This invention relates to a system for adjusting the length of a strap connecting two articles together, or connecting two sides of the same article. In particular, the invention relates to a system having a ratchet adjustment device that can be used to incrementally adjust the length of the strap to a desired setting.
Sliding adjustment buckles are often used to adjust the size of a hat or helmet, or to adjust features on clothing or bags. In a conventional sliding adjustment buckle such as shown in U.S. Pat. No. 8,474,113 to Badrenas Buscart, a long strap with a set of teeth is caused to pass through a main body, and when the strap arrives the desired position, the lock element of the main body can buckle the same and keep the strap in place. The lock element of the main body is movable, and a metal spring is generally used to move the position of the lock element. When a ratchet strap is to be withdrawn from the main body, the lock element needs to be pressed, such that the metal spring can change the position of the lock element of the main body. The lock element of the main body is separated from the ratchet of the long strap, such that the ratchet strap can be withdrawn.
This arrangement requires several separate pieces, as well as a metal spring. It would be desirable to form a secure ratchet system that does not require the use of metal springs, which can become deformed and/or disengaged over time.
It is therefore an object of the invention to provide a strap adjustment system that allows for incremental adjustment of the length of a strap in a simple and effective manner, without the use of metal springs.
This object is accomplished by an adjustment system comprising a housing, a cam lid and a ratchet strap. The housing has a bottom, two side walls, an elastic arm connected to each one of the side walls, a front opening and a rear opening. The cam lid is rotatably connected to the side walls of the housing, and has a top, a bottom, two side walls, an interior cavity, a front opening, a rear opening, two elastic arms extending under the bottom surface, and at least one locking element disposed in the interior cavity. The ratchet strap has an elongated body with a plurality of teeth disposed on one side thereof. The ratchet strap is fed through the openings in the front and rear of the housing and cam lid and the at least one locking element engages at least one tooth of the ratchet strap to lock the ratchet strap to the cam lid. The ratchet strap is released by pressing the elastic arms of the housing toward each other, which causes the elastic arms of the housing to press against the sides of the cam lid and rotate the cam lid. The elastic arms have a sloped contour, which slide against a correspondingly sloped contour on the sides of cam lid, to rotate the cam lid downward, which then compresses the elastic arms of the cam lid against the bottom of the housing. This moves the locking element out of engagement with the teeth of the ratchet strap and allows the strap to move freely within the housing and cam lid until the elastic arms are released. Then, the spring force of the compressed elastic arms of the cam lid force the cam lid back into its original locked position. The elastic arms of the housing and cam lid replace the need for a metal coil spring, and simplify the manufacturing and assembly of the adjustment system.
In order to attach the system to an article, there is at least one leg projecting from the bottom surface of the housing, and a back plate that is securable to the at least one leg, so that the housing can be secured to an element by inserting the at least one leg through a hole in the element and securing the back plate to the leg. Preferably, there are two legs, each connected to a singular back plate. In a preferred embodiment, the back plate is configured to be reversible, such that the at least one leg is securable at two different depths within the back plate. This allows the adjustment system to be used on fabrics of varying thicknesses.
In one embodiment, the teeth of the strap are triangular and the locking element comprises a triangular protrusion disposed on the bottom of the cam lid, the protrusion being configured to fit within two adjacent teeth of the strap and lock the strap in place. In particular, the teeth of the strap are shaped so that a front of each tooth forms an angle with a bottom of the strap that is smaller than an angle formed by a back of each tooth with the bottom of the strap, and wherein the locking element is formed with a smaller angle relative to the bottom of the cam lid on a front side and a larger angle relative to the bottom of the cam lid on a rear side so that the strap can be pulled through the housing and cam lid in a forward direction without locking, but rearward motion of the ratchet strap locks the strap to the cam lid.
The other end of the strap can be secured to the article in different ways. In one embodiment, a locking plate is disposed on the other end of the strap. This locking plate can be directly sewn to an article, or it can be equipped with at least one leg projecting below the locking plate, and a back plate configured for attachment to the at least one leg, such that the second end of the ratchet strap is connectable to an article by inserting the at least one leg through an opening in the article and attaching the back plate to the at least one leg.
The housing and cam lid can be equipped with guides for guiding the strap through in a smooth manner. In one embodiment, the guides are formed by protrusion extending from the top of the cam lid into the cavity, and another protrusion extending from the bottom of the housing. These protrusions slide along the sides and top of the ratchet strap to keep the ratchet strap properly aligned in the cam lid and housing.
In one embodiment, the cam lid is connected to the housing by a protrusion on each one of the side walls of the housing, and an aperture on each side wall of the cam lid. The protrusions extend through the apertures to rotatably connect the cam lid to the housing.
In another embodiment, there is an extension extending from a rear of the housing, the extension covering a portion of the ratchet strap that extends beyond the rear of the housing. A slot can run through the extension, so that the end of the ratchet strap is encased within the extension.
Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.
In the drawings, wherein similar reference characters denote similar elements throughout the several views:
Referring now in detail to the drawings and, in particular,
Starting with housing 10, as shown in
Cam lid 20 is rotatably connected to housing 10. Cam lid 20 is shown in detail in
Ratchet strap 30 is shown in detail in
The rear end of ratchet strap 30 has a locking plate 33, which can be configured with locking legs 19 in the same manner described above with respect to housing 10. Locking legs 19 can be locked to back plate 40 to attach ratchet strap 30 to an article in the same manner described above. Alternatively, locking plate 33 can be configured without legs, as shown in
In use, the rear end of ratchet strap 30 is connected to an article by either legs 19 or by direct sewing, and housing 10 is also connected to the article (or another article) via legs 19 and back plate 40. Cam lid 20 is connected to housing 10 by placing protrusions 66 of housing 10 (shown in
As shown in
Any free end of ratchet strap 30 after adjustment exits through rear opening 17 of housing 10, and extends through slot 80 in extension 18.
Locking latches 77 are shaped to correspond to the space between teeth 32, so that teeth 32 become caught on locking latches 77 under any rearward pressure. The low angle of the front side of each tooth allows ratchet strap 30 to be adjusted in the forward direction F. The specific angle of teeth 32 can be seen enlarged in
To release ratchet strap 30 from housing 10, the user presses elastic arms 14, 15 toward each other. This causes elastic arms 14, 15 to slide against the sides of cam lid 20, forcing cam lid 20 to rotate in direction W as shown in
Accordingly, while only a few embodiments of the present invention have been shown and described, it is obvious that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.
Number | Name | Date | Kind |
---|---|---|---|
8220117 | Lovato | Jul 2012 | B2 |
8348113 | Huang | Jan 2013 | B2 |
8474113 | Badrenas Buscart | Jul 2013 | B2 |
20110290840 | Huang | Dec 2011 | A1 |