Tensioning buckle

A buckle fitting that can tension with leverage, lengths of belt or webbing. The buckle will lock the belt at any point along its length until freed by a quick release mechanism. The buckle consists of two u-sections pivotably connected at one end to allow a hinge action of the longer upper section about the lower section. A spring loaded cam with a limited movement, rocks away from the surface of the lower section to allow belt to move forward and moves closer to the surface of the lower section to prevent belt moving backwards. A cylindrical roller locates across the lower section between the cam and the hinged join. A slot in the upper section allows belt to pass through when the upper section is closed over the lower section. When the upper section is levered in an arc about the lower section the relative aspect of the slot alters enabling belt to be caught and pulled further through the cam in the lower section. Repeating this action further advances the belt through the buckle. The locking cam can be overriden manually in order to release the tensioned belt.

BACKGROUND OF THE INVENTION 
This invention relates to buckle type fittings capable of locking belt in 
load bearing situations. 
In many situations there is a need to be able to achieve a high degree of 
tension in a belt, maintain the tension securely and quickly release it 
when desired. 
While existing buckle fittings may be capable of some or all of these 
functions, they usually involve complicated construction and fallible 
ratchet and spool mechanisms. The need is recognised to produce a 
tensioning buckle of lightweight, slim design with a simple construction 
and operation as well as being capable of the mentioned functions. 
BRIEF SUMMARY OF THE INVENTION 
An object of the present invention is to provide a simple buckle fitting 
that can apply, maintain and instantly release tension in lengths of belt. 
Another object is to provide a buckle that is in principle applicable to 
all sizes of belt. 
Another object is to provide a buckle fitting that can effectively lock at 
any point along the length of an unperforated belt without distorting or 
winding the excess belt onto a spool mechanism. 
Another object is to provide a buckle fitting as described, of simple 
construction and operation, light weight, thin dimension and having few 
parts. 
In general summary the buckle includes two u-sectioned bodies pivotably 
connected at one end. The lower body houses a spring loaded cam which 
allows belt to advance through the buckle but prevents the belt slipping 
back. A roller also located in the lower body facilitates the belt 
movement and reduces friction. The longer upper body contains a tongue and 
slot which, when levered about the pivot attachment to the lower body will 
grip and pull belt further through the cam. Repeating this lever action 
advances and maintains tension in the belt until released via the cam 
mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The drawings depict a tensioning buckle comprising a u-sectioned lower body 
1, being pivotably connected at hinge pivots 3,4 to a similarly sectioned 
slightly wider, upper body 2. Upper body 2 may thus close over lower body 
1 and pivot freely, up to 180 degrees, about lower body 1 at hinge pivots 
3,4. 
Protruding edges of cam 5 locate laterally in lower body 1 by seating in 
holes 6,7. Holes 6,7 are suitably shaped to allow a limited turning action 
of cam 5 about a line through holes 6,7. The turning action of cam 5 
effectively raises and lowers the belt contact edge 5b relative to the 
surface of lower body 1 while the opposite relative movement occurs at 
finger contact end 5a. Means to apply pressure tending cam belt contact 
edge 5b towards lower body 1 is achieved by torsion spring 8. A medial 
portion of torsion spring 8 contacts cam 5 while the ends locate in tabs 
9,10 in lower body 1. 
A cylindrical roller 11 locates laterally in lower body 1 between cam 5 and 
hinge pivots 3,4. Round holes 12,13 locate roller 11 in lower body 1 so as 
to allow turning and enable belt 16 to pass between. 
The surface of lower body 1, between the roller 11 and and hinge pivots 3,4 
protrudes upwards to form a tongue 14, which correlates to a similar 
tongue 15 projecting down from upper body 2. When upper body 2 is 
positioned to overlap lower body 1, tongues 14 and 15 converge to provide 
means to direct belt 16 through a slot 17 in upper body 2. 
Means to attach one end of belt 16 to lower body 1 is provided by studs 18 
passing through holes in plate 19, belt 16 and lower body 1. 
The end of upper body 2 extending furthest from hinge pivots 3,4 is 
upturned at grip 2a to facilitate manual lifting and levering of upper 
body 2 about lower body 1. 
In the use and operation of the invention; belt 16 is passed around objects 
to be restrained and the free end of belt 16 is passed along the upper 
surface of lower body 1, between cam 5 and roller 11. With upper body 2 
closed over lower body 1, belt 16 is guided by tongue 14 onto tongue 15 
and through slot 17. Upper body 2 is then manually levered about hinge 
pivots 3,4 on lower body 1. As the aspect of slot 17 alters, belt 16 is 
gripped and pulled further along the surface of lower body 1, between the 
roller 11 and cam belt contact edge 5b. After the lever arc of upper body 
2 is completed it is returned to seat over lower body 1, while cam 5 
prevents belt 16 as belt contact edge 5b locks into belt 16 and against 
lower body 1. Repeating the lever action further advances belt 16 through 
the buckle until the desired tension is achieved. Upper body 2 is then 
returned to cover lower body 1 thus preventing accidental release of the 
cam 5. To release belt 16, upper body 2 is levered about lower body 1 
allowing recess to cam finger contact end 5a. Depressing cam 5 at finger 
contact end 5a raises the belt contact edge 5b from the surface of the 
belt 16 thus releasing it. 
The above description details an embodiment of the invention thats true 
spirit and scope are embraced in the following claims;