Abstrict A method and apparatus for simultaneously filling adjacent sides
of a window spacer frame with a desiccant material is characterized
by a fill head having a discharge port in communication with a desiccant
chamber, a releasable clamping device for clamping the open ends
of the adjacent sides in alignment with the discharge port, and
the chamber is pressurized with air to force the desiccant material
through the discharge port for a time interval necessary to fill
the sides of the spacer frame. An air conveyor is provided to induce
the flow of desiccant material from a reservoir for the purpose
of periodically refilling the desiccant chamber when empty, and
a filter system in the air conveyor will separate the desiccant
material from the air stream while permitting the air stream to
be exhausted to atmosphere during the filling operation.
Claims We claim:
1. In apparatus for depositing a desiccant material in particle
form into two adjacent sides of a rectangular spacer frame member
in which said two adjacent sides have adjacent open end portions,
the improvement comprising:
a normally sealed chamber containing a desiccant material therein;
a fill head including a single discharge port in communication
with the interior of said chamber and means on said fill head for
releasably clamping said adjacent sides of said frame member to
position both of the open ends thereof in alignment with said single
discharge port;
means for pressurizing said chamber whereby to force said desiccant
material through said discharge port into said adjacent sides of
said frame material;
said fill head having opposed, downwardly inclined surfaces extending
away from said discharge port; and
means mounting said fill head for rotation about an axis through
said fill head and between said downwardly inclined surfaces to
vary the angle of inclination of said downwardly inclined surfaces.
2. In apparatus according to claim 1 said releasable clamping
means including a fixed block on one side of said discharge port
and a slidable block on the opposite side of said discharge port
to said fixed block, and means for advancing said slidable block
toward and away from said fixed block.
3. In apparatus according to claim 1 including a supply conduit
extending between said desiccant chamber and said fill head, and
means for advancing said supply conduit between a closed position
and an open position aligned with said discharge port for directing
desiccant material from said chamber through said discharge port.
4. In apparatus according to claim 3 a valve member interposed
between said chamber and said supply conduit, and means for selectively
opening and closing said valve member.
5. In apparatus according to claim 1 a desiccant storage reservoir,
and air conveyor means for conveying desiccant material from said
reservoir into said chamber.
6. In apparatus according to claim 5 said air conveyor means including
a separator, and air pick-up means for transporting desiccant material
from said reservoir into said separator, and means for filtering
said desiccant material from said air conveyor means to exhaust
said air to the atmosphere.
Desiccant descriptionThis invention relates to dispensing comminuted
granular materials, such as, a desiccant material; and more particularly
relates to a novel and improved method and apparatus for introducing
desiccant materials under pressure into window pane spacers, such
as, hollow aluminum spacer frames employed in the fabrication of
insulated glass units.
BACKGROUND AND FIELD OF THE INVENTION
Desiccant materials are utilized in fine, granular form to fill
hollow frames, such as, the hollow spacer frames for insulated glass
units in order to minimize the formation of condensation on the
inside surfaces between the window panes. Representative of approaches
which have been followed in the past is U.S. Pat. No. 3183560
to E. Brichard where a dehydrating agent is introduced under vacuum
into a tube. In U.S. Pat. No. 3030673 to H. J. London, a silica
gel is introduced into hollow frame sections for a window; and in
U.S. Pat. No. 4151696 to R. N. Knights et al the material is a
viscous sealing material which is injected under pressure by means
of a pumping unit through a series of injection nozzles. Other patents
of interest are U.S. Pat. Nos. 2037893 to M. Greenan; 3280523
to C. E. Stroud et al; 4261145 to H. Brocking; 4660271 to K.
Lenhardt and 4698891 to R. Borys.
Among other problems associated with desiccant filling devices
which have been utilized in the past for filling spacer frames is
the inability to consistently fill a given space or length of frame
in a minimum amount of time. In filling, it is desirable to provide
for automated filling of different spacer frame lengths and widths
and whether or not the frames are bent prior to filling.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide for
a novel and improved method and apparatus for dispensing desiccant
materials and in particular for the introduction of desiccant materials
under pressure into spacer frames of the type employed in insulated
glass units.
Another object of the present invention is to provide for a method
and apparatus of filling spacer frames for insulated glass units
with a desiccant material wherein the material can be injected in
a minimum amount of time at a predetermined pressure; and further
wherein the apparatus is adaptable for use in filling a wide range
of lengths and sizes of spacer frames.
It is a further object of the present invention to provide in a
desiccant-filling system for a novel method and means for conveying
the material from a bulk packaging container into a chamber which
can be pressurized in such a way as to minimize distribution of
dust or of wasting or spilling the desiccant material.
It is a still further object of the present invention to provide
for an apparatus for injecting desiccant materials into different
lengths and types of spacer frames; and further wherein the system
is both modular and transportable while requiring a minimum amount
of maintenance.
In accordance with the present invention, a method of dispensing
desiccant material has been devised and which is specifically adaptable
for use in filling open-ended hollow elongated window frame members
and comprises the steps of depositing the desiccant material into
a normally sealed chamber, positioning at least one open end of
a frame member to be filled in communication with the interior of
the chamber, and pressurizing the chamber with air so as to force
the desiccant material under pressure into the frame member. Preferably,
the frame member is releasably clamped in position with respect
to a discharge port in the chamber, and the discharge port is selectively
opened in coordination with pressurization of the chamber to permit
the desiccant material to be forced into the frame member. The chamber
is periodically refilled through the utilization of an air conveyor
system having fluid amplifiers to induce the flow of desiccant material
from a reservoir into a separator which will permit the desiccant
material to pass by gravity into the chamber.
In a preferred apparatus in accordance with the present invention,
a normally sealed chamber is provided for the desiccant material,
a fill head including a discharge port in communication with the
interior of the chamber includes means for releasably clamping adjacent
sides of a frame member to position the open ends of the adjacent
sides in alignment with the discharge port, and means are provided
for pressurizing the chamber to force the desiccant material through
the discharge port simultaneously into adjacent sides of the frame
member. In order to facilitate simultaneous filling of adjacent
sides of a frame member, the fill head is provided with opposed,
downwardly inclined surfaces extending away from the discharge port,
and the releasable clamping means includes a slidable block on each
inclined surface which moves toward and away from a fixed block
to clamp the frame members therebetween. The fill head is mounted
for rotation about a horizontal axis to permit adjustment of the
inclination or attitude of the inclined surface.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a preferred form of apparatus in
accordance with the present invention;
FIG. 2 is an enlarged top plan view of the fill head of the preferred
form of the present invention shown in FIG. 1;
FIG. 3 is a side view of the preferred form of the fill head shown
in FIG. 2;
FIG. 4 is a cross-sectional view taken about lines 4--4 of FIG.
2;
FIG. 5 is a cross-sectional view taken about lines 5--5 of FIG.
3;
FIG. 6 is a view taken at line 6 of FIG. 5;
FIG. 7 is an enlarged view in more detail and partially in section
of the desiccant fill chambers of the present invention;
FIG. 8 is a sectional view enlarged and in more detail of the lower
end of the pick-up tube for the desiccant fill chambers; and
FIG. 9 is a cross-sectional view taken about lines 9--9 of FIG.
7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring in more detail to the drawings, there is illustrated
in FIG. 1 a preferred form of desiccant filling apparatus 10 which
is broadly comprised of a base 13 a support stand 12 having a telescoping
standard 14 and upon which is mounted a control housing 16. A fill
head 18 is rotatably mounted in one sidewall 19 of the housing 16
for the purpose of receiving adjacent free legs of a rectangular
spacer frame member F and filling the legs F with a desiccant material
represented at D which is supplied from a chamber 20 mounted on
top surface 21 of the control housing 16. A supply tube 22 extends
from the lower end of the chamber 20 for the purpose of delivering
desiccant particles from the chamber 20 into the fill head, and
the chamber 20 is pressurized by selectively admitting air under
pressure from line 23.
Typically, the legs of a spacer frame are perforated along their
inner edges, and accordingly, a moisture-absorbing or desiccant
material is inserted into at least a pair of the legs to absorb
any moisture that would condense on the inside surfaces between
the two parallel sheets of glass of an insulated glass unit, not
shown. A suitable type of desiccant material is an insulating glass
absorbent material manufactured and sold by W. R. Grace & Co.
of Baltimore, Md. and is characterized by being a fine bead-like
substance. One problem in handling this material, particularly in
forcing the material into limited spaces or openings for insulation
purposes is its tendency to create dust and to the extent that it
can become a health hazard. Thus, while the chamber 20 may be manually
filled with desiccant material, it is desirable to provide means
for automatically filling the chamber from a larger container or
reservoir 24 and in such a way as to be dust-free and completely
self-contained. To this end, a pick-up tube 25 extends from the
reservoir upwardly into a filter bowl or separator 26 which is mounted
on a platform 27 above the chamber 20. In a manner to be described
in more detail with respect to FIG. 7 a vacuum is established in
the reservoir 24 by directing air under pressure through an air
line 28 into air amplifiers at the lower ends of the tube 25 and
the filter bowl 29. This vacuum or negative pressure will operate
to induce the flow of desiccant material from the reservoir through
the pick-up tube 25 into the filter 26. The filter 26 will prevent
any of the larger desiccant particles from passing through the connecting
tube 30 between the filters 26 and 29. The larger particles of the
desiccant material D will therefore be free to advance by gravity
into the chamber 20 and any air will pass through the filter 29
and be exhausted to the atmosphere.
An important feature of the present invention resides in the construction
and arrangement of the fill head 18. As shown in FIGS. 2 to 6 the
fill head 18 comprises an elongated, inverted V-shaped body 40 and
a circular mounting plate 38 at the rearward end of the body 40
which is secured to the end of a bolt 41 projecting through the
wall panel 19 of the control housing 16. The mounting plate 38 is
releasably secured against rotation to the surrounding edge of an
opening in the panel 19 by clamping screws 39 which extend through
the plate and threadedly engage clamping plates 39' behind the panel
19 to tighten or lock the plate 38 against rotation. When the clamping
screws 39 are loosened, the fill head body 40 and the plate 38 can
be rotated for a purpose to be hereinafter described. The body 40
has inclined surfaces 42 on opposite sides which slope or diverge
downwardly and away from an upper feed area 44 and a horizontal
plate 44' has an opening 44'' which receives the lower end of the
supply tube 22. A fixed guide block 46 and movable block 47 are
disposed on each of the inclined surfaces 42 to define a common
entrance 48 for insertion of a leg or side of a spacer frame F.
The fixed block 46 has an extension plate 49 which extends across
the entrance in spaced parallel relation to each inclined surface
42 so as to define a substantially rectangular space or opening
at the entrance for insertion of the spacer frame, as best seen
from FIG. 6.
Each movable guide block 47 is attached with shoulder bolts 47'
slidable in an elongated slot 50 under the control of a double-acting
cylinder 52. Each cylinder 52 includes a piston rod 53 pivotally
connected to a slide bar 54 which rides beneath each inclined surface
42 and is connected by the shoulder bolts 47' to the block 47 to
control its movement along the slot 50 toward and away from the
fixed block 46 in response to air under pressure directed into one
of the pressure lines L.sub.3 and L.sub.4. In this way, the block
47 is selectively movable into a closed position, as shown in FIG.
3 to clamp a spacer frame between the blocks 46 and 47 with the
upper end of the spacer frame in communication with a discharge
port 56 extending downwardly from the feed area 44.
The tube 22 is movable lengthwise of the feed area 44 into and
out of alignment with the supply ports 56 under the control of a
double-acting cylinder 62 having air pressure lines L.sub.1 and
L.sub.2. A piston rod 63 is pivotally connected to a slide bar 64
with the lower end of the tube 22 affixed to the slide bar for advancement
under the control of the piston rod 63. Spring-loaded steel balls
65 yieldingly engage the undersurface of the plate 44 to apply a
controlled clamping force to the mating surfaces of the slide bar
64.
Referring in more detail to the air conveyor assembly, as shown
in FIGS. 7 to 9 the lower end of the pick-up tube 25 has an air
flow amplifier 70. The air amplifier 70 includes a generally conical
plug 71 which is centered within the throat region 72 and air is
delivered under pressure through the line 28 to flow through the
circumferential inlet 73 and upwardly across the venturi formed
between the throat 72 and plug 71 in order to induce upward flow
of the desiccant material from the reservoir 24 through the lower
open end 74. A bracket 75 is disposed across the opening 74 for
the purpose of mounting the plug 71 in centered relation to the
throat 72. The desiccant material is drawn with the air through
the tube 25 and is fed tangentially into the separator 26 so that
the air will follow a circular path tending to draw the desiccant
from the air against the wall of the separator and will roll downwardly
by gravity through funnel 78 into the desiccant chamber 20. A butterfly
valve 80 is positioned across the lower end of the funnel and is
controlled by a pneumatic actuator 81 illustrated in FIG. 1 to
seal off the separator 26 from the chamber 20 during desiccant fill
operations when dessicant is being discharged under pressure from
the chamber 20 through the fill head 18. Of course, to refill the
chamber 20 the butterfly valve 80 is opened by the actuator 81
which in turn is energized by directing air under pressure via line
82 from a pilot operated valve, not shown, in the housing 32. A
manually operated push button valve 84 on the side of the valve
housing 32 provides pilot pressure for operation of the valve for
the actuator 81 as well as a valve 36 which opens the inlet line
L to initiate the air conveyor operation for refilling of the chamber
20.
A second fluid flow amplifier 86 is disposed at the lower end of
the filter 29 having a frustoconical plug 87 centered within a generally
venturi-shaped throat region 88 and receives air under pressure
via the pressure line 28 from the control housing 32. This air is
directed into a circumferential recess and caused to pass downwardly
through the venturi region 88 to create a negative pressure inducing
the air to flow through the filter 29 and overcome any pressure
loss across the filter medium 29'. As noted earlier, a minimum velocity
of air must be maintained in the pick-up tube 25 in order to carry
the largest particles from the desiccant reservoir 24 upwardly into
the desiccant chamber; otherwise, lower velocities will transport
only the smaller particles or not at all. Accordingly, a minimum
outlet pressure from the fluid amplifier 70 is required to overcome
the maximum pressure head which will develop as a result of lifting
the desiccant through the vertical distance into the desiccant chamber
20.
Referring in more detail to the separator 26 preferably a cyclone
separator is employed to separate the desiccant material from the
air. By feeding the desiccant in at a tangent, the air flow will
follow a circular path through the separator in order to encourage
the desiccant to advance outwardly against the wall of the separator
and to roll downwardly through the funnel-shaped area 78. A filter
screen is mounted in the center of the separator which is coarse
enough to allow air and dust particles to exit the top of the separator
26 while blocking the larger desiccant particles. In the filter
29 a cloth bag 29' may provide filtration down to 40 microns. Also,
a filter paper can be inserted to filter out particles down to the
order of 5 microns. Accordingly, the air amplifier 86 is mounted
at the lower end of the filter 29 to overcome the pressure drop
across the filter and to increase the pressure differential across
the pickup tube 25. For the purpose of illustration, one suitable
form of air amplifier for the amplifiers 70 and 86 is that sold
under the trademark "TRANSVECTOR" by the Vortec Corporation,
Cincinnati, Ohio.
The foot valve 34 includes pressure and return lines designated
at 35 into the main housing 16 for controlling the desiccant fill
operation. When the foot valve 34 is activated, air is directed
under pressure from an external compressed air source, not shown,
via the inlet line L through a separate pressure line 23' to the
control housing 16. Through suitable valving in the housing 16
the actuation of the foot valve 34 will permit air under pressure
to be directed from the pressure line 23' through the upper tube
23 into the top of the chamber 20 in order to pressurize the desiccant
in the chamber 20.
In each desiccant fill operation, a fill timer control T on the
side of the control housing 32 may be set to regulate the time of
each fill; also, a clamping pressure regulator C permits adjustment
of the degree of clamping pressure by controlling the amount of
air pressure directed into the double acting piston 52 for the slide
block 47. Typically, a spacer frame F is of generally rectangular
cross-sectional configuration with upper inclined sides or legs
terminating in free ends, such as, illustrated in FIG. 6. In accordance
with well-known practice, it is necessary only to fill two sides
of a spacer frame in order to efficiently dry or remove moisture
along the window surfaces when installed. Accordingly, the fill
timer T will be set to assure introduction of a specific volume
or quantity of desiccant which can be loaded under pressure into
the two legs of the frame. The legs of the frame are inserted into
the entrances 48 on opposite sides of the end 18 followed by depressing
the foot valve 34. Sequentially, when the foot valve is activated,
it will cause the clamp or slide blocks 47 to be urged against the
ends of the spacer frame, advance the fill tube 22 to a position
aligned with the ports 56 followed by introduction of air under
pressure into the desiccant chamber D to positively force desiccant
material through the fill tube 22 into the legs of the spacer frame
and for a time period as determined by the fill switch T. When the
foot valve 34 is released, the sequence is reversed to interrupt
the flow of air under pressure to the chamber 20 retract the supply
tube 22 to a closed position, and release the clamping blocks 47.
The spacer frame is then removed and a corner splice or plug is
inserted into the free ends of the legs of the spacer frame to retain
the desiccant within the frame.
It should be noted that throughout each fill sequence the butterfly
valve 80 remains in a closed position to seal the chamber 20. However,
when the supply of desiccant in the chamber 20 is depleted, the
valve 80 is opened by the pneumatic actuator 81 and air under pressure
is then introduced through the pressure line 28 to refill the chamber
20 in the manner described. The air conveyor sequence for refilling
the chamber is initiated by the conveyor button 84 on the valve
housing 32. Of course, it will be appreciated that the desiccant
chamber may be filled manually without the assistance of the air
conveyor as described. In addition, the fill head 18 can be rotated
within the face plate 19 by loosening the clamps 39 for example,
to facilitate handling extended lengths of spacer frames without
interference from the floor surface. In certain cases, one side
of the fill head 18 may be plugged or blocked off so that the desiccant
material is directed only through the raised or upper port 56. Moreover,
the adjustable telescoping standard 14 enables suitable height adjustment
of the machine according to the size of the spacer frame to be filled.
Accordingly, it is to be understood from the foregoing that various
modifications and changes may be made in the construction and arrangement
of elements comprising the present invention without departing from
the spirit and scope thereof as defined by the appended claims. |