Different Columbia Reproducer Needle Bar

[Phono+888]

I picked up a couple of Columbia Reproducers and this one has a different type of needle bar I haven't seen before. Thought I would share this.

[Inigo]

What is this movable part on top of the needle chuck for? It's it kind of a silencer? Is it a rotating key for fixing the needle?

[Phono+888]

It rotates to tighten the collet to hold the needle. Not seen like this. I've seen the usual spring lever type and an earlier thumb screw version.

[Inigo]

I see.. thanks. What a strange arrangement! Never seen before... Although it is true that some Meltrope soundboxes have a similar arrangement, but the pressing element is a knurled collar. And the IM cactus needle sharpener has also a collar too to grip the needles.