Air table

An improved air table of the type having an article support surface with a plurality of holes therethrough, the holes being in communication with their respective air pipes which laterally project in spaced relationship from a longitudinally extending air manifold that is connected to a source of pressurized air. An air tube and the respective holes are associated with each of the juxtaposed sections of the table which form the support surface. The improvement comprises a valve on each of the pipes to restrict the flow of air from the manifold to the holes, the valve operable by an actuating responsive to an article being on or adjacent to a section so as to allow the air to be delivered to a selective section to maintain the article above the table surface as the article is moved to the next section.

BACKGROUND OF THE INVENTION 
(1) Field of the Invention 
The present invention relates to an article support system and, more 
particularly, to an improved air table. 
(2) Description of the Prior Art 
It is old in the art to use work tables that utilize pressurized air blown 
through holes in the table surface to move articles therealong, as in the 
garment industry with spreads of cloth. The blown air floats the cloth 
above the table surface, the cloth being piled on the table from a few ply 
to as many as 200 ply and in spread lengths of from 2 or 3 yards to as 
many as 20 to 30 yards. The spreads are floated to wherever required which 
is usually to the automatic cutting machines. 
Normally, high volume low pressure air is applied simultaneously through 
all of the holes along the entire length of the table in order to 
accomplish this float, thereby requiring several air blowers with an 
attendant large amount of power consumption. The old tables are, 
therefore, inefficient and expensive. 
SUMMARY OF THE INVENTION 
The disadvantages of the prior art are overcome by the present invention 
which provides for the delivery of pressurized air to only a selected, 
desired section of the work table in order to move an article, such as 
spreads of cloth, from that section to at least the next adjacent section. 
The invention is utilized on air tables of the type having a flat work 
surface with a plurality of air holes therethrough. The surface is divided 
along its length into a number of sections, each section having an air 
pipe which laterally extends from an air manifold which is connected to an 
air blower. Flexible tubing connects each hole with its respective air 
pipe. 
A valve means is on each air pipe to control the flow of air therethrough 
between the manifold and the holes associated with each air pipe and is 
operable by an actuating means which is responsive to the spread of cloth 
being on that particular section. Normally, each of the valve means is in 
the closed position so that the blown air does not reach the air holes for 
that section in the table surface. When the actuating means senses the 
cloth on a particular section of the table, the valve means on the air 
pipe for that section is actuated so as to move to an open position, 
allowing the delivery of the pressurized air to the air holes and 
"floating" the cloth above the surface. The cloth can then be easily moved 
to the next work section on the table. 
The valve means comprises a pinch or bladder valve which is operable 
between its open and closed positions by means of compressed air acting on 
a flexible diaphragm to transversely constrict by a pinching action to 
allow or restrict the flow of air therethrough. A slide valve assembly is 
disposed on the air line between the pinch valve and a second source of 
pressurized air, the slide valve being normally open to allow the 
pressurized air from the second source to act on the diaphragm to pinch it 
close. 
The actuating means is connected to the slide valve assembly. The first 
embodiment of the actuating means involves a level arm which extends up 
through a slot in each of the sections and is pivotally mounted to the 
slide valve assembly. The spread of cloth engages the arm to pivot it 
downwardly, causing the slide valve to close. The air flow from the second 
source to the diaphragm is cut off, allowing the diaphragm to radially 
expand so that the pressurized air flowing through the manifold from the 
first source travels through the respective air pipe to the air holes 
associated with that section to float the spead. 
In the second embodiment, pressurized air from a third source is 
continually passed upwardly through one of the air holes of each section. 
That air hole is in communication with a spool valve that is in 
communication with the slide valve assembly and which is normally in a 
closed position so as to prevent pressurized air from a fourth source from 
acting upon the slide valve. When the cloth moves over that air hole, the 
back pressure of the pressurized air from the third source opens the spool 
valve so that the air from the fourth source moves the slide valve to its 
closed position, opening the pinch valve and allowing pressurized air to 
flow through the air holes of that particular section. 
It is, therefore, a primary object of the present invention to provide an 
improved air table wherein pressurized fluid is independently delivered to 
a selected section of the table only when needed. 
Another object of the present invention is to provide a valving system for 
an air table whereby pressurized air may flow to individual sections of 
the table, as needed. 
A further object of the present invention is to provide a low-cost and 
power-efficient air table.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS 
Referring to the figures of the drawings, the numeral 10 represents 
generally the air table of the present invention. As seen in FIGS. 1 and 
2, the table 10 includes a flat, rectangular-shaped article support 
surface 12 which is generally constructed of chipboard and which is 
maintained above the floor by means of a support frame that is generally 
designated by the numeral 14. A plurality of air holes 16 extend through 
the surface 12 in a regular, spaced attitude along its length. 
Pressurized fluid (normally air) is delivered to the holes 16 by means of a 
conventional air blower 18 powered by motor 20. The discharge end of 
exhaust pipe 22 from blower 18 is connected to one end of an air manifold 
24 that longitudinally extends beneath surface 12 adjacent one of its 
sides. The other end of manifold 24 is closed. The horsepower of motor 20 
may vary, depending upon the load requirements. 
Cylindrical air pipes 26 laterally extend from manifold 24 beneath surface 
12 in spaced, parallel relationship along the length of the table 10. The 
air pipes 26 are perforated, with flexible tubing 28 interconnecting each 
perforation with each air hole 16. Each pipe 26 defines a separate section 
I, II, etc. on the table 10, each section being of equal dimensions. A 
typical table 10 is 100 feet in length, made up on 4-foot sections. 
Referring to FIGS. 3 and 4, a valve means is shown on an air pipe 26 and 
includes a sleeve type pinch or bladder valve which is generally 
referenced by numeral 30. The valve 30 comprises a cylindrical valve 
sleeve 32 that is approximately of the same diameter as pipe 26 and which 
defines an inner air chamber 34. A flexible, circular diaphragm 36 of 
elastomeric material is disposed within chamber 34 and is of a greater 
length than sleeve 32. The end portions 38 of the diaphragm 36 are folded 
over the outer surface of the sleeve 32 and are held in sealing air-tight 
engagement therewith by means of flange members 40 which are of a greater 
diameter than air pipe 26 and which join the valve 30 to the pipe 26. 
Typically, 2-inch diameter PVC pipe that is approximately 5 inches long is 
utilized for each valve 30. 
A hollow threaded connection 42 extends into chamber 34 with air line 44 
being connected thereto by means of complimentary threaded coupling nut 
46. As seen in FIGS. 7 and 8, the air line 44 extends into the outlet 
opening 48 through the housing 50 of valve 52. The valve 52 includes a 
chamber 54 in which a piston 56 is slidably disposed, the piston 56 being 
biased by spring 58 into the position as shown in FIG. 7 whereby the 
respective ends of the passageway 60 through piston 56 are in registration 
with outlet opening 58 and intake opening 62. Air line 64 connects the 
intake opening 62 with a source of pressurized air, shown in FIG. 10 as 
numeral 66, through line 68 and pressure regulator 70. 
Means is provided for actuating the valve 52 to move piston 56 between an 
open position as shown in FIG. 7 and a closed position as shown in FIG. 8. 
Two embodiments of the actuating means are disclosed. 
The first embodiment is shown in FIG. 10 and includes a rigid element or 
lever arm 72 that extends upwardly through a slot 74 formed in each 
section of surface 12 and is pivotally mounted on housing 50 at point A. 
The lower end 76 of arm 72 is designed to engage the front face 78 of 
piston 56 when the arm 72 contacts the cloth and is moved to position 72', 
thereby moving the piston 56 to its position as shown in FIG. 8. The air 
vent or exhaust opening 80 then is in registration with vertical channel 
82 and outlet opening 48. When the cloth is removed from engagement with 
the arm 72, the arm 72' returns to its original position and piston 56 
returns to its open position as shown in FIG. 7. 
The second embodiment of the actuating means is shown in FIGS. 7-9 and 
comprises a spool valve 84 for each valve 52 and which is in communication 
with air line 86 which interconnects air hole 88 with air line 90 which is 
connected to a source of low pressure air (as, for example, 1 p.s.i.). 
Line 92 is a high pressure air line (such as 30 p.s.i.). Line 94 
interconnects the chamber 54 of valve 52 with the valve 84. 
A spindle 96 is normally in the position as shown in FIG. 7 whereby air 
flow between lines 92 and 94 is blocked. When the hole 88 becomes covered 
by the cloth, as shown in FIG. 8, the air back pressure in line 86 presses 
the spindle 96 downwardly, establishing communication between lines 92 and 
94, thereby pushing piston 56 to its closed position, opening valve 30. 
Referring to FIGS. 10 and 11, line 68 is the main air feeder from air 
source 66 to the other lines 64 and valves 52 on the first embodiment of 
table 10. In FIG. 9, it can be seen that line 92 is off of main branch 98 
which directs high pressure air to the remaining valves 84 in the second 
embodiment of the present invention. Pressure through line 98 is 
controlled by regulator 100. Lines 68 and 98 may branch off of main line 
102 from a pressurized air source (not shown). 
As an example of the utility of the present invention, a conventional air 
table which is 100 feet in length and 51/2 feet wide normally requires 3 
air blowers to force air through all of the holes in the table surface. 
With the air table 10, only one blower 18 is required for a 100 foot long 
table having 52 air holes in each 4 foot section, or a total of 25 air 
valves. The blower 18 can be 5 hp. with one (1) pound of pressure which 
will be sufficient pressure for 416 holes. Thus, the requirement for 
blower 18 is that it be capable of delivering high volume, low pressure 
air. The blower 66, on the other hand, should deliver high pressure, low 
volume air.