Mécanique de Façonné

Mécanique de façonné
We take again our example of fabric:
We wanted to create a pattern measuring 90 cm wide, on a chain having a width of 90 cm with 12 threads to the centimeter. The design will spread over the entire width of the fabric ...
Calculations:
The chain includes: 90 cm x 12 threads = 1080 threadsThe 90 cm pattern will span the entire width of the fabric using the 1080 threads.
We will have 1080 threads each on a single (smooth) mesh, a total of 1080 meshes. When lifting a stitch, a thread will be lifted. By raising the 1080 mesh, all the warp yarns will be lifted.
Principle of shaped mechanics:
The working principle of the mechanics of shaping is very simple to explain ... and to understand.
In our demonstration, we will not clutter with details and go to the basics in order to fully understand the actions of the mechanics of shaping.
We have therefore understood that each wire of our chain can be lifted individually by a hook of the mechanics, to which it is connected by means of a string and an independent (smooth) mesh.
Small reminder of the previous episode:
For our fabric we have:
1080 warp threads1080 individual meshes (smooth)1080 twine1080 hooks on a molded mechanics
The question that arises right away is: how will the mechanics know which yarns, what hooks, it must lift with each shot, according to the drawing to be executed?Well, she's not going to guess it all alone ... We have to get the information every time the frame passes.
Small Appearance:
You have certainly read or heard (one sees cà everywhere), that the Jacquard mechanics is the ancestor of the computer. Indeed, we can find an analogy between these two machines. This analogy simply resides in the mode of codification of information. And this mode of codification, which is called "binary system", is common to them. In the binary system, there are only two basic coding elements. Whether they are called "0 or 1", "true or false", "on or off" is always binary.
And in a fabric, how do we define the play of warp threads?Well, a warp thread is either "caught" or "left".That is the analogy.
The chain of cartons:
It is therefore assumed that we can codify the play of a warp thread with each stroke of frame by saying:
The warp thread is caught or the warp thread is left.
It is taken if it passes over the frame. It must be lifted by its hook.
It is left if it passes below the frame. It should not be lifted by its hook.
The information is then easy to transmit thus to the mechanics of fashion.
It is the role of cartons to transmit this information to him.We must, for each frame to pass, indicate to the mechanics which are the hooks to be lifted. For this purpose we will use one carton for each frame, and write on this card, in one way or another, which hooks must rise for this frame.
Before explaining how to codify this information on cartons, we need to describe the set of brackets.