Abstract:
An apparatus with no moving parts that enables the adjustment of the length and tautness of a serpentine article simply by sliding the apparatus. A self-locking and adjustable apparatus is described that consists of a body, an angled passage through the body for passing and gripping the serpentine article, and an anchoring channel for the attachment of one end of the serpentine article to form a loop in the serpentine article. The self-locking and adjustable apparatus can be used alone to apply circumferential force or with fasteners to apply linear force.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     DESCRIPTION OF ATTACHED APPENDIX 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     This invention relates generally to the field of tension devices and more specifically to a self-locking and adjustable apparatus for changing and maintaining the length and tautness of a serpentine article. 
     Adjustable tension devices for a serpentine article has many applications including tie-down cords, belts, straps, rigging, and tourniquets. These devices have found uses in homes and in the entertainment, sporting, travel, marine, medical, and other industries. 
     Easy adjustability and secure gripping have been sought after features of adjustable tension devices. The amount of tautness a tension device will maintain before it slips or breaks depends not only upon the tensile strength of the serpentine article but also the design and composition of the device. 
     A patented adjustable tension device utilizing an elastic cord in a loop configuration is the invention of Libecco, U.S. Pat. No. 6,389,655 B2, May 2002, ADJUSTABLE ELASTIC TIE-DOWN CORD. The prior art of Libecco&#39;s invention is illustrated in FIG.  1 . The ADJUSTABLE ELASTIC TIE-DOWN CORD consists of an adjusting retainer bar, two hooks, and an elongated elastic cord. Elastic cord  11  originates at stop knot  12 , passes through passage  13 , forms an adjustable loop to which hook  14  is attached, passes through passage  15  that has protrusions, and terminates in a non-adjustable loop that has hook  16  attached. The length and tautness of the tie-down cord is adjusted by sliding cord  11  through passage  15  in retainer bar  10 . The protrusions provided in passage  15  engage and penetrate the stretch cord for assisting and locking it in position within the passage. 
     A patented buckle for adjusting the length and tautness of a serpentine article is the invention of Plzak, U.S. Pat. No. 6,295,700, October 2001, BUCKLE FOR MAINTAINING TENSION IN A SERPENTINE ARTICLE. The prior art of Plzak&#39;s invention is illustrated in FIG.  2 . The BUCKLE FOR MAINTAINING TENSION IN A SERPENTINE ARTICLE consists of pin  20 , first cam load bearing portion  21 , second cam load bearing portion  22 , first structure load bearing portion  23 , second structure load bearing portion  24 , serpentine article  25 , axis of rotation  26 , cam  27 , handle  28 , and channel  29  in handle  28 . To adjust the tension on serpentine article  25 , serpentine article  25  is passed through the circuitous route within the buckle. Tension on serpentine article  25  causes cam  27  to rotate clockwise around axis  26  and pinch serpentine article  25  between (1) the first cam  21  and first structure  23  load bearing portions, and between (2) second cam  22  and second structure  24  load bearing portions. Handle  28  attaches to cam  27 . Channel  29  in handle  28  provides space for the passage of serpentine article  25 . To release the tension on serpentine article  25 , handle  28  is depressed. Cam  27  rotates on pin  20 . 
     The deficiencies of the ADJUSTABLE ELASTIC TIE-DOWN CORD of Libecco are (1) the strength of the grip is limited to the strength of the protrusions within the passage in the retainer bar, (2) the diameter of the holes in the retainer bar must be closely matched with the diameter of the cord because the protrusions must penetrate the cord to lock it into position, (3) the protrusions restrict sliding and hinder cord adjustments, (4) the protrusions penetrate the cord and may damage and weaken the cord, and (5) when the two hooks are under tension, the line of force is through channel  15  and not through the center of the loop, this causes the retainer bar to pivot which may lead to instability of the tension device. 
     The deficiencies of the BUCKLE FOR MAINTAINING TENSION IN A SERPENTINE ARTICLE of Plzak are as following. (1) The rotary cam is a key feature of Plzak&#39;s invention. Because it is movable, the buckle has the problems inherent of moving parts, particularly since the parts are exposed to environmental conditions. Dust and debris can collect between the cam and the pin with potential malfunction of the moveable cam. Depending upon the composition of the pin, salt water may corrode the pin when made of metal and cause the cam to malfunction. (2) The multiplicity of weight bearing parts, cam  27 , housing structures  23  and  24 , and pin  20 , increases the number of items that are subject to wear and damage by the stress of heavy loads as compared to a tension device constructed of a single part. The strength of the buckle depends not only upon the composition of the housing structure and cam, but also on the composition of pin  20  and how pin  20  is attached to the housing. 
     Unlike the invention of Libecco, which is designed for a round elastic cord, my tension device can secure a serpentine article of any shape and made of non-elastic or elastic material. One reason my invention is more versatile is that my lock mechanism is not dependent upon protrusions but due to forces applied by the angled channel. In Libecco&#39;s invention while the protrusions engage the cord under tension they also impede the movement of the cord for adjusting the overall length of the tie-down. The channel in my invention is smooth and the serpentine article easily slides through my invention for adjusting the tautness or length. 
     When detaching an elastic tie-down, it is safer to release the tension of the tie-down by sliding the tension device prior to unfastening the hooks. Because Libecco&#39;s invention has protrusions holding the cord in place, it would be difficult to loosen his tie-down while under tension. With my invention it is easy to lengthen or shorten the tie-down while under tension. 
     The strength of a tension device is an important parameter when securing a load. The strength of the tension device can be limited by the grip on the serpentine article and the strength of the material of the device. The strength of the invention of Libecco is as strong as the protrusions in the channel that engage the cord. The strength of the invention of Plzak is the strength of the weakest component: the cam, the housing, or the pin that holds the cam. Since the preferred embodiment of my invention has no protrusions that engage the serpentine article and no component or moving parts, the strength of the preferred embodiment is limited by only the strength of the material from which the tension device is constructed, be it, plastic, wood, or metal. 
     BRIEF SUMMARY OF THE INVENTION 
     The primary object of the invention is to provide a self-locking and adjustable tension device to change the tautness of a serpentine article while under tension. 
     Another object of the invention is to provide for a self-locking and adjustable tension device that easily secures a serpentine article shortened to any selected length and that the selected length is further adjustable. 
     Another object of the invention is to provide for a self-locking and adjustable tension device that will accommodate serpentine articles of different diameters and shapes. 
     Another object of the invention is to provide for a self-locking and adjustable tension device that has only one piece and thereby is as strong and as durable as the material from which it is constructed. 
     Another object of the invention is to provide for a self-locking and adjustable tension device for elastic and non-elastic serpentine articles. 
     Another object of the invention is to provide a self-locking and adjustable tension device that has no rotating parts so that there is no possibility of corrosion and malfunction due to moving parts. 
     Yet another object of the invention is to provide a self-locking and adjustable tension device that adjusts the length of a serpentine article simply by sliding the body of the tension device. 
     Still yet another object of the invention is to provide a self-locking and adjustable tension device in which the forces are evenly distributed across the body and the body does not tilt while under tension. 
     A further object of the invention is to provide an adjustable tension device that will adapt to multiple situations that has previously been fulfilled by several individual adjustable and non-adjustable serpentine articles. My invention obviates acquiring a variety of tension devices to prepare for unforeseen needs. 
     A Still further object of the present invention is to provide a self-locking and adjustable tension device with a loop that surrounds an object and exert circumferential force that can be applied and adjusted with one hand. 
     Other objects and advantages of the present invention will become apparent from the following descriptions, taken in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the present invention is disclosed. 
     In accordance with a preferred embodiment of the invention, there is disclosed a tension device that adjusts the length and tautness of a serpentine article comprising: a body, an angled passage through the body for passing and gripping the serpentine article, and a method of attaching one end of the serpentine article to the body to form a loop. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention. 
     FIG. 1 is a perspective view of the prior art of the invention of Libecco. 
     FIG. 2 is a cross-sectional view of the prior art of the invention of Plzak. 
     FIG. 3 is an isometric view of my self-locking and adjustable tension device. 
     FIG. 4 is an isometric view of my self-locking and adjustable tension device with hooks and a serpentine article arranged to exert linear force. 
     FIG. 5 is an isometric view of my self-locking and adjustable tension device with a serpentine article arranged to exert circumferential force. 
     FIG. 6 is an isometric view of my self-locking and adjustable tension device adjusted to shorten the serpentine article as compared to FIG.  4 . 
     FIG. 7 is an isometric view of my self-locking and adjustable tension device adjusted to reduce the circumferential distance of the loop as compared to FIG.  5 . 
     FIG. 8 is a schematic view of an alternative embodiment of my self-locking and adjustable tension device showing a triangular body and alterative shapes of the channels. 
     FIG. 9 is a schematic view of an alternative embodiment of my self-locking and adjustable tension device showing a rectangular body and alterative shapes of the channels. 
     FIG. 10 is a schematic view of an alternative embodiment of my self-locking and adjustable tension device showing a round body and alterative shapes of the channels. 
     FIG. 11 is a perspective view of an additional embodiment of my self-locking and adjustable tension device showing perforated partitions. 
     FIG. 12 is a perspective view of an additional embodiment of my self-locking and adjustable tension device constructed of parts. 
    
    
     REFERENCE NUMERALS IN DRAWINGS 
       10  retainer bar 
       11  elongated elastic cord 
       12  stop knot 
       13  passage 
       14  hook 
       15  passage with protrusions 
       16  hook 
       20  pin 
       21  first cam load bearing portion 
       22  second cam load bearing portion 
       23  first structure load bearing portion 
       24  second structure load bearing portion 
       25  serpentine article 
       26  axis of rotation 
       27  cam 
       28  handle 
       29  channel in arm handle 
       30  body 
       31   a  first segment of channel 
       31   b  second segment of channel 
       31   c  third segment of channel 
       32  anchoring channel 
       34  recess 
       35  bore hole 
       36  first aspect 
       37  second aspect 
       38  first bend 
       39  second bend 
       41  hook 
       42  hook 
       43  knot 
       44  segment of serpentine article 
       45  loop 
       46  serpentine article 
       50  serpentine article 
       51  loop 
       52  knot 
       80  bend 
       81  bend 
       82  sphere 
       83  serpentine article 
       90  bend 
       91  bend 
       92  bend 
       93  serpentine article 
       100  bend 
       101  bend 
       103  serpentine article 
       110  slot 
       111  slot 
       112  partition 
       113  partition 
       114  partition 
       115  channel 
       116  channel 
       117  channel 
       118  channel 
       119  serpentine article 
       120  body 
       121  channel 
       122  channel 
       123  channel 
       124  channel 
       125  back 
       126  partition 
       127  partition 
       128  partition 
       129  screw 
       130  body 
       131  serpentine article 
     DETAILED DESCRIPTION OF DRAWINGS 
     Description—FIGS.  1  and  2 —Prior Art 
     In FIG. 1 is illustrated the prior art of the ADJUSTABLE ELASTIC TIE-DOWN CORD of Libecco. The invention consists of retainer bar  10 , elongated elastic cord  11 , end with stop knot  12 , passage  13  without protrusions, hook  14  attached to adjustable loop, passage  15  with protrusions for gripping the cord, and hook  16  attached to non-adjustable loop. 
     In FIG. 2 is illustrated the prior art of the BUCKLE FOR MAINTAINING TENSION IN A SERPENTINE ARTICLE by Pizak. The invention consists of pin  20 , first cam load bearing portion  21 , second cam load bearing portion  22 , first structure load bearing portion  23 , second structure load bearing portion  24 , serpentine article  25 , axis of rotation  26 , cam  27 , handle  28 , and channel  29  in handle  28 . 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The term serpentine article is used herein to denote an object that is flexible and elongated, having unspecified length, and a cross-sectional ratio of unity or less; where the cross-sectional ratio is the smallest cross-sectional diameter divided by the largest cross-sectional diameter. Some examples of serpentine articles include: lines, cords, straps, cables, ropes, belts, and strings. This list is illustrative only and many more examples of serpentine articles with which my tension device is useful will be obvious to one skilled in the art. 
     Detailed descriptions of the preferred embodiment are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner. 
     Description—FIGS.  3 - 7 —Preferred Embodiment 
     In accordance with the present invention, FIG. 3 shows my tension device consisting of body  30 , slide and lock channel  31   a-c,  bore hole  35 , anchoring channel  32 , and recess  34  of channel  32 . Channels  31   a-c  and  32  extend across body  30  from first aspect  36  to second aspect  37  of body  30 . Channel segment  31   a  pierces body  30  near the bottom edge of first aspect  36 . Channel segment  31   c  pierces body  30  near the center of second aspect  37 . Channel  32  pierces body  30  near the top edge of first aspect  36  and the top edge of second aspect  37 . The diameter of recess  34  is large enough to accept a terminus that is larger than the diameter in the other part of channel  32 . Bore hole  35  permits access for constructing channel  31   b.  The channels in the preferred embodiment are round, however, the channels can be other shapes: a few examples are oval, octagonal, and rectangular. In the preferred embodiment, body  30  is composed of acetal resin, however, it can be constructed of other materials, such as, other plastics, wood, or metal. 
     In accordance with an important feature of the present invention, there is shown in FIG. 4 where slide and lock channel  31   a-c  has two bends, first bend  38  and second bend  39 . Segment  31   b  between bends  38  and  39  is of substantial length so that serpentine article  46  completes bend  38  and passes straight prior to reaching bend  39 . The angle of the second bend  39  depends upon the angle of first bend  38 . In the preferred embodiment, first bend  38  is 45 degrees and second bend  39  is 90 degrees. However, first bend  38  can be any angle that in conjunction with second bend  39  orients segment  31   c  to exit near the center of second aspect  37 . 
     The force on knot  43  is directed through the opening of channel  32  at the upper edge of first aspect  36  to loop  45 . In the preferred embodiment, the relative positions of channels  31   a  and  32  are such that serpentine article  46  between second aspect  37  and hook  42  aligns with the center of loop  45 . 
     FIG. 4 shows the setup for my tension device to adjust the linear length By comparing FIGS. 5 and 7, you will see that the diameter of loop  51  decreases as body  30  slides away from knot  52 . By comparing FIGS. 5 and 7, you will see that the diameter of loop  51  decreases as body  30  slides away from knot  52 , cut off segment  44  from serpentine article  46  determines the maximum length between hooks  41  and  42 . After segment  44  is cut off, knot  43  is tied in serpentine article  46  and concealed in recess  34 . In the preferred embodiment, serpentine article  46  is anchored by knot  43 ; however, the terminus can be a mechanical device, such as, sphere  82  as seen in FIG.  8 . 
     In the preferred embodiment serpentine article  46  is round and constructed of a stretchable material, however, it can be other shapes and constructed of a non-stretchable material. It is a feature of the invention that hooks attach to serpentine article  46 ; however, snaps, clips, or other fasteners can be substituted for the hooks. 
     Turn now to FIG. 5 to see the illustration of my tension device setup to adjust circumferential length and tautness of serpentine article  50 , a configuration of a belt, tourniquet, or other constricting devices. Serpentine article  50  is without hooks. Knot  52  prevents serpentine article  50  from sliding through body  30 . In the preferred embodiment, knot  43  anchors serpentine article  50  to body  30 , however, anchoring can be by a permanent fastener, such as, a staple, or a fastener that can be released, such as, a snap or another quick release device. In the preferred embodiment serpentine article  50  is round and constructed of a stretchable material, however, it can be of other shapes and constructed of a non-stretchable material. 
     FIGS. 8-10, Alternative Embodiments 
     There are alternative configurations of the channels within my tension device. In the preferred embodiment the angle between channel segments  31   a  and  31   b  is 45 degrees and between channel segments  31   b  and  31   c  is 90 degrees. An example of an alternative configuration of the slide and lock channel is seen in FIG. 8 by bends  80  and  81 , which are each 90 degrees. It is also possible that the slide and lock channel can have only one bend. When there is a single angle in the slide and lock channel, the angle of the bend can ranges from (1) an obtuse angle, such as, bend  90  as shown in FIG. 9 to (2) an acute angle, such as, bend  100  shown in FIG.  10 . 
     As seen in the preferred embodiment, anchoring serpentine article  46  to body  30  can be by knot  43  in straight anchoring channel  32 , however, the channel may not be straight, as exemplified by bends  91  and  92  in FIG.  9  and bend  101  in FIG.  10 . Sphere  82  is the anchoring terminus of serpentine articles  83 ,  93 ,  103 . 
     The shape of the body of my tension device can be other than rectangular body  30 , the preferred embodiment. The triangular shaped body seen in FIG.  8  and the circular shaped body shown in FIG. 10 are examples of some alternative shapes for my invention, however, it should be understood that the shape of the body of my invention is not limited to these examples. 
     FIGS. 11 and 12, Additional Embodiments 
     Configured differently than the continuous channel of the preferred embodiment, but sharing the unifying principles of angled pathway and force alignment to the center of the serpentine article loop are the embodiments illustrated in FIGS. 11 and 12. Directing your attention to FIG. 11, you will be see one-piece body  120  with slots  110  and  111 , partitions  112 ,  113 , and  114  with channels  115 ,  116 ,  117 , and  118 , and serpentine article  119 . The width of the slots and the thickness of the partitions are discretionary and based upon the cross-sectional diameter of serpentine article  119 , weight of the anticipated load on serpentine article  119 , and the desired physical size of body  120 . A face to cover the slots and partitions could increase the strength of body  120 , but is not essential for the operation of my invention; however, the construction of such a cover would obvious to the skilled artesian. 
     Turning to FIG. 12, you will see body  130  is constructed of parts. Back  125  is joined to partitions  126 , 127 , and  128  by screws similar to screw  129 . Alternatively a bonding agent can substitute for the screws. Channels  121 , 122 ,  123 , and  124  align and grip serpentine article  131 . Body  130  serves only as one example of my invention constructed of parts and it should be understood there are many other possible configurations that would be evident to those skilled in the art. 
     Operation of the Preferred Embodiment 
     The preferred embodiment, when setup to adjust the linear length and tautness of a serpentine article, is configured with sliding hook  41  attached to loop  45  and a stationary hook  42  attached to the free end serpentine article  46  as seen in FIG.  4 . When using my invention as a tie-down, the following steps are taken. Firstly, set the overall length of the serpentine article for the specific application by pulling the serpentine article through anchoring channel  32  until hooks  41  and  42  are separated the desired distance. Secondly, tie knot  43  and cut off segment  44  of the serpentine article. Thirdly, fasten hooks  41  and  42  to objects in preparation for traction; for example, attach one hook to a brace of a boat trailer and the other hook through an eyelet in the tarp that covers the boat. Lastly, move body  30  in the direction of hook  42  until the objects are under the desired amount of tension, for the example above, until the tarp is taut. My tension device self-locks and additional stress on the serpentine article will not result is slippage of the serpentine article. While under tension, my invention can be adjusted to increase or decrease tautness. Upon comparing FIGS. 4 and 6, it will be seen that by sliding body  30  toward hook  42 , the distance between hooks  41  and  42  is shortened. To reduce tension on the serpentine article, simply slide body  30  in the direction of hook  41 . 
     The preferred embodiment, when arranged to adjust the circumferential length and force is setup with a loop and no hooks or fasteners as illustrated in FIG.  5 . For example, in the case of a tourniquet, once the overall size of loop  51  is adjusted by tying anchoring knot  43 , loop  51  is placed around an extremity of a subject and serpentine article  50  is tightened until the desired tautness is achieved. By comparing FIGS. 5 and 7, you will see that the diameter of loop  51  decreases as body  30  slides away from knot  52 . Serpentine article  50  can be tightened in two ways; (1) body  30  can be held in one hand while counter force is applied to serpentine article  50  or (2) serpentine article  50  can be pulled tangentially with one hand and body  30  will advance and tighten the tourniquet around the extremity. The one handed technique of tightening a tourniquet is an ideal method to secure a bleeding limb when an individual is alone. To loosen the tourniquet, one simply pulls body  30  away from the extremity. 
     Advantages 
     From the description above a number of advantages of my invention become apparent. 
     a. The one-piece construction makes my tension device simple to manufacture and simple to operate. 
     b. The absence of the rotary parts in my invention eliminates the problems inherent of moving parts. 
     c. My tension device is easier to adjust than other tension devices, simply slide the tension device, no release arm to press or no protrusions to move against. 
     d. Unlike the invention of Libecco, my tension device can be easily adjusted to shorten or lengthen the serpentine article while under tension. This makes my invention safer to use because the tension on the serpentine article can be easily released prior to unhooking the elastic tie-down. 
     e. Unlike the invention of Libecco, my tension device can accommodate elastic or non-elastic serpentine articles of different diameters and shapes. 
     f. My tension device does not pivot while under tension because forces are evenly distributed across the body of my tension device and not weighted to one side as are the forces affecting Libecco&#39;s retainer bar. 
     g. Unlike the invention of Plzak, the strength of my tension device is related to only the composition of the material of the body, and not to multiple components. 
     h. When used as a tourniquet, only one hand is needed to operate the tension device. 
     While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.