Abstract:
A soft cable boot is snapped on or molded around a cable or cable harness. The cable boot has a three dimensional interlock structure on its circumference via which it interlocks with an interlock teeth profile of a boot clamp. While the boot clamp is mounted and tied down, the interlock teeth profile is pressed into the three dimensional interlock structure and the cable or cable harness is three dimensionally form fitting and elastically fixed, whereby vibration related cable wear is reduced. A boot assembly tool may be used to snap the cable boot onto the cable and/or to inject a sealant into the assembled boot clamp or mold the boot clamp around the cable.

Description:
CROSS REFERENCE 
       [0001]    The present invention cross references US patent application of the same inventor titled “Cable Constraining Device For Reduced Cable Wear”, application Ser. No. 12/131,096, filed 1 Jun. 2008 and US Continuation in Part patent application of the same inventor, titled “Cable Constraining Device For Reduced Cable Wear”, application Ser. No. 12/200,904, filed 28 Aug. 2008, both of which are herewith incorporated by reference. 
     
    
     FIELD OF INVENTION 
       [0002]    The present invention relates to cable fixture and clamping systems. In particular, the present invention relates to cable fixture and clamping systems employing an elastic cable boot in a three dimensionally formfitting interlock with a mounting clamp. 
       BACKGROUND OF INVENTION 
       [0003]    In motorized vehicles such as aircrafts, cables and cable strands are commonly exposed to substantial vibrations. Such vibrations may be transferred onto the entire cable or cable strand at their mounting sites as three dimensional linear and rotational micro movements that may excite the unsupported portions of the cable or cable strand in between their adjacent mounting sites. This commonly causes wear of the cable insulation at the mounting interface where the cable or cable strand is fixedly held. Therefore, there exists a need for a cable or cable strand mounting system that minimizes micro movements and that dampens vibrations in the mounting interface while at the same time providing a solid three dimensional fix of the cable or cable strand. The present invention addresses this need. 
         [0004]    Another common cause for cable wear or deterioration of the cable insulation is dust, debris and/or moisture creeping into the mounting interface. Therefore, there exists a need for a sealed cable or cable strand mounting interface. The present invention addresses also this need. 
       SUMMARY OF INVENTION 
       [0005]    A cable clamp system features a cable boot with a cable through hole and a peripheral three axes interlock structure that engages with a correspondingly shaped interlock teeth profile of a boot clamp. The boot clamp encompasses the cable boot and features a mounting interface via which both the boot and the clamp may be mounted. The cable boot is of relatively soft material and tapers out towards its two opposing ends to provide a gradual stiffness decline towards its two respective opposing ends. In that way, cable movement of the freely suspended cable extending from the cable boot is transferred onto the boot with minimized friction between the cable and the boot at its two opposing ends. Particularly for aviation cable strands that are exposed to strong vibrations, the cable clamp system of the present invention may reduce wear and insulation cracking in the transition between the fixed and freely suspended portions of the cable or cable strand. The interlock teeth profile may further feature a damping configuration as described in the cross referenced applications to dampen vibrations transmitted from the cable or cable strand onto the cable boot. 
         [0006]    A cable boot assembly tool may be part of the system, featuring a separable boot cavity within which an open cable boot may be placed and snap closed around the cable or cable harness. The cable boot assembly tool may further feature an injection molding device to inject mold material such as thermosetting plastic or resin into the boot clamp to seal and/or snugly encapsulate the cable or cable strand inside the boot clamp. Alternately, the boot clamp itself may be formed by injection molding around a portion of the cable or cable strand that is held inside the boot cavity. 
         [0007]    The dual system of a flexible boot and a frame supported clamp provides a firm mounting and at the same time a soft but three dimensionally stable positioning of the cable or cable strand. Vibrations and wear of the cable or cable harness are opposed and minimized. The sealed fix of the cable or cable strand inside the cable boot keeps dust, debris or moisture away, which may also contribute to an extended lifespan of the cable insulation inside the cable boot. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0008]      FIG. 1  is a first perspective view of a first embodiment of the invention assembled around a cable strand. 
           [0009]      FIG. 2  is a second perspective view of the embodiment of  FIG. 1 . 
           [0010]      FIG. 3  is the second perspective view of the embodiment of  FIG. 1  cut along a radial symmetry plane. 
           [0011]      FIG. 4  is a third perspective view of the cable boot of  FIG. 1 . 
           [0012]      FIG. 5  is the third perspective view of a cable boot according to a second embodiment of the invention partially assembled on a cable strand. 
           [0013]      FIG. 6  is the third perspective view of a first embodiment of a cable boot assembly tool of the present invention in opened position around a cable boot and cable harness. 
           [0014]      FIG. 7  is the third perspective view of a second embodiment of a cable boot assembly tool having an injection molding device. The cable boot assembly tool is closed around a cable strand. 
           [0015]      FIG. 8  is the third perspective view of the second embodiment of the cable boot assembly tool of  FIG. 7 , a cable strand and a cable boot, all cut along a radial symmetry plane. 
           [0016]      FIG. 9  is the third perspective cut view of the cable boot and cable harness of  FIG. 8  with injected mold material. 
           [0017]      FIG. 10  is the third perspective cut view as  FIG. 8  without cable boot in the boot cavity. 
           [0018]      FIG. 11  is the third perspective cut view of a cable boot monolithically molded around the cable strand in accordance to  FIG. 10 . 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    Referring to  FIGS. 1-4 , a cable clamp system  100  according to a first embodiment of the invention features a cable boot  104  and a boot clamp  108 . The cable boot  104  has a cable through hole  128  configured to fixedly hold a cable or cable strand  96 . The cable boot  104  has also on its periphery a three axes interlock structure  124  including a circumferential groove  125  and at least one but preferably a number of axial ribs  126  that are inside the circumferential groove  125 . The peripheral three axes interlock structure  124  encompasses the cable through hole  128 . The boot clamp  104  features an interlock teeth profile  112 , a clamp frame  116  that is circumferentially connected to the interlock teeth profile  112  and a clamp mounting interface  120 . The interlock teeth profile  112  may have vibration damping configuration as described in the cross referenced applications. The interlock teeth profile  112  matches the peripheral three axes interlock structure  124  while the cable boot  104  is clamped in the boot clamp  108 . The clamping of the cable boot  104  in the boot clamp  108  and a three axes interlock between them is established by use of a clamping segmentation of the clamp frame  116  such that while the boot clamp  108  is tied down via the clamp mounting interface  120 , the interlock teeth profile  112  is forced towards the peripheral three axes interlock structure  124 . 
         [0020]    Referencing also to  FIGS. 4 ,  5 , the cable boot  104  may include preferably two body segments  104 A,  104 B, each featuring a mating face  132 A/ 132 B. Each one of the mating faces  132 A/ 132 B is extending substantially radially outward from the cable through hole  128  and facing an opposite one other of the mating face  132 B/ 132 A while the boot clamp is assembled. In that way, the cable through hole  128  is circumferentially open while the body segments  104 A,  104 B are apart and a cable or cable strand  96  may be conveniently inserted as shown in  FIG. 5 . When the two body segments  104 A,  104 B are assembled together around the cable or cable strand  96 , the cable or cable strand  96  is preferably fully encapsulated inside the cable through hole  128 . 
         [0021]    The mating faces  132 A,  132 B have one of a snap stud  136  and a snap hole  140  via which the body segments  104 A,  104 B may be snapped together while the mating faces  132 A,  132 B are in contact and while the cable through hole  128  is circumferentially closed. The cable boot  104  may also feature circumferential tie guide holes  148  and at least one but preferably two circumferential tie grooves  144  that extend circumferentially across the mating faces  132 A,  132 B while the two body segments  104 A,  104 B are snapped together. The circumferential tie grooves  144  and tie holes  148  are preferably in the vicinity of the openings of the cable through hole  128  to hold optional boot ties  152  axially in position. The boot ties  152  may be wrapped around and tying together the body segments  104 A,  104 B in addition or alternating to the snap studs  136  and snap holes  140  to firmly hold the body segments  104 A,  104 B together. 
         [0022]    As depicted in  FIG. 5 , one or more flexible film joints  156  may be employed that connect rotationally free the body segments  104 A,  104 B, with each other. In that way, they may assist the handling of the two body segments  104 A,  104 B during their assembly around the cable or cable strand  96 . Also by employing the flexible film joints  156 , the body segments  104 A,  104 B may be monolithically fabricated by well known injection molding techniques. 
         [0023]    To oppose dust, debris or moisture from entering the eventual gaps between individual strands of the cable strand  96  and/or in between the cable or cable strand  96  and the cable through hole  128 , following features may be employed either alone or in combination with each other as may be well appreciated by anyone skilled in the art. To seal any eventual gap between opposing mating faces  132 A,  132 B radially towards the cable through hole  128 , seal ridges  160  and seal valleys  164  may be positioned along an edge between a portion of the cable through hole  128  and one of the mating faces  132 A,  132 B as shown in  FIG. 5 . To seal the openings of the through holes  128  particularly in case of a held cable strand  96 , radial seal ribs  170  may extend substantially radially inward the cable through hole  128 . The radial seal ribs  170  may correspond to the circumferential contours of the cable strands  96  for a snug sealing contact as may be well appreciated by anyone skilled in the art. The radial seal ribs  170  may also assist in fixedly holding individual strands of the cable  96  thereby particularly contributing to minimizing vibration related micro-friction and wear of the cable strand&#39;s  96  insulation. 
         [0024]    A snug fix, good sealing and eventual adhesive connection of the cable or cable strand  96  inside the cable boot  104  may also be accomplished by providing the cable boot  104  with an internal sealant distribution cavity  168  and a peripheral sealant access port  172  that is in communication with the internal sealant distribution cavity  168 . The internal sealant cavity  168  extends radial outward the cable through hole  96  and axially in between both cable through hole  96  openings. It may receive a fluid sealant via the peripheral sealant access port  172  while the clamp boot  104  is assembled around the cable or cable strand  96  as depicted in  FIG. 9 . The sealant may cure once distributed. Alternately, the entire boot clamp  104  may be molded around the cable or cable strand  96  as depicted in  FIG. 11 . 
         [0025]    Snapping together of the body segments  104 A,  104 B, and/or sealant injection and/or cable boot  104  molding may be accomplished by a cable boot assembly tool  174  as depicted in  FIGS. 6-8 ,  10 . According to  FIG. 6 , a basic configuration of the cable boot assembly tool  174  features cable alignment openings  180 , a separable boot cavity  178 , and a hand operable cavity open and close mechanism  188 . The separable boot cavity  178  has a three axes interlock structure negative shape and is shaped with respect to the cable alignment openings  180  such that a substantially continuous cable boot negative shape including a three axes interlock structure negative shape is defined around the cable or cable strand  96  held in the cable alignment openings  180  while the cable boot assembly tool is closed around the cable or cable strand  96 . In that way the body segments  104 A,  104 B may be snugly fitted into the cable boot assembly tool  174  such that irrespective a softness of the body segments  104 A,  104 B of about . . . (Please provide an targeted Shore hardness), the body segments  104 A,  104 B may be firmly snapped together. 
         [0026]    In an alternate embodiment depicted in  FIGS. 7 ,  8 ,  10 , the cable boot assembly tool  174  features also an injection port  176 , a release able closing ratchet  192  as part of the hand operable cavity open and close mechanism  188 , a molding material storage cavity  196 , an optional storage cavity heater  200  in case of a thermosetting sealant or molding material, and an injection mechanism  204  that is preferably manually operable. 
         [0027]    The cable boot  104  may be initially assembled on a predetermined position along the cable or cable strand  96  by snapping on the two body segments  104 A,  104 B followed by an optional additional tightening with boot ties  152 . To snap the two body segments  104 A,  104 B together, the cable tool assembly tool  174  may be employed. After the cable boot  104  is assembled on the cable or cable strand  96  and in the embodiment where an internal sealant distribution cavity  168  and a peripheral sealant access port  172  are provided by the cable boot  104 , sealant may be injected into the cable through hole  128  via the cable boot assembly tool  174 . 
         [0028]    In case the cable boot  104  is molded directly on a predetermined location of the cable or cable strand  96 , the boot cavity  178  may tied around the cable or cable strand  96  at that predetermined location and the optional release able closing ratchet  192  may be set to hold the boot cavity  178  closed while mold material  97  is injected into the boot cavity  178  around the cable or cable strand  96 . Once the mold material  97  has sufficiently cooled down or cured to hold its shape, the closing ratchet  192  may be released and the cable boot assembly tool  174  removed. 
         [0029]    Once the cable boot  104  is assembled on the cable or cable strand  96 , the boot clamp  108  may be wrapped with its interlock teeth profile  112  around the peripheral three axis interlock structure  124 . Once the boot clamp  108  is tied down, the cable boot  104  becomes three dimensionally form fitting and elastically fixed with its peripheral three axis interlock structure  124  onto the interlock teeth profile  112 . 
         [0030]    Accordingly, the scope of the invention described in the figures and specification above is set forth by the following claims and their legal equivalent: