastic snap buckles and more specifically relates to a snap buckle with a safety latch to prevent it from accidental release.

2. Background of the Invention

Plastic snap buckles are widely used for securing mounting belts for a large variety of bags and harnesses. Such snap buckle consists of a male plug and a female receptacle. The male plug is mounted to the end of one belt and the female receptacle is mounted to the end of the other belt such that the male plug and the female receptacle may be slidably engaged with one another to secure the two belts together. The male plug has two flexible arms which will engage with two side openings in the female receptacle when the male plug is slidably inserted into the female receptacle. To release the engagement, the flexible arms are pushed and held inwards towards one another while pulling the male plug away from the female receptacle. The engagement and release may be executed easily and quickly. Such plastic buckles are convenient to use and may be produced with relatively low cost. However, the buckle may become released accidentally when the flexible arms of the male plug are pushed in inadvertently either by hand or by abutting to other objects. More often, due to wear and tear in use, the engagement of the two components becomes less positive and it may be disengaged by a slight force exerted to the flexible arms of the male plug. Furthermore, when such buckle is used on the securing belt of a waist bag or wallet, the latter may be easily removed by some one forcibly gripping the flexible arms of the male plug to release the buckle to remove the worn bag. Thus, it becomes rather unsafe to use the buckle for such purposes. To prevent such forcible release and removal, safety latch may be provided in the buckle. However, theretofore, the safety latch constructions are rather complex in structure and are difficult to operate or the safety latch may itself be accidentally unlatched.

SUMMARY OF THE INVENTION

It is a principal object of the present invention to provide a snap buckle having a safety latch which operates effectively to prevent accidental or unintended release of the buckle.

It is another object of the present invention to provide a snap buckle having a safety latch which is itself protected from inadvertent release.

It is another object of the present invention to provide a snap buckle having a safety latch which is simple in structure yet is easy to operate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to the drawings in which like reference numerals designate corresponding parts in the several views, the snap buckle10of the present invention includes a male plug11and a shell-like female receptacle12which may engage with one another for securing two belts together. The male plug11has a main frame13with an end mounting bar14adapted for mounting to an end of one belt and the female receptacle12also has an end mounting bar15adapted for mounting to an end of the other belt. These belts may be harness belts for mounting a carrying bag or a waist wallet or the like to a person. Two parallel spaced flexible arms17and18extend outwards from the main frame13opposite to the end mounting bar14. The free ends of the flexible arms17and18have enlarged arcuate portions19and20respectively extending inwards towards one another and two rearwardly facing hooks19A and20A are formed on the outer side of the flexible arms17and18adjacent to the rear end of the arcuate portions19and20. An elongated bar21is located at the middle of a cross bar22of the main frame13opposite to the end mounting bar14and equally spaced from the flexible arms17and18. An elongated open slot23is formed in the center portion of the elongated bar21.

A generally rectangular latch member24is slidably mounted on the elongated bar21. The latch member24has an inverted T-shaped pin25located at its bottom surface. The inverted T-shaped pin25slidably engages with the open slot23for mounting the latch member24on the elongated bar21such that the latch member24may be slidable relative to the elongated bar21. The latch member24has a length equal to the distance between the arcuate portions19and20of the flexible arms17and18so that when the latch member24is slidably located at the position between the arcuate portions19and20of the flexible arms17and18, it prevents the flexible arms17and18from being pushed inwards towards each other. It can be appreciated that the latch member24may alternatively be oval, triangular or multi-sided in shape to provide the same function as long as it has a length equal to the space between the arcuate portions19and20of the flexible arms17and18. The latch member24has a flexible extension arm26which normally extends rearwards parallel to the elongated bar21and it is flexible in the up and down directions relative to the elongated bar21in a cantilever manner. A raised button portion27is formed at the end portion of the upper surface of the extension arm26.

The female receptacle12has a shell-like body with two arcuate openings28and29formed at its two sides. The shell-like body has an upper wall30and a lower wall31. The male plug11may be inserted into the female receptacle12through its front opening32until the hooks19A and20A of the male plug11engage with the rear edge of the arcuate opening28and29in a snap action to retain the two parts together.

An elongated slot opening32formed at the central portion of the lower wall31parallel to the central longitudinal axis of the female receptacle12. The width of the slot opening32is equal to the width of the raised button portion27of the extension arm26such that when the male plug11and fully inserted into the female receptacle12the raised button portion27is slidably engaged with the slot opening32. During the insertion of the male plug11into the female receptacle12the extension arm26is bent in a cantilever manner by the inner surface of the female receptacle until the raised button portion27engages with the slot opening32in a snap action to position slightly below the lower wall31of the female receptacle12. After the male plug11and the female receptacle12have locked together in a snap action with the arcuate portions19and20of the male plug11engaged with the arcuate openings28and29, the latch member24may be moved forward slidably to the position between the arcuate portions19and20by pushing the raised button27so as to prevent the flexible arms17and18from being pushed inwards towards each other to release the engagement between the male plug11and the female receptacle12. The buckle10may be released only by sliding the latch member24forward to the position away from the space between the arcuate portions19and20of the flexible arms17and18of the male plug11so that the flexible arms17and18may be squeezed inwards to disengage from the arcuate openings28and29in order the male plug11and the female receptacle12may be pulled apart from the locked engagement. Since the raised button27of the latch member24is located in the slot opening26at the lower wall31of the female receptacle12, it is not accessible unless the buckle10is turned over upside down. As the belt is tightly mounted to the body of the person, such action is difficult to carry out without the cooperation of the person wearing the device. Thus, it prevents the latch member24from being inadvertently operated by abutting to other object or the buckle being operated forcibly to remove the device worn by the person.

While the present invention has been shown and described in the preferred embodiment thereof, it will be apparent that various modifications can be made therein without departing from the spirit or essential attributes thereof, and it is desired therefore that only such limitations be placed thereon as are imposed by the appended claims.