| 摘要 |
<p>In a convertible sofa-bed in which a mattress is folded over upon itself, a bed-folding linkage is provided which compresses the mattress with great leverage, thus providing means for facilitating the opening and closing of the sofa-bed, even when using relatively thick mattresses. The bed mechanism includes a mattress support having first, second, third and fourth hinged sections whose folding is controlled by the bedfolding linkage. The mattress-compression linkage includes a first link connected to the first or foot section, and a second link connected to the third section of the mattress support structure. An abutment is provided on the third section. The abutment is located so that when the bed is folded up, the second link hits the abutment and this causes the linkage to be pulled tight and locked in place to compress the folded mattress in a compressed condition. The pivot point of the mattress-compression linkage on the first section of the mattress support is a substantial distance from the junction between the first and second sections of the mattress support, thus giving substantial leverage to the mattress-compression linkage. A further linkage is provided for moving the pivot point on the first section even farther away from the junction so as to increase the leverage even further. A locking linkage is provided to lock the corner between the second and third sections of the mattress support and hold it in a rigid position when the bed is folded.</p> |
