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RELATED APPLICATIONS
Reference is made herein to my copending application Ser. No. 846,900,
filed concurrently herewith on Oct. 31, 1977 and entitled MAKING OF
CONTAINERS WITH TRI-LAMINATED END WALLS.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to fluid handling apparatus. More
particularly, the invention relates to a multiple nozzle fluid dispenser,
such as a glue gun, and a multiple nozzle valve assembly for the
dispenser.
Prior Art
As will become readily evident from the ensuing description, the features
of this invention may be embodied in a variety of fluid handling devices
which require control of fluid flow in a number of separate fluid
passages. The primary application of the invention, however, is in a
multiple nozzle fluid dispenser for dispensing fluids in preselected
complex fluid delivery patterns. For this reason, the invention will be
described in this particular context. More specifically, the invention
will be described in connection with a multiple nozzle glue dispenser, or
glue gun as it is commonly called, for applying a complex pattern of glue
stripes or beads to a workpiece. This workpiece may be a preformed
cardboard container body blank which may be folded or erected to a
container configuration.
The prior art is replete with a vast assortment of multiple nozzle glue
dispensers or glue guns. Examples of such glue dispensers are found in
U.S. Pat. Nos. 3,420,208; 3,126,574; 3,286,689; 3,190,259; 3,348,520;
3,509,849; and 3,088,433. Another example of a multiple nozzle glue
dispenser or glue gun is found in my prior U.S. Pat. No. 3,991,917.
SUMMARY OF THE INVENTION
According to one of its aspects, this invention provides an improved
multiple nozzle fluid dispenser which is particularly useful as a multiple
nozzle glue gun. A unique feature of this dispenser resides in its
adjustable fluid dispensing or delivery pattern which may be preset to any
one of an unlimited number of complex delivery patterns.
Another aspect of the invention is concerned with a novel multiple nozzle
valve assembly for the fluid dispenser. This valve assembly has a
plurality of valves which are actuable jointly by common operating means
for controlling fluid flow through corresponding nozzles of the assembly
and are independently adjustable to selectively preclude, inhibit, or
regulate their opening movement by the common valve operating means. The
valve assembly includes at least one additional valve actuable
independently of the jointly actuable valves for controlling fluid flow
through a corresponding nozzle or nozzles of the valve assembly. The
jointly actuable and independently actuable valves are interchangeable
such that the valve assembly may embody any number of each of these valve
types and any arrangement of the valves.
The jointly actuable valve structure of this dispenser or glue gun is
essentially identical to that described in my prior U.S. Pat. No.
3,991,917. In this patented glue gun, the individual, jointly actuable
valves have flexible valve stems which are deflected laterally by the
common valve operating means to open and close the valves in common.
The adjustability of the individual, jointly actuable valves of the fluid
dispenser to selectively prevent, inhibit, or regulate their opening and
closing movement by the common valve operating means, the independent
actuability of the independently actuable valves, and the
interchangeability of the latter valves and the jointly actuable valves,
cooperate to provide a fluid dispenser capable of dispensing fluid in a
wide variety of dispensing patterns. The glue dispenser of the invention,
for example, is ideally suited for use in the container forming machine of
my earlier mentioned copending application, Ser. No. 846,900.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a glue dispenser according to the invention
for applying glue stripes or beads to a workpiece;
FIG. 2 is an enlarged elevational view of the glue dispenser taken on line
2--2 in FIG. 1;
FIG. 3 is an enlarged fragmentary perspective section through the glue
dispenser; and
FIG. 4 is a further enlarged exploded perspective view of one independently
operable valve of the glue dispenser.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIGS. 1 and 2, there is illustrated a multiple nozzle
fluid dispenser 10 according to the invention. In this instance, the
dispenser is a multiple nozzle glue dispenser or glue gun for applying
glue stripes or beads 12 to a work sheet 14. This work sheet might be a
preformed container body blank to be erected into a container
configuration. Glue, such as hot melt glue under pressure, is supplied to
all of the nozzles of the glue gun through a glue line 16. A pressurized
working fluid, such as air, is supplied through an air line 18 to
independently operable solenoid control valves 20 for independently
controlling glue valves 22 and to an independently operable solenoid
control valve 24 for jointly actuating glue valves 25.
The basic glue gun structure is identical in all essential respects to that
described in my prior U.S. Pat. No. 3,991,917 and, accordingly, need not
be described in elaborate detail. This basic glue gun structure comprises
an elongate bar-like body 26 (FIG. 3). This body functions, in part, as a
common valve body for a multiple valve assembly 28, comprising the jointly
actuable valves 25, and the independently operable individual valves 22.
The jointly actuable valves 25 are operable between open and closed states
by common valve operating means 32 for controlling glue flow from the glue
line 16 to corresponding glue dispensing nozzles 34 spaced along the lower
side of the body 26. Each dispenser nozzle 34 has a generally cup-like
shape and is threaded in the underside of the body 26. Extending axially
through each nozzle is a passage 36, reduced at one end to form a
dispensing orifice 38 opening through the outer or lower end of the
nozzle. Surrounding the inner end of this orifice is an O-ring 40 forming
a valve seat about the orifice. Nozzle passages 36 open to a bore 42
extending longitudinally through the body 26, and providing a manifold
communicating the glue line 16 to the nozzle passages. Entering the upper
side of the body 26 on the axis of each nozzle 34 is a threaded bore 44.
Each bore 44 opens to the longitudinal body bore or glue manifold 42,
diametrically opposite the corresponding dispenser nozzle 34.
Each jointly actuable valve 25 is contained within and comprises a stem
holder 46 threaded in one of the body bores 44. Secured at its upper end
to each stem holder 46 by a ball and socket connection (not shown) is a
laterally flexible valve stem 48. The lower end of each valve stem has a
valve element or ball 50 engagable with the corresponding nozzle valve
seat 40. The several valve stems 48 traverse the body bore or manifold 42.
The common valve operating means 32 comprises a valve operator or operator
bar 52 extending axially through the body bore 42. Spaced along this bar
are slots 54 through which extend the valve stems 48. The outboard end of
the operator bar in FIG. 3 is releasably secured to a piston 56 (FIG. 1)
movable in a cylinder 58 within a cylinder block 60. Cylinder block 60 is
removably secured in any convenient way to the end of the dispenser body
26. The cylinder block 60, piston 56, cylinder 58, and operator bar 52 are
removable from the dispenser body 26.
Control valve 24 connects the air line 18 to the operator bar cylinder 58.
Operation of the valve 24 to one position pressurizes the cylinder 58 to
move the valve operator bar 52 to the left in FIG. 3. Operation of the
solenoid valve 24 to the other position vents the cylinder 58. The valve
operator bar 52 is then retracted to the right to its position of FIG. 3
by a spring (not shown).
The operator bar slots 54 are longitudinally dimensioned to release the
flexible valve stems 48 for engagement of their valve elements 50 with the
corresponding valve seats 58 to close the glue valves 25 when the operator
bar 52 occupies its normal retracted position of FIG. 3. When extended to
the left in FIG. 3 by air pressure upon opening of control valve 24, the
valve operator bar 52 deflects the valve stems 48 laterally to open the
glue valves 25, as more fully explained in my U.S. Pat. No. 3,991,917. As
also explained in this patent, the valve stem holders 46 are adjustable
axially in their respective body bores 44 to selectively prevent, inhibit
or regulate opening and closing movement of each valve 25 by the operator
bar.
In the fluid dispenser or glue gun of my U.S. Pat. No. 3,991,917, all of
the dispensing glue valves of the gun are flexible stem valves which are
operable jointly in the manner described above. In contrast, the valve
assembly 28 of the improved fluid dispenser or glue gun of this invention
includes the independently actuable valves 22 in addition to the jointly
actuable valves 25. Independently actuable valves 22 are threaded in
selected bores 44 of the dispenser body 26 and serve to control glue flow
from the glue line 16 to the corresponding dispenser nozzles 34.
As explained below, the independently actuable and jointly actuable valves
22, 25 are interchangeable. That is to say, any jointly actuable valve 25
may be replaced by an independently actuable valve 22. Conversely, any
independently actuable valve 22 may be replaced by a jointly actuable
valve 25. As explained below, the common valve operating bar 52 must be
conditioned to accomodate this interchange of the independently and
jointly actuable valves.
This interchangeability of the valves 22, 25, the adjustability of the
valve stem holders 46 to selectively prevent, inhibit and regulate the
opening and closing movements of valves 25 by the common valve operator
bar 52, and the independent actuability of the independently actuable
valves 22 cooperate to provide a fluid dispenser or glue gun capable of
adjustment to provide a wide variety of complex glue dispensing or
delivery patterns. One such pattern is illustrated in FIG. 1. My earlier
mentioned copending application Ser. No. 846,900 illustrates another
possible glue pattern.
Referring particularly to FIGS. 3 and 4, each independently actuable glue
valve 22 comprises a tubular barrel 62 threaded at its lower end in a
dispenser body bore 44. Snugly fitted in the upper end of the barrel 62 is
a coaxial boss 64 on the lower end of a cylinder 66. A stepped bore 68
extends coaxially into the upper end of this cylinder.
Slidable in the upper, large diameter end of the cylinder bore 68 is a
piston 70. A valve rod 72 extends centrally through the piston 70, the
cylinder 66, and the barrel 62. The lower end of this valve rod is
threaded and extends below the lower end of the barrel 62, through a slot
74 in the valve operator bar 52, and into the corresponding dispenser
nozzle 34. On the lower end of the valve rod is a valve element or ball 76
for engagement with the corresponding nozzle valve seat. The valve rod 72
may be relatively rigid throughout its length. The particular valve rod
shown has an upper rigid portion 72a and a lower flexible portion 72b of
the same flexible material as the valve stems 48.
On the upper end of the valve rod 72 is threaded a nut 78 forming a thrust
shoulder engaging the top of the piston 70. Threaded on the lower end of
the rod is a fluted nut 80 forming a spring seat on the rod. A spring 82
acting between the spring seat 80 and a washer on a shoulder 84 in the
valve barrel 62 urges the valve rod 72 downwardly to the closed position
of the left hand valve 22 in FIG. 3. In this closed position, the valve
piston 70 seats downwardly against a shoulder 85 in its cylinder bore 68
which limits downward travel of the piston. The valve element 76 engages
its valve seat 40 to close the corresponding nozzle 34.
Each valve 22 has two adjustments to assure proper seating contact of its
valve element 76 with its valve seat 40 when the valve piston 70 occupies
its lower limiting position of contact with its cylinder bore shoulder 85.
One of these adjustments involves axial adjustment of the upper nut 78
along the valve rod 72 to adjust the valve element 76 axially relative to
the valve piston 70 and hence relative to the valve seat 40. The other
adjustment involves axial adjustment of the valve barrel 62 in its
threaded bore 44 of the body 26.
Just above the barrel shoulder 84 is a seal ring 86, coaxially sandwiched
between a pair of back up rings, for sealing the valve rod 72 to the
barrel 62. Leakage of glue through flutes of nut 80 and past this seal
ring is indicated by passage of glue through glue escape holes 88 just
above the seal ring. These holes may double as wrench holes for threading
the valve barrel 62 into and from the dispenser body 26 both to assemble
the dispenser and adjust the valve element 76 relative to its valve seat
40, as just described.
The upper end of the valve rod 72 slides in the lower end of the valve
cylinder bore 68. A seal ring 90 seals the rod to the cylinder 66. Above
the seal ring 90 is a washer 92 which seats downwardly on a shoulder in
the cylinder. A sleeve 94 surrounds the valve rod 72 above the washer 92.
The cylinder bore 68 of each independently actuable valve 22 is connected
to the air line 18 through an air hose 96 and a solenoid control valve 20.
As shown in FIG. 3, the valve barrels 62 may be made in different lengths
to permit two valves 22 to be located in close side by side relation
without interference. If the sizing and/or the spacing of these valves is
such to preclude interference of adjacent valves, of course, all of the
valves 22 may have the same length.
Operation to one position of the control valve 20 for an independently
actuable valve 22 pressurizes the valve cylinder bore 68 below its piston
70. The piston, and thereby its valve rod 72 and valve element 76, are
then driven upwardly to the upper open position of the right hand valve 22
in FIG. 3. Return of the control valve 20 to its original position vents
the independently operable valve cylinder bore 68 to permit spring return
of its valve rod 72 and valve element 76 to closed position and causes the
piston to press downwardly on the valve sleeve 94 to thereby press the
valve rod seal ring 90 back into its seat. The slots or grooves in the
lower spring seat nut 80 of the valve permit free passage of glue past the
nut during this opening and closing movement of the valve rod 72 to
prevent the glue in the valve barrel 62 above the nut from inhibiting
opening of the valve.
The valve rod clearance slots 74 in the common valve operating bar 52 are
sized to clear the valve rods 72 throughout the full stroke of the bar.
Thus, the valve operator bar 52 exerts lateral deflection forces on the
laterally deflectable valve stems 48 only to effect joint opening and
closing movement of only the jointly actuable valves 25.
As noted earlier, the independently actuable valves 22 and jointly actuable
valves 25 are interchangeable. Thus, either a valve 22 or a valve 25 may
be threaded in each body bore 44. Accordingly, the numbers of
independently and jointly actuable valves 22, 25 and the arrangement of
these valves in the fluid dispenser 10 may be varied. A valve operator bar
with the proper arrangement of the slots 54, 74, will be provided for each
of these possible valve arrangements. When the arrangement of the
independently and jointly actuable valves 22, 25 is changed, the existing
valve operator bar 52 is removed and replaced by the correct operator bar
by removing the cylinder block 60, piston 56, cylinder 58, and bar 52 in
the manner discussed earlier. Alternatively, all of the operator bar slots
may be made like the large slots 74 and slot reducing inserts may be
provided for removable placement in the bar slots in accordance with the
arrangement of the jointly actuable valve stems 48.
Referring to FIGS. 1 and 2, the fluid dispenser 10 is secured to an upright
post 98 fixed to a supporting frame 100, or the like, in essentially the
same manner as in my prior U.S. Pat. No. 3,991,917. The dispenser overlies
the path of movement of the work piece 14 past the gun. The solenoid
control valves 20, 24 are mounted on a supporting bar 102 which also
overlies the path of the workpiece 14 and is secured to an upright post
104 on the frame 100.
The workpiece 14 moves past the underside of the dispenser 10 between the
latter and spring fingers 106. The spring fingers urge the workpiece
upwardly against the lower ends of the dispenser nozzles 34, as shown best
in FIG. 2. As also shown in the latter Figure, the nozzle axes of the glue
gun are inclined relative to the plane of the workpiece in a direction
opposite to the direction of movement of the workpiece.
The operation of the fluid dispenser or glue gun 10 is believed to be
obvious in the preceding description. During this operation, the solenoid
control valves 20, 24 may be selectively operated in any desired timing
relative to one another, as by a preprogrammed control circuit, to open
and close the corresponding independently and jointly actuable valves 22,
25 of the dispenser. In the particular application shown, opening of each
valve effects dispensing of a stripe or bead 12 of glue through the
corresponding dispenser nozzle 34 onto the workpiece 14.
It is readily apparent that the independent operability of the
independently operable valves 24, the adjustability of the jointly
actuable valves 25 to selectively inhibit or regulate their opening and
closing movement by the joint valve operating bar 52, the capability of
varying the numbers and arrangements of the valves 22, 25, and the ability
of controlling the solenoid valves 20, 24 in any desired fashion permits
operation of the glue gun 10 to produce a wide variety of glue stripe or
glue bead patterns on the workpiece 14.
The pattern of distribution of glue beads 12 on the body blank 14 of FIG. 1
is a hypothetical case to demonstrate the versatility of the invention. At
positions 1, 6, 10, and 14 of the gun 10, independently actuable valves 22
have been mounted in the manner previously described. Valves 25 are
mounted at positions 7, 8, 9, 15, and 16 of the gun but with their
respective adjusting screws or stem holders 46 axially adjusted inwardly
so that the valve remains inoperative irrespective of actuation of the
actuating bar 52, i.e., the condition of the valve 25 shown at position 16
in FIG. 3. The other valves 25 at positions 2, 3, 4, 5, 11, 12, and 13 are
operated in unison by the common operator bar 52. Then, assuming an
appropriate program of control of the several solenoid valves 20, 24, the
complex pattern of glue stripes 12 illustrated may be achieved, e.g., with
each of the independently operable valves 25 at the positions 1, 6, 10,
and 14 delivering a stripe pattern different from that of any other of the
independently controllable valves during a cycle in which the commonly
operable valves 30 are operated at some point or points.
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