making custom kvm switch

I am making custome KVM switch, and I am looking for a part.

It is a round "switch" with 4 positions. It has 27 contacts for output, and 27 contacts for each of 4 inputs, and they are all switched at once. I found one in a very old KVM, all it has writen on it is: "PAT. 113525/zl 95227724.7"

I searched, but I could not find this pattent number listed, and I don't even know what one of these switches is called.

Anyone know what they are called, or where I might find them online?

[EDIT]
I guess nobody knows what these switches are called; so I bought several old KVM units online...They all have different versions of the same basic switch design. Now I just need to find two more of them, a bunch of DVI-DL connectors, and a few HDMI sockets...then the hard part starts.