Patent Application
20060090309
The present invention relates to a clasp for joining together two webs. Such devices are sometimes called “clips” and “buckles” and the words “clasp”, “buckles” and “clips” are used synonymously in this specification.
Clasps for connecting together webs and straps are well known and widely used for such diverse applications as securing the two ends of a belt together, closing rucksacks and other bags and sacks, fastening coats and waterproofs and so on. The almost universally accepted design nowadays for such clasp consists of two parts secured to respective webs, one of the parts (the male part) consists of a pair of prongs, each having an outwardly extending barbed tooth and the other part (the female part) has a channel into which the prongs can be pushed. The width of the channel is smaller than the distance between the outsides of the prongs and so, as the male part is pushed into the channel, the prongs are flexed inwardly by the outer walls of the channel. The walls includes a pair of openings into which the barbed teeth can snap when the male part has been pushed sufficiently far into the channel. The engagement of the barbs in the channel wall openings retains the two parts together and so connects the webs attached to the two parts.
A guide prong is provided between the two barbed prongs in the male part of the clasp; the guide prong engages ridges in the channel of the female member to ensure that the male member travels axially along the channel.
In order to undo the clasp, the prongs are pinched to move towards each other thereby releasing the barbs from the openings and allowing the male part to be withdrawn from the female part.
Because the openings are exposed, it is possible for a user to catch his/her fingers between the barb and the opening, which can be painful.
U.S. Pat. No. 5,203,058, U.S. Pat. No. 5,735,024, EP-0305130 and GB 21116626 each describes a clasp or buckle for fastening straps having two identically-shaped parts; each part has a male prong and a female channel with the male prong of each part being arranged opposite to the female channel of the other part so that when the two parts are pushed together, the male prongs can engage in the respective female channels. The prongs have barbs that engage in openings in the channels to hold the buckle in a fastened condition. The barbs can be moved to disengage the barbs from the openings and so release the buckle. The two parts of the buckle, once the barbs are released, must be separated to open the buckle completely unless the tension in the straps is sufficient to pull the prongs out of the channels; however, if the tension is sufficient to pull the parts of the buckle apart, the same tension can make it difficult to release the prong barbs from the channel openings.
The present invention provides an alternative design of clasp where the two parts of a buckle separate from each other without the need for tension in the straps.
According to the present invention, there is provided a clasp that comprises a first part and a second part that can be joined together to fasten the clasp and that can be separated from each other to release the clasp, wherein the first and the second parts are identical to each other, and each of the first and second parts includes:
As used in the present specification, the expression “axial direction” is intended to denote the direction in which a part is moved to fasten the clasp. The term “transverse direction” is intended to denote a direction generally perpendicular to the axial direction.
The sloping interface surfaces mean that the parts move apart from each other on release of the two parts of the clasp.
Because the two parts of the clasp are identical, only one mould is required to make the clasp and only one stock number is necessary. It also makes packaging easier as compared to the prior art since where there is a need to ensure that one male and one female part are provided together. In addition, it makes the handling of the parts easier as compared to the prior art where it is sometimes necessary to ensure that the male and female parts are attached to specific webs.
On each part, the barb and the catch are preferably not arranged side-by-side in the transverse direction but rather the catch is located axially behind the barb so that the shaft of the latch can be engaged by the user to press it inwardly to release the barb from the catch and so release the clasp. In this way, the shafts of the latches that are pressed to release the clasp are located opposite to each other, which makes the opening of the clasp easier.
The latch preferably forms a wall of the housing of each of the parts, the latch being moveable with respect to the rest of the housing to release the barb from the catch and open the clasp.
There will now be described, by way of example only, an embodiment of the clasp according to the present invention by reference to the accompanying drawings in which:
Referring initially to
The two parts 10,12 each have a housing 16 formed by a rounded upper surface 18 and a flat bottom surface (shown in
At the rear of the housing 16, each part has a pair of forked arms 22 and a pair of bars 24 extend between these arms to form a ladder fastening for securing the clasp to webs or straps that are to be joined. The webs are threaded around the bars in a known manner. Alternatively, the webs can be stitched onto the bars 24.
Referring now to
The housing 16 and the interface surfaces 20 are clearly visible in
The housing 16 is hollow and has an internal cavity 32. As shown, the latch 14 is located along one side of the housing and indeed forms a side wall of the housing. In the opposite side wall, there is a catch 35 (not visible but it is shown in broken lines in
The barb 26 has an under-surface 34. When the clasp is to be fastened, the two parts 10,12 are pushed towards each other in the direction of arrows A and B (
In order to release the clasp, the latches 14 on the opposed sides of the clasp should be squeezed to move the latches in the direction of arrow C to a position in which the barbs 26 lie inwardly of the corresponding catches 35 and so the two parts 10,12 can be separated. Because the buttons 31 of the two parts 10,12 are located opposite each other, the act of pressing them does not cause the clasp to slew round when pressed. The clasp has depth to it, which makes it stable when pressing the release buttons 31.
Very little physical strength is needed to separate the parts 10,12 of the clasp, making it available to children, the elderly and the infirm.
The flat base 44 allows the clasp to lie flat against a surface if the webs are tensioned, e.g. if the webs are straps on a suitcase, the flat base 44 lies against the suitcase and does not press into the case. The flat surface also allows the manufacturer to mark the product, either with its own name or with advertising.
The D-shape cross section of the housing 16 dictates to users how the two parts 10,12 should be connected together since it is apparent that the flat base of the two parts 10,12 should align with each other.
The shape of the diagonal interface surface 20 is important. If the parts 10,12 are not properly aligned, the engagement of the surfaces 20 of the two parts 10,12 with each other pushes the parts 10,12 into their correct alignment for fastening. There is thus no need for a central guide prong to help align and locate the two parts 10,12 as is the case with the prior art. In addition, as the clasp has a diagonal interface surface, the pressing on buttons 31 will tend to cause the housing parts 18 to slide along the diagonal interface as soon as the barbs 26 are released causing the clasp to fly apart, which means that opening of the claps is simple.
Since the catch 35 is not accessible from the outside, users cannot pinch their fingers when releasing the clasp.
The clasp can be made with one 3-pan set of injection moulds: upper half, lower half and centre core. The catch 36 and much of the spacing around the button 31 are moulded from the bottom half of the mould. The clasp can be moulded in any suitable plastic, e.g. nylon, and in any colour.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/GB03/02704 | 6/24/2003 | WO | 10/18/2005 |
