Where does “раскладушка” come from?

раскладушка (Russian) comes from Russian раскладываться, from Russian -ся, from Old East Slavic сѧ, from Proto-Slavic sę, from Proto-Balto-Slavic *sen, from Proto-Indo-European swé — self.

раскладушка (Russian): folding bed, camp bed, cot

Definitions

folding bed, camp bed, cot

Ancestry of “раскладушка”, step by step

Step	Language	Word	Meaning
1	Russian	раскладываться	to unpack; to unfold, to spread out, to open up,...
2	Russian	-ся	Reflexive suffix appended to finite verbs and...
3	Old East Slavic	сѧ	—
4	Proto-Slavic	sę	oneself: myself, yourself, himself, herself,...
5	Proto-Balto-Slavic	*sen	oneself
6	Proto-Indo-European	swé	self

Every word from Proto-Indo-European swé →Every word from Russian -ся →Every word from Proto-Balto-Slavic *sen →