Slaw bed

Does anyone know the origin of "slaw bed"? It looks like the forerunner of our Murphy bed but was probably used around 1700.

Do you mean to say that you have seen a picture, or have a reference from around 1700? Some context would help, to save me from the awful disgrace of saying the phrase conjures up the picture of a bed of cabbage. SS

I've looked in my references, especially regional slang, and haven't found anything.

The 1667 home I work in has one - it is hung on hooks and at night it can be placed on the floor. There are ropes and a feather mattress - I'm still looking for the origin

Nancy