They are slide hammers, made by Sapmeister, used to insert and remove taps for tree sap collecting.

I can not tell you what these are or who made them. This is another example of how machinist made tools screw with the world. Do to the inconsistencies between them like the stand off length between the handle and parallel rods I can tell you they are not production made. The grips are from a bicycle. They are not very rugged so my conjecture would lean toward glass work, likely stain glass.

References:

http://www.ebay.com/itm/Vintage-Antique-Bicycle-Impliment-Handle-Bar-Grips-3-...

Reason:
Could you tell me what they are and what they're for?

They are slide hammers, made by Sapmeister, used to insert and remove taps for tree sap collecting.

References:

https://sapmeister.com/product/slide-hammer/