Childproof Lever Doorknob with Clamp

This is a remix of spiridios's "Childproof Lever Doorknob" by adding a clamp.
Original: https://www.thingiverse.com/thing:1647704

Children and cats sometimes pull down the lever to open the door.
If you install this device on the door, you can open the door by lifting up only, not pulling down.

I thought that's a brilliant idea.
I tried to install the original one, but it was difficult to remove my doorknob.
So I decided to design this version.
I added a clamp mechanism to adjust the tightness.

I scaled it down for my doorknob.
The minimum diameter of the backing plate is 55 mm.
I didn't test on other diameters. But I expect it works fine.

Installation (Modified from the original)

• Insert an M4 screw and an M4 nut
• Slide childproof device behind doorknob
• Rotate the device so that raised portion is below the lever and the lever is just barely in contact with the raised portion
• Tighten the screw
• Test to make sure the device doesn't slip. If it slips, tighten screws some more. If you can't get it tight enough for it not to slip, do not rely on the lock for safety.

You can check the detail on my blog post (in Japanese).
https://arundolon.hatenablog.com/entry/2021/12/06/221300