Note: Descriptions are shown in the official language in which they were submitted.
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CLAMSHELL HOUSING FOR DISPENSING TUBE OF METERING DISPENSER
TECHNICAL FIELD
[0001] The present disclosure relates to metering dispensers, and more
particularly to
housings for holding the flexible dispensing tube of a metering dispenser in
place for a
plunger that opens and closes the tube.
BACKGROUND
[0002] Solenoid-driven metering systems are well known in the food service
arts, and are
used for metered dispensing of liquids such as cream and milk, and granular
solids such as
sugar, for beverages such as coffee and tea. Such systems are sold under the
trademark
SureShot Dispensing Systems by A.C. Dispensing Equipment Inc., having an
address at 100
Dispensing Way, Lower Sackville, Nova Scotia, Canada B4C 412.
[0003] Figures 1 to 2B show an exemplary prior art solenoid-driven metering
system 10. The
metering system 10 comprises a flexible dispensing tube 12, a plastic housing
14 surrounding
a portion of the dispensing tube 12, and a solenoid plunger 16. Other
components of the
solenoid-driven metering system, such as the solenoid itself, related control
systems, the
support structure and other elements have been omitted for clarity of
illustration; these
elements and their placement will be apparent to one skilled in the art.
[0004] Referring specifically to Figure 1, an upper end 12A of the dispensing
tube 12
communicates with a reservoir of the material to be metered (not shown) and a
lower end 12B
communicates with an outlet (not shown), which may simply be an open end of
the
dispensing tube 12. In a typical example, the reservoir is a flexible plastic
bag containing
milk or cream which is sealed except that it opens into an attached dispensing
tube 12 to allow
the milk or cream to be dispensed. The dispensing tube 12 is arranged
generally vertically,
with the upper end 12A above the lower end 12B, so that material will flow
downwardly
through the tube from the upper end 12A to the lower end 12B under the
influence of gravity,
unless the dispensing tube 12 is constricted.
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[0005] The housing 14 comprises two opposed halves 14A, 14B removably hingedly
secured
to one another in a clamshell arrangement by a hinge 18 and securable around
the dispensing
tube 12 in a closed configuration. Two opposed channels 20A, 20B defined in
the tube-
receiving faces of the two opposed halves 14A, 14B cooperate to define a
vertical passageway
20 through the housing 14 for the dispensing tube 12. The half 14A of the
housing 14 facing
the solenoid plunger 16 has a plunger aperture 22 which exposes the dispensing
tube 12. The
housing 14 is maintained in the closed configuration by a thumbscrew 19 that
is rotatably
journalled in a bore (not shown) through the half 14B of the housing 14 that
does not face the
solenoid plunger 16 and is threadedly received in a correspondingly positioned
threaded
aperture 21 (Figure 1) in the half 14A facing the solenoid plunger 16. The
threaded aperture
21 is formed in a metal insert 23 which is in turn secured in a larger
aperture in the half 14A
facing the solenoid plunger 16, so as to provide improved strength relative to
the plastic from
which the housing 14 is formed.
[0006] Typically, a temperature sensor insert 17 formed from aluminum is
installed in the
channel 20A in the half 14A facing the solenoid plunger 16. The insert 17
carries a
temperature sensor such as a thermistor (not shown) and engages the dispensing
tube 12 so
that the insert 17 will assume the approximate temperature of the material in
the dispensing
tube 12 and allow this temperature to be detected by the temperature sensor.
[0007] The solenoid plunger 16 comprises a solenoid-actuable armature shaft 24
and a
plunger head 26 secured to one end of the armature shaft 24. The plunger head
26 is formed
from plastic and comprises a base 28 secured to the armature shaft 24, four
support members
30, a disc-shaped portion 32 and a closure member 34. The support members 30
are ogee-
shaped and arranged in cruciform relation to one another, and extend outwardly
from the base
28 to support the disc-shaped portion 30, which in turn supports the closure
member 34.
[0008] When assembled, the plunger aperture 22 in the half 14A of the housing
14 facing the
solenoid plunger 16 is in registration with the closure member 34 on the
plunger head 26.
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[0009] In operation, as shown in Figures 2A and 2B, the solenoid plunger 16 is
arranged for
reciprocal motion toward and away from the housing 14 under the control of the
solenoid (not
shown).
[0010] The "resting" or "closed" position of the solenoid plunger 16 is shown
in Figure 2A;
in this position the closure member 34 on the plunger head 26 has been
received in the
plunger aperture 22 in the half 14A of the housing 14 facing the solenoid
plunger 16, and the
plunger 16 may be maintained in this position by, for example, a suitable
biasing member
such as a spring (not shown). In this position, the closure member 34
compresses the
dispensing tube 12 and pinches it against the back wall 36 of the passageway
20 defined by
the channels 20A, 20B (Figure 1) in the two halves 14A, 14B of the housing 14.
This
pinching of the dispensing tube 12 substantially completely obstructs the
dispensing tube 12,
inhibiting material flow past the closure member 34. Typically, the half 14B
opposite the half
14A having the plunger aperture 22 includes a strike plate (not shown) for the
plunger,
typically formed from aluminum, that is integrated into the back wall 36 of
the passageway to
be in registration with the plunger aperture 22.
[0011] When it is desired to dispense material, the solenoid (not shown) is
actuated to move
the solenoid plunger 16 into the "active" or "open" position, as shown in
Figure 2B, for a
fixed period of time before disengaging the solenoid and allowing the solenoid
plunger 16 to
return to the "rest" or "closed" position shown in Figure 2A. During the
period of time that
the solenoid plunger 16 is in the "active" or "open" position (Figure 2B), the
dispensing tube
12 is unobstructed and a predetermined volume of liquid or granular material
is able to move
past the position of the solenoid plunger 16 before the dispensing tube 12 is
again obstructed
as the solenoid plunger 16 returns to the "rest" or "closed" position (Figure
2A).
[0012] The plunger head 26 is secured to the armature shaft 24 by way of a tab
38 extending
from the base 28 of the plunger head 26 and which is received in a
corresponding slot 40 at
the end of the armature shaft 24 and held in place by a rivet 42.
[0013] When a reservoir of the material being metered, such as a bag of cream
or milk, is
empty and must be replaced, a user will unscrew the thumbscrew 19 and then
separate the two
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opposed halves 14A, 14B by pivoting the half 14B having the thumbscrew 19 away
from the
other half 14A, which is mounted to the dispenser, so as to expose the
dispensing tube 12.
This enables the user to remove the empty bag and its associated dispensing
tube 12 and
install a new, full bag and insert the associated new dispensing tube 12 into
the channel 20A.
The user then pivots the half 14B having the thumbscrew 19 back toward the
other half 14A,
trapping the new dispensing tube 12 in the vertical passageway 20, and then
screws the
thumbscrew 19 back into the threaded aperture 21. This procedure is time
consuming,
especially in the context of a quick-service restaurant, where seconds count
and customers
expect to be served in less than a minute. Moreover, with repeated use, the
thumbscrew 19
may develop a tendency to bind in the threaded aperture 21, making it more
difficult to screw
and unscrew and thereby increasing both the difficulty of changing the
reservoir as well as the
time required to do so.
[0014] In addition, the barrel portions 18B of the plastic hinge 18 joining
the two halves 14A,
14B are prone to breakage, as shown by the arrow "B" in Figure 2. Such
breakage requires
that the entire housing 14 be replaced, necessitating a costly maintenance
call and also
requiring that the metering dispenser be taken out of service.
SUMMARY
[0015] A housing for a dispensing tube of a metering dispenser comprises a
mounting half for
mounting the housing to a metering dispenser and a strike half for receiving
plunger strikes.
The strike half is carried by the mounting half. The mounting half has a
mounting half tube
channel defined therein for receiving a dispensing tube and also has a
mounting half tube
channel for receiving a plunger, and the strike half has a plunger strike
surface. The strike
half is pivotally carried by the mounting half so as to be pivotable, relative
to the mounting
half, between a first pivotal position in which the strike half at least
partially covers the
mounting half tube channel and a second pivotal position in which the strike
half exposes the
mounting half tube channel. The strike half is further slidably carried by the
mounting half so
as to be slidable relative to the mounting half, at least when the strike half
is in the first
pivotal position, between a first slide position in which pivotal movement of
the strike half
relative to the mounting half from the first pivotal position toward the
second pivotal position
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is obstructed, and a second slide position in which pivotal movement of the
strike half relative
to the mounting half from the first pivotal position to the second pivotal
position is permitted.
At least when the strike half is in the first pivotal position and in the
first slide position, the
plunger strike surface is in registration with and facing the plunger aperture
to receive a
plunger head.
[0016] In one embodiment, the strike half is hingedly carried by the mounting
half by way of
a pivot extending between the mounting half and the strike half and on which
the strike half is
rotatably received so as to be rotatable about the pivot between the first
pivotal position and
the second pivotal position, and the strike half is further slidable along the
pivot, at least when
the strike half is in the first pivotal position, between the first slide
position and the second
slide position.
[0017] In certain embodiments, one of the mounting half and the strike half
has at least one
locking finger and the other one of the mounting half and the strike half has
at least one latch
arm extending therefrom, with each latch arm forming a receiving slot for
receiving a
respective locking finger. When the strike half is in the first pivotal
position and the first slide
position, each locking finger is in registration with its respective latch
arm, inside the
receiving slot formed by the respective latch arm, so that each latch arm
engages its respective
locking finger to obstruct movement of the strike half from the first pivotal
position toward
the second pivotal position. When the strike half is in the first pivotal
position and the second
slide position, each locking finger is out of registration with its respective
latch arm and
outside of the receiving slot formed by the respective latch arm whereby
movement of the
strike half from the first pivotal position toward the second pivotal position
is permitted.
[0018] In particular embodiments, the at least one locking finger comprises a
plurality of
locking fingers spaced longitudinally apart from one another to define a
locking finger gap
between each adjacent pair of locking fingers, and the at least one latch arm
comprises a
plurality of latch arms spaced longitudinally apart from one another to define
a latch arm gap
between each adjacent pair of latch arms. When the strike half moves between
the first
pivotal position and the second pivotal position while in the second slide
position, at least one
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latch arm fits in a corresponding locking finger gap, and at least one locking
finger fits in a
corresponding locking arm gap.
[0019] The locking finger(s) or the latch arm(s), or both, may each have a
tapered guide
surface for guiding the strike half into the second slide position as the
strike half moves into
the first pivotal position.
[0020] In some embodiments, the strike half has a strike half tube channel
defined therein,
and the strike half tube channel cooperates with the mounting half tube
channel, when the
strike half is in the first pivotal position, to form a dispensing tube
channel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] These and other features will become more apparent from the following
description in
which reference is made to the appended drawings wherein:
[0022] Figure 1 is a rear perspective view showing a portion of a prior art
solenoid-based
metering system including a prior art solenoid plunger;
[0023] Figure 2 is a front perspective view of the prior art metering system
of Figure 1;
[0024] Figure 2A is a side view of the portion of the prior art metering
system of Figure 1,
showing the prior art solenoid plunger in a first position that inhibits flow
of material through
the prior art metering system;
[0025] Figure 2B is a side view of the portion of the prior art metering
system of Figure 1,
showing the prior art solenoid plunger in a second position that permits flow
of material
through the prior art metering system;
[0026] Figure 3 is a first top perspective view of an exemplary housing for a
dispensing tube
of a metering dispenser, showing the housing in a closed and locked
configuration;
[0027] Figure 4 is a second top perspective view of the housing of Figure 3,
showing the
housing in a closed and locked configuration and showing passage of a flexible
dispensing
tube through the housing;
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,
[0028] Figure 5 is a bottom perspective view of the housing of Figure 3,
showing the housing
in an open configuration;
[0029] Figure 6 is a top perspective view of the housing of Figure 3, showing
the housing in
two alternate open configurations;
[0030] Figure 7 is a top perspective view of the housing of Figure 3, showing
the housing
moving between an open and a closed configuration;
[0031] Figure 8 is a first side view of the housing of Figure 3, showing the
housing moving
toward a closed configuration;
[0032] Figure 9 is the same side view as in Figure 8, showing the housing in a
closed and
unlocked configuration;
[0033] Figure 10 is the same side view as in Figure 8, showing the housing in
a closed and
locked configuration;
[0034] Figure 11 is a second side view of the housing of Figure 3, showing the
housing in a
closed and unlocked configuration;
[0035] Figure 12 is the same side view as in Figure 11, showing the housing in
a closed and
locked configuration;
[0036] Figure 13 is the same perspective view as in Figure 4, showing the
housing in a closed
and unlocked configuration;
[0037] Figure 14 is the same perspective view as in Figure 4, showing the
housing in a closed
and locked configuration;
[0038] Figure 15 is a side view of the housing of Figure 3, showing a solenoid
plunger in a
"resting" or "closed" position;
[0039] Figure 16 is the same side view as in Figure 15, showing the solenoid
plunger in an
"active" or "open" position;
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[0040] Figure 17 is a side view of an embodiment of a solenoid plunger
according to an
aspect of the present invention; and
[0041] Figure 18 is an exploded perspective view of the solenoid plunger of
Figure 17
DETAILED DESCRIPTION
[0042] Reference is now made to Figure 3, which shows an exemplary housing 300
for a
dispensing tube of a metering dispenser (not shown). The housing 300 comprises
a mounting
half 302 for mounting the housing 300 to a metering dispenser and a strike
half 304 for
receiving plunger strikes, with the strike half 304 being carried by the
mounting half 302.
The use of the terms "mounting half' and "strike half' refer to the clamshell
structure of the
housings described herein, and is not intended to imply that the mounting half
and strike half
are, or need be of equal size or identical shape. Indeed, as will be apparent
from the
drawings, in the exemplary illustrated embodiment the mounting half 302 has a
substantially
larger footprint than the strike half 304. Both the mounting half 302 and the
strike half 304
are preferably monolithic and are preferably formed from metal of suitable
strength, more
preferably from aluminum, and most preferably from anodized aluminum. Other
materials,
such as plastic of suitable strength, may also be used. The mounting half 302
and the strike
half 304 may be made of different materials.
[0043] The strike half 304 can move relative to the mounting half 302 so that
the housing 300
has a closed and locked configuration (Figures 3, 4, 10, 12 and 14 to 16), a
closed and
unlocked configuration (Figures 9, 11 and 13), and at least one open
configuration (Figures 5
and 6). To enable the housing 300 to be placed into the various
configurations, the strike half
304 is both pivotally and slidably carried by the mounting half 302, as
described in greater
detail below. The mounting half 302 and the strike half 304 each have
respective tube-
receiving 302A, 304A and outer faces 302B, 304B. The outer face 302B of the
mounting half
may be mounted to a metering dispenser, and when the housing 300 is in the
closed and
locked configuration and in the closed and unlocked configuration, the tube-
receiving faces
302A, 304A face one another.
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[0044] As best shown in Figures 4 and 5, in the illustrated embodiment the
mounting half 302
has a mounting half tube channel 306 defined in its tube-receiving face 302A
for receiving a
flexible dispensing tube 308 of the metering dispenser, and a plunger aperture
310 is defined
through the mounting half 302, and in particular through the mounting half
tube channel 306,
for receiving a plunger 1700 (see Figures 15 and 16). The strike half 304 has
a strike half
tube channel 312 defined in its tube-receiving face 304A, and has a plunger
strike surface 314
(Figure 6) on the tube-receiving face 304A interrupting the strike half tube
channel 312. In
the illustrated embodiment in which the mounting half 302 and the strike half
304 are made
from metal, in particular anodized aluminum, the plunger strike surface 314 is
preferably
integral with the monolithic strike half 304; in embodiments where the strike
half 304 is
formed from a material not suitable for withstanding direct plunger strikes, a
separate plunger
strike plate may provide the plunger strike surface. While the exemplary
embodiment in
Figures 3 to 16 shows the plunger strike surface 314 as a recessed part the
tube-receiving face
304A, in other embodiments the plunger strike surface may be coplanar with the
remainder of
the tube-receiving face aside from the strike half tube channel.
[0045] At least when the housing 300 is in the closed and locked configuration
(Figures 3, 4,
10, 12 and 14 to 16) the strike half 302 partially covers the mounting half
302 so as to
obstruct access to the mounting half tube channel 306, and the strike half
tube channel 312
cooperates with the mounting half tube channel 306 to form a dispensing tube
passage 316
through the housing 300. The dispensing tube passage 316 receives the
dispensing tube 308
of the metering dispenser and positions the dispensing tube 308 for engagement
by a plunger
of the metering dispenser. Moreover, at least when the housing 300 is in the
closed and
locked configuration (Figures 3, 4, 10, 12 and 14 to 16) the plunger strike
surface 314 is in
registration with the plunger aperture 310 to receive a plunger head.
[0046] In other embodiments, the strike half may omit any strike half tube
channel, and the
mounting half tube channel may be correspondingly deeper, so that the entire
dispensing tube
can be accommodated within the mounting half tube channel.
[0047] As noted above, the strike half 304 is both pivotally and slidably
carried by the
mounting half 302. The strike half 304 is pivotally carried by the mounting
half 302 so as to
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be pivotable, relative to the mounting half 302, between a first pivotal
position in which the
strike half 304 at least partially covers the mounting half tube channel 306
(Figures 3, 4 and 8
to 16); and a second pivotal position (Figure 6) in which the strike half 304
exposes the
mounting half tube channel 306. The strike half 304 is further slidably
carried by the
mounting half 302 so that, at least when the strike half 304 is in the first
pivotal position, the
strike half 304 is slidable, relative to the mounting half 302, between a
first slide position
(Figures 3 to 6, 10, 12 and 14 to 16) and a second slide position (Figures 7,
9, 11 and 13).
When the strike half 304 is in the first slide position and is also in the
first pivotal position
(Figures 3, 4, 10, 12 and 14 to 16), pivotal movement of the strike half 304,
relative to the
mounting half 302, from the first pivotal position toward the second pivotal
position is
obstructed. When the strike half 304 is in the second slide position, pivotal
movement of the
strike half 304 relative to the mounting half 302 from the first pivotal
position to the second
pivotal position is permitted.
[0048] The angular distance between the second pivotal position and the first
pivotal position
of the strike half 304 relative to the mounting half 302 should be such that
the strike half 304
exposes the mounting half tube channel 306 and hence the dispensing tube 308.
As shown in
solid lines in Figure 6, in the illustrated embodiment an angular distance of
about 90 degrees
from the first pivotal position is sufficient for the strike half 304 to
expose the mounting half
tube channel 306 and the dispensing tube 308. However, in the illustrated
embodiment shown
in Figures 3 to 16, the second pivotal position of the strike half 304
relative to the mounting
half 302, shown with broken lines in Figure 6, has an angular distance
slightly greater than
180 degrees from the first pivotal position. This provides greater access to
the mounting half
tube channel 306 for removal of an old dispensing tube 308 and installation of
a new
dispensing tube 308. The second pivotal position shown with broken lines in
Figure 6 is a
limit position defined by engagement of the pivot-side sidewall 324 of the
strike half 304 with
the pivot side sidewall 326 of the mounting half 302. Alternately, if it is
desired to define the
second pivotal position at a lesser angular distance from the first pivotal
position, such as
about 90 degrees as shown in solid lines in Figure 6, a suitable stop can be
provided on one or
more of the mounting half 302, the strike half 304 or the metering dispenser
itself adjacent the
housing 300.
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[0049] In the exemplary embodiment shown in Figures 3 to 16, the strike half
304 is hingedly
carried by the mounting half 302 by way of a pivot 328 extending between the
mounting half
302 and the strike half 304 and on which the strike half 304 is rotatably
received so as to be
rotatable about the pivot 328 between the first pivotal position and the
second pivotal
position. In particular, the pivot 328 is a cylindrical rod carried at its
ends by two opposed
pivot carriers 330 extending from the tube-receiving face 302A of the mounting
half 302
adjacent the pivot-side sidewall 326 of the mounting half 302, and the pivot
328 is rotatably
received in a barrel 332 extending from the pivot-side sidewall 324 of the
strike half 304. As
best seen in Figures 3, 11 and 12, the barrel 332 is shorter in length than
the distance between
the facing edges 334 of the pivot carriers 330, that is, the edges 334 of the
pivot carriers 330
that face one another. This enables the barrel 332, and hence the strike half
304, to slide
along the pivot 328 between the facing edges 334 of the pivot carriers 330,
which act as stops
to limit the movement of the barrel 332 and strike half 304 and thereby define
the first slide
position and the second slide position.
[0050] In the illustrated embodiment shown in Figures 3 to 16, pivotal
movement of the strike
half 304 relative to the mounting half 302 is independent of sliding movement
of the strike
half 304 relative to the mounting half 302. In other words, the strike half
304 can slide
relative to the mounting half 302 without pivoting relative to the mounting
half 302, and the
strike half 304 can pivot relative to the mounting half 302 without sliding
relative to the
mounting half 302.
[0051] As best seen in Figures 4 and 6 to 10, in the particular exemplary
embodiment shown
in Figures 3 to 16, the strike half 304 has a plurality of locking fingers 336
extending from the
distal sidewall 338 of the strike half 304, that is, the sidewall 338 that is
distal from the pivot-
side sidewall 324 of the strike half 304. The locking fingers 336 are
longitudinally spaced
apart from one another along the distal sidewall 338 of the strike half 304 so
as to define
locking finger gaps 340 between each adjacent pair of locking fingers 336. As
used herein,
the term "longitudinally" refers to the sliding motion of the strike half 304
relative to the
mounting half 302.
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[0052] The mounting half 302 has a plurality of latch arms 342 extending from
the tube-
receiving face 302A of the mounting half 302, adjacent the distal sidewall 344
thereof, that is,
the sidewall 344 distal from the pivot-side sidewall 326 of the mounting half
302. Similarly
to the locking fingers 336, the latch arms 342 are spaced longitudinally apart
from one
another so as to define latch arm gaps 346 between each adjacent pair of latch
arms 342. As
best seen in Figures 6 and 7, the latch arms 342 are each generally L-shaped
and comprise a
spacer portion 348 extending from the tube-receiving face 302A of the mounting
half 302 and
a retaining portion 350 extending from the outer end of the spacer portion 348
toward the
pivot-side sidewall 326 of the mounting half 302. Each latch arm 342 thereby
forms a
receiving slot 352 between the retaining portion 350 and the tube-receiving
face 302A of the
mounting half 302 for receiving a respective locking finger 336.
[0053] As shown in Figures 4, 10 and 14, when the strike half 304 is in the
first pivotal
position and the first slide position, each locking finger 336 is in
registration with its
respective latch arm 342, inside the receiving slot 352 formed by the
respective latch arm 342.
This is the closed and locked configuration (Figures 3, 4, 10, 12 and 14 to
16), and in this
configuration each latch arm 342, in particular the retaining portion 350
thereof, engages its
respective locking finger 336 to obstruct movement of the strike half 304 from
the first pivotal
position toward the second pivotal position. Conversely, as shown in Figures 9
and 13, when
the strike half 304 is in the first pivotal position and the second slide
position, each locking
finger 336 is out of registration with its respective latch arm 342, and hence
outside of the
receiving slot 352 formed by the respective latch arm 342. This is the closed
and unlocked
configuration (Figures 9, 11 and 13). In this closed and unlocked
configuration, the retaining
portions 350 of the latch arms 342 do not engage the respective locking
fingers 336, and
therefore movement of the strike half 304 from the first pivotal position
toward the second
pivotal position is permitted.
[0054] As can be seen by reference to Figures 8 and 9, when the strike half
304 moves
between the first pivotal position and the second pivotal position while in
the second slide
position, each of the upper three latch arms 342 fits in a corresponding
locking finger gap
340, and each of the lower three locking fingers fits in a corresponding latch
arm gap 346. As
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best shown in Figure 8, the underside of each of the locking fingers 336 forms
a tapered guide
surface 354 that slopes generally upwardly toward the tube-receiving face 304A
of the strike
half 304. As the strike half 304 moves into the first pivotal position, it may
be not be
precisely in the second slide position, i.e. the strike half 304 may be
slightly lower than the
second slide position, so that the locking fingers 336 are not in registration
with the latch arm
gaps 346. In this case, the tapered guide surfaces 354 will engage the
retaining portions 350
of the corresponding latch arms 342 and guide the strike half 304 upwardly
into the second
slide position as the strike half 304 moves into the first pivotal position.
[0055] Instead of providing tapered guide surfaces on the undersides of the
locking fingers, or
in addition thereto, the upper surfaces of the retaining portions may comprise
tapered guide
surfaces sloping upwardly toward the tube-receiving face 302A of the mounting
half 302.
Similarly, in alternate embodiments the strike half may have the latch arms
and the mounting
half may have the locking fingers.
[0056] To facilitate locking and unlocking of the housing 300, the strike half
304 should be
slidable along the pivot 328 between the first slide position and the second
slide position at
least when the strike half 304 is in the first pivotal position. In the
illustrated embodiment
shown in Figures 3 to 16, the strike half 304 is slidable along the pivot 328
between the first
slide position and the second slide position at any pivotal position of the
strike half 304
relative to the mounting half 302.
[0057] It is contemplated that in other embodiments (not shown), the strike
half may only be
able to slide between the first and second slide positions when the strike
half is in or nearly in
the first pivotal position. In one exemplary implementation, the pivot carrier
that is
lowermost when the housing is in an upright position may include a projecting
portion
extending toward the barrel to define a partial shoulder, and the end of the
barrel closest to
that pivot carrier may include a corresponding recess. In such an
implementation, sliding of
the barrel, and hence the strike half, would only be permitted when the
projecting portion and
recess were in registration with one another; when the projecting portion and
recess were out
of registration the shoulder on the projecting portion would engage the non-
recessed part of
the end of the barrel to prevent sliding of the barrel along the pivot and
thereby prevent any
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substantial sliding of the strike half relative to the mounting half.
Accordingly, by arranging
the projecting portion and recess so that they will only be in registration
when the strike half
is in or nearly in the first pivotal position, the projecting portion will
engage the end of the
barrel to maintain the strike half in the second slide position unless the
strike half is in or
nearly in the first pivotal position. When the strike half is in or nearly in
the first pivotal
position, the projecting portion and recess will be in registration so that
the projecting portion
on the lowermost pivot carrier is received in the recess as the barrel slides
toward that pivot
carrier to enable the strike half to slide from the second slide position to
the first slide
position. Such an arrangement could also be constructed to prevent or inhibit
the access
portion from pivoting from the first pivotal position to the second pivotal
position unless the
access portion were in the second slide position, by arranging the projecting
portion and the
recess so that a side of the projecting portion would engage a side of the
recess so as to block
pivoting unless the access portion is in the second slide position.
[0058] Operation of a metering dispenser incorporating a housing as described
herein, such as
the housing 300, is similar to operation of a metering dispenser incorporating
the prior art
housing 14. Reference is now made to Figures 15 and 16, which show the
exemplary housing
300 in the closed and locked configuration with a dispensing tube 308
installed therein
together with a solenoid plunger 1700. The exemplary solenoid plunger 1700
shown in
Figures 15 and 16 is of the type shown and described in U.S. Patent
Application No.
12/880,016 (published as US2012/0061599A1) and corresponding Canadian Patent
Application No. 2714916. As with the illustration of the prior art housing 14
and prior art
solenoid plunger 16, in Figures 15 and 16 the other components of the metering
dispenser,
such as the solenoid itself, related control systems, the support structure
and other elements,
have been omitted for clarity of illustration as these elements and their
placement will be
apparent to one skilled in the art.
[0059] Figure 15 shows solenoid plunger 1700 in the "resting" or "closed"
position, in which
the closure member 1730 on the plunger head 1726 is received in the plunger
aperture 310 in
the mounting half 302 of the housing 300, compressing the dispensing tube 308
and pinching
it against the plunger strike surface 314, thereby inhibiting material flow
past the closure
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member 1730. The solenoid plunger 1700 may be maintained in this position by,
for
example, a suitable biasing member such as a spring (not shown). To dispense
material, the
solenoid (not shown) is actuated to move the solenoid plunger 1700 into the
"active" or
"open" position, as shown in Figure 16, for a fixed period of time before
disengaging the
solenoid and allowing the solenoid plunger 1700 to return to the "rest" or
"closed" position
shown in Figure 15. While the solenoid plunger 1700 is in the "active" or
"open" position
(Figure 16), the dispensing tube 308 is unobstructed, enabling a predetermined
volume of
liquid or granular material to move past the position of the solenoid plunger
1700 before the
solenoid plunger 1700 returns to the "rest" or "closed" position (Figure 15),
again obstructing
the dispensing tube 308.
[0060] When the reservoir is empty and must be replaced, the user first moves
the strike half
304 from the closed and locked configuration (Figures 3, 4, 10, 12 and 14 to
16) to the closed
and unlocked configuration (Figures 9, 11 and 13) by sliding the strike half
304 upwardly
along the pivot 328 from the first slide position to the second slide
position. With the strike
half 304 in the second slide position, the user pivots the strike half 304
from the first pivotal
position through the intermediate pivotal position shown in Figure 7 to the
second pivotal
position, thereby placing the housing 300 in an open configuration (Figure 5
and 6). This
enables the dispensing tube 308 of the empty reservoir to be replaced with the
dispensing tube
308 of the new reservoir. When the housing 300 is installed, the strike half
304 will be biased
toward the first slide position by gravity, especially when it is made of
metal and can slide
smoothly along the pivot 328. At any time after the locking fingers 336 are
clear of the latch
arms 342, the user can allow the strike half 304 to slide under gravity from
the second slide
position to the first slide position, or alternatively can hold the strike
half 304 in the second
slide position while replacing the dispensing tube 308. Once the reservoir and
flexible
dispensing tube 308 have been replaced, the user then pivots the strike half
304 from the
second pivotal position through the intermediate pivotal position shown in
Figure 7 toward
the first pivotal position and, if the user has not held the strike half 304
in the second slide
position, slides the strike half 304 into the second slide position. This
enables the upper three
latch arms 342 to enter the corresponding locking finger gaps 340 while the
lower three
locking fingers 336 enter the corresponding latch arm gaps 346. Thus, when the
strike half
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304 reaches the first pivotal position, the strike half 304 will be in the
second slide position
and therefore in the closed and unlocked configuration (Figures 9, 11 and 13).
The user can
then either manually move the strike half 304 into the first slide position
or, where the strike
half is heavy enough and can slide smoothly along the pivot 328, the user can
simple release
the strike half 304 and allow it to fall into the first slide position under
gravity, in either case
returning the housing to closed and locked configuration (Figures 3, 4, 10, 12
and 14 to 16).
To enable the strike half 304 to fall into the first slide position under
gravity to transition from
the closed and unlocked configuration to the closed and locked configuration,
the clearance
between the locking fingers 336 and the receiving slots 352 formed by the
latch arms should
be sufficient to enable the strike half 304 to fall smoothly into place. The
strike half 304
includes an upper grip recess 388 in its outer face 304B and a lower grip
recess 390 defined in
the lower edge of the strike half 304 to assist a user in grasping and moving
the strike half
304.
[0061] Referring now to Figures 5 and 6, a pair of mounting bores 356 are
defined through
the mounting half 302 on either side of the mounting half tube channel 306.
The mounting
bores 356 each include an intermediate annular shoulder 358 (Figure 7) and can
receive a bolt
(not shown) for securing the mounting half 302 to a metering dispenser, as is
known in the art.
[0062] A temperature sensor aperture 360 (Figure 5) is also defined through
the mounting
half 302, in the mounting half tube channel 306 above the plunger aperture
310, for receiving
a thermistor 362 or other temperature sensor. Where the mounting half 304 is
made from
aluminum or another suitable material having good thermal conductivity, the
need for an
insert made from such material is obviated.
[0063] In addition, as best seen in Figure 6, a closure sensor aperture 364 is
defined through
the mounting half 302 for receiving a closure sensor, such as the illustrated
reed switch 366
which detects a rare earth magnet (not shown) held by a bolt or screw 370 in a
correspondingly positioned magnet aperture 368 defined in the tube receiving
face 304A of
the strike half 304. The closure sensor aperture 364 and the closure sensor
366 may be
positioned on either side of the housing.
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[0064] The solenoid plunger 1700 shown in Figures 15 and 16 will now be
described in more
detail with reference to Figures 17 and 18.
[0065] The solenoid plunger 1700 comprises a solenoid-actuable armature shaft
1724 and a
plunger head 1726 secured to a first end 1724A of the armature shaft 1724. The
plunger head
1726 is preferably formed from metal, and more preferably from aluminum or an
aluminum
alloy to provide strength at a low weight, and comprises a cylindrical portion
1734, a
campanulate or bell-shaped portion 1728, a disc-shaped portion 1732 and a
closure member
1730. The campanulate portion 1728 has a wide end 1728A and a narrow end
1728B, with
the wide end 1728A being further from the first end 1724A of the armature
shaft 1724 than
the narrow end 1728B. The closure member 1730 is further from the first end
1724A of the
armature shaft 1724 than the campanulate portion 1728 and defines a first end
1726A of the
plunger head. The cylindrical portion 1734 is disposed between the narrow end
1728B of the
campanulate portion 1728 and the first end 1724A of the armature shaft 1724,
and the disc-
shaped portion 1732 is disposed between the wide end 1728A of the campanulate
portion
1728 and the closure member 1730. The cylindrical portion 1734, campanulate
portion 1728
and disc-shaped portion 1732 are all longitudinally coaxial with one another,
with the
cylindrical portion 1734 having a substantially smaller diameter than the disc-
shaped portion
1732 and being substantially longer than the disc-shaped portion 1732,
measured in the
longitudinal direction. The narrow end 1728B of the campanulate portion 1728
has
approximately the same diameter as the cylindrical portion 1734, with the wide
end 1728A of
the campanulate portion 1728 having a substantially greater diameter than that
of the
cylindrical portion 1734.
[0066] The campanulate portion 1728 includes a cylindrical region 1740 at the
wide end
1728A thereof, adjacent the disc-shaped portion 1732 and having a smaller
diameter than the
disc-shaped portion 1732 so as to define an annular shoulder 1742 between the
campanulate
portion 1728 and the disc-shaped portion 1732. As best seen in Figure 18, the
closure
member 1730 is an H-shaped member extending from the disc-shaped portion 1732
and
tapering into a wedge 1744 distal from the disc-shaped portion 1732. More
particularly, the
closure member 1730 comprises two opposed flanges 1746 connected by a web
1748, with
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the flanges 1746 tapering inwardly toward the web 1726 to form the wedge 1744
at the end of
the closure member 1730 that is distal from the disc-shaped portion 1732. The
nose 1750 of
the wedge 1744 is blunt so as not to rupture a flexible tube of a solenoid-
driven metering
system.
[0067] The armature shaft 1724 is cylindrical and includes an annular groove
1752 on the
outer surface thereof for receiving a stop (not shown), and the second end
1724B of the
armature shaft defines a frusto-conical tip 1754.
[0068] Referring now to Figure 18, it can be seen that a threaded shaft 1756
extends from the
second end 1726B of the plunger head 1726, longitudinally coaxial with the
cylindrical
portion 1734, campanulate portion 1728 and disc-shaped portion 1732 of the
plunger head
1726. The threaded shaft 1756 is preferably integrally formed as part of the
plunger head
1726. Correspondingly, the first end 1724A of the armature shaft 1724 has a
threaded bore
1758 defined therein, coaxial with the longitudinal axis of the armature shaft
1724. The
plunger head 1726 is secured to the first end 1724A of the armature shaft 1724
by the
threaded shaft 1756 being threadedly received in the threaded bore 1758, and
is further
secured to the first end 1724A of the armature shaft 1724 by a pin 1760
passing through a
crossbore. The crossbore is defined by a first passage 1762 extending through
the threaded
shaft, perpendicular to the longitudinal axis thereof and a second passage
1764 extending
through the threaded bore, perpendicular to the longitudinal axis thereof.
When the threaded
shaft 1756 is fully threaded into the threaded bore 1758, the first and second
passages 1762,
1764 are in registration with one another to define the complete crossbore.
The pin 1760
may, for example, be friction fit or interference fit into the first and
second passages 1762,
1764 or the pin 1760 and the first and second passages 1762, 1764 may be
threaded.
[0069] Certain currently preferred embodiments have been described by way of
example. It
will be apparent to persons skilled in the art that a number of variations and
modifications can
be made without departing from the scope of the claims. The above description
is intended in
an illustrative rather than a restrictive sense. Variations to the exact
embodiments described
may be apparent to those skilled in the relevant art without departing from
the spirit and scope
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of the claims set out below. It is intended that any such variations be deemed
within the scope
of this patent.
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