What took them so frigging long to think of this?

No way, everyone would see all my empty coffee cups, discarded socks, dog leashes, pens, gardening tools, books, maps, hair clips, etc that reside on the floor of my car.

That's okay if it's not raining hard. Here, it rains hard a lot.

Joe, you understand hardware. (slight change of subject here, sorry). Why do the Americans call the type of knife which we call a clasp knife, or pocket knife, or penknife, or folding knife, a jack-knife?

Where did the name jack-knife come from?

jackknife
Origin: 1711

Americans may not have been the first to think of making a knife safe and portable by giving it a blade that folds into the handle, but we were the first to call it a jackknife. Our earliest notice is in the official records of Springfield, Massachusetts, for 1711: "One Dozen of Jack Knives, at six pence the knife" on one occasion, and "Eleven iron handled Jack knives" on another.

Jackknives were a traditional accouterment for boys who were growing up in America. Without them the playing of mumble-te-peg (an English game which antedates jackknife by eighty years at least) and the whittling of sticks (which probably antedates English and perhaps even the Bronze Age) can only be practiced by the possessors of the larger and more formidable sheath knife (1837). The practical advantage to the jackknife lies in its relatively safe transportability in one's pocket.

Where did we get the term? Perhaps it came from the Scottish word for a similar knife, jockteleg knife or Jock the Leg Knife, attested as early as 1672. Or perhaps it was from Jack meaning "sailor," since the knife was used by sailors.

Joe, you understand hardware. (slight change of subject here, sorry). Why do the Americans call the type of knife which we call a clasp knife, or pocket knife, or penknife, or folding knife, a jack-knife?