~69Z25 This invention relates to a type of bed construc- tion which is particularly intended for use in freight trucks and the like. It has become common practice to employ two drivers on trucks which are required to travel long dis- tances necessitating day and night travel. One driver rests and attempts to sleep while the other drives and the move- ment of the truck, particularly when rough road conditions are encountered, make it very difficult to get proper rest or sleep. Normally, a bed is installed in the cab of a track to extend across the cab in the same manner as the driver's seat and conventional compression springs usually are relied upon to cushion vertical displacement of the mattress support which the resting driver would otherwise ; 15 find distressing. A particularly disturbing movement of a mattress support in a truck is the rapid sideways movement - caused when the tractor cab rocks back and forth about a transverse axis. This rocking movement about a pitch axis is exaggerated in the upper parts of the cab where the bunk is located and the tendency is to roll the resting driver off his bunk. Mattress supports have previously been design to reduce some of these sleep-disburbing movements but none of the known supports offer a completely satisfactory solution to the rapid sideways movement experienced by a ` 25 driver stretched out on a mattress which extends transverse to the longitudinal axis of the vehicle. Finally, there is ' always a certain amount of rocking or side-to-side motion in : .: . ;:., the cab and this is increased when the truck is changing ~' lanes at high speeds or during normal turns. This side : .: ~ swaying motion about a rolling axis is exaggerated in the upper part of the truck cab and a resting driver finds this ~ -1- ~ :'"-"' ' : . : - .~ : . 1~6gZ2S disturbing as well. The present invention provides a type of bed or bunk construction which cushions or absorbs much of the above mentioned road shocks and which is particularly effective in dampening the pitching motion a resting driver experiences as a sideways rolling motion. Thus, a driver is able to rest on the present bed construction in relative comfort so as to feel refreshed when it is his turn to take the wheel. More specifically, a mattress-supporting bunk assembly for trucks according to the present invention may be defined as a bed construction which is adapted to be installed on the floor of a sleeping compartment of a highway vehicle and comprises a frame assembly, mounting means supporting corners of the frame assembly above the floor with the longitudinal axis of said assembly extending transversely of the corresponding axis of the vehicle, said mounting means each including vertically opposed support ~` members secured one to the frame assembly and one to the ` floor, a roller journalled on one of the support members of each mounting means for rotation about an axis substantially - parallel to the longitudinal axis of the frame assembly, and a curved track on the other support member of each mounting means engaging each roller, said curved tracks each having a - 25 radius of curvature centered on a point vertically spaced ` from and eccentrically disposed with respect to the axis of rotation of the adjacent roller. In dra~ings which illustrate a preferred embodi- ment of the invention, Figure 1 is a perspective view of a frame assembly ' '.'' ' 1~69~ 5 constructed in accordance with the present invention, Figure 2 is a longitudinal section, part broken away, taken on the line 2-2 of Figure 1, Figure 3 is a vertical slection taken on the line 3-3 of Figure 2, Figure 4 is an enlarged horizontal section taken on the line 4-4 of Figure 1, Figure 5 is a longitudinal section taken on the line 5-5 of Figure 4, and Figure 6 is a vertical section taken on the line 6-6 of Figure 5. In the drawings, the numeral 10 indicates gen- erally a mattress-supporting frame assembly constructed in accordance with the present invention. The assembly is shown mounted on a floor 12 of the sleeping compartment of a long-hall truck which has two drivers who-take turns occu- pying the bunk and driving the vehicle. The assembly 10 comprises rectangular upper and lower frames 14 and 15. These frames are spaced apart at each corner of the assembly by compression springs 16. End hinges 17 interconnect the two vertically spaced frames of the assembly. In addition, the two frames are joined together by diagonally extending braces 18. The upper frame generally indicated at 14 has side , ` 25 and end members 20 and 21 formed of angle material. At each of its four corners, the upper frame is reinforced by a horizontal corner plate 22. Longitudinal and transverse straps 23 and 24 (shown broken away in Figure 1 only) are strung between t]he frame members to support a mattress which ~ . has purposely been omitted from the drawings for sake of ' ~ ,'": ~ -3- ' ' ' ~0692Z5 clarity. The lower frame generally indicated at 15 is formed of similar angle lengths to provide side and end members 26 and 27. Large, horizontally disposed corner 5 plates 28 brace the frame 15 against diagonal distortion but otherwise the lower frame is open to the floor 12 on which the frame assembly is mounted. The frame 15 is supported above the frame 14 by the coil springs 16, there being one such spring at each corner of the assembly. The opposite ends of the heavy, wide-diameter coil springs 16 bear against opposing faces of the corner plates 22 and 28, the ends being suitably secured to these corner plates so that the springs cannot be dis- placed when the upper frame is moved towards and away from the lower frame. As previously mentioned, the two frames of the ~ ~- assembly 10 are also interconnected by the hinges which are . : generally indicated at 17. As shown best in Figures 2 and 3, the hinges 17 are located one at each opposite end of the ~- frame assembly. Each hinge is formed of members 32 and 33 which are interconnected at their overlapping edges by a - hinge pin 34. The end members 21 and 27 of the upper and lower frames are provided with transversely spaced lugs 35 and 36 and other hinge pins 3/ and 38 secure opposite ends ~ ~` of the hinge members to these lugs with the hinge members sloping inwardly towards the center of the assembly. Thus, if a downwardly directed load is imposed on one of the end ` members of the upper frame, the hinge at that end of the assembly will fold inwardIy with the folding movement being . .. . . resisted by the adjacent coil springs. It will be noticed that the several hinge pins are disposed parallel to one -~ b .'`,` - '''''' 1~692ZS another and at right angles to the longitudinal axis of the frame assembly 10. The coil spring 16 and the hinges 17 allow the upper frame to be moved up and down as well as endways relative to the lower frame. However, such movement is resisted by the braces generally indicated at 18. As shown best in Figures 2 and 3, the braces 18 comprise lengths of cable 42 which are each fitted with a spring 43. These springs are suitably secured to the lugs 35 and 36 on the end members of the two frames so that the cables extend diagonally of the assembly and are transversely spaced apart. Thus, the upper frame can be loaded at either end so as to be pushed towards the lower frame but this distortion ` of the bunk assembly is resisted not only by the coil springs 16 but also by the action of the springs 43 on the - cable braces. In order to function properly, the present sleeping -~ bunk for a truck driver must be mounted so that the longi- tudinal axis of the frame assembly 10 is disposed at right ~ ; 20 angles to the longitudinal axis of the vehicle. The present -~ frame is supported above the floor 12 of the sleeping compartment in the required transversely-extending position -~ by mounting means generally indicated at 50. The means 50 ~ -- at each corner of the assembly is shown in detail in Figures . , . . 4, 5 and 6 as comprising a rectangular plate 52. Bolts 53 secure this plate to the floor 12. Mounted on the floor ; : . - . ; plate 52, are closely spaced rollers 56 and 57. Roller 56 rotates about a spindle 58 which extends between a pair of brackets 59 carried by the floor plate. The horizontal spindle 58 supports the roller in a vertical position and so -, ~ ~'' .... . ., - . , .. :. , . ~ - . , . " ~ . . . 1069Z25 the axis of rotation of the roller parallel to the longi- tudinal axis of the frame assembly 10. The horizontally disposed roller 57 is mounted on a post 60 carried by the floor plate 52 and so as to be rotatable about a vertical axis with the outer edge of the roller being close to and only slightly above the horizontal axis of the spindle 58. Each of the mounting means 50 includes a track 62 and, preferably, the corner plate 28 is cut and shaped to ; form the upwardly curving track, see particularly Figure 5. The formation of this track provicles the corner plate with parallel side edges 63 and 64 which are at right angles to the longitudinal axis of the frame assembly. The track 62 rests on the vertical roller 56 and the side edge 63 bears against the periphery of the horizontal roller 57. Mounting 15 means of this type at each of the four corners of the frame - assembly enable the assembly to move transversely to a slight extent but the rollers 57 engaging their adjacent side edges 63 prevent the lower frame 15 of the assembly from moving longitudinally relative to the sleeping com- partment floor, A truck rolling along a highway tends to bounce upand down for some extent even when the road surface is -, fairly smooth. This vibrational movement is particularly ~ - noticeable in the cab of a truck-trailer unit which is occupied by both drivers of the vehicle. The tractor, of , course, weighs much less than the trailer and the load - imposed upon the fifth wheel of the tractor is closer to the rear wheels than to the front wheels. These weight and load ~; factors explain some of the vertical bouncing the drivers ., f .... have to contend with and there is a lesser amount of side- .~, .. . ' '. :, ,. ~ ,-'' ' ' 1~6922S sway as well. The bouncing movement becomes a pitching or rocking movement of the tractor cab about a transverse axis and a spare driver trying to rest in a bed extending across the length of the cab is rocked from side to side in a conventional truck bunk and finds this particularly dis- turbing. However, the present invention absorbs and cus- hions such rocking movements mainly because of the mounting means 50. The drivers weight on the frame assembly 10 tends to keeps the rollers 56 directly beneath the highest points of the tracks 62, or in that position shown best in Figure 5. As the floor 12 rocks back and forth due to the above- described pitching movement, the inertia resulting from the combined weight of the driver and the frame assembly tends ; 15 to hold the assembly stationary while the rollers 56 travel ` back and forth to a slight extent at least along the curved `. tracks 62. Thus, a great deal of the sleep-disturbing bouncing and rocking movement is absorbed by the present invention and the spare driver is able to rest in relative ` 20 comfort. Sidesway is taken care of by the combined action : of the springs 16, the hinges 17, and the spring-loaded .: . braces 18. , - ~ '.' ~ - , ' :, - , ~ '. '~ ' :' .' ~: 7