| 摘要 |
The spring bridges of an undermattress are provided with lifting slats (9) which lift the unloaded mattress during the day for the purpose of better airing of the plywood springs (4, 5). During loading by a reclining person, the lifting slats (9) fall back below the upper edge of the plywood springs (4, 5) so that the mattress is then supported normally. |
