December 3, 2022
Description
This is a 3D printable cobra-clip made in FreeCAD and fairly nicely parameterized. The current preset is for a (tiny) 15mm webbing and being held together with filament-rivets.
Because it's printed, we can integrate the springs into the pawls so the part count is very low (I don't know why other 3D printable cobra buckles don't do this).
It is designed to be easy to release under load (actuating the clips doesn't require the buckle to move).
Print out all the parts (1x everything except 2x pawl.stl).
Ream out the holes to accept your bolt of choice (I used filament as rivets, but M1.5 bolts should also work).
Assemble as shown. Note how the thin part of the pawl goes into the matching slot in the bracket.
The Cobra Buckle is patented until 2031 as US8561268B2 to AustrailPin who make rock-climbing gear. Production or sale of this item may possibly count as infringing this patent despite some differences in design. This includes production for personal use. Publishing the models here does not (as far as I can tell) violate a patent because a patent blocks production of an item but makes the design public. This printable and the files therein can be considered a detailed sketch replicating the design, rather than a physical implementation of the design.
It is also worth noting that the general shape of a cobra buckle has been patented under USD621743S1, so you cannot produce things that look like a cobra buckle (I did not know this was possible! Definitely not a fan of this)
So in the files in the repository are freely shareable, but if you actually print one it is at your own risk.
Austalpin's designs are all designed to be impossible to release under load. This design is the opposite. It is designed to be easy to release under load. However, this is not mentioned as a claim in the patent, so will not stand in court.
Claim 6 states:
A belt buckle according to claim 1, wherin the latches in their locking positions are
acted upon by spring elements.
The design in the printable does NOT meet the requirements of claim 6:
The springs are integrated into the latches, therefore the latches are not acted upon by spring elements, they are their own spring elements.
When the latches are in the locked position, the latches built-in-springs do not apply any force onto the latches. Therefore again, the latches are not acted upon when the latches are in their locking position
As a result the files in this repository represent a "new invention" as it does not comply with Claim 6.
Claim 1d, 7d and 8d state:
The insertion opening beginning at the inserting side of the basic body and forming a
penetrating opening pentrating the basic body to the belt opening.
The design in this repository does NOT meet the requirements of claim 1d, 7d or 8d because the hole into which the insertion part is inserted does not penetrate into the belt opening.
In fact, the patent even mentions a similar buckle (Background column 1, line 59) that lacks this feature and instead has a blind hole, however some other differences are also mentioned so the unnamed buckle there does not constitute prior art (aka the patent is valid).
(The blind hole was actually an oversight on my part when doing the design, and means that my design is more succeptable to debris. It would however be pretty trivial to add a debris clearing port that opened to the top or the bottom and it still wouldn't comply with claims 7d or 8d.)
I do not consider my design to be a replication of Patent US8561268B2. But I am not a patent lawyer, and it may not hold up in court.
There are several other trivial modifications that could be made to the design to make it not comply with various other parts of the patent.
So in theory the files in this repository are definitely freely shareable but manufacturing them is possibly against one of the several patents in this area. If you 3D print one of these it is at your own risk.
I have selected Public Domain for the license for this model, because that is the license I (as the creator of the 3D model) have chosen. It does not indicate that the design is also Public Domain.
Yeah, what a mess. Sorry.
License:
Creative Commons — Public Domain
sdfgeoff
