Abstract:
A camming clamp has a fixed jaw, a pair anchored in the fixed jaw, and a moving jaw threaded onto the guides. A levered cam is threaded onto at least one guide. A backing surface is threaded onto the same one guide. It sandwiches the levered cam between itself and the moving jaw. An adjustable locking provision locks the backing surface at fixed positions along this guide with the levered cam. Wherein, the levered cam has a cam head with an over-center axis such that, when rolled on one side of the over-center axis the camming clamp is slack and adapted to position the jaws on opposite sides of an object to be clamped, and, when rolled over the other side of the over-center axis the jaws clamp tight on said object. The over-center axis prevents the cam head from auto-pivoting back to slack.

Description:
CROSS-REFERENCE TO PROVISIONAL APPLICATION(S) 
     This application claims the benefit of U.S. Provisional Application No. 61/340,824, filed Mar. 22, 2010 and was originally presented as U.S. Provisional Application No. 61/211,344, filed Mar. 26, 2009. All the foregoing patent disclosures are fully incorporated herein by reference. 
    
    
     BACKGROUND AND SUMMARY OF THE INVENTION 
     The invention relates to a gunwale clamp for boating accessories and, more particularly, to a camming clamp for gunwales or pontoon-boat rails such that the clamping and releasing (un-clamping) thereof can be done quickly by hand and without tools. 
     A number of additional features and objects will be apparent in connection with the following discussion of the preferred embodiments and examples with reference to the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       There are shown in the drawings certain exemplary embodiments of the invention as presently preferred. It should be understood that the invention is not limited to the embodiments disclosed as examples, and is capable of variation within the scope of the skills of a person having ordinary skill in the art to which the invention pertains. In the drawings, 
         FIG. 1  is a perspective view of a first embodiment of a camming clamp in accordance with the invention; 
         FIG. 2  is a side elevational view thereof; 
         FIG. 3  is an elevational view thereof from a viewpoint 90° to the right of FIG.  2 &#39;s; 
         FIG. 4  is a reduced-scale elevational view comparable to  FIG. 3  except showing the lever inverted; 
         FIG. 5  is a perspective view comparable to  FIG. 1  except likewise showing the lever inverted as in  FIG. 4 ; 
         FIG. 6  is an exploded view of the first embodiment of the camming clamp in accordance with the invention; 
         FIG. 7  is a perspective view comparable to  FIG. 1  except of a second embodiment of a camming clamp in accordance with the invention; and 
         FIG. 8  is a perspective view comparable to  FIG. 3  except of the second embodiment of a camming clamp in accordance with the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIGS. 1 through 6  show a first embodiment of a camming clamp  20  in accordance with the invention. This application is commonly-owned, commonly-invented with U.S. Pat. No. 7,555,994—Arnall, for a pontoon boat cover system. The intended field-of-use of the present invention comprises clamping the clamp  20  to gunwales and/or pontoon-boat rails (eg., pontoon boats don&#39;t formally have gunwales, but they have counterparts, which are rails). 
     The camming clamp  20  affords quick connection and disconnection to and from a gunwale or handrail and thereafter serve as a base on which to mount any number of various, interchangeable accessories. Such non-limiting examples include the pontoon-boat cover system in the above-referenced patent; rod holders; drink holders; as well as outboard hook for suspending a lantern, bait bucket or fish keep; and so on. 
     As  FIG. 6  shows better, the camming clamp  20  comprises two parallel rods  22  and  24 . One rod  22  is a smooth rod and comprises a track  22 . The other rod  24  is threaded  24 . It is an option to employ a lag bolt as the threaded rod  24 . In any event, the threaded rod  24  comprises the bite adjustment for the camming clamp  20 . Wherein, the bite of the clamp  20  comprises the gap between the jaws  26  and  28  when clamped tight to an object (no object shown).  FIG. 1  shows better that, the rods  22  and  24  are assembled to a fixed jaw  26  (ie., it being an L-shaped bracket), a moving jaw  28  (ie., a sliding plate), and a levered cam  30  that, when is shut, forces the moving jaw  28  into a clamped position. All of  FIGS. 1 through 5  show the levered cam  30  in the shut, clamped-tight position. 
     The moving jaw  28  has a guide sleeved  32  rigidly affixed to it, preferably by welding or the like. The guide sleeve  32  is formed with a hollow cylindrical core. The track rod  22  is likewise rigidly affixed to the fixed jaw  26 . Preferably this is also accomplished by welding or the like. The smooth rod  22  inserts through the hollow core of the guide sleeve  32 . The tolerance between the hollow cylindrical core of the guide sleeve  32  and smooth cylindrical outer wall of the track rod  22  is tight such that there is very close clearance. That way, the guide sleeve  32  slides back forth on the track rod  22 , maintaining the clamping surface of the moving jaw  28  very nearly parallel with the clamping surface of the fixed jaw  26 . As an aside, preferably the guide sleeve  32  slides back forth on the track rod  22  such that it maintains the clamping surface of the moving jaw  28  very nearly perpendicular to the axis of the track rod  22  over the extent of its travel on the track rod  22 . 
     The levered cam  30  comprises a cam head  34  and a lever arm  36  connected thereto (ie., the lever arm  36  is omitted from view in  FIG. 6 ). The camming clamp  20  further comprises a loosely sliding washer  42  and resilient O-ring  44  inserted between the cam head  34  of the levered cam  30  and the moving jaw  28 . There is also a backing washer  46  and lock nut  48  for the levered cam  30  for backing the cam head  34 . 
     The jaws are optionally covered by grip pads. The rods and lever arm are optionally inserted in vinyl tube in order to better protect against scratching the finish of the gunwale or handrail. 
     The drawings show the lock nut(s)  48  as implemented by a wing nut. It is an option of the invention that wing nuts are a non-limiting example and that other kinds of nuts can be used, including nylon lock nuts (not shown). Nylon lock nuts hold their position on a threaded rod more firmly than a wing nut. However, nylon lock nuts can typically only be spun by a wrench (not shown), whereas wing nuts can be spun by hand. 
     In use, a user adjusts the lock nut  48  at the outset in order to fix the distance between the moving jaw  28  and fixed jaw  26  when the levered cam  30  is shut. In other words, a user sets the grip distance for a given gunwale or handrail upon an initial use. Once this setting is adjusted to, the user can repeatedly connect and disconnect the camming clamp  20  to the same given gunwale or handrail—quickly and without re-adjusting the lock nut  48 &#39;s position—and without ever having to return to re-adjusting the original setting of the lock nut  48 . That way, the camming clamp  20  can be put on quickly and taken off quickly, over and over again, on the water, and manually so as to not ever again have to resort to re-adjusting the lock nut  48 &#39;s position. Importantly, this most significantly means without tools. 
     In use, the moving jaw  28  slides loosely on the pair of rods  22  and  24 , as does the resilient O-ring  44  and the pair of washers  42  and  46  which flank the cam head  34  of the levered cam  30 . The terminal lock nut  48  is set at a fixed distance away from the fixed jaw  26 . The cam head  34  is produced from a rolled-half-plate to produce a pair of cam ears  52 . The cam ears  52  have aligned holes through them to accept an apertured pivot pin  54 . The pivot pin  54 &#39;s aperture accepts the insertion of the respective threaded rod  24  and slides loosely thereon. 
     The cam ears  52  of each cam head have an over-center axis  66 - 66 .  FIG. 2  shows the near-side (eg., near-side in the view) cam ear  52  pivoted past the cam ear  52 &#39;s over-center axis  66 - 66 . The resilient O-ring  44  allows the cam ears  52  to travel past the over-center axis  66 - 66  by squishing flat. Once the levered cam  30  shuts (as shown in  FIG. 2 ), the cam ears  52  have gone past their over-center axis  66 - 66 , and the O-ring  44  restores itself somewhat, but remains pretty squished all the same. The cam ears  52  have one flat surface  62  for the locking position. This flat surface  62  is backed by the backing washer  46  in the locked position. That way, the O-ring  44  applies a retaining force on the cam ears  52 , which keeps the locking flat  62  abutted against the backing washer  46  and thereby prevents the cam ears  52  from freely pivoting open (eg., pivoting back across their over-center axes  66 - 66 ), which would detrimentally open the clamp  20 . 
     When the clamp  20  is open, the lever arm  36  would be flared in  FIG. 2  to about an 8 o&#39;clock position (but this is not shown in  FIG. 2 ). The cam ears  52  have a second flat surface  64  for the unlocked position. When the clamp  20  is open, the slack-position flat surface  64  more or less abuts the washer  42  that protects the O-ring  44 . To roll the cam ears  52  back and forth between the flat surfaces  62  and  64  requires rolling two teeth  66  to force apart the washers  42  and  46  against the compressibility of the O-ring  44 . The diameter (or chord) which stretches across the cam ears  52  and terminates in the diametrically opposite teeth  66  comprises the over-center-axis  66  for the cam ears  52 . 
       FIGS. 4 and 5  show that the levered cam  30  can be taken completely off the threaded rod  24 , inverted, and still be operable. Whereas in  FIGS. 1 through 3 , the lever arm  36  lies flush parallel alongside the threaded rod  24  when in the clamped shut position,  FIGS. 4 and 5  show that the lever arm  36  points about 180° in the opposite direction in the clamped shut position. This provides the user convenience of orienting the clamp  20  in any orientation and having the lever arm  36  swing wherever wanted, preferably inside the boat rather than outboard. 
     In use, when the user has shut the levered cam  30  to the point of taking the slack out of the jaws  26  and  28 , and is approaching rolling the cam ears  52  over their over-center-axes  66 - 66 , it is also preferred if the following is true. That is, when the user prepares for the final squeeze to get the cam ears  52  to travel past the over-center axes  66 - 66  therefor, it is preferred if the final squeeze intentionally takes some muscle. Whereas the lever arm  36  does provide leverage, it is preferred that—in order to get tight and secure clamping pressure—the final squeeze requires a fairly hard squeeze in order get a good tight clamp on a gunwale or handrail. 
       FIGS. 7 and 8  show an alternate embodiment of a camming clamp  80  in accordance with the invention. In contrast to the first embodiment, the track rod  22  and guide sleeve  32  formations have been replaced with a twin of the levered cam  30  and threaded rod  24  of the first embodiment. Hence the alternate embodiment camming clamp  80  requires squeezing two lever arms  36  shut in order to get the clamp  80  to be clamped shut.  FIGS. 7 and 8  both show the lever arms  36  in the shut position. When the lever arms  36  are shut, and there is a solid object in the jaws  26  and  28  of the clamp  80  (no object shown), the cam ears  52  have pivoted past their over-center axes  66 - 66 . The squishing of the O-rings  44  permitted the cam ears  52  to pivot across their over-center axes  66 - 66  by going flat as possible. And now the squished O-rings  44  apply a continual expansion force on the cam ears  52  so that they cannot auto-pivot back across the over-center axis  66 - 66  in the absence of an external force:—namely, in the absence of the user pulling the lever arms  36  apart. Again,  FIG. 2  provides a better view of a squished O-ring  44 . 
     The jaws  26  and  28  comprise a series of threaded sockets  74  distributed around. As mentioned previously, the fixed jaw  26  is an L-shaped bracket. One leg serves as the fixed jaw  26 , the other leg serves as a mounting base  72 . Actually, the fixed jaw leg  26  as well as the moving jaw  28  also serve as mounts for accessory sockets  74 , as both have threaded sockets  74  (welded-in nuts) which allows accessories to be twisted in on axes parallel with the parallel rods  22  and  24 . In contrast, the mounting base  72  has a threaded socket  74  (eg., welded-in nut) which allows accessories to be twisted in on an axis perpendicular with the parallel rods  22  and  24 . As oriented in  FIG. 2 , the mounting base  72  supports accessories which extend out over the water, while up the fixed jaw leg  26  supports accessories which extend up into the air. The moving jaw  28  would support accessories which extend over the boat&#39;s floor (no accessories shown). 
     The invention having been disclosed in connection with the foregoing variations and examples, additional variations will now be apparent to persons skilled in the art. The invention is not intended to be limited to the variations specifically mentioned, and accordingly reference should be made to the appended claims rather than the foregoing discussion of preferred examples, to assess the scope of the invention in which exclusive rights are claimed.