Patent Publication Number: US-4369535-A

Title: Mattress assembly

Description:
The invention relates to a mattress assembly comprising an elongated framework, a plurality of parallel laths fastened thereto in the direction of width and a mattress consisting at least partly of foam material. Such a mattress assembly usually comprises two separate parts i.e. the framework with the laths and the mattress respectively. Such a known assembly has the disadvantage that the mattress does not lie firmly on the framework and can readily shift in place, particularly when the framework is partly bent upwards. Moreover, many frameworks with laths appear to produce noise when used, whilst bedsteads comprising such a mattress assembly are hardly suitable to sit down on them. 
     The invention has for its object to obviate these disadvantages and provides a mattress assembly of the kind set forth, which is characterized in that the central parts of the laths are located in the mattress and surrounded by foam material, whereas the end parts on both sides emerge from the mattress. The mattress assembly thus obtained is satisfactorily employed, it has a stable position in a bedstead and is quite suitable as a seat, whilst the laths to be used may be thinner and the production of noise is avoided. 
     Since the combination of the framework and the laths with the mattress might be a hindrance to &#34;cramming&#34; of blankets it is preferred to leave a free space between the end parts of the laths and the mattress extending up to the side of the mattress assembly for inserting the edges of the blankets into it. In order to firmly retain the edges of the blankets at the correct place it is advisable for the space near the side of the mattress assembly to have a smaller height than the central part of the mattress assembly. 
     In order to facilitate the manufacture and to simply enlarge the assortment, the central parts of the laths are preferably enclosed in a bottom block of foam material fastened to the bottom side of a horizontally larger upper block of foam material. In this way large numbers of lower blocks can be manufactured, which can subsequently be provided with upper blocks having different covering materials, different degrees of rigidity or different shapes. 
     By using foam materials of different degrees of rigidity in the lower block and the upper block it is possible, for example, to make a soft support, whilst nevertheless the various laths will not be loaded quite independently, which results in a firm and healthy support. 
     An easy finish of the upper block and a reliable anchorage of the two parts are obtained when the lower block is partly embedded in the upper block. 
     In the central part the laths should be completely surrounded by the foam, but at the ends they should protrude to an extent such that a satisfactory support is obtained. 
     When using known laths having an upwardly cambered central part, whereas the two ends are located substantially horizontally, foam material can be saved, whilst nevertheless the advantages of the curved laths are maintained when the laths have an upward curve on both sides of the central upward curve. In a mechanically advantageous embodiment the top sides of the lateral upward curves are slightly lower than the top sides of the central upward curve. 
     The invention will be described more fully with reference to the accompanying drawing of a few embodiments thereof. 
    
    
     The drawing shows in 
     FIG. 1 a vertical sectional view of a mattress assembly in a preferred embodiment, 
     FIG. 2 a vertical, longitudinal sectional view taken on the line II--II in FIG. 1 and 
     FIG. 3 a vertically cross-sectional view like FIG. 1 of a variant of a mattress assembly in accordance with the invention. 
    
    
     The figures show a rectangular framework comprising two length profiles 2 provided with a hinge and at both ends two transverse profiles 3. These profiles have a vertical web 4 having an outer flange 5 at the top and an inner flange 6 on the bottom side. To the inner flanges are fastened curved transverse laths 8 by means of elastic buffers 7. The outer flanges 6 serve to support the mattress assembly in a bedstead. 
     The laths 8 have horizontal end parts 9 and an upwardly curved central part 10, on both sides of which they have parts 11 curved upwards to a lesser extent. With the exception of the end parts 9 the laths are arranged in a lower block 12 of foam material having a vertically rectangular sectional area, the upper part of said block being received in a correspondingly shaped recess in an upper block 13 of foam material, the outer surface of which is provided with a suitable coating 14. 
     Preferably, the lower block 12 has a higher degree of rigidity than the upper block 13. The dimensions of the upper block 13 are such that this block just extends on all sides beyond the framework. 
     Between the end parts 9 of the laths connected with the longitudinal profiles 2 and the peripheral part 15 of the upper block 13 is left a space 16 for cramming blankets. Near the side of the mattress assembly between the side edge of the upper block 13 and the upper edge of the framework said space 16 has a smaller height than further to the center of the mattress assembly. As a result a considerable part of a blanket can be crammed in and firmly clamped without any appreciable deformation of the mattress. From FIG. 2 it will be apparent that even on the narrow sides of the mattress assembly a corresponding space 16 may be provided. 
     From FIG. 1 it will be apparent that the coating 14 can be quite readily finished between the two blocks. Obviously matresses forming single units may be provided in the manner described above as well with laths embedded therein. 
     FIG. 3 shows in a cross-sectional view a different embodiment of a mattress assembly. A rectangular-section framework of longitudinal and transverse wooden laths 22 and 23 respectively has fastened to it straight laths 25 of stratified wood with the aid of blocks 24 of rubber-elastic material. Apart from the two ends each lath 25 is embedded in a block 26 of foam material, which is fastened to the bottom of a broader block 27 of foam material. With the exception of the part covered by the small block 26 the latter block 27 having rounded-off corners on the top side is surrounded by textile coating 28.