Creality seems to have patented a new filament buffer concept.
What’s a filament buffer? It’s an essential part of any desktop FFF 3D printer that uses a filament swapping accessory, like Bambu Lab’s AMS or Creality’s own CFS.
The buffer is a mechanism that is able to act as a shock absorber between the filament swapper and the extruder. Here’s the problem: the extruder has a motor that pushes and pulls the filament, but so does the filament swapper. Unless they are perfectly coordinated, you might get one pushing and the other pulling, causing either tension or compression on the filament. A little tug-of-war, so to speak.
The buffer is a simple mechanism to handle that slight overlap between movements. It is usually a spring-loaded system where a slider can absorb some of the excess motion to protect the filament. You see these all the time on recent 3D printers.
But what is this patent all about? The abstract for patent WO2026021437A1 says:
“Provided in the present application are a consumable buffering device, a consumable conveying device, and a 3D printing apparatus. The consumable buffering device comprises a housing, which comprises a first shell and a second shell covering the first shell; a first material tube, which is fixedly arranged on the first shell in a first direction; a second material tube, the second material tube being in communication with the first material tube, and the second material tube being movable relative to the first material tube; and a buffering assembly, which comprises a first elastic connecting member elastically connected to a first end of the second material tube, the first elastic connecting member being configured to buffer an acting force between the first material tube and the second material tube, and further comprises a second elastic connecting member arranged between the second material tube and the inner wall of the second shell, the second elastic connecting member being configured to buffer an acting force between the second material tube and the inner wall of the second shell. Thus, buffering adjustment of consumable transmission is achieved, ensuring consistency in the transmission of consumables between different consumable conveying devices.”
That’s a bit hard to understand, but boiling it down, we have something like this:
A telescoping, coaxial “tube buffer”, which is a fixed upstream tube and a downstream tube that slides along the filament axis with preload springs and end-of-travel sensing, intended to absorb force mismatches between an upstream feeder (CFS / box) and a downstream feeder (extruder) even when the two devices aren’t perfectly synchronized.
OK, but that sounds EXACTLY like all the filament buffers I’ve seen on recent 3D printers.
Has Creality just patented a device that is found on many 3D printers? What could that mean? Might they demand royalties from any other party using this approach? Why didn’t anyone else patent this earlier?
On the other hand, there might be some variations in Creality’s patent that make it legally distinct from other designs. It’s also possible someone else has previously patented a buffer, and here Creality is nailing down their own specific design.
One aspect that seems a bit different is that this design is coaxial: one tube fits over the top of the other and slides along it. It’s a “telescoping” design. A second is that there are two springs, one to handle force in each direction.
One very interesting feature is the ability to handle multiple filaments. The design also allows for a 4-to-1 inlet manifold, which would be ideal for multiple filament swapper units.
It seems that Creality is hardening their CFS ecosystem against typical feed failures, and therefore increasing reliability, service life, and possibly keeping costs down, too.
Via Patentscope
