Brother knitting machines with model numbers KH800 and KH801 have a very unique patterning mechanism: a combination of a punchcard reader with the ratchet tool activating the needle being pushed forward (also known as “needle selection”)
When I was refurbishing a Brother KH800, I had to open the case up to see why the machine was mispatterning. I, thus, had a lot of fun looking at how the patterning works. (By the way, mispatterning was due to the selection strips/plates being tucked together – nothing that a good layer of Kroil oil can’t fix).
Brother KH8000 and KH801 accept punchcards with 12 holes. There are also twelve selection rods.

Punchcard-reader pins poke through the holes in the punchcard when the ratchet tool is moved.

This pattern is then transferred to the patterning rods, which move according to the holes in the punchcard (see the video).

Notice in the picture below how the distance between the rods is no longer even because some of the rods were activated and some were not. This “activation selection” is determined by the punchcard pattern. I was testing this machine with the punchcard with every other hole unpunched.

These rods determine which tabs are pushed towards the needles.

Notice below how these tabs push forward only every other needle….

…according to our punchcard pattern.

Here is a closer look at these patterning tabs. Notice they are grouped in twelve.

Another view from a different angle:

So, if your machine mispatterns, it is very likely due to this mechanism. The good news is: it is probably easy to fix since everything is 100% mechanical.
Although I did not really open up any of the pushbutton machines (4-button like KH551 or 8-button like KH581, KH585, KH588, KH710, etc.) to watch their needle selection mechanism, I suspect that it is performed the same way as on Brother KH800 and KH801.
Even 24-stitch punchcard-reading knitting machines (KH8XX series, like KH840 and KH891) have similar patterning rods.




















