Abstract:
A quick release buckle particularly for use on backpacks including a two part body, an engagement part and a receptor part each of which include attachments for a strap or belt. The body parts telescope into engagement with one body part including a flexible finger and the other a catch. A buckle release strap is secured to the flexible finger and to the body by a snap fastener. At least one upstanding wing on a body part protects the buckle release strap from unintended release.

Description:
FIELD OF THE INVENTION 
     This invention relates to the field of carriers and more particularly to buckles and fasteners for use on backpack straps or belts in which a reliable quick release capability is required along with effective protection from inadvertent release. 
     BACKGROUND OF THE INVENTION 
     In recent years there has been an tremendous expansion of interest in the design of new and improved fasteners which has matched the expansion of the use of strap carried backpacks for adults and school children, hikers and the military. The result has been that easy release fasteners have been produced employing mating engaging plastic parts of easily moldable materials such as nylon and the acetyl resin of the type sold under the trademark DELRIN. Innovative designs have produced easy engagement buckles with acceptable reliability. 
     When the requirement of easy release is added to the design requirements, the danger of unintended release becomes a real challenge to the buckle designer. When a buckle must be released by a single hand, one or two fingers, in a matter of a second or two, the danger exists of some unintended intervening action releasing the buckle. Examples of such intervening actions are brushing against branches or structures or casual contact of a hand or an object carried with the buckle. In the case where the buckle is on a belt, there may be a loss of the entire belt and its carried equipment. In the case of buckles on a backpack strap, the unintended release at the least is a distraction which may result in a possible accident to the wearer of the backpack. In the case of military applications, quick release of a buckle may also be critical in a tactical situation where unintended release may be life threatening. 
     The need for quick release buckles, particularly for military applications, is well described in U. S. Pat. No. 5,205,021 which discloses a two part plastic buckle with a flexible tongue with an enlarged end, designed to be easily grasped by a gloved hand to release the buckle. 
     BRIEF DESCRIPTION OF THE INVENTION 
     Faced with this general need for an improved quick release buckle, we have invented a new two part telescoping, interlocking buckle body with an internal protected flexible finger which is integral with one of the two parts and engages the second part for positive locking. The two body parts include a receptor body part and an engaging body part (female and male respectively). A flexible tab is secured to the flexible finger to lift the finger and release it to allow the engaging and the receipt or strap or body parts to disengage. The flexible strap includes a snap fastener and one of the plastic parts also includes the matching snap fastener part so that the buckle can not release until the snap fastener is disengaged. The flexible strap and its snap fastener part extend through a protective channel defined by integral wings of the plastic body parts so that the strap is secure from release from any force acting from either side of the buckle. The outer end of the strap extends beyond the buckle by a short distance which is sufficient to all allow the end of the strap to be grasped by either a gloved or bare hand. 
     The snap fastener can be released only by the strap being pulled or lifted nearly normal (e.g. 70°-90°) to the face of the buckle. The first intentional action releases the strap but does not disengage the buckle so that a mere disengagement of the strap carried snap fastener from its mating part does not release the buckle. To release the buckle, a second direction of movement of the strap is required. The strap must be pulled away from the face of the buckle. These two movements can easily be learned to be combined in one natural movement. 
     If the buckle is used on a shoulder strap of a backpack, the releasing movement is a lifting up of the flexible strap to release of the snap fastener and pulling the strap away from the buckle. The buckle then releases. Engagement of the buckle involves telescoping and snapping the two snap fastener parts together in a conventional telescoping movement followed by snapping the snap fastener parts together. The protective wings also provide a second function of directing the strap into the protective channel for easy manual engagement of the snap fastener without the need to observe the strap or the snap fastener. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     This invention may be better understood from the following Detailed Description of the Invention and by reference to the drawing, in which: 
     FIG. 1 is a perspective view of a hiker with a large backpack which includes the buckles of this invention; 
     FIG. 2 is an enlarged perspective elevation view of the buckle of FIG. 1 including fragmentary portions of the straps to which the buckle parts are secured in a typical backpack shoulder strap application; 
     FIG. 3 is a perspective view of the female or receptor member of the buckle of FIGS. 1 and 2; 
     FIG. 4 perspective view of the male or engaging member of the buckle of FIG. 1; 
     FIG. 5 longitudinal sectional view of the buckle of FIGS. 1&amp; 2 taken along line 5--5 of FIG. 2. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     For a view of a strap or belt buckle, which combines the properties of effective locking and quick release, reference should now be made to FIGS. 1 through 5. In FIG. 1, a backpack BP of the type generally shown in U. S. Pat. 5,564,612 of the assignee of this invention is shown with the buckle of this invention in use. In this case, the pack is shown without a belly band. The buckle, generally designated 10, is hardly visible and constitutes an unobtrusive yet critical element of the backpack BP. As shown the backpack is on a typical hiker but a more critical application of this invention is its use on a military pack. 
     The typical hiker as shown in FIG. 1, removes a backpack BP by slipping one arm out of one shoulder strap, for example, the right shoulder strap RSS, shown in FIG. 1 followed by the second arm out of the left shoulder strap unshown in the drawing. However, in the case where instant dropping of the backpack BP is required without the several maneuvers required for traditional pack removal, the user need only grasp and pull a depending flexible strap 13, best shown in FIG. 2 of one or both the left or right shoulder strap buckles 10L or 10R in the manner described below, and the backpack BP instantly drops off behind the user. 
     An example of the buckles 10L and 10R is best seen in FIG. 2 as being made up of two basic body parts. The buckle body parts comprise a receptor or female part 11 of FIGS. 2 and 3 and an engaging or male part 12 of FIGS. 2 and 4. The buckle 10 also includes a flexible strap 13 secured to the receptor part 11 by a stitched loop 13SL and selectively secured to the engaging part 12 by a snap fastener 14, the cap 14C of which appears in FIG. 2. The strap 13 includes an overhanging end 15 for grasping and release. The overhanging end 15 extends beyond the end 12E of engaging part 12. 
     The buckle 10 body parts 11 and 12, as best seen in FIGS. 3 and 4, respectively, are reengaged merely by holding the receptor body part 11 by its sides with its receptor opening 11RO of FIG. 3 by inserting a tang 12T shown in FIG. 4 of the engaging member 12 into the receptor opening 11RO. Locking of the buckle 10, as is described below, occurs when an integral flexible finger 12F appearing in FIG. 4 engages an internal locking step 11LS and an integral stop 11S of receptor 11 as is shown in FIGS. 3 and 5. 
     FIGS. 2 and 3 also illustrate that the receptor 11 includes a pair of cross bars 11CB, one shown in FIG. 2 with the left shoulder strap LSS encircling the upper cross bar 11CB. FIG. 3 shows the second or lower cross bar 11CB. These cross bars 11CB constitute attachment means for attaching the buckle body part 11 to a strap or belt. In certain applications the upper shoulder strap LSS will encircle both the cross bars 11CB for greater strength and security. Such an arrangement appears in FIG. 5. 
     FIG. 4 shows the base 14B of the snap fastener 14 secured to the outer end region 12E of the engaging part 12 opposite the tang 12T not in FIG. 4. Of major importance is the fact that the base 14B of the snap fastener 14 is secured to the engaging part between a pair of integral wings 12W which shield the snap fastener 14 and the strap 13 from any side contact which might otherwise result in unintended release of the buckle 10. The wings 12W are smooth in surface to avoid any place for catching on branches, the user&#39;s clothing or any other interfering object. Likewise, the wings 12W extend above the top of the cap 14C of the snap fastener 14 when it is properly engaged as is shown in FIGS. 2 and 5. 
     If the user passes a finger across the wings 12W of the buckle 10, and touches the cap 14C, the user knows even without looking that the snap fastener 14 is disengaged and takes corrective action snapping the fastener 14. He is thereby warned to engage the snap fastener 14 if not intending to release the buckle 10. 
     To engage the snap fastener, the user need only press a finger, gloved or bare against the face of receptor 12 between the wings 12W and the fastener 14 will easily engage. With the snap fastener 14 engaged, the buckle 10 will not open under any but abnormal severe stressed conditions outside of any expected or recommended use. 
     Now refer to FIG. 5 which is a longitudinal vertical sectional view of the buckle 10, engaged and locked by the snap fastener 14 and secured to a shoulder strap SS made up of two parts, the upper and lower shoulder strap parts LSS. The upper shoulder strap SS engages both cross bars 11CB. The lower shoulder strap LSS engages a single cross bar 12CB and extends below the part 12 and the fastener 14 and is secured to the lower portion of the backpack CB, BP unshown in FIG. 5 but appearing in FIG. 1. 
     In FIG. 5, the buckle parts 11 and 12 are secured together by the integral resilient finger 12F in engagement with the locking stop 11LS and limited in inward travel by the integral stop 11S. The finger 12F has sufficient resiliency so that it deflects upon insertion of the tang 12T into the receptor 11 to slide over the locking stop 11LS and the tang 12T continues until it reaches the integral stop 11S of receptor 11. The finger 11F snaps back to its normal downward angle and is then securely locked against the locking stop 11LS. 
     The strap 13 encircles an integral cross bar 12FCB in finger 12F and extend toward engaging part 12 within mating wings 11W of receptor 11 and the complementary wings 12W of the engaging part 12 to be below the level of the top surface of buckle 10 throughout the length of the buckle 10. Therefore the strap 13 is protected from snagging at any part of its length between the finger 12F and the snap fastener 14 by the wings 11W and 12W. Only the strap end 15 is exposed for grasping and release. The strap end 15 is flexible and free of any rigid parts which might snag on some object. This unintended freedom from release by contact with any foreign object is an important feature of this invention. 
     Another feature of this invention is illustrated in FIG. 5 and is noted in the drawing by a pair of dashed lines I and II radiating from the point of attachment of the strap 13 to the integral finger 12F. The line I illustrates an approximate angle at which the tab 13 is released from the snap fastener base 14B at which occurrence, the buckle 10 may be released. It does not, however, allow release of the buckle 10 at that point which still maintains its full holding power. 
     If the tab 13 is pulled further away from the buckle 10 to approximately the angle represented by line II, the finger 12F is flexed sufficiently to lift it from locking stop 11LS and the two buckle parts 11 and 12 will automatically separate in response to the weight of the backpack BP and the pack will fall off of the wearer. An unintentional release of the snap fastener 14 without the outward pull of the tab 13 to at least the angle denoted by line II will not allow the buckle 10 to separate. 
     The combination of each of the features described above results in the reliable locking yet quick release buckle of this invention. 
     The foregoing description and the drawings illustrate the concept of this invention but one must not consider that the invention is limited to the specific embodiments disclosed. Instead, this invention is defined by the following claims including the scope of protection afforded by the Doctrine of Equivalents.