Apparatus for supplying an air curtain into a pit to facilitate
combustion of material disposed within the pit includes an air supply
tube mounted on wheels and having an inlet end and an outlet end,
a nozzle structure disjointably mounted on the air supply tube at
the outlet end thereof and in transverse relation thereto, a motor
driven fan for supplying air through the air supply tube and the
nozzle and into the pit, the junction between the air supply tube
and the nozzle being readily disjointable to accommodate mounting
of the nozzle atop the air supply tube for transport along a roadway.
1. Apparatus for supplying an air curtain into a pit of generally
rectangular horizontal cross sectional configuration to facilitate
combustion of material disposed within the pit, said apparatus comprising
an air supply tube of generally rectangular cross sectional configuration
and having an inlet end and an outlet end, a generally horizontal
support member which in vertical cross section corresponds approximately
to an inverted V and which is secured atop the outlet end of said
air supply tube in transverse relation thereto, a nozzle structure
disjointably mounted on said outlet end of said air supply tube
in connection therewith and in transverse relation thereto and having
support structure secured to its upper part and arranged to overlie
and partially to envelope said support member, disjointable locking
means including a locking bar rotatably mounted on a lower part
of said nozzle and at least one locking tab thereon for engaging
and disengaging a part of said air supply tube and operable to secure
lower portions of said air supply tube and said nozzle together
and means for supplying air through said air supply tube and through
said nozzle and into said pit.
2. Apparatus according to claim 1 wherein said support structure
is at least in part of complementary cross sectional configuration
to said support member.
3. Apparatus according to claim 1 wherein said air supply tube
includes wheels for roadway portability and support brackets projecting
upwardly for engaging and supporting said nozzle when disconnected
from said outlet end of said air supply tube and disposed atop said
air supply tube.
4. Apparatus according to claim 1 wherein said nozzle is of converging
cross sectional configuration in the direction of its outlet edge.
5. Apparatus according to claim 1 wherein lifting brackets are
secured atop said nozzle for engagement by lifting apparatus arranged
to hoist said nozzle into and out of its service position of connection
to said air supply tube and into and out of its portable position
atop said air supply tube.
6. Apparatus according to claim 1 where an adjustable jack is secured
to said nozzle adjacent each end thereof and engageable with the
ground to impart stability to the apparatus.
7. Apparatus according to claim 1 wherein said locking bar includes
a manually operable operating handle.
8. Apparatus according to claim 7 wherein disjointable fastening
means is arranged to secure said operating handle in its locking
This invention relates to apparatus for supplying a curtain of
air into a pit of generally rectangular horizontal cross sectional
configuration and which contains material to be burned such as tree
limbs, stumps and other debris.
U.S. Pat. No. 3,773,000 issued Nov. 20, 1973 discloses an air curtain
apparatus in which a wheel mounted air supply tube is hingedly connected
to a nozzle structure disposed in transverse relation to the air
supply tube at the outlet end of the air supply tube. The hinged
connection is designed to allow the nozzle portion of the apparatus
to swing alongside of the air inlet tube in order to facilitate
the transport of the apparatus from one job to another. One objection
to this type of apparatus is that it is of considerable width due
to the side by side orientation of the air supply tube and the nozzle.
Also, the hinged connection is cumbersome and time consuming to
Another known apparatus for supplying an air curtain to a pit for
burning material within the pit is disposed alongside the pit and
includes an elongated nozzle tube having air outlets along the length
and which is supplied with air from one end thereof through a coaxial
air supply tube. With such apparatus it is difficult to insure a
uniform volume of air throughout the entire length of the pit due
to changes in the velocity of air flow along the length of the conduit
due to friction between the air and the inner surfaces of the nozzle
Still another known arrangement for supplying a curtain of air
to a pit containing material to be burned includes an air inlet
tube connected at its air outlet end with a transversely disposed
nozzle structure, the interconnection between these two elements
being in the form of complementary flanges which are bolted together.
Obviously such an arrangement is difficult to manipulate since the
bolt holes in the cooperating flanges must be aligned and because
uneven conditions of the ground near the pit further enhance the
difficulty of making the bolted connection between the cooperating
According to this invention in one form, an air supply tube is
of generally rectangular configuration and a generally horizontal
support member is disposed in transverse relation across the upper
part of the outlet end of the air supply tube, while a complementary
structure formed on the upper part of an associated nozzle overlies
and partially envelops the support member and disjointable clamping
means is arranged to secure the lower portions of the nozzle with
lower portions of the outlet end of the air supply tube, suitable
means being provided for supplying atmospheric air into the inlet
end of the air supply tube through the nozzle and into the pit containing
material to be burned. The inner connection between the nozzle and
the outlet end of the air supply tube is readily disjointable so
that the transverse nozzle may be hoisted by convenient means to
a position atop the air supply tube where the nozzle is supported
by upstanding brackets forming a part of the air supply tube. The
fast, easy, efficient and convenient procedure for connecting and
disconnecting the nozzle and the air supply tube constitutes a principal
feature of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, FIG. 1 is an overall perspective view of apparatus
for supplying an air curtain into a pit and which is formed according
to this invention;
FIG. 2 is a view of a portion of FIG. 1 and which shows the outlet
end of an air supply tube in spaced relation from the nozzle;
FIG. 3 is a cross sectional view taken generally along the line
designated 3--3 in FIG. 2 and which in addition shows the cooperating
adjacent end of the associated air supply tube; and
FIG. 4 is a perspective view showing the nozzle structure mounted
atop the air supply tube and in condition for transmission along
a roadway, an additional pair of wheels being shown for stability.
BEST MODE OF CARRYING OUT THE INVENTION
In FIG. 1, a pit is designated at P and contains debris such as
trees, limbs, stumps and the like which are to be burned. The numeral
1 generally designates a nozzle disjointably connected with an air
supply tube generally designated by the numeral 2. Air is supplied
to the inlet end 3 of the air supply tube 2 by means of a fan not
shown and which is rotated by a conventional gasoline or diesel
engine generally designated at 4 which is mounted on frame element
5 which forms an extension of the main frame structure 6 which is
mounted on and supported by a pair of wheels 7 only one of which
is observable in FIG. 1 together with a pedestal 8 supported by
the ground and engageable with the part 5 of the frame 6. At the
outlet end of air supply tube 2, a support member 9 is secured atop
the air supply conduit 2 as is best shown in FIGS. 2 and 3. The
support member 9 is generally configured in cross section as an
inverted V which cooperates with a complementary structure 10 fixedly
mounted atop the horizontal element 11 forming a portion of nozzle
When the nozzle 1 is mounted in cooperative relation with the air
supply tube 2, the element 10 overlies the element 9 as best shown
in FIG. 3.
For securing the lower portion of the nozzle 1 to the lower portion
of the air supply tube 2, a locking bar 12 is rotatably mounted
within journals 13, 14, and 15 which are secured to transverse plate
16 forming a part of the nozzle 1 immediately below the aperture
17 formed in back plate 18 of nozzle 1 and disposed between the
side baffle plates 19 and 20 which are physically secured to the
back plate 18 of the nozzle 1 so as to facilitate a secure pneumatic
connection between the nozzle 1 and the air supply tube 2. The ends
of nozzle 1 are closed by plates 18a and 18b. Locking tabs 21 and
22 are rigidly affixed to locking bar 12 and rotation of locking
bar 12 is by manually operable handle crank 23 integrally formed
with one end of locking bar 12. Thus rotation of locking bar 12
in a generally clockwise direction as viewed in FIGS. 2 and 3 causes
the locking tabs 21 and 22 to swing into locking engagement with
a transverse bar 24 securely affixed and projecting downwardly from
a lower portion of the air supply tube 2 at the outlet end thereof.
Locking handle 23 is secured in locking position by means of locking
chain 25 which is disposed within a notch 26 formed in angle iron
27 welded to the cross piece 11 of nozzle 1.
For the purpose of affording stability to the apparatus, an adjustable
jack 28 is secured to one end of the plate 18 of nozzle 1 while
a similar adjustable jack 29 is mounted on the opposite end of the
back plate 18. Vertical adjustment of the vertical elements of these
jacks affords stable contact with the ground which of course may
be uneven. In FIG. 3, the handle 23 is shown in phantom lines because
this structure would not be observable in the cross sectional view
taken along the line 3--3 as designated in FIG. 2.
The flow of air is designated by the arrows such as 30 as shown
in FIG. 3 and proceeds from left to right and out of the exhaust
slot 31 formed between the lower portion of plate 32 and bottom
plate 33. Vertical bars B are spaced apart from each other and secure
the adjacent parts of plates 32 and 33.
From FIGS. 1 and 3 it is apparent that the nozzle 31 is disposed
but a short distance over and beyond the adjacent edge of the pit
P so as to avoid undue heating of the outlet part of nozzle 1.
In order to disconnect the nozzle 1 from the air supply tube 2,
it is only necessary to lift the chain 25 out of the notch 26 formed
in angle iron 27 and to rotate the handle 23 in a counterclockwise
direction as viewed in FIGS. 2 and 3. The nozzle 1 may then be lifted
away from air supply tube 2. As shown in FIG. 2, lift hooks 34 and
35 are rigidly affixed to the plate 32 of nozzle 1 and serve as
points of interconnection with hoisting cables such as are indicated
in FIG. 2 at 36 and 37. As is apparent in FIG. 1, horizontal bars
38, 39 and 40 are interconnected at their ends with vertical posts
such as 41, 42 and 43 and their counterparts 41a, 42a, and 43a.
Thus the nozzle 1 is lifted by suitable lifting apparatus and the
cables 36 and 37 and swung into position atop the air supply tube
2 to a position of rest on the bars 38, 39 and 40 as represented
in FIG. 4. For stability during transit over roadways, an additional
pair of wheels 7a may be used if desired.
Obviously with the nozzle 1 disposed atop the air supply conduit
2, the width of the structure is considerably reduced from a horizontal
disposition of these elements and thus facilitates roadway travel.
The quick and easy disjointability of the nozzle 1 from the air
supply tube 2 further contributes substantially to the practical
applicability of this apparatus and greatly facilitates the transfer
of the apparatus from one job site to another.