Hand Drill @museum.de

With this extraordinary drilling machine, it's a case of: watch yourself and duck! Because when you turn the handle and set the machine in motion, the two arms at the top with the great spheres open up. And then they fly through the air, rotating at full speed, rather like the baskets on a swing carousel. Because this machine makes use of centrifugal force and the energy of the two balls to lower the drill. So the feed operates independently, which means less effort for the operator, and it produces neater results. A brilliant invention!

But... of course, we're in a museum ... and – er ... you're not really allowed to ... I mean... to touch anything. But... Would you like to hear what this little drill sounds like when the balls are really whirring and flying through the air?

Go on, have a listen:

Incidentally, I have a copy of a patent specification dated 1899, which describes exactly this mechanism in engineering terms. I quote:

Hmm... hmmm... hmmm... that a governor is attached to the drill spindle, the balls of which rise as the spindle turns and force it down along with the drill bit in accordance with the speed of the machine. If the speed decreases markedly or the machine stops, the balls are lowered and retract the drill bit from the drilled hole.

The upper part of the spindle c, which is positioned in the usual way on the frame b, above the drilling table a, is square ... hmm... hmmm... rotating bush g, supports h.... Here: device to advance the drill bit in drilling machines, characterised by the drill spindle c being pushed down by a regulator connected to it during operation of the machine and returned to an upward position once the rotation stops.

Patent dated the 9th of May 1899. And all I can say is: a really ingenious machine!