U.S. patent number 3,895,604 [Application Number 05/370,347] was granted by the patent office on 1975-07-22 for duct coating apparatus.
Invention is credited to John W. Ryan.
United States Patent |
3,895,604 |
Ryan |
July 22, 1975 |
Duct coating apparatus
Abstract
A remote-controlled, self-propelled, vehicular apparatus adapted
to travel tractionally within a rectangular duct and, by way of a
spraying operation, coat the four walls of the duct internally with
a suitable treating liquid such as a solvent, a rust or other
corrosion inhibitor, paint, lacquer, or the like.
Inventors: |
Ryan; John W. (Chicago,
IL) |
Family
ID: |
23459249 |
Appl.
No.: |
05/370,347 |
Filed: |
June 15, 1973 |
Current U.S.
Class: |
118/306;
118/DIG.10 |
Current CPC
Class: |
B05B
13/06 (20130101); B08B 9/049 (20130101); Y10S
118/10 (20130101) |
Current International
Class: |
B05B
13/06 (20060101); B08B 9/02 (20060101); B08B
9/04 (20060101); B05c 007/02 () |
Field of
Search: |
;118/306,215,254,305,DIG.10 ;15/104.05 ;134/167R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: McIntosh; John P.
Attorney, Agent or Firm: Gerlach; Norman H.
Claims
Having thus described the invention, what I claim as new and desire
to secure by Letters Patent is:
1. In a self-propelled vehicular apparatus for applying a liquid
coating material to the inner wall surfaces of a rectangular duct
having horizontal top and bottom walls and vertical side walls, in
combination, a chassis in the form of a rectangular frame having
front and rear transverse frame members and a pair of side frame
members, front and rear axles projecting across said side frame
members, driving drums on the outer ends of the rear axle, driven
drums on the outer end of the front axle, crawler treads connecting
each driving drum to an associated driven drum, a reversible
electric drive motor mounted on said chassis in the medial region
thereof, a gear reduction drive mounted on said chassis rearwardly
of the motor, means operatively connecting the gear reduction
device to the motor, means operatively connecting the gear
reduction device to one of said driven drums in driving
relationship, a spraying device mounted on said chassis adjacent to
the forward end of the latter and having a forwardly facing
discharge slot designed for wide angle distribution of sprayed
liquid coating material both laterally and vertically for
simultaneous application thereof to the horizontal and vertical
walls of the duct, a pair of outwardly diverging roller-supporting
arms removably bolted to the front transverse frame member of said
frame and projecting forwardly and laterally of the frame, a
similar pair of roller-supporting arms removably bolted to the rear
transverse frame member of said frame and projecting rearwardly and
laterally of the frame, and a guide roller rotatably mounted on the
distal end of each of said arms.
Description
The present invention relates to an apparatus for internally
treating the four walls of a rectangular sheet or other ducts such
as are commonly used in large office buildings, factories, and
other commercial establishments in connection with air conditioning
or ventilating systems, hot air furnace systems, and the like. Such
ducts require periodic attention in that, after a period of use,
they become contaminated with dirt and other foreign material which
may, under certain circumstances, give rise to unpleasant odors, as
well as impair the efficiency of the ducts insofar as their
air-flow characteristics are concerned. It is advisable that,
immediately after any given duct-cleaning operation has been
resorted to, the inner surfaces of the duct be coated with a
suitable rust or other corrosion-inhibiting liquid, various
commercial oils or other liquids being available for this purpose,
or that such inner surfaces be freshly painted for sanitary and
other purposes.
Where a rectangular duct of large size is concerned, it is possible
that such cleaning and coating operations may be performed manually
with the operator working within the duct while the latter is
illuminated. This is a laborious procedure inasmuch as it is
necessary for the operator to carry his cleaning and coating
equipment with him, such equipment including open receptacles of
the coating liquid which is subject to becoming spilled within the
duct. Furthermore, such a manual procedure involves frequent exit
and reentry of the operator from and into the duct in order to
replenish his supply of the coating liquid. Where ducts of small
size are concerned, both cleaning and coating operations are
extremely difficult and, insofar as coating is concerned,
long-handled brushes are used to spread the coating material within
the duct, these brushes being introduced into the duct through
adjacent access openings, utilizing internal duct illumination
wherever possible.
The present invention is designed to overcome the abovenoted
limitations that are attendant upon present day methods of applying
a coating material to the inner wall surfaces of rectangular ducts
and toward this end, the invention contemplates the provision of a
fully automatic, duct-cleaning apparatus embodying a self-propelled
carriage which is adapted to travel in either direction, i.e.,
forwardly or rearwardly, through a rectangular duct and on which
there is mounted a conventional spraying unit which carries its own
supply of the liquid coating material. The apparatus also embodies
a caterpillar-type drive mechanism having crawler treads which make
wide area frictional contact with the bottom wall of the duct in
order thus to insure positive propulsion of the carriage, even in
the event that the liquid coating being used by the apparatus
possesses lubricating qualities which, ordinarily, would tend to
reduce the coefficient of friction between the traction surface and
the traction drive members. An electric motor on the carriage is
operatively connected in driving relationship to the propulsion
means and remote control means are provided exteriorly of the duct
for regulating the movements of the carriage in either direction
and also for setting the spraying unit into operation or
discontinuing the spraying operation. This remote control means may
assume the form of a control panel embodying a Sonar system whereby
signals emitted therefrom are received by suitable electrical
equipment on the movable carriage within the duct, to the end that
the drive motor for the carriage may be reversed or regulated for
speed. Alternatively, the control panel may be directly connected
by electrical lead-out wires to such motor for the same purpose.
Irrespective of the particular control mechanism which is employed,
the essential features of the invention are at all times
preserved.
In order to guide the carriage along the duct when traveling in
either direction, novel outrigger guide rollers are provided at
both the front and the rear end of the apparatus and are designed
for tractional engagement with the side walls of the duct, thus
enabling the apparatus to follow the contour of the latter, even
when moderate curves or bends are involved.
The provision of an apparatus which is relatively simple in its
construction and, therefore, may be manufactured at a low cost; one
which is comprised of a minimum number of parts, particularly
moving parts and, therefore, is unlikely to get out of order; one
which is capable of ease of assembly and dismantlement for purposes
of inspection, replacement or repair of parts; one which is smooth
and silent in its operation, and one which, otherwise, is well
adapted to perform the services required of it, are further
desirable features which have been borne in mind in the production
and development of the present invention.
Other objects and advantages of the invention, not at this time
enumerated, will readily suggest themselves as the nature of the
invention is better understood from a consideration of the
following detailed description.
In the accompanying single sheet of drawings forming a part of this
specification, one illustrative embodiment of the invention is
shown.
In these drawings:
FIG. 1 is a perspective view of a duct-spraying apparatus embodying
the present invention, such view showing the apparatus operatively
disposed in a rectangular duct with portions of the duct being
broken away in the interests of clarity;
FIG. 2 is a vertical transverse sectional view taken on the line
2--2 of FIG. 1 and in the direction of the arrows; and
FIG. 3 is a vertical longitudinal sectional view taken on the line
3--3 of FIG. 2.
Referring now to the drawings in detail, a duct-spraying apparatus
embodying the present invention is designated in its entirety by
the reference numeral 10 and is shown as being operatively
installed or positioned within a duct 12, the latter being
rectangular in cross section and having vertical side walls 14 and
16, a top wall 18 and a bottom wall 20. The apparatus is in the
form of a self-propelled vehicle or carriage which is electrically
powered and carries a spraying device 22 by means of which a liquid
coating material may be applied to the four walls of the duct 12 as
the carriage travels through the latter. The apparatus further
includes a caterpillar-type drive or propulsion mechanism 24 by
means of which the carriage may be propelled in either direction
longitudinally along the duct 10.
The carriage is comprised of a rectangular chassis 25 including
side frame members 26 and 28, a front transverse frame member 30
and a rear transverse frame member 32. These frame members are
preferably, but not necessarily, of channel shape design.
The caterpillar-type drive mechanism 24 serves tractionally to
support the chassis 25 and, accordingly, it embodies a rear drive
shaft 34 which carries a pair of driving drums 36, and a front
driven shaft 38 which carries a pair of driven idler drums 40.
Endless crawler treads 42 encompass the driving and driven drums in
the usual manner of caterpillar drive construction. The two shafts
36 and 38 are rotatably carried by the side frame members 26 and 28
of the rectangular chassis 25.
The caterpillar-type drive mechanism 24 is powered by an electric
motor M, the latter being fixedly mounted on a platform 44 which is
supported at its ends on the side frame members 26 and 28 and is
secured thereto by bolts 46. The motor M has associated therewith a
gear reduction device 48, the output shaft 50 of which carries a
drive sprocket 52 which is operatively connected by an endless
chain 54 to a sprocket 56 which is secured to the drive shaft 34.
The motor M is of the reversible type to the end that the vehicular
apparatus may be caused to move in either a forward or a reverse
direction. In the illustrated form of the invention, the electric
motor M is supplied with energizing current by means of a branch
cable 60 (see FIG. 3) which extends from a main manifold cable 62.
The latter leads from a suitable control panel (not shown) which is
positioned exteriorly of the duct 12 and may be of the portable
type so that it may be positioned on a floor surface in the
vicinity of duct-cleaning operations. A sheet metal box-like cover
or casing 64 encompasses the motor M and is suitably secured on the
platform 44.
The spraying device 22 may be of any suitable
commercially-available type, the particular device illustrated
herein being a purchased unit which is manufactured and sold by
Electro Engineering Products Co. of Chicago, Illinois under the
trade name "Electro-Airless." This unit bears Model No. 2400 and is
in the form of a composite casing including an upper motor section
70 and a lower container section 72 which is threadedly received on
the upper section as indicated at 73. The upper motor section
encloses an electric motor M2, the container section 72 being
adapted to receive therein a supply of the particular liquid
coating material which is to be sprayed on the walls of the duct
12. The disclosure of the spraying device 22 herein is entirely
schematic, the device being of the rotating centrifugal disk-type
wherein liquid coating material which is deposited on a rotatable
disk 74 within the upper section 70 of the casing is flung radially
outwardly through a discharge slot 76 in the wall of the casing
section 70. The discharge slot 76 is designed for wide angle
distribution of the coating material therefrom as indicated by the
diverging broken lines, the discharged liquid spray possessing wide
lateral directional distribution for application of the spray to
both the side walls 14 and 16 of the duct and the vertical
directional distribution for application of the spray to the duct
top and bottom walls 18 and 20. The lower section 72 of the
composite casing of the spraying device 22 is supported within a
retaining ring 78 which is secured by brackets 80 to the chassis. A
pump 82 which is disposed within the lower section 72 of the
sprayer casing serves to elevate the liquid coating material
through a riser tube 84 for deposition on the upper surface of the
rotating disk. Both the disk 74 and the pump 82 are driven by the
motor M2 and the latter is supplied with energizing current through
a second branch cable 86 leading from the main cable 62.
A generally L-shaped control casing 88 of the pistol grip-type
contains an electrical off-on switch (not shown) which is operable
under the control of a trigger member 90, the switch, when in its
"on" position at the time the trigger is depressed, serving to
supply electrical current to the motor M2 in order to drive both
the disk 74 and the pump 82. A locking button 92 projects through
one side of the control casing 88 and, when depressed, serves to
maintain the trigger in its retracted position.
In order to maintain the carriage centered within the duct 12 and
to guide the same therealong in either direction, a series of four
outrigger guide rollers 100 are rotatably mounted at the outer ends
of a series of four quadrilaterally-arranged supporting arms 102,
there being a pair of such arms on the forward end of the carriage
and a similar part of arms on the rear end of the carriage. The
various arms are suitably bolted as indicated at 104 to the front
and rear transverse frame members 30 and 32 and the arms of each
pair diverge outwardly and serve to maintain their respective
rollers in such spaced apart relationship that their over-all
spread is slightly less than the transverse dimension or width
between the side walls 14 and 16 of the duct. It is contemplated
that in the commercial production of the herein described spraying
apparatus 10, the diameter of the driving and driven drums 36 and
40, as well as the spread of the roller-supporting arms 102 will be
varied to accommodate ducts having varying dimensions so that,
insofar as practicable, the height of the discharge slot 76 may be
maintained at the proper elevation for application of the sprayed
liquid coating material to the four walls 14, 16, 18 and 20 of the
duct 12.
In the operation of the herein described duct-spraying apparatus
10, consideration will first be given to the dimensions of the
particular duct which is to be treated and, accordingly, a spraying
apparatus in which the diameters of the driving and driven drums 36
and 40 will bring the height of the discharge slot 76 to an
approximate mid-level position within the duct 12, and a lateral
roller spread of the supporting arms 102 which will bring the
rollers 100 into close proximity with the side walls 14 and 16 of
the duct, will be selected and introduced into the duct. Such
introduction of the apparatus 10 into the duct will, of course, be
accomplished in the most expedient manner available, considering
the nature of the duct. For example, where a given duct is of the
overhead type, and is provided with access openings in the bottom
wall thereof, the apparatus will be lifted, hoisted, or otherwise
introduced upwardly and into the duct. As previously stated, remote
control wireless signalling means embodying a floor-supported
control box or panel (not shown) may be provided for selectively
actuating the two motors M and M2, while suitable motor control
solenoids may be carried by a junction box or the like (likewise
not shown) which is mounted on the chassis 25, these solenoids
being responsive to appropriate control switches which are
associated with the floor-supported control panel. However, in the
illustrated form of the invention, electric wires are employed for
conducting energizing current to the motors M and M2, such wires
being associated with the aforementioned main cable 62 and the
branch cables 60 and 86.
Upon introduction of the spraying apparatus 10 into the duct 12,
the trigger 90 will be manually depressed and locked in such
depressed condition and the motors M and M2 will then be energized
so as to drive the apparatus in a forward direction while
simultaneously operating the spraying device 22. During travel of
the apparatus through the duct, the liquid coating material which
is flung peripherally from the disk 74 and emerges from the
discharge slot 76 in cone-like fashion as indicated by the broken
lines in FIG. 3 is deposited on all four walls 12, 16, 18 and 20 of
the duct, as hereinbefore pointed out. If the bottom wall 20 of the
duct 12 is provided with a series of access openings, the duct may
be treated by successive operations wherein the apparatus is caused
to travel in one direction from its region of introduction to an
adjacent access opening and then, by reversing the motor drive,
caused to return to its point of introduction. Thereafter, the
apparatus may be caused to travel in the other direction to the
other adjacent access opening and similarly caused to return. If
dual coating operations are desired, the motor M2 of the spraying
apparatus will be maintained energized during both forward and
rearward movement of the apparatus. Otherwise, the motor M2 will be
maintained energized only during travel in one direction. It will
be understood, of course, that the pulling power which is exerted
by the apparatus as it travels forwardly is adequate to pull the
cable behind it. During return movement of the apparatus in a
reverse direction, the cable may be drawn rearwardly by the
operator or by a suitable automatic winding and reeling mechanism
(not shown). Upon such return of the apparatus, and before the
latter is withdrawn from the duct, the trigger 90 will, of course,
be released to shut off the supply of coating material.
The invention is not to be limited to the exact arrangement of
parts shown in the accompanying drawings or described in this
specification as various changes in the details of construction may
be resorted to without departing from the spirit or scope of the
invention. Therefore, only insofar as the invention is particularly
pointed out in the accompanging claim is the same to be
limited.
* * * * *