Abstract:
A latch device comprises a base suitable for attachment to a substrate, a cover, an elongate strap hinge that connects the base and cover, a hinge guide structure and/or a camming structure, and a locking mechanism. The cover is selectively movable about the strap hinge relative to the base between an open position and a closed position. The hinge guide structure includes a curved surface proximal to the elongate strap hinge that assists in distributing forces throughout a significant portion of the entire length of the strap hinge as the cover is moved relative to the base. A camming structure may be included that has a camming surface that biases the cover toward the open position. The latch device is useful in a variety of areas, including tie downs for sail boats, campers, tarps, suit cases, back packs, and other sporting goods.

Description:
BACKGROUND OF THE INVENTION 
   1. The Field of the Invention 
   The present invention relates to a latch device that may be used in a variety of areas, for example, tie downs for boats, campers, tarps, suit cases, back packs, and other sporting goods. 
   2. The Relevant Technology 
   Latch devices are used in a variety of areas to clamp or otherwise secure various articles. Existing devices can be rather complex, difficult to use, and often wear out prematurely. Because of these difficulties, there is a need for a simple, easy to use, durable latch device which can be used to secure a wide range of articles such as tie downs for boats, campers, tarps, suit cases, back packs, and other sporting goods. 
   It would be an improvement in the art to provide a latch device that is easy to open and close without use of any special tools or excessive force, that can be manufactured at low cost, and that exhibits high durability. 
   BRIEF SUMMARY OF THE PREFFERED EMBODIMENTS 
   The present invention is directed to a latch device that may be used in a variety of areas, including tie downs for boats, campers, tarps, suit cases, back packs, and other sporting goods. 
   The latch device includes a base that is suitable for attachment to a substrate, an elongate strap hinge, a cover that is attached to the base by the elongate strap hinge, a camming structure, and a locking mechanism. The cover moves about the strap hinge between open and closed positions relative to the base. 
   The camming structure may be disposed on the cover or on the base. It includes a curved surface around which the elongate strap hinge bends when the cover is selectively moved relative to the base so that the elongate strap hinge bends over a significant portion of its entire length. The article to be held is placed between on the base (e.g., in a slot formed within the base) and then the cover is subsequently closed and locked to the base. 
   Because the elongate strap hinge bends around the curved surface of the camming structure, the strap hinge is especially resistant to breakage. The curved surface prevents kinking and concentration of the stresses and forces associated with the operation of the hinge that might otherwise occur. Because the elongate strap hinge bends around the curved surface of the camming structure, the stresses and forces are distributed along a significant portion of the length of the strap hinge. 
   According to one embodiment, the curved surface of the camming structure is disposed on the base, adjacent to the elongate strap hinge. In addition to the curved surface, the camming structure may also include a camming surface that is located opposite the curved surface. The camming surface interacts with the base so as to bias the cover towards an open position. 
   According to one embodiment, the camming structure fits within and substantially fills a void space between the base and the elongate strap hinge when the cover is in the closed position. 
   The latch device may be formed integrally as a single piece, for example, by injection molding of a thermoplastic material. 
   According to one embodiment, the elongate strap hinge has a cross-sectional thickness that is less than the thickness of the cover and base where the cover and base are attached to the elongate strap hinge. 
   The locking mechanism may be any mechanism which holds the cover against the base in a closed position. Exemplary locking mechanisms may include a cotter pin inserted through a hole formed through the cover and the base, a bolt and nut for locking the cover to the base, a threaded auger screw that is threaded through the cover and base, locking them together, or a locking pin that inserts through a slot in the cover and base, or mechanical interaction or interlocking between the cover and base themselves. These exemplary locking mechanisms are illustrative, and many others could alternatively be used. 
   These and other advantages and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     To further clarify the above and other advantages and features of the present invention, a more particular description of the invention will be rendered by references to specific embodiments thereof, which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
       FIGS. 1A-1C  are perspective views of an exemplary latch device that is being used for securing a line to a boat; 
       FIGS. 2A-2C  illustrate an alternative latch device according to the invention; 
       FIGS. 3A-3D  illustrate operation of a latch device according to the invention that includes mechanically interlocking structures provided by the base and cover; and 
       FIG. 4  illustrates an exemplary latch device that includes a locking mechanism comprising a threaded bolt that fits in a hole through the cover and base; 
       FIG. 5  illustrates an exemplary latch device that includes a locking mechanism comprising a pin that fits within corresponding holes in the cover and base; 
       FIG. 6  illustrates an exemplary latch device that includes a locking mechanism comprising a threaded auger screw that passes through a hole in the cover and threadably mates with a threaded hole in the base; 
       FIG. 7  illustrates a latch device that includes a locking mechanism comprising a locking pin that includes a locking tongue that fits in a recess or groove in the cover; and 
       FIG. 8  illustrates an exemplary latch device that includes a locking mechanism comprising a rotatable latch on the base that fits into an eyelet on the cover. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A detailed description of the latch device of the invention will now be provided with specific reference to the drawings illustrating preferred embodiments of the invention. It will be appreciated that like structures will be provided with like reference designations. The latch device includes a base suitable for attachment to a substrate, an elongate strap hinge, a cover attached to the base by the elongate strap hinge, a camming structure, and a locking mechanism. 
     FIGS. 1A and 1B  depict a latch device  100  having a base  102  to which a cover  104  is hingedly attached. The latch device  100  further includes an elongate strap hinge  106  that is attached at one end to the base  102  and at an opposite end to the cover  104 . In this way, the cover  104  is hingedly attached to the base  102  and is able to be selectively moved (e.g., rotated) between an open position and a closed position relative to the base  102 . The latch device also includes a camming structure  108 , and a locking mechanism. In a preferred embodiment, the latch device can be made (e.g., by injection molding) from a single type of material, e.g., a thermoplastic material. 
   Because the strap hinge  106  of the latch device  100  is elongated, it is able to bend gradually over a significant portion of its entire length rather than at a single point or line. This results in a hinge that is more resilient and durable over time because it is not overly bent or stressed at any particular point or line. Moreover, because the elongate strap hinge  106  can bend gradually over a significant portion of its entire length, it can be of a thicker, stronger construction compared to a hinge that is required to bend at a single point or line. This results in a hinge that is significantly stronger and more resistant to breakage than it might otherwise be. 
   In some embodiments, the elongate strap hinge  106  will have a cross-sectional thickness that is less than the cross-sectional thicknesses of the adjoining cover  104  and base  102 . Nevertheless, it is within the scope of the invention for the elongate strap hinge  106  to have a material cross section that is as thick or thicker than the adjoining cover  104  and/or base  102 . 
   According to one aspect of the invention, the elongate strap hinge  106  may be constructed so that the cover  104  remains in an open position relative to the base  102  when the strap hinge  106  is in a relaxed condition. The ability of the cover  104  to remain in the open position without having to apply force to the cover  104  helps facilitate placement of an article (e.g., a rope  110 ) to be clamped between the cover  104  and the base  102 . 
   The latch device  100  includes a camming structure  108  that includes a curved surface that interacts with the elongate strap hinge  106  to assist in causing the hinge  106  to bend gradually along a significant portion of its entire length as the cover  104  is selectively moved between open and closed positions relative to the base  102 . The camming structure and curved surface may either comprise an integral part of the cover  104  or base  102 , or alternatively, a separate piece attached to the cover  104  or base  102 . In the embodiment illustrated in  FIGS. 1A and 1B , the camming structure  108  is integrally attached to the cover  104 . 
   In  FIG. 1A , camming structure  108  is illustrated as having a camming surface  112  and a curved hinge-guiding surface  114 . The hinge-guiding surface  114  is an example of a curved surface that interacts with the elongate strap hinge  106  to assist in gradually bending the strap hinge  106  along a significant portion of its entire length as the cover  104  is moved relative to the base  102 . The hinge-guiding surface  114  is advantageously curved so as to interact with the elongate strap hinge  106  by distributing forces along a significant portion of its entire length as the cover  104  is moved. Distributing forces along a significant portion of the length of the elongate strap hinge  106 , rather than allowing the forces to concentrate at a single location, results in a hinged latch device that is more resistant to breakage of the hinge compared to devices in which the hinge is bent abruptly at a specific point or line. In one embodiment, the hinge-guiding surface  114  may help maintain the cover  104  (in combination with an exemplary locking mechanism discussed more fully below) in the locked position by exerting outward pressure against the elongate strap hinge  106 . This, in turn, effectively shortens the length of the cover  104 , thereby causing the exemplary locking mechanism to hold the cover  104  more tightly (e.g., so as to remove play). 
   The camming surface  112  is curved or angled in such a way so that it interacts with the base  102  in order to bias the cover  104  toward the open position when the cover  104  is in an unlocked configuration relative to the base  102 . This improves access to the inside clamping surfaces of the base  102  and cover  104 , facilitating insertion or removal of an article to be held. 
   In the embodiment illustrated in  FIG. 1A , camming structure  108  is integrally attached to the inner surface of the cover  104  in a manner so as to extend toward the base  102 . Further, and as is shown in particular in  FIG. 1B , the camming structure  108  is received within a recess  116  between the base  102  and the elongate strap hinge  106  when the cover  104  is in the closed position. This results in a more compact latch device  100 . 
   The latch devices according to the invention include a locking mechanism for maintaining the cover  104  in a closed position once the cover has been closed. As shown in  FIGS. 1B and 1C  the illustrated embodiment shows an exemplary locking mechanism in which a cotter pin  118  is inserted through a hole  120  formed through the cover  104  and base  102 . It will be appreciated that any locking mechanism known in the art may be used to selectively lock and unlock the cover  104  relative to the base  102 . 
   The latch device may further include a bearing protrusion  122  and corresponding slot  124 . Bearing protrusion  122  may be provided on the inside and middle of the cover  104  that extends toward the slot  124  when the cover  104  is in the closed position. The bearing protrusion  122  assists in fixing an article (e.g., a rope, cable, strap, ring, bar, rod, pin, and the like) to be clamped within the slot  124  when the cover is in the closed state ( FIG. 1B ). 
     FIGS. 2A and 2B  depict an alternative embodiment of a latch device  200  according to the invention that includes a simplified hinge guide structure disposed on the base. The latch device  200  depicted in  FIGS. 2A and 2B  includes a base  202  and a cover  204  attached to the base  202  by means of an elongate strap hinge  206 . The base  202  further includes a curved end surface  208  that acts as a hinge guide in order to cause the elongate strap hinge  206  to bend gradually over a significant portion of its entire length. In this way, the curved end surface  208  of the base  202  act in similar manner to the curved hinge-guiding surface  114  of the camming structure  108  of the latch device  100  depicted in  FIG. 1A-1B . Thus, as the cover  204  is moved from an open position ( FIG. 2A ) to a closed position ( FIG. 2B ), the elongate strap hinge  206  at least partially abuts the curved end surface  208 . The abutment between the elongate strap hinge  206  and the curved end surface  208  causes the elongate strap hinge  206  to bend gradually around the curved end surface  208  so as to better distribute the bending forces and bending angles along substantially the entire length of the elongate strap hinge  206 . 
     FIG. 3A  is a side view that shows another embodiment of a latch device  300  with the cover  304  in an open position relative to the base  302 . The cover  304  can be manually opened by rotating it about the elongate strap hinge  306  so that the camming structure  308  just barely abuts an upper surface of the base  302 . It will be appreciated, however, that, depending on the nature of the elongate strap hinge  306 , it is possible for the cover  304  to be biased either toward or away from the base  302  when the cover  304  is in a fully open position relative to the base  302 . In the embodiment shown in  FIG. 3A , however, the elongate strap hinge  306  gently biases the cover  304  toward the base  302  in order for the camming structure  308  to lightly contact an upper surface of the base  302  while the cover  304  is in an open position relative to the base  302 . 
   As seen in  FIG. 3B , when the cover  304  is pushed down toward the base  302 , the camming surface  312  of the camming structure  308  makes abutting contact with, and slides against, an upper surface of the base  302 , thereby causing the camming structure  308  to be biased in a spring-like fashion towards the elongate strap hinge  306 . As a result, the camming structure  308  can act as a spring that exerts an opposing biasing force that, in combination with the camming action of camming surface  312 , biases or urges the cover  304  toward the open position relative to the base  302 . Thus, if the latch device  300  is in the conformation depicted in  FIG. 3B  and the cover  304  is released, it may spontaneously spring back to a conformation like the one illustrated in  FIG. 3A . It should be understood, however, that the exact resting conformation of the cover  304  is dependent upon the size, shape and relative positions of the camming structure  308  and the upper surface of the base  302  with which it comes into contact. 
   As the cover  304  is pushed down further toward the base  302  as seen in  FIG. 3C , the camming surface  312  of the camming structure  308  continues to make contact with the base  302 , thus pushing the camming structure  308  further toward the elongate strap hinge  306 . Thus, if the latch device  300  is in the conformation depicted in  FIG. 3C , and the cover  304  is released, it will spontaneously spring back to a conformation like the one illustrated in  FIG. 3A  (subject to the actual size, shape and angles of the camming structure  308  and base  302 ). This tendency of the cover  304  to remain in an open position absent external force is advantageous to the user because it facilitates the insertion of an article to be held between the cover and the base. 
   Additionally, when the latch device  300  is in the conformation illustrated in  FIG. 3C , the curved hinge-guiding surface  314  of the camming structure  308  is in contact with the inside surface of the elongate strap hinge  306 . This contact between curved surface  314  and the elongate strap hinge  306  distributes forces associated with closing the cover  304  (i.e., while bending the hinge) gradually along the entire contact length between the curved surface  314  and the elongate strap hinge  306  as the cover  304  is progressively closed. This results in the elongate strap hinge  306  bending along its entire length, or at least a significant portion of its entire length, as the cover  304  is closed, rather than bending at a single point or line. This characteristic allows the elongate strap hinge  306  to bend without kinking, thereby decreasing the likelihood of fatigue and unwanted breakage. Because the elongate strap hinge  306  bends gradually along a significant portion of its entire length, rather than abruptly at a distinct localized bending angle, the film hinge  306  can be significantly thicker than film hinges that bend at a discrete localized bending angle. The combination of these characteristics results in a much stronger and more durable hinge that resists breakage when subjected to shearing or bending forces. 
   The cover  304  is held in a closed position by means of mechanical interaction between a locking protrusion  324  that extends from an end of the cover  304  opposite the strap hinge  306  and a locking recess  326  within the base  302 . The locking protrusion  324  bends outwardly as the cover  304  is pushed beyond nose  328  on the base  302 . to unlock the cover  304 , the locking protrusion  324  is withdrawn from the locking recess  326  and flexed up and over nose  328 . It should be understood that any combination of protrusions and recesses located on or attached to the cover  304  and/or base  302  may be utilized as the locking mechanism, either alone or in combination with any other locking devices disclosed herein or known in the art. 
   Alternative exemplary locking mechanisms are illustrated in  FIGS. 4-8 .  FIG. 4  illustrates the use of a bolt  418  inserted through a hole  420  in the cover  404  and base  402 . A nut  419  is fastened to the bolt  418  so as to secure the bolt  418  within the hole  420 . The cover  404  can be selectively locked and unlocked relative to the base  402  by inserting and removing bolt  418  into and out of hole  420 . 
     FIG. 5  illustrates a pin  518  that is selectively inserted or withdrawn from a corresponding hole  520  in the front of cover  504  and base  502 . The cover  504  can be selectively locked and unlocked relative to the base  502  by inserting and removing pin  518  into and out of hole  520 . 
     FIG. 6  illustrates use of a threaded auger screw  618  which is passed through a hole  620  in the front of cover  604  and screwed into a threaded hole  621  in the front of base  602  so as to selectively secure and release the cover  604  to and from the base  602 . 
     FIG. 7  illustrates a locking pin  718  which is inserted through a hole  720  and turned in order for a locking tongue  723  to fit within a recess or groove  725  in the cover  704  so as to selectively secure and release the cover  704  to and from the base  702 . 
     FIG. 8  illustrates a locking mechanism that includes a latch  818  rotatably connected to the base  802  that can be selectively inserted into and withdrawn from an eyelet  820  attached to or formed on cover  804 . 
   The foregoing locking mechanisms are exemplary, and any locking mechanism capable of securing the cover to the base may be used. 
   It should be understood that the general concept of a cover attached to a base by means of an elongate strap hinge and a curved surface that helps the strap hinge bend along a substantial portion of its length and/or a camming surface that biases the cover toward an open position can be generalized to be usable together with other known mechanisms or devices. For example, rather than being attached to a base, the cover might be attached to, for example, a box or other container by means of an elongate strap hinge. A curved, hinge guide structure and/or an interactive camming surface that biases the cover toward the open position may also be included in order for the benefits disclosed herein to be extended to lids or covers that can be selectively moved between open and closed positions relative to a box, container, or other substrate. 
   The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.