quilt, bedding
衾 centers on a large, soft covering used for sleeping: a quilt or bedding. It is a specific type of cloth item for warmth and comfort.
衾 combines 今 (which likely contributes a phonetic element) with 衣 (clothing), suggesting a type of cloth covering. The exact historical development is uncertain, but the component structure points to a garment or bedding item.
The top 今 looks like a roof or cover, and the bottom 衣 is clothing. Picture a large cloth draped over you like a tent, becoming a warm quilt.
For キン, imagine a king-sized quilt: king -> キン, and the quilt covers the king's bed.