unknown opener

[jimwrench]

 Can one of you widely experienced oldsters or one of you knowledgeable younger folks tell me what this was for.
 Closing the handle advances the rack approx 1/4 inch No markings.

[Bill Houghton]

Can you adjust the placement of the slide?  I'm wondering if it's a jar opener: adjust the slide to fit the lid, clamp closed, turn.  We have a similar device with an open frame that's been handy at times.

Not sure what the two prongs on the other side are.  I'd speculate that the prong on the end was probably originally vertical to the body of the tool, like the prong on the slide.  What that did, though, not sure.  Maybe clearing out nostrils for people with severe head colds.

[jimwrench]

                                      yes the placement of the slide is adjustable. I think I've seen one of these before but can't recall usage if I ever knew it.  Would have limited usage as nut cracker.

[Lewill2]

Looks like a combination can opener and a jar wrench. One side is a can opener using the point. The other side looks like it would grip a jar lid.

[Plyerman]

Tool For Removing Screw Caps From Jars, patent #736,455

http://www.datamp.org/patents/displayPatent.php?number=736455&typeCode=0

Earliest ones had a cast iron handle, then later they went to a pressed steel handle like yours has.

[turnnut]

 perhaps the point is used to lift the lid after removing the canning jar band.

 if the lid is sealed properly, you have to pry it to break the vacuum.

[amecks]

Well the patent is the jar opener and DATAMP description cites a known example with can opener.  My question is why the shape and apparent slot at the non handle end of the jar opener?
I have an Edlund jar opener and use it often.  Like this one...

[jimwrench]

 Thanks for the info. I tagged it with that patent and hung it with my jar openers.

[Papaw]

I have one of the Edlund types and use it often.

[mvwcnews]

perhaps the point is used to lift the lid after removing the canning jar band.

 if the lid is sealed properly, you have to pry it to break the vacuum.

The can opener works by stabbing the point into the middle of the top, and working the cutter around the edge of the can to cut the top out -- a repeated "stab. slide forward. stab".. with the cutter blade.  Without slicing your fingers during the process. 

[mvwcnews]

Well the patent is the jar opener and DATAMP description cites a known example with can opener.  My question is why the shape and apparent slot at the non handle end of the jar opener?
I have an Edlund jar opener and use it often.  Like this one...

EDLUND TOP-OFF in in DATAMP as well  ( http://www.datamp.org/patents/displayPatent.php?number=1894556&typeCode=0 ) -- the gearing only works to screw tops off,  unlike most jar wrenches that can be used to loosen & tighten lids.
The present category count shows 112 jar wrench patents in DATAMP.