Abstract:
A webbing clamp incorporating a hollow base frame adapted to receive elongated webbing segments in threaded relation through a pair of opposing slot openings and a hinging camming door structure rotatably mounted within the base frame about an axis of rotation. The camming door structure includes a lever projection for user engagement and a camming ear portion extending below the lever projection for disposition at the interior of the base frame. The camming door structure is mounted transverse to the threading direction of the webbing segments and rotates about an axis generally aligned with the threading direction of the webbing segments. Upon closing the hinging door structure, the camming ear portion engages the webbing segments in a compressing manner thereby blocking relative sliding action with the webbing clamp.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This non-provisional application claims the benefit of and priority from U.S. Provisional Application 61/439,694 filed Feb. 4, 2011. The contents of such prior application are hereby incorporated by reference in their entirety as if fully set forth herein. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to clamps, and more particularly to clamps adapted for sliding engagement and lock-down of straps or other webbing elements. Such clamps may be used in environments such as helmets, backpacks, clothing and the like. 
     BACKGROUND OF THE INVENTION 
     Clamps that slidingly engage webbing segments and which may be selectively locked down relative to such webbing segments are known. Such prior clamps typically incorporate a base frame adapted to receive webbing segments such that the base frame can slide along the length of the webbing segments and such that the webbing segments can be adjusted relative to one another by being selectively pulled through the base frame. Some prior clamps have incorporated lock-down elements in the form of camming doors which are held within a carrier frame in overlying relation to the webbing segments. However, in known prior clamps having hinging lock-down camming doors, the doors have typically been oriented to rotate on an arc which is generally aligned with the travel direction of the webbing segments. Such an orientation minimizes the potential for tilting displacement of the camming door when the webbing segments are pulled. 
     SUMMARY OF THE INVENTION 
     The present invention departs from prior designs by providing a webbing clamp incorporating a hollow base frame adapted to receive elongated webbing segments in threaded relation through a pair of opposing slot openings and a hinging camming door structure rotatably mounted within the base frame about an axis of rotation. The camming door structure includes a lever projection for user engagement and a camming ear portion extending below the lever projection for disposition at the interior of the base frame. The camming door structure is mounted transverse to the threading direction of the webbing elements and rotates about an axis generally aligned with the threading direction of the webbing elements. Upon closing the hinging door structure, the camming ear portion engages the webbing elements in a compressing manner thereby blocking relative sliding action of the webbing elements within the clamp. 
     In accordance with one exemplary aspect, the present invention provides an adjustable webbing clamp adapted to selectively slide along one or more elongate webbing segments and to lock such webbing segments in place at the interior of the webbing clamp. The webbing clamp includes a base frame having a plurality of walls at least partially surrounding an interior cavity. A door acceptance opening is disposed between a pair of opposed lateral sidewalls. Each of the lateral sidewalls includes a webbing slot extending through the sidewall. The webbing slots are adapted to receive the elongate webbing segments in threaded relation in a travel path across the interior cavity. The webbing clamp further includes a camming door adapted for receipt within the door acceptance opening. The camming door includes a lever portion and a camming ear adapted to be received within the interior cavity. The camming door is rotatably mounted at the base frame along an axis of rotation oriented in transverse relation to the lateral sidewalls and in substantial alignment with the travel path of the webbing segments. Upon rotating the lever portion to a raised position away from the base frame, the camming ear is raised away from the travel path of the webbing segments and upon rotating the lever portion towards the base frame, the camming ear is lowered into compressing, clamping relation against the webbing segments. A method of selectively clamping webbing is also provided. 
     Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, and drawings in which like numbers are used to designate like features. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of one exemplary embodiment of a webbing clamp in accordance with the present invention with components in a disassembled state; 
         FIG. 2  is a view of the webbing clamp of  FIG. 1  in an assembled state; 
         FIG. 3  is a schematic elevation view illustrating the assembled webbing clamp of  FIG. 2  engaging threaded webbing segments extending through opposing openings in the webbing base; 
         FIG. 4  is a schematic cut-away view taken generally along line  4 - 4  in  FIG. 3  illustrating the camming door in locked orientation compressing the webbing; 
         FIG. 5  is a schematic cut-away view similar to  FIG. 4  illustrating the camming door in open, unlocked relation to relieve the compression on the webbing segments; and 
         FIGS. 6 and 7  illustrate the webbing clamp of  FIG. 2  engaging a pair of webbing segments for selective tightening of a helmet chinstrap structure. 
     
    
    
     Before the embodiments of the intention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use herein of “including”, “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof, as well as additional items and equivalents thereof. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made to the drawings, wherein to the extent possible, like elements are designated by like reference numerals in the various views. Referring now to  FIGS. 1 and 2 , a webbing clamp  10  in accordance with one exemplary embodiment is shown. As shown, in the exemplary configuration, the webbing clamp  10  includes a camming door  12  adapted to be rotatably mounted within a base frame  14  of generally hollow bin-like construction. The camming door  12  and the base frame  14  each may be of substantially unitary molded construction formed from a suitable moldable polymeric material such as nylon, acetal resin or the like. However, non-polymeric materials may also be used if desired. In this regard, the camming door  12  and the base frame  14  may be formed from similar or dissimilar materials. By way of example only, and not limitation, the camming door  12  and the base frame  14  may each be formed from Nylon 6 or Nylon 6,6 by injection molding or a similar process. 
     As best illustrated through joint reference to  FIGS. 1 ,  4  and  5 , in the illustrated exemplary construction the camming door includes a lever portion  16  defining an outwardly projecting tongue for manipulation by a user between open and closed positions in a manner as will be described further hereinafter. The camming door  12  further includes an asymmetrical lobed camming ear  18  extending away from the plane defined by the lever portion  16 . As best seen in  FIGS. 4 and 5 , the lever portion  16  in combination with the camming ear  18  cooperatively define a generally “b” shaped profile. As shown, in the illustrated configuration, the camming ear  18  has a rear surface  22  extending away from the plane defined by the lever portion  16 . In the exemplary embodiment, the rear surface  22  is curved or angled radially inwardly and faces generally away from the direction in which the lever portion projects. As shown, the rear surface  22  may extend to a generally planar lower edge  24  defining oriented in a plane substantially parallel to the lever portion  16 . As will be described further hereinafter, such a planar lower edge defines an extended surface compression foot for application of pressure against webbing segments  26  when the clamp is in a closed condition ( FIG. 4 ). By way of example only, and not limitation, other profile shapes such as “L” shapes, “T” shapes, “J” shapes and the like with camming ears extending away from a lever portion to compress webbing segments  26  at the interior of the base frame also may be used if desired. 
     As noted previously, the camming door  12  is adapted to be supported in rotatable relation within the base frame  14 . By way of example only, and not limitation, in the illustrated exemplary construction the camming ear  18  may include outwardly projecting pins  28  oriented in aligned relation to one another on opposing sides of the camming ear  18 . In the exemplary embodiment, the base frame  14  has a generally bin configuration with an open top and including a pair of aligned through holes  30  extending through opposing lateral sidewalls  32 . As may be understood through joint reference to  FIGS. 1 and 2 , the camming ear  18  of the door  12  may be pressed into the interior of the base frame  14  between the lateral sidewalls  32  until each of the pins  28  snaps into a corresponding one of the through holes  30 . In this regard, as best seen in  FIG. 1 , in the exemplary construction the base frame  14  includes a door acceptance opening designated generally as  34  extending longitudinally along the top of the base frame  14  between the lateral sidewalls  32 . The door acceptance opening  34  narrows progressively along its length from a relatively wide opening at a first end wall  36  to a more narrow width adjacent the opposing second end wall  38 . According to the exemplary practice, the width of the door acceptance opening  34  adjacent the first end wall  36  will preferably accommodate insertion of the camming ear  18  with the outer surfaces of the pins  28  engaging the inner surfaces of the lateral sidewalls  32 . As the camming ear  18  is inserted and the pins  28  are urged towards the through holes  30 , the lateral walls  32  are forced outwardly to a slight degree by the pins  28  and then snap back as the pins  28  enter the through holes  30 . The camming door  12  is thereby locked into place with the pins  28  projecting into the through holes  30 . In this condition, since the outer diameter of the pins  28  is slightly smaller than the inner diameter of the through holes  30 , the camming door  12  may be rotated relative to the base frame  14  about an axis of rotation  35  defined generally by the pins  28 . 
     As shown, in the exemplary construction, the lever portion  16  may include a relatively wide distal lip  40  which extends beyond the first end wall  36  in the assembled condition ( FIG. 2 ). As will be appreciated, this distal lip defines an overhang to facilitate finger manipulation by a user during rotation of the camming door  12 . In the exemplary embodiment, the lever portion  16  also may include angled wing elements  42  extending downwardly from the perimeter of the lever portion on either side slightly rearward of the distal lip  40 . As best seen in  FIG. 2 , the angled wing elements  42  may curve around underlying surfaces of the base frame  14  when the camming door  14  is in the closed position, thereby aiding in maintaining the closed position prior to intentional manipulation of the distal lip  40  by a user. 
     In the illustrated exemplary embodiment, the base frame  14  includes a pair of webbing slots  44  extending through the opposing lateral walls  32  at an elevation below the through holes  30 . In practice, these webbing slots are adapted to receive one or more webbing segments  26  which extend in threaded relation through the webbing slots in transverse orientation to the base frame  14  and to the rotational direction of the camming door  12 . That is, the length dimension of the webbing segments  26  is oriented in general alignment with the axis of rotation  35  of the camming door  12 . 
     As shown in  FIG. 4 , the camming ear  18  is characterized by a distance “a” between the planar lower edge  24  and the pins  28  which is greater than the distance “b” between any portion of the rear surface  22  and the pins  28 . Thus, as the camming door  12  is rotated about the axis defined by the pins  28  from the closed position of  FIG. 4 , to the open position of  FIG. 5 , the surface of the camming ear  18  is raised away from the travel path of the webbing segments  26 . As shown in  FIG. 5 , when the camming door  12  is rotated to the fully open condition, the surface of the camming ear  18  may be disposed above the upper boundary of the webbing slots and the webbing segments  26  may slide freely through the webbing slots  44  relative to the base frame  14 . Conversely, when the camming door  12  is rotated to the closed position ( FIG. 4 ), the lower edge of the camming ear  18  moves to a position at least partially blocking the webbing slots  44  and compressing the webbing segments  26 . In this compressed condition, the webbing segments  26  are constrained from sliding through the webbing slots  26 . The webbing segments  26  are thus locked in place relative to the base frame  14 . Moreover, as shown in  FIG. 2 , there is a slight gap in the closed position between the camming door  12  and the second end wall  38 . As will be appreciated, this gap aids in preventing interference between the camming door  12  and the second end wall  38  during rotation from a closed to an open condition. 
     In the illustrated exemplary embodiment, the webbing slots  44  are oriented in planes which are substantially perpendicular to the axis of rotation  35  of the camming door as defined by the pins  28 . Thus, the camming door  12  rotates through an arc which is transverse to the travel direction and length dimension of the webbing segments  26 . Due to this orientation, when the webbing clamp  10  is in the closed and locked condition as illustrated in  FIG. 4 , the application of tension to the webbing segments  26  is transmitted to the camming ear  18  as a tilting force urging the camming door  12  to tilt relative to the lateral sidewalls  32  generally in the direction of the axis of rotation  35  defined by the pins  28 . However, such tilting is blocked by the lateral sidewalls  32 , thereby maintaining a stable locked condition. 
     Referring now jointly to  FIGS. 4-7 , the use of a webbing clap  10  to tighten and lock down webbing segments  26  cooperatively forming helmet chinstrap will now be described. As shown, in the exemplary environment of use a helmet  50  may be provided with a pair of elongated webbing segments extending downwardly away from the sides of the helmet to cooperatively form a chinstrap  52 . As illustrated, the webbing segments  26  may converge at a position below a user&#39;s ear and travel as a double layer under the user&#39;s chin until separating again at a position below the opposing ear on the far side of the user&#39;s face (not shown). As will be appreciated, the effective length of the chinstrap  52  may be adjusted by changing the position at which the webbing segments  26  converge. Thus, the chinstrap  52  may be tightened or loosened by adjusting the position at which the webbing segments  26  converge. In this regard, if the webbing segments are held together in converging relation at a position close to the ear, the chinstrap  52  will be relatively tight corresponding to a short effective length, while moving the position of convergence away from the ear will result in a looser fit corresponding to a longer effective length. 
     When the user initially puts on the helmet  50 , it is generally desirable for the chinstrap  52  to be relatively loose. Once the helmet  50  is adjusted to the proper position, it is then desirable to tighten the chinstrap  52  to hold the helmet  50  in place. As shown through joint reference to  FIGS. 5 and 6 , after the webbing segments  26  have been threaded through the webbing slots  44 , the desired adjustment may be carried out with the camming door  12  opened to the position shown in  FIG. 5  such that the camming ear  18  has been raised away from contacting relation with the webbing segments  26 . In this condition, the webbing clamp  10  may slide freely along the length of the chinstrap  52  to provide the desired degree of tightening or loosening. 
     Once the desired tightness has been achieved, the webbing clamp  10  may then be locked down as shown in  FIG. 7 , by closing the camming door  12  such that the camming ear compresses the webbing segments  26  ( FIG. 4 ). This compression thereby prevents further relative movement of the webbing clap  10  along the length of the chinstrap  52  until the camming door  12  is reopened. As noted previously, the application of tension to chinstrap  52  with the camming door  12  in the closed position results in a tilting force being transmitted to the camming ear  18  thereby urging the camming door  12  to tilt relative to the lateral sidewalls  32 . However, such tilting is blocked by the lateral sidewalls  32 , thereby maintaining a stable locked condition. Of course, a similar clamping arrangement may be used on the opposing side of the helmet  50  thereby providing additional adjustability if desired. 
     Variations and modifications of the foregoing are within the scope of the present invention. It is understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art.