My dad was a US Navy aviator during the Korean War. He flew Corsairs. We were recently going through some of his old gear (flight suits, helmets, etc.) and came across an object we could not identify.
The only identifying mark is the text, “H-P TOOL”, stamped into the metal. We found it with his first aid/survival packs. It appears to have been part of a purely first aid kit (i.e., all medical stuff), not the survival kit, which also had non-medical items (like sunscreen, water purifying tablets, etc.). But the packs had been reshuffled over the years, so it may have been part of either one (or neither) and had just been stuck in there for convenience. He flew in Korea, but also flew in peacetime before and after, so it may have been from any time during the 1950s, more or less. He went into the medical corps at the end of his career, so I doubt he flew after 1960ish.
A cursory Googling turned up nothing. Anyone recognize it?
Those slots are usually found on things that take button batteries, and the proper tool to open one is… a button battery. When you open it, you use the new battery you’re about to put in, and when you close it, you use the old battery you’re about to throw out. And if you don’t have a new battery, then why are you opening it?
No. These fasteners hold sheet metal cowling panels in place over engines and such. The idea is to be able to easily open them to inspect or repair what’s inside. While sitting on the ground. The tool is essentially a fancy screwdriver for turning these oddball “screws.”
My very most recent experience with one was that the relevant battery (bog standard CR2032) was too thick to engage the slot. It seemed designed for a US 25 cent piece.
I agree they ought to be designed as you say. And sometimes even are. But not always. Unfortunately.
The overwhelming majority of the time I am opening it up to figure out what type of battery it takes so that I can pick one up the next time I’m passing a CVS or whatever.
Since 1950’s, H.P. Manufacturing has offered quality products, technical advice and pro-active customer service for the aerospace, automotive, fastener and metal working industries.
I have a 1915 Webley MkVI (the old British Service Revolver, seen in basically every WWI movie, Zulu, etc.) The one screw that gets the cylinder out for cleaning in the field is sized to be turned by the edge of a shilling coin (but an American nickel works if you’re not an Edwardian British officer).
But yeah, all those battery doors and things are designed for coins, just a few happen to take a battery the same thickness. Source: I collect cameras and light meters, and so have come across a lot of those slots, all the same size (fits a US quarter but I suspect they were actually designed with Yen in mind, being mostly from Japanese companies), with wildly varying shapes and sizes of batteries underneath. Several even close the cover over a 9V.