Claims:
I claim
1. A buckle comprising an elongated body having a bottom side and a top side and means at one end for securing one end of a strap thereto, a strap-tensioning lever having a pivotal connection at one end to said body between the ends of the body and movable from tensioning position to nontensioning position, a strap guide bar on said body and disposed between said means and said pivotal connection longitudinally of the body and between said bottom side of the body and an axial plane of said pivotal connection that is approximately parallel to said greatly side of the body, a strap-tensioning bar carried by said lever to have a portion of said strap looped therearound, said tensioning bar being disposed on the same side of said axial plane as said strap guide bar when said lever is in tensioning position, providing for the lever to be held in strap-tensioning position automatically by the tension on the strap, said lever being movable about said pivotal connection to move the lever into nontensioning position with said tensioning bar disposed at the opposite side of said axial plane.
2. A buckle as defined in claim 1 wherein said strap tensioning bar is disposed intermediate the ends of said lever.
3. A buckle as defined in claim 1 wherein said strap tensioning bar is located at the free end of said lever.
4. A buckle as defined in claim 1 wherein said body comprises two parallel side plates rigidly connected by crosspieces one of which constitutes said means for attaching a strap end and another of which constitutes said strap guide bar, said lever comprises two parallel sidepieces pivotally connected to the respective sideplates of said body and rigidly connected together by at least one cross bar which serves as said strap tensioning bar.
5. A buckle as defined in claim 1 wherein said body comprises two parallel side pieces rigidly connected by crosspieces one of which constitutes said means for connecting one end of a strap to said body while another constitutes said strap guide bar, a strap-tensioning lever having two parallel side arms rigidly connected by at least, one crosspiece adapted to have a portion of said strap looped therearound to serve as said strap-tensioning bar, said side arms having coaxial pivotal connections with the respective sidepieces of the body.
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to buckles having strap tightening levers which are particularly intended for use with tiedown straps or cargo security equipment, but which have general utility.
2. Prior Art
Buckles of this general type are shown, for example, by U.S. Pat. Nos. 2,679,670 and 2,825,109.
Such buckles comprise two sections pivotally connected together, one to be connected to, for example, one end of a strap, and the other section having crossbars related to each other and to the pivotal connection of the sections so that when the other end of the strap is threaded between and over said crossbars, pivotal movement the second-mentioned section will cause a tightening of the strap.
The prior art buckles or strap or belt tightening gear either are too large or complicated or too expensive in relation to the degree of tension provided, or the degree of tension provided is so small that the use of the buckle is limited to a relatively small area, or the design of the buckle is such that the buckle bends or warps under the average required tension, or during the strap tightening operation one end of the lever hits the cargo so the swinging of the lever is hindered or the cargo is marred by the lever.
SUMMARY
An object of the present invention is to provide a buckle in which the body section and the lever section are constructed and combined so that the buckle is capable of producing a degree of tension which is large in proportion to the small size, simplicity and low cost of the buckle.
The invention particularly contemplates a sheet metal buckle the construction of which enables the buckle to produce a large degree of tension in a strap with a minimum of danger of bending, twisting or warping of the sheet metal buckle sections and with minimum effort by the operator.
More especially the invention provides a body for connection at one end to one end of a strap and a strap-tensioning lever pivotally connected at one end to said body intermediate the ends of the body, said body having a strap guide bar between its ends and between the bottom side of the body and an axial plane of said pivotal connection that is approximately parallel to said bottom side and said lever having a strap-tensioning bar around which a portion of said strap is looped so that as the lever is swung about said pivotal connection said strap tensioning is disposed on the same side of said axial plane as said guide bar for tensioning the strap and is movable to the opposite side of said plane into nontensioning position.
The buckle embodying the invention also reduces to the minimum the possibility of slippage of the strap when the tensioning lever is in clamping position.
A BRIEF DESCRIPTION OF THE DRAWINGS
For a complete understanding of the invention, reference should be had to the following description in conjunction with the accompanying drawings in which:
FIG. 1 is a top plan view of a buckle embodying the invention with the body section and the lever section in the relative positions that are assumed when the sections are in strap tensioning position;
FIG. 2 is a side elevational view thereof;
FIG. 3 is a transverse vertical sectional view on the plane of the line 3--3 of FIG. 1;
FIG. 4 is an enlarged longitudinal sectional view of the buckle with a strap attached thereto and in released or nontensioning position around cartons, the strap and cartons being shown in elevation;
FIG. 5 is a similar view with the buckle shown in strap tensioning and clamping position;
FIG. 6 is similar to FIG. 4 showing a modification of the invention and with the strap tensioning lever in nontensioning position;
FIG. 7 is a similar view showing the strap tensioning lever in tensioning position;
FIG. 8 is a transverse vertical sectional view approximately on the plane of line 8--8 of FIG. 6, with the strap omitted;
FIG. 9 is a view similar to FIG. 1 showing another modification of the invention with the strap omitted and with the lever in tensioning position; and
FIG. 10 is a longitudinal sectional view of the buckle shown in FIG. 9 and with the strap attached thereto, showing the lever in tensioning position in solid lines and in nontensioning position in dot and dash lines.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Specifically describing the form of the invention shown in FIGS. 1 through 5, the buckle includes a sheet metal body section A shown as comprising two parallel sideplates 1 rigidly connected together by crossbars 1, 2, and 3 and 4 the latter of which constitutes means for connecting one end of a strap B to the buckle as indicated at 5 in FIG. 4.
A strap tensioning lever C is approximately U-shaped and has two parallel sidepieces 6 rigidly connected at one end by handle plate 7 and having the other end pivotally connected by rivets 8 to the respective sideplates 1 intermediate the ends of the body section. A strap tensioning bar 9 is carried by the lever C and has its ends rigidly connected as by riveting to the sidepieces 6 and the body section A has a strap guide bar 10 rigidly connected as by riveting to the sideplates 1. The guide bar is disposed between the approximately flat bottom side of the body section and an axial x--x plane of the pivotal connection 8 that is approximately parallel to the bottom side of the body section and also between the strap attaching bar 4 and the pivotal connection.
In threading the strap B through the buckle the lever C is swung into nontensioning position as shown in FIG. 4. The end of the strap opposite the end 5 connected to the body section is threaded through the slot between the plates 2 and 3 of the body section and then beneath the guide bar 10, after which the strap is looped around the tensioning bar 9 and then between the guide bar 10 and the first-mentioned portion of the strap. In FIG. 4 the strap is shown as used in encircling relation to a load such as the cartons D, and to tighten the strap around the cartons the free end of the strap is manually pulled to preliminarily tighten the strap around the load. Then, to tension the strap tightly around the load the handle plate 7 is gripped by the hand of the operator and pulled so as to swing the lever C in a clockwise direction in FIG. 4 so that the strap is looped and guided around the guide bar 10 and the strap tensioning bar 9 draws the strap taut as shown in FIG. 5. The lever is swung until the axis of the tensioning bar 9 is disposed between said axial plane x--x of the pivots 8 and the axis of the guide bar 10 so that the tension on the strap holds the lever in clamping position, although if desired additional means, for example projections 11 on the lever to snap resiliently frictionally into recesses 12 on the body section may be provided.
A modification of the invention is shown in FIGS. 6, 7 and 8 wherein the body section E which is similar to the body section A has two approximately parallel side plates 13 which are rigidly connected by crossbars 13, 14, 15 and 16 the latter of which has one end of the strap F connected thereto as indicated at 17. The body section has a strap guide bar 18 which in the present instance is shown as stamped integrally with the side plates with the stamped out portion doubled upon itself to provide two thicknesses of the sheet metal in the guide bar.
The strap tensioning lever G has parallel sidepieces 19 rigidly connected at one end by a combined handle plate and strap tensioning bar 20 which is stamped up integrally with the sidepieces and is formed of two superposed thicknesses of the sheet metal. The other ends of the sidepieces are pivotally connected by rivets 21 to the respective side plates 13 of the body.
In use of the buckle, the lever G is swung first into nontensioning position as shown in FIG. 6 and the strap is threaded around the guide bar 13 and the tensioning bar 20 in the same manner in which the strap is threaded around the guide bar 10 and the tensioning bar 9 in FIG. 4. To tighten the strap around the load H, the free end is preliminarily manually pulled taut as shown in FIG. 6 after which the lever is gripped at its free end and swung clockwise into the final tensioning position shown in FIG. 7. Here the rounded edge of the tension bar 20 around which the strap is looped is located between the approximately flat bottom side of the body section and an axial plane of the pivotal connection 21 which is approximately parallel to said bottom side of the buckle so that tension on the strap holds the lever in clamping position without additional locking devices, although if desired means such as projections 22 may be provided on the lever to resiliently frictionally coact with recesses 23 on the sideplates of the body section.
The sheet metal buckles shown in FIGS. 1 through 8 inclusive are strong and permit the buckles to produce a large amount of tension in the strap with a minimum of danger of bending, twisting or warping of the sheet metal buckle sections and with minimum effort by the operator. However, in many instances it may be desirable to provide less expensive buckles that are especially adapted to use where low degrees of tension on the strap will suffice. FIGS. 9 and 10 show a modification of the buckle wherein both the body section I and the lever section K are formed of heavy wire. The body section I is approximately U-shaped and has approximately parallel side pieces 24 rigidly connected by a crosspiece 25 which serves as means of connection for one end of a strap L. The ends of the sidepieces are angularly disposed to the general plane of the side pieces and formed with eyes 26 to which are pivotally connected the respective side arms 27 of the lever K. As shown, the lever K is approximately U-shaped and has the end portions of the arms 27 angularly disposed and rotatably fitted in the eyes 26 as indicated at 28.
A strap guide bar 29 is shown in the form of a strip of sheet metal which has its end portions looped around and rigidly secured to the side pieces 24 of the body section, while the strap tensioning bar 30 is shown as having its ends looped around and rigidly secured to the arms 27 of the lever section K. The guide bar 29 is disposed between the approximately flat plane of bottom side of the body section and an axial plane of the pivot eyes 26 that is parallel to said bottom side, and is also disposed between the crosspiece 25 and the eyes 26. The strap is threaded through the wire buckle in substantially the same manner in which the straps are threaded through the sheet metal buckles, as shown by FIG. 10 where the lever K is shown in strap tensioning position by solid lines and in bottom position by dot and dash lines.