1. Field of the Invention
The present disclosure is related to releasable two-part buckles. More particularly, the present disclosure is related to releasable two-part buckles that can easily be engaged and disengaged, yet are resistant to inadvertent disengagement.
2. Description of Related Art
Common two-part buckles are well known for connecting the end of a flexible strap to another flexible strap or to a mating part on another object. Various approaches have been used to effect the engagement and disengagement of such buckles.
An approach frequently used in buckles for commercial applications makes use of plastic molded first and second parts which are fastened to two strap ends desired to be coupled together. The first part snap-engages into a socket defined within the second part. Specifically, the first part has a pair of longitudinal resilient arms, each of them provided with a hook, which lock the buckle by cooperating with respective edges formed within the second part. The engagement of the buckle can be released by simultaneously pressing the two hooks, forcing the resilient arms to bend inward and disengage from the edges of the second part.
Prior art buckles have a variety of disadvantages that emerge when the buckle needs to be small, strong and easy to use at the same time, especially when it has to be engaged/disengaged without visual feedback and when the user is wearing gloves.
For example, it has been determined by the present disclosure that the first and second parts of prior art buckles can often inadvertently disengage or release from one another when placed in tension, due to a leverage that forces the resilient arms of the first part to bend inwards. In order to avoid this issue, some prior art buckles simply increase the resiliency of the arms so that the force necessary to press the two arms inward is increased. Unfortunately, this increased releasing force makes it difficult for the user to engage/disengage the two buckle parts, especially without visual feedback and/or when the user is wearing gloves.
Simply stated, it has been determined by the present disclosure that the arms of the prior art buckles need to be stiff against bending to achieve high tensile strength of buckle, but increasing the bending-stiffness of the arms make the arms difficult to release.
Further, the hooks on the resilient arms of the first part are the interface for the user to release the buckle by pressing the hooks inwards. As the hooks need to slide through an opening of the second part to engage, they need to be of a smooth shape and will always be recessed in the second part. This makes it hard for a user to find the hooks without visual feedback or when wearing gloves.
Finally, the hooks extend forward on the resilient arms of the first part, increasing the overall length of the prior art buckle.
Accordingly, it has been determined by the present disclosure that there is a need for releasable two-part buckles that overcome, alleviate, and/or mitigate one or more of the aforementioned and other deleterious effects of prior art buckles.
Advantageously, the present disclosure provides a two-part buckle that is both strong in tension, while having easy-to-flex arms, that allows the region where the user applies a removal force to be on the resilient arm instead extending forward of the hook so that the overall length of the buckle is reduced as compared to the prior art.
A releasable two-part buckle is provided that includes a first part and a second part. The first and second parts each have a forward end and a rearward end. A stationary hook extends towards the forward end of the first part, while an arm extends toward the forward end of the second part. The stationary hook has a first engagement surface. The arm has a center axis and defines a loop proximate the forward end. The loop has a second engagement surface. The arm is resiliently movable between an engaged state having the first and second engagement surfaces engaged with one another at a contact surface and a disengaged state having the first and second engagement surfaces disengaged from one another.
In some embodiments, the two-part buckle is configured so that the contact surface is bisected by the center axis in the engaged state.
A releasable two-part buckle is also provided that includes a first part with a first strap engaging portion and a pair of stationary hooks and a second part with a second strap engaging portion and a pair of arms. Each arm has a center axis and a looped end, where the pair of arms are resiliently movable between an engaged state having the pair of hooks and arms engaged with one another and a disengaged state having the pair of hooks and arms disengaged from one another. The pair of hooks and arms can be configured so that, when in the engaged state, a strap tension applied to the first and second parts induces substantially no bending moment in the pair of arms towards the disengaged state.
In some embodiments, two-part buckle also includes a first centering member extending from the first part between the pair of stationary hooks and a second centering member extending from the second part between the pair of arms. The first and second centering members are slidably engagable with one another to align the pair of arms and the pair of stationary hooks during engagement.
In still further embodiments, the two-part buckle includes a locking member movable between a first position that prevents inward movement of the pair of arms and a second position that allows movement of said pair of arms. The locking member can be slidably positioned on the first or second centering member, when present.
A releasable two-part buckle is provided that includes a first part having a pair of stationary hooks and a second part having a pair of arms. Each hook of the pair of stationary hooks has a leg and a barb, where the leg extends along a first of three perpendicular planes and the barb extends inward from the leg along a second of the three perpendicular planes. Each arm of the pair of arms has a first finger, a second finger, and a loop. The first and second fingers extends along the first of the three perpendicular planes and are spaced from one another along a third of the three perpendicular planes a sufficient distance to accept the barb between the first and second fingers. The loop extends along the third of the three perpendicular planes and closes an end of the first and second fingers. The arms are resiliently movable between an engaged state having the barb engaged with the loop of a corresponding hook and a disengaged state having the barb disengaged from the loop of the corresponding hook.
The above-described and other features and advantages of the present disclosure will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims.
Referring to the drawings and in particular to
Generally, first part 12 includes one or more stationary hooks 16 and second part 14 includes one or more arms 18. Arms 18 are resiliently movable between an engaged state (
Advantageously, buckle 10 is configured so that first and second parts 12, 14 can easily be engaged and disengaged from one another when desired, while mitigating instances of the parts being inadvertently disengaged one another when placed in tension, which is illustrated by arrows (T) of
Without wishing to be bound by any particular theory, it is believed that tension (T) applied, when applied to first and second parts 12, 14 in the engaged state, induces substantially no bending moment in movable arms 18 of the second part.
Rather, it is believed that tension (T) merely places arms 18 under tensile stress such that a releasing force (F) required to flex the arms toward the disengaged state is separate from the ability of buckle 10 to withstand the tension (T). The insulation of arms 18 from bending moments in the direction of releasing force (F) is believed by the present disclosure to be possible by ensuring that, when in the engaged state, the contact surface defined between hooks 16 and arms 18 is bisected by a center axis (C) of the arms as will be described in more detail herein below. By way of analogy, it is believed that arms 18, function much like a loop of rope, where the arms are only required to withstand tensile stress when placed under tension (T).
In this manner, the strength of buckle 10 to resist tension (T) does not depend on bending stiffness of arms 18. Rather, arms 18 can be strong in tension (T) to provide the desired strength of buckle 10 to resist inadvertent release when placed under tension, but weak in bending to allow for easy release upon application of low removal force (FR).
Buckle 10 will now be described in greater detail with simultaneous reference to
First part 12 has a forward end 20 and a rearward end 22 with stationary hooks 16 extending toward the forward end. Stationary hook 16 has a leg 24 that extends in the x-direction and a barb 26 that extends from the leg a desired distance in at least the y-direction. Barb 26 includes a first engagement surface 28 facing rearward end 22.
Hook 16 is described herein by way of example as being “stationary”. For purposes of the present disclosure, it should be understood that hook 16 may, depending on the materials and geometry of first part 12, be movable or flexible. However, first part 12 does not require movement or flexion of hook 16 during the engagement and disengagement of first and second parts 12, 14 and, thus, is referred to as being “stationary”.
Second part 14 also has a forward end 30 and a rearward end 32 with arms 18 extending toward the forward end. Each arm 18 has a first finger 34, a second finger 36, and a loop 38. In some embodiments, loop 38 can be a closed loop. As used herein, the term “closed loop” shall mean any shape or form that has a closed geometry as is a common usage for such structures in Computer Aided Design (CAD) software. Thus, the “closed loop” of the present disclosure can have any desired geometry that is closed at its terminal end such as, but not limited to, a triangle, a square or a circle. Thus, the “closed loop” of the present disclosure can, in its simplest form, be formed by a hole extending through arm 18. In other embodiments, loop 38 can be an open loop, an example of which is shown in
First and second fingers 34, 36 extend along the x-direction and are spaced from one another along the z-direction a distance that is sufficient to accept barb 26 between first and second fingers 34, 36. Closed loop 38 extends along the z-direction forming a closed end of first and second fingers 34, 36 and defining a second engagement surface 40 facing rearward end 32.
As seen in
More specifically, arms 18 are movable upon application of removal force (FR) along the y-direction so as to move second contact surface 40 along the y-direction from a normal position in which surfaces 24, 40 are engaged with one another at contact surface 42 to a flexed position in which surface 40 is free from contact with surface 24. Second part 14 is sufficiently resilient to return arms 18 along the y-direction to the normal position upon removal of the force (FR).
Thus, arms 18 are normally biased to the position necessary for the engaged state but can be resiliently flexed upon application of the removal force (FR) to disengage the first and second parts 12, 14 from one another. Once disengaged, first part 12 can be withdrawn from second part 14 by applying tension (T) along the x-direction to the parts.
Conversely, first and second parts 12, 14 can be engaged with one another by compressing the parts, opposite to tension (T), along the x-direction until arms 18 flex from the normal position and then return to the normal position with surfaces 24, 40 are engaged with one another at contact surface 42.
In some embodiments, first part 12 can include a first lead-in surface 44 on arms 18 and second part 14 can include a second lead-in surface 46 on hooks 16. During assembly, first and second lead-in surfaces 44, 46 act as cams to convert the force of compression along the x-direction that is imparted to first and second parts 12, 14 into force (FR) along the y-direction to resiliently bias arms 18 inward along the y-direction. Once first part 12 has been inserted into second part 14 a distance sufficient to allow first engagement surface 24 to mate with second engagement surface 40, arms 18 resiliently return outward along the y-direction.
It is contemplated by the present disclosure for the resiliency of arms 18 to be inherent in the materials and/or shape of fingers 34, 36, inherent in the materials and/or shape of second part 14, inherent in the materials and/or shape of arms 18, and any combinations thereof.
First and second engagement surfaces 24, 40 can have any desired shape. In a preferred embodiment, first and second engagement surfaces 24, 40 have complimentary shapes so as to maximize the area of contact defined by contact surface 42.
In some embodiments, second part 14 can include one or more surfaces 50 (only one shown) extending from arms 18. Surfaces 50 are configured to assist the user in the application of force (FR) to arms 18.
Preferably, surfaces 50 are proximate forward end 30 so as to minimize the force (FR) necessary to deflect arms 18. However, buckle 10 provides a freedom of design not previously possible, which can shorten the overall length in the x-direction of second part 14 and, thus, of the buckle. For example, since buckle 10 is configured so that the releasing force (FR) required to flex arms 18 toward the disengaged state is separate from the ability of buckle 10 to withstand the tension (T), surfaces 50 can be positioned, along the x-direction, between first end 32 and second engagement surface 40.
Additionally, in buckle 10, surfaces 50 don't slide into a female housing as in the prior art. Thus, buckle 10 allows for freedom of design of surfaces 50 not previously possible and thereby allows the surfaces to be optimized for maximum usability and tactile feedback, especially when the user is wearing gloves.
In many applications, buckle 10 can find use in connecting the ends of straps (not shown) to one another. Here, first part 12 can include a first strap engaging portion 52 extending toward rearward end 22, while second part 14 can include a second strap engaging portion 54 extending toward rearward end 32. First and second strap engaging portions 52, 54 are illustrated by way of example as a slot configured to receive a strap end therethrough. Of course, it is contemplated by the present disclosure for first and second strap engaging portions 52, 54 to have any known configuration sufficient to permanently, removably, or adjustably secure a strap to each part.
In some embodiments, buckle 10 can include centering members to assist during the engagement of first and second parts 12, 14. For example, first part 12 can include a first centering member 60 that extends toward forward end 20 along the x-direction, while second part 15 can include a second centering member 62 that extends toward forward end 30 along the x-direction. First and second centering members 60, 62 are slidably engagable with one another to align arms 18 and hooks 16 during assembly. Preferably, centering members 60, 62 slidably engage one another during assembly before first lead-in surface 44 on arms 18 contacts second lead-in surface 46 on hooks 16.
In the illustrated embodiment, first centering member 60 is illustrated as a hollow tube 64 having a flared end 66 and second centering member 62 is illustrated as a post 68 that is slideably received in the hollow tube to align first and second parts 12, 14 during assembly. Of course, it is contemplated by the present disclosure for centering members 60, 62 to have any desired configuration sufficient to align first and second parts 12, 14 during assembly.
Referring now to
In the illustrated embodiment, buckle 10 includes first and second centering members 60, 62. Here, locking member 70 is shown received on an outer diameter of hollow tube 64 and retained on the hollow tube by flared end 66. Locking member 70 can be a non-continuous ring that is snap fit over first centering member 60 so that the locking member can slide in the x-direction along first centering member 60 between the first and second positions. Alternately, locking member 70 can rotate around first centering member 60 between the first and second positions.
Of course, it is contemplated by the present disclosure for locking member 70 be any device sufficient to selectively allow or prevent movement of arms 18 so as to prevent accidental release of buckle 10.
Referring now to
For ease of discussion, barb 26 is shown with first engagement surface 28 being planar and closed loop 38 is shown having a circular cross-section such that second engagement surface 40 is circular. In this manner, contact surface 42 is shown in its simplest form, namely as a point of contact which has a minimal dimension in the y-direction and the z-direction.
The point of contact is located on center axis (C) of arm 18, which results in tension (T) along the x-direction acting on the point of contact so as to induce substantially no bending moment in the arm.
Moving towards more complex examples, contact surface 42 can have any desired dimension in the y-direction and/or the z-direction and can have any desired shape. Regardless of the shape or dimensions of contact surface 42, the surface is bisected by center axis (C) when first and second parts 12, 14 are in the engaged state. It should be recognized that the term “bisect” is meant to accommodate deviations from the exact center provide that substantially no bending moment in the y-direction to the disengaged state is induced.
Buckle 10 according to the present disclosure provides mechanical advantages that allow buckles that are smaller, stronger and easier to use at the same time. Three attributes buckle 10 has that allow it to be smaller, stronger and more user friendly at the same time include: (1) Using one length unit for two functions, (2) resolving the flexibility conflict, and (3) freedom of design on the release surfaces.
The attribute of using one length unit for two functions, refers to arms 18 of the second part 14 providing two functions in one length, namely the engagement and disengagement mechanism and the user interface.
In buckle 10, surfaces 50 are between the pivot point of arms 18 and contact surface 42, integrating two functions into one length, which allows for a decrease in the overall length of the buckle as compared to prior art buckles.
In buckle 10, the tension in arms 18 has been decoupled from the flexion of the arms. Thus, the forces in arms 18 are straight tensile forces when buckle 10 is under tensile load, which means the arms can be flexible without affecting the strength of the buckle. That means that the forces the user needs to apply to release the buckle can be light while at the same time the buckle is very strong in tension. Moreover, hooks 16 of first part 12 do not have to flex and hence can be designed to be very strong without negatively affecting the usability of buckle 10.
Buckle 10 requires less material than prior art buckles, and, hence reduces the weight and cost. Specifically, buckle 10 requires no outer shell as required by prior art buckles. This decreases its cost, weight and reduces the environmental footprint by reducing the amount of material used and reducing the energy needed for transportation due to the lower weight. This also simplifies the production process and reduces the risk of dirt or ice getting stuck in and inhibiting the function of buckle 10.
Referring now to
Buckle 10 is shown in
In
Once in the position shown in
Thus, buckle 10 has a first set of cam surfaces, namely surfaces 72, 74, which assist to move first and second parts 12, 14 along the x-direction and out of engagement with one another by converting the removal force (FR) into the first force (F1) along the x-direction. Additionally, buckle 10 has a second set of cam surfaces, namely surfaces 44, 46, which further assist to move first and second parts 12, 14 along the x-direction and out of engagement with one another by converting the natural resiliency of arms 18 returning to the normal position upon release of the removal force (FR) into the second force (F2) along the x-direction.
In this manner, buckle 10 is configured, when surfaces 50 are pushed and released, to automatically separate first and second parts 12, 14 from each other.
Buckle 10 can be made of any desired material. In a preferred embodiment, buckle 10 is injection molded from polymer materials.
However, it is also contemplated by the present disclosure for one or more portions of buckle 10 to be formed from stamped metal parts that are bent into shape or cast metal parts that are cast into shape.
For example, and referring to
It is also contemplated by the present disclosure for one or more portions of buckle 10 to be formed from metal wire that is bent into shape. For example, and referring to
In the embodiment of
Although not shown, it is contemplated by the present disclosure for first part 12 to also be formed of metal wire or coated metal wire that is bent into shape.
As discussed above, the loop can be a closed loop 38 as in
Loop 338 still generally maintains the features of the closed loop 38, except the loop is open in that it does not form a completed loop rejoining to arm 318. Specifically and without wishing to be bound by any particular theory, it is believed that tension (T) applied, when applied to first and second parts 314 in the engaged state, induces substantially no bending moment in movable arms 318 of the second part.
Rather, it is believed that tension (T) merely places arms 318 under tensile stress such that a releasing force (F) required to flex the arms toward the disengaged state is separate from the ability of buckle 10 to withstand the tension (T). The insulation of arms 318 from bending moments in the direction of releasing force (F) is believed by the present disclosure to be possible by ensuring that, when in the engaged state, the contact surface defined between hooks 16 and arms 318 is bisected by a center axis (C) of the arms. By way of analogy, it is believed that arms 318, function much like a loop of rope, where the arms are only required to withstand tensile stress when placed under tension (T).
Advantageously, second part 314 having loop 338 is particularly configured for manufacture from bent metal wire or coated metal wire. Additionally and although not shown, it is again contemplated by the present disclosure for first part 12 to also be formed of metal wire or coated metal wire that is bent into shape.
It should also be noted that the terms “first”, “second”, “third”, “upper”, “lower”, and the like may be used herein to modify various elements. These modifiers do not imply a spatial, sequential, or hierarchical order to the modified elements unless specifically stated.
While the present disclosure has been described with reference to one or more exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment(s) disclosed as the best mode contemplated, but that the disclosure will include all embodiments falling within the scope of the appended claims.