Table extension for the handicapped

A table extension suitable for use by a person confined to a wheelchair which is mountable beneath an existing table, and also a table in combination with such a table extension. The Table extension includes a pair of opposed spaced side frame members forming a housing, means for securing the housing to the underside of a table top, a first planar member, support means in each side frame member for slidably supporting the first planar member, a second planar member disposed above and substantially parallel to the first planar member, and locking hinge means connecting the planar members and providing for movement of the planar members from a collapsed position within the housing to an extended position wherein the second planar member is raised to a position substantially at the same level as the table top.

BACKGROUND 
(1) Field of the Invention 
This invention pertains to the furniture field, to devices for providing an 
extension to a table top or other planar surface, and more particularly to 
table extensions which may be mounted to an existing table. 
(2) Description of the Prior Art 
Because of the interference from the table legs and cross supports beneath 
a table, those handicapped persons confined to a wheelchair have a 
difficult, and often impossible, time maneuvering their wheelchairs 
underneath a standard table. Thus, a standard table presents an obstacle 
to a handicapped person nearly as great as a set of stairs without a ramp. 
Conventional table extensions do not alleviate the problems of the 
handicapped with tables for a variety of reasons. 
Table extensions are known that have been built into a table and may be 
used by a person in a wheelchair once the extension is in place. See, for 
example, U.S. Pat. Nos. 236,589; 1,167,905; and 2,852,325. However, the 
complex paths of motion necessary to set these table extensions up cannot 
be readily performed by a person sitting in a wheelchair. The typical drop 
leaf extension hangs down low and a handicapped person finds it difficult 
to move the leaf upward and into a locked position. 
It accordingly is an object of the present invention to provide a table 
extension of relatively simple construction which may be operated easily 
by a person confined to a wheelchair. 
U.S. Pat. No. 2,868,597 discloses a table extension which may be operated 
by a person confined to a wheelchair. This extension is positioned beneath 
a table top and may be moved into an extended position by simply pulling 
the extension straight out from under the table and locking it into place. 
However, this table extension has the disadvantage of requiring a specific 
table bottom surface to accommodate the table extension. Therefore, this 
table extension must be built into the basic design of the table. A person 
desiring such a table extension would need to purchase an entire table. 
It is a further object of the present invention to provide a table 
extension for handicapped persons which may be attached to an existing 
table. 
SUMMARY OF THE INVENTION 
Accordingly, I have invented a table extension which may be mounted beneath 
an existing table top or other planar surface, or built into an existing 
table, and easily pulled into place by a person sitting before the table 
in a wheelchair. My table extension includes a pair of opposed spaced side 
frame members forming a housing, means for securing the housing to the 
underside of a table top, a first planar member, support means in each 
side frame member for slidably supporting the first planar member, a 
second planar member disposed above and substantially parallel to the 
first planar member, and locking hinge means connecting the planar members 
and providing for movement of the planar members from a collapsed position 
within the housing to an extended position wherein the second planar 
member is raised to a position substantially at the same level as the 
table top. The housing may also include one or more cross support members 
between the frame members, and an upper support member secured to the top 
of each side frame member to attach the housing beneath the table top. The 
support means is preferably a longitudinal channel in each frame member 
which engages one edge of the first planar member. The preferred locking 
hinge means is a pair of opposed Z-hinges and means on the first planar 
member for locking the Z-hinges in an open position whereby the planar 
members are held in the extended position. A handle may be provided on the 
second planar member for grasping and moving the planar members from the 
collapsed position to the extended position and vice versa.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, my table extension, which is preferably made of wood, 
includes a pair of upper support members 10, a side frame member 12 
suspended from each upper support member 10, a pair of spaced cross 
supports 14 and 16 disposed between the frame members 12 and attached 
thereto, and a lower support 17 disposed beneath the frame members 12 and 
attached thereto. Together these elements form a housing 18. A first or 
lower planar member or board 20 is disposed within the housing 18 between 
the frame members 12. The outside edge 22 of the lower board 20 engages a 
support means in each frame member 12. As will be explained in more detail 
later in connection with FIG. 3, the lower board 20 includes first and 
second recessed portions 24 and 25. The support means is preferably a 
first groove or channel 26 running substantially the length of each frame 
member 12, but may also be an angle iron or the like attached to each 
frame member 12. The lower board 20 is thus supported in the first 
channels 26 between the frame members 12 and is adapted to slide in and 
out of the housing 18 in the direction indicated by the double-headed 
arrow A. 
A second or upper planar member or board 28 is disposed above and parallel 
to the lower board 20, and also within the housing 18 and between the side 
frame members 12. A locking hinge means, which preferably includes a pair 
of Z-hinges 30, is secured between the upper and lower boards 28, 20. A 
handle 32 may be provided on the front edge 34 of the upper board 28 in 
order to grasp and slide the boards within the housing 18. Preferably the 
boards are rectangular shaped and are narrower than the distance between 
the arms of a wheelchair. 
FIG. 2 shows the table extension, indicated generally by item 36, with the 
housing 18 mounted beneath a standard table which includes a top 38 and 
legs 40, as viewed from one end of the table and in the collapsed 
position. The upper support members 10 are mounted to the underside of the 
table top 38 by fasteners such as screws 42 or adhesively. The boards 20, 
28 are located between the frame members 12, beneath the cross supports 14 
and 16 and above the lower support 17. The upper board 28 is mounted to 
the lower board 20 by a pair of Z-hinges 30. A second channel 27 is 
provided immediately above the first channel 26 in each frame member 12 to 
provide clearance for the Z-hinges 30 when the table extension is 
collapsed. 
FIG. 3 shows the table extension underneath a table and in its extended 
position. For illustration purposes, this Figure, and also FIGS. 4 and 5, 
shows the table extension with one frame member 12, upper support member 
10, the cross supports 14 and 16 and the lower support 17 removed. It is 
to be understood that the opposite side of the table extension is 
identical but of reverse hand to that shown in FIGS. 3, 4, and 5. The 
upper board 28 extends completely beyond a front edge 44 of the table top 
38 and is positioned by the Z-hinges 30 at substantially table top level. 
The lower board 20 remains partially under the table supported by the 
channel 26 in each frame member 12. A stop 23 mounted beneath the lower 
board 20 prevents the boards from moving past the position where the stop 
23 abuts the lower support 17 (not shown). Each Z-hinge 30 includes a 
front hinge arm 46 and a rear hinge arm 50, each pivotally mounted between 
the boards 20, 28. A middle hinge arm 52 is pivotally mounted between 
upper board front hinge pivot point 48 and lower board rear hinge pivot 
point 56. The middle hinge arm 52 pivots in its center at point 54 and may 
be locked in a rigid position by resting in a locking channel or ramp 55 
in the lower board 20. It can be seen, by referring to FIGS. 3 and 3A, 
that when downward pressure is applied to the upper board 28 the middle 
hinge arm 52 pivots downward, but the locking ramp prevents further 
movement. Thus the Z-hinge 30 is supported in the extended position by the 
locking ramp 55. While the preferred locking hinge means is a Z-hinge in 
combination with the locking ramp 55, any collapsible hinge mechanism 
which can maintain the upper board 28 rigidly in its extended position, 
yet permit the upper board 28 to be moved immediately adjacent the lower 
board 20 when in the collapsed position, may also be used. 
Along each side of the lower board 20 are first and second recessed 
portions 24 and 25 which provide room to mount the Z-hinge 30, but permit 
the hinge 30 to clear the inside of the frame members 12. The first hinge 
arm 46 is mounted to the lower board 20 in the first recessed portion 24 
and the rear hinge arm 50 is mounted in the second recessed portion 25. 
The locking ramp 55 extends between the first and second recessed portions 
24, 25 as shown in FIGS. 3, 3A, 4, and 5. The first channel 26 supports 
the lower board 20 along its outer edge 22 and permits the boards 20, 28 
to be moved in and out of the housing 18. The first channel stops 56 near 
the end of the frame members 12 to prevent the lower board from being 
moved out the rear of the housing 18. The second channel 27 extends far 
enough to provide clearance for the Z-hinges 30 when the table extension 
is in its fully collapsed position within the housing 18. 
The sequential operation of the table extension is illustrated by FIGS. 4, 
5, and 3. When the extension is in its collapsed position as shown in FIG. 
4, the extension can be "opened" by grasping and pulling outward on the 
handle 32, causing the boards 20, 28 to slide together from under the 
table top 38 as shown in FIG. 5. When the upper board 28 has completely 
passed the cross supports 14, 16 further pulling will cause the hinges 30 
to rotate in an upward direction. The front and rear hinge arms 46, 50 
rotate counterclockwise (with reference to the lower board 20) until they 
are substantially perpendicular with each board. The middle hinge arm 52 
is supported in its rigid position by resting in the locking ramp 55 and 
prevents the front and rear hinge arms 46 and 50 from pivoting. Thus, the 
Z-hinges 30 will support the upper board 28 substantially on the same 
level as the table top 38 as shown in FIG. 3. When the table extension is 
in this extended position, the upper board 28 serves as the table top 
portion of the table extension. To return the table extension to its 
collapsed position, middle hinge arm is pivoted backwards, the upper board 
28 is moved down adjacent to the lower board 20, and both boards are moved 
back under the table into the housing 18. 
The table extension may easily be attached to an existing table by merely 
securing the unit underneath the table top by screws or other fasteners 
and requires no modification of the table. The table extension may also be 
built into a new table. 
The Z-hinge 30 is preferably constructed of metal, and the remaining 
elements are constructed out of wood; however, any other satisfactory 
material may also be utilized. Furthermore, while the preferred use for 
this invention is as a table extension, it may also be used as an 
extension to any planar surface such as the top of a desk, work bench, 
counter or the like. 
Having described presently the preferred embodiment of the invention, it is 
to be understood that it may be otherwise embodied within the scope of the 
appended claims.