An improved seat-bed extender assembly for a convertible seat-bed. The assembly includes an attachable platform and corresponding linkage to allow conversion to a full-sized bed in conjunctive relation with a convertible seat and for operation of the platform independently of the seat.

FIELD OF THE INVENTION 
This invention relates to a convertible seat-bed, and will have special 
application to an extender for converting the seat-bed into a full size 
bed. 
SUMMARY OF THE INVENTION 
The seat-bed extender assembly of this invention is principally adapted for 
use with convertible seat-bed assemblies in a vehicle such as a camper or 
van. Heretofore, seat-bed assemblies were convertible from a seating 
position into a fold out twin or double sized bed. This type of 
construction is embodied in U.S. Pat. Nos. 4,321,716 and 4,543,675, 
incorporated herein by reference. 
The seat-bed extender assembly of this invention utilizes convertible 
extension connected to the seat frame of a convertible seat-bed as 
embodied in U.S. Pat. No. 4,321,716. The extender assembly allows an 
extended platform to move between a vertical stored position to a 
horizontal use position. When the seat-bed assembly is in its seat 
position, the extender assembly can operate independently from the 
seat-bed to allow its platform to be shifted into its use position. When 
the seat-bed assembly moves into its horizontal bed position from its seat 
position, the extender assembly platform moves into its use position. The 
linkage system of the extender assembly is essentially hidden, allowing 
unincumbered use of the platform, when the platform is in its use position 
with the seat-bed assembly in its seat position. 
Accordingly, an object of this invention is to provide a novel add-on 
seat-bed extender assembly. 
Another object of this invention is to provide a linkage system which is 
for a seat-bed assembly and which allows the seat to be converted into a 
full-size bed. 
Another object of this invention is to provide for a seat-bed assembly 
which has a separately operable extender linkage system. 
Other objects of this invention will become apparent upon a reading of the 
following description.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The preferred embodiment herein described is not intended to be exhaustive 
or to limit the invention to the precise form disclosed. It is chosen and 
described to explain the principles, application and practical use of the 
invention to thereby enable others skilled in the art to utilize the 
invention. 
The extender assembly 70 and seat-bed assembly 10 of seat-bed 5 shown in 
the drawings are adapted for use in vans, campers and other recreational 
vehicles. Both extender assembly 70 and seat-bed assembly 10 have 
identical linkage constructions on opposed ends of the device. Thus, only 
one of each linkage construction will be specifically described for each 
of the seat-bed and extender assemblies with the understanding that a like 
assembly is located and used at the opposite end of each assembly. 
Seat-bed assembly 10 includes a base or support frame 11 formed of spaced 
U-shaped end members 12. End members 12 are preferably connected by 
longitudinal cross members 15 which extend the width of the assembly. Each 
end member 12 includes vertical legs 13 between which a support 16 
extends. As shown in FIGS. 3-7, guide channel 20 is carried upon each 
support 16. The connecting linkage extending from each end member is shown 
and will now be described. 
FIGS. 3-7 show the structure, connection and relation of the various links 
of seat-bed assembly 10 and extender assembly 70. A link 24 is pivotally 
connected at 26 to front leg 13 of U-shaped member 12 and is pivotally 
connected to the front of a seat support 28 at 30. A bench type seat 
cushion 103 is attached to support 28. A leg 32 extends from the rear of 
support 28 and is slidably retained at its lower end 34 for movement along 
guide channel 20 by a roller (not shown) located within the guide channel. 
A link 38 is pivotally connected at one end 40 to seat support 28 and is 
slidably retained for movement along guide channel 20 at its other end 42 
by another roller (not shown) located within the guide channel. 
A lazy tong-like linkage controls movement of a back support 46 and 
includes links 48, 50 and 52. A back cushion 104 is attached to cushion 
frame 105 and support 46. One end 54 of link 48 is pivotally connected to 
end 42 of link 38 for slidable movement along guide channel 20. End 62 of 
link 48 is pivotally connected to an intermediate part of link 52. Link 52 
is pivotally connected at 60 to back support 46 and at its other end 64 to 
a curved link 80. Link 50 is pivotally connected at one end 56 to back 
support 46 and at its center 51 to link 48 and is pivotally connected at 
its other end 58 to rear leg 13 of U-shaped frame member 12. Link 50 is 
also pivotally connected at 51 to an intermediate part of link 48. 
Extender assembly 70 attaches seat-bed assembly 10 along the rear vertical 
leg 13. Mounting plate 72 of extender assembly 70 is bolted or otherwise 
connected to cross member 15 along leg 13. A lower horizontal arm 73 
extends rearward from the lower portion of mounting plate 72. Horizontal 
arm 73 has a vertical part 75. An upper horizontal arm 76 extends from the 
upper portion of mounting plate 72 and connects to arm part 75. Thus, so 
connected, plate 72, arm 73, and arm 76 become functionally a part of 
support frame 11. 
Links 88 and 92 and extender support 100 carry extender platform 102 and 
extender cushion 106. Link 88 is pivotally connected at 89 to brace 76 and 
at 90 to extender platform support 100. Link 92 is pivotally connected at 
end 93 to horizontal portion 74 of arm 73 and at end 94 to extender 
platform support 100 at a location rearwardly of link 88. Link 92 has a 
skid plate 95 secured at an intermediate point 96. A helical spring 98 is 
pivotally connected at one end to an intermediate point 97 of link 92 and 
at the other end to the extender support 100 at a point adjacently 
rearward of connection 94 between link 92 and extender support 100. 
Extender cushion 106 is preferably removably secured to platform 102 to 
form a bed when extender assembly 70 is in its use position of FIGS. 2 and 
5-7, but can be readily detached when platform 102 is used as a table 
surface such as seen in FIG. 6. 
A curved actuating link 80 connects the linkage of extender assembly 70 to 
the linkage of seat-bed assembly 10. A link 84 is pivotally connected at 
end 85 to horizontal arm 73 and at end 86 to an intermediate point 82 
along the rearward portion of curved link 80 inwardly from its end 83. 
Link 80 is pivotally connected to link 52 of seat-bed assembly 10. End 83 
of curved link 80 serves as a lever and contacts link 92 along a skid 
plate 95 secured to the link between its pivot connection 93 and spring 
98. 
Seat-bed assembly 10 is operated as follows: In its position of FIG. 3, 
assembly 10 functions as a conventional seat with extender platform 102 
raised. By grasping seat cushion 103 and sliding it outwardly, as seen in 
FIG. 4, cushions 103 and 104 assume a horizontal aligned orientation, as 
explained in U.S. Pat. No. 4,321,716, with seat support 28 resting upon 
end member 12. Simultaneously, the movement of link 52 counter-clockwise, 
as seen in FIG. 4, urges link end 83 of curved link 80 against skid plate 
95 forcing the outward rotation of links 88 and 92. This movement causes 
extender platform 102 and extender cushion 106 to shift into an aligned 
horizontal down position as seen in FIG. 5. In this position, cushion 103, 
104 and 106 form a flat, full-sized bed. Spring 98 shifts into an 
overcenter position and holds platform 102 in its horizontal use position. 
To restore seat-bed assembly 10 to its seat position, seat cushion 103 is 
pivoted inwardly to bring back cushion 104 upwardly. Extender assembly 70 
is then restored to its vertical stored position by grasping and urging 
platform 102 pivotally upward. Platform 102 preferably cannot be raised 
with when seat-bed assembly 10 is in its down or bed position to prevent 
injury to the user. 
With assembly 10 functioning as a conventional seat, extender assembly 70 
can operate independently of movement of seat-bed 10. By grasping extender 
platform 102 and sliding it downward, platform 102 assumes a horizontal 
aligned orientation supported by vertical leg 75, as seen in FIGS. 6 and 
7. Again, spring 98 in its overcenter position holds extender assembly in 
its horizontal down position. In the horizontal use position, extender 
platform 102 and extender cushion 106 serves as an addition sitting 
surface or as a table with cushion 106 removed. To restore extender 
assembly 70 to its vertical stored position, extender platform 102 is 
grasped and urged pivotally upward to bring assembly 70 to its vertical 
position. 
It should be noted that bed assembly 10 and extender assembly 70 may be 
extended either by hand or by mechanized means such as a motor and gear 
drive, not shown. Also extender assembly 70 can be used as an add-on 
feature for existing convertible beds. 
It is understood that the above description does not limit the invention to 
the embodiment herein described, but that it may be modified within the 
scope of the appended claims.