Strap clamp with transverse oriented cam door

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.

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.

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 toFIGS. 1 and 2, a webbing clamp10in accordance with one exemplary embodiment is shown. As shown, in the exemplary configuration, the webbing clamp10includes a camming door12adapted to be rotatably mounted within a base frame14of generally hollow bin-like construction. The camming door12and the base frame14each 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 door12and the base frame14may be formed from similar or dissimilar materials. By way of example only, and not limitation, the camming door12and the base frame14may each be formed from Nylon 6 or Nylon 6,6 by injection molding or a similar process.

As best illustrated through joint reference toFIGS. 1,4and5, in the illustrated exemplary construction the camming door includes a lever portion16defining 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 door12further includes an asymmetrical lobed camming ear18extending away from the plane defined by the lever portion16. As best seen inFIGS. 4 and 5, the lever portion16in combination with the camming ear18cooperatively define a generally “b” shaped profile. As shown, in the illustrated configuration, the camming ear18has a rear surface22extending away from the plane defined by the lever portion16. In the exemplary embodiment, the rear surface22is curved or angled radially inwardly and faces generally away from the direction in which the lever portion projects. As shown, the rear surface22may extend to a generally planar lower edge24defining oriented in a plane substantially parallel to the lever portion16. As will be described further hereinafter, such a planar lower edge defines an extended surface compression foot for application of pressure against webbing segments26when 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 segments26at the interior of the base frame also may be used if desired.

As noted previously, the camming door12is adapted to be supported in rotatable relation within the base frame14. By way of example only, and not limitation, in the illustrated exemplary construction the camming ear18may include outwardly projecting pins28oriented in aligned relation to one another on opposing sides of the camming ear18. In the exemplary embodiment, the base frame14has a generally bin configuration with an open top and including a pair of aligned through holes30extending through opposing lateral sidewalls32. As may be understood through joint reference toFIGS. 1 and 2, the camming ear18of the door12may be pressed into the interior of the base frame14between the lateral sidewalls32until each of the pins28snaps into a corresponding one of the through holes30. In this regard, as best seen inFIG. 1, in the exemplary construction the base frame14includes a door acceptance opening designated generally as34extending longitudinally along the top of the base frame14between the lateral sidewalls32. The door acceptance opening34narrows progressively along its length from a relatively wide opening at a first end wall36to a more narrow width adjacent the opposing second end wall38. According to the exemplary practice, the width of the door acceptance opening34adjacent the first end wall36will preferably accommodate insertion of the camming ear18with the outer surfaces of the pins28engaging the inner surfaces of the lateral sidewalls32. As the camming ear18is inserted and the pins28are urged towards the through holes30, the lateral walls32are forced outwardly to a slight degree by the pins28and then snap back as the pins28enter the through holes30. The camming door12is thereby locked into place with the pins28projecting into the through holes30. In this condition, since the outer diameter of the pins28is slightly smaller than the inner diameter of the through holes30, the camming door12may be rotated relative to the base frame14about an axis of rotation35defined generally by the pins28.

As shown, in the exemplary construction, the lever portion16may include a relatively wide distal lip40which extends beyond the first end wall36in 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 door12. In the exemplary embodiment, the lever portion16also may include angled wing elements42extending downwardly from the perimeter of the lever portion on either side slightly rearward of the distal lip40. As best seen inFIG. 2, the angled wing elements42may curve around underlying surfaces of the base frame14when the camming door14is in the closed position, thereby aiding in maintaining the closed position prior to intentional manipulation of the distal lip40by a user.

In the illustrated exemplary embodiment, the base frame14includes a pair of webbing slots44extending through the opposing lateral walls32at an elevation below the through holes30. In practice, these webbing slots are adapted to receive one or more webbing segments26which extend in threaded relation through the webbing slots in transverse orientation to the base frame14and to the rotational direction of the camming door12. That is, the length dimension of the webbing segments26is oriented in general alignment with the axis of rotation35of the camming door12.

As shown inFIG. 4, the camming ear18is characterized by a distance “a” between the planar lower edge24and the pins28which is greater than the distance “b” between any portion of the rear surface22and the pins28. Thus, as the camming door12is rotated about the axis defined by the pins28from the closed position ofFIG. 4, to the open position ofFIG. 5, the surface of the camming ear18is raised away from the travel path of the webbing segments26. As shown inFIG. 5, when the camming door12is rotated to the fully open condition, the surface of the camming ear18may be disposed above the upper boundary of the webbing slots and the webbing segments26may slide freely through the webbing slots44relative to the base frame14. Conversely, when the camming door12is rotated to the closed position (FIG. 4), the lower edge of the camming ear18moves to a position at least partially blocking the webbing slots44and compressing the webbing segments26. In this compressed condition, the webbing segments26are constrained from sliding through the webbing slots26. The webbing segments26are thus locked in place relative to the base frame14. Moreover, as shown inFIG. 2, there is a slight gap in the closed position between the camming door12and the second end wall38. As will be appreciated, this gap aids in preventing interference between the camming door12and the second end wall38during rotation from a closed to an open condition.

In the illustrated exemplary embodiment, the webbing slots44are oriented in planes which are substantially perpendicular to the axis of rotation35of the camming door as defined by the pins28. Thus, the camming door12rotates through an arc which is transverse to the travel direction and length dimension of the webbing segments26. Due to this orientation, when the webbing clamp10is in the closed and locked condition as illustrated inFIG. 4, the application of tension to the webbing segments26is transmitted to the camming ear18as a tilting force urging the camming door12to tilt relative to the lateral sidewalls32generally in the direction of the axis of rotation35defined by the pins28. However, such tilting is blocked by the lateral sidewalls32, thereby maintaining a stable locked condition.

Referring now jointly toFIGS. 4-7, the use of a webbing clap10to tighten and lock down webbing segments26cooperatively forming helmet chinstrap will now be described. As shown, in the exemplary environment of use a helmet50may be provided with a pair of elongated webbing segments extending downwardly away from the sides of the helmet to cooperatively form a chinstrap52. As illustrated, the webbing segments26may converge at a position below a user's ear and travel as a double layer under the user's chin until separating again at a position below the opposing ear on the far side of the user's face (not shown). As will be appreciated, the effective length of the chinstrap52may be adjusted by changing the position at which the webbing segments26converge. Thus, the chinstrap52may be tightened or loosened by adjusting the position at which the webbing segments26converge. In this regard, if the webbing segments are held together in converging relation at a position close to the ear, the chinstrap52will 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 helmet50, it is generally desirable for the chinstrap52to be relatively loose. Once the helmet50is adjusted to the proper position, it is then desirable to tighten the chinstrap52to hold the helmet50in place. As shown through joint reference toFIGS. 5 and 6, after the webbing segments26have been threaded through the webbing slots44, the desired adjustment may be carried out with the camming door12opened to the position shown inFIG. 5such that the camming ear18has been raised away from contacting relation with the webbing segments26. In this condition, the webbing clamp10may slide freely along the length of the chinstrap52to provide the desired degree of tightening or loosening.

Once the desired tightness has been achieved, the webbing clamp10may then be locked down as shown inFIG. 7, by closing the camming door12such that the camming ear compresses the webbing segments26(FIG. 4). This compression thereby prevents further relative movement of the webbing clap10along the length of the chinstrap52until the camming door12is reopened. As noted previously, the application of tension to chinstrap52with the camming door12in the closed position results in a tilting force being transmitted to the camming ear18thereby urging the camming door12to tilt relative to the lateral sidewalls32. However, such tilting is blocked by the lateral sidewalls32, thereby maintaining a stable locked condition. Of course, a similar clamping arrangement may be used on the opposing side of the helmet50thereby providing additional adjustability if desired.