Valve assembly and method for dispensing gelatinous materials

A valve assembly for dispensing a measured quantity of a gelatinous semisolid material into a receptacle comprises a cylindrical housing provided with a piston actuatable to move through the throughbore of the housing to a cap provided with a cylindrical sleeve. Mounted within the sleeve is a hollow valve body connected to a sealing member having an end of circular cross-section and a slidable hollow cylindrical body provided with an orifice whose cross-section is substantially equal to that of the end of the sealing member. The barrel is connected to the valve body by springs. In the valve closed position the end of the sealing member is situated in the barrel orifice, preventing the dispensing of the gelatinous material; in the valve open position the barrel is pushed away from the sealing member, allowing the material to be dispensed. The barrel returns to the valve closed position after the material has been dispensed. In use, the material is introduced into the housing; weighing the valve assembly before and after dispensing enables the quantity of dispensed material to be verified.

FIELD OF THE INVENTION 
This invention relates to delivery of material through a valve, and more 
particularly to a valve assembly and method for dispensing a gelatinous 
semisolid material into a receptacle. 
BACKGROUND OF THE INVENTION 
Many devices for the delivery of various materials through a valve or 
nozzle have been described in the art. For example, hose nozzles with 
constricted outlets for the spraying water from a hose are disclosed in 
U.S. Pat. Nos. 3,102,691 and 4,840,313. Pneumatic guns for dispensing 
flowable sealants and adhesives are described in U.S. Pat. Nos. 4,376,498, 
5,058,769, and 5,064,098. A filler nozzle and valve with a 
concave-conoidal non-drip tip for delivering fluids of various viscosities 
is disclosed in U.S. Pat. No. 4,363,429. A nozzle assembly that includes a 
wire mesh screen for dripless, splashless dispensing of liquids is 
described in U.S. Pat. No. 5,188,289. 
Valve devices for the delivery of air and other gases are also known in the 
art. For example, U.S. Pat. No. 2,596,909 describes a valve for admitting 
ventilation air in which a slidable tubular member seats against a conical 
plug situated in a spherical housing. Also, U.S. Pat. No. 4,721,129 
discloses a pressure relief valve for gases which has a spring biased 
piston which operates internally of the valve to relieve pressure and is 
then resealed in an air-tight manner. 
PROBLEM TO BE SOLVED BY THE INVENTION 
In pre-production testing to develop a formulation employed in the 
production of photographic materials, gelatin, or addenda having gelatin 
as one of the ingredients, may be added to the mix contained in a 
receptacle such as a kettle. Such gelatin may include a dispersion of a 
dye or a dye-forming coupler that may itself be colored. This addition is 
frequently carried out by raising the temperature of the gelatin to 
liquefy it, then pumping it in the molten state into the kettle and 
metering the quantity delivered. Such a procedure requires a complex array 
of containers, hoses, pumps, and heaters that must be dismantled and 
cleaned after each use. It would be highly advantageous to dispense 
automatically and reproducibly a desired measured quantity of the gelatin 
as a semisolid gelatinous material directly into the coating mix without 
the need to liquefy and then pump it into the kettle. This desirable 
objective is met by the valve assembly and method of the present 
invention. 
SUMMARY OF THE INVENTION 
In accordance with the invention, a valve assembly for dispensing a 
measured quantity of a gelatinous semisolid material into a receptacle 
comprises: 
(a) a cylindrical housing having a first end and a second end and a 
throughbore of circular cross-section, the housing being provided with a 
piston actuatable by pressure means to move through the throughbore 
towards the second end; 
(b) a cap attached at the second end of the housing, the cap being provided 
with a cylindrical sleeve having a throughbore with a cross-section 
smaller than the cross-section of the throughbore of the housing; 
(c) a hollow cylindrical valve body mounted within the throughbore of the 
sleeve and having an external cross-section slightly smaller than the 
throughbore of the sleeve, the valve body having a first end and a second 
end, the first end of the valve body being situated within the sleeve and 
being provided with retaining means for preventing ejection of the valve 
body from the sleeve by the pressure means; 
(d) a sealing member connected to the second end of the valve body and 
comprising an end having a circular cross-section; and 
(e) a hollow cylindrical barrel mounted within the throughbore of the 
sleeve and having an external cross-section slightly smaller than the 
throughbore of the sleeve, the barrel being slidable from a valve closed 
position to a valve open position, the barrel having a first end and a 
second end and encompassing the sealing member, the first end of the 
barrel being situated within the throughbore of the sleeve in close 
proximity to the second end of the valve body, the second end of the 
barrel having an orifice with a cross-section substantially equal to the 
circular cross-section of the sealing member, the barrel being connected 
to the valve body by resilient means actuatable by pressure exerted by the 
gelatinous semisolid material; 
wherein, in the valve closed position of the barrel, the sealing member is 
situated within the orifice of the barrel, thereby preventing the 
dispensing of the gelatinous semisolid material, and in the valve open 
position of the barrel, the orifice of the barrel is displaced away from 
the sealing member, thereby allowing the dispensing of the gelatinous 
semisolid material into the receptacle. 
Also in accordance with the invention, a method for dispensing a measured 
quantity of a gelatinous semisolid material from a valve assembly having a 
known tare mass comprises: 
(a) introducing a mass of the gelatinous semisolid material into a 
cylindrical housing included in the valve assembly, the housing having a 
first end and a second end and a throughbore of circular cross-section, 
the housing being provided with a piston that is situated in close 
proximity to the first end and is actuatable by pressure means to move 
through the throughbore towards the second end; the valve assembly further 
comprising: a cap attached at the second end of the housing, the cap being 
provided with a cylindrical sleeve having a throughbore with a 
cross-section smaller than the cross-section of the throughbore of the 
housing; a hollow cylindrical valve body mounted within the throughbore of 
the sleeve and having an external cross-section slightly smaller than the 
throughbore of the sleeve, the valve body having a first end and a second 
end, the first end of the valve body being situated within the sleeve and 
being provided with retaining means for preventing ejection of the valve 
body from the sleeve by the pressure means; a sealing member connected to 
the second end of the valve body and comprising an end having a circular 
cross-section; and a hollow cylindrical barrel mounted within the 
throughbore of the sleeve and having an external cross-section slightly 
smaller than the throughbore of the sleeve, the barrel being slidable from 
a valve closed position to a valve open position, the barrel having a 
first end and a second end and encompassing the sealing member, the first 
end of the barrel being situated within the throughbore of the sleeve in 
close proximity to the second end of the valve body, the second end of the 
barrel having an orifice with a circular cross-section substantially equal 
to the circular cross-section of the sealing member, the sealing member 
being situated within the orifice in a valve closed position, the barrel 
being connected to the valve body by resilient means; 
(b) determining a gross mass comprising the tare mass of the valve assembly 
and the mass of the gelatinous semisolid material introduced into the 
housing; 
(c) applying pressure by the pressure means to the piston to impel the 
piston through the throughbore of the housing to the cap, thereby forcing 
the gelatinous semisolid material through the sleeve and the valve body 
into the barrel, wherein the material exerts pressure at the orifice, 
thereby causing the resilient means to be compressed and the orifice to be 
displaced away from the sealing member to a valve open position, thereby 
enabling the dispensing of the measured quantity of gelatinous semisolid 
material from the valve assembly into the receptacle, the orifice 
returning to the valve closed position by the action of the resilient 
means after the dispensing of the measured quantity of material into the 
receptacle; 
(d) determining an adjusted tare mass comprising the tare mass of the valve 
assembly together with the mass of gelatinous semisolid material remaining 
within the valve assembly; and 
(e) subtracting the adjusted tare mass from the gross mass, thereby 
verifying the quantity of gelatinous semisolid material that has been 
dispensed into the receptacle. 
ADVANTAGE OF THE INVENTION 
The present invention enables a measured quantity of a gelatinous semisolid 
material, such as a gelatin based dye dispersion, to be conveniently and 
reproducibly dispensed as a gelatinous semisolid into a mix contained in a 
kettle without the need for heaters, hoses, and pumps to liquefy the 
gelatin and transport it to the kettle. The valve assembly containing the 
gelatinous semisolid may be weighed before and after the material has been 
delivered to the kettle, thereby providing verification of the amount 
dispensed. The minimal constriction within the valve assembly allows the 
semisolid to be ejected by application of compressed air at relatively low 
pressure, and the movement of the barrel and the inclusion, in a preferred 
embodiment, of concentric grooves at the end of the sealing member enables 
the gelatinous semisolid to be dispensed without residual material 
remaining on the exterior of the valve assembly. After use, the assembly 
may be readily disassembled, cleaned, and reassembled for subsequent use.

DETAILED DESCRIPTION OF THE INVENTION 
As depicted in FIG. 1, the valve assembly 100 for dispensing a gelatinous 
semisolid material into a receptacle comprises a cylindrical housing 101 
provided at the first end with a piston 102 actuatable by pressure means 
(not shown) to move through the throughbore of the housing to a cap 103. 
In a preferred embodiment, as shown in FIG. 1, the cap is detachably and 
sealably connected to the second end of the housing, which further 
comprises a gasket 104, for example, an O-ring seal. 
The cap is provided with a cylindrical sleeve 105 having a throughbore with 
a cross-section smaller than the cross-section of the housing throughbore. 
The sleeve may be coaxial with the cylindrical housing or, as depicted in 
FIG. 1, the axis of the sleeve may be canted with respect to the housing 
axis. Mounted within the sleeve is a hollow cylindrical valve body 106 
having an external cross-section slightly smaller than the sleeve 
throughbore and being provided at one end with retaining means from 
preventing ejection of the valve body from the sleeve by the pressure 
means. The other end of the valve body is connected to a sealing member 
that comprises an end with a circular cross-section. 
Also mounted within the sleeve is a hollow cylindrical barrel having an 
external cross-section slightly smaller than the sleeve throughbore. The 
barrel encompasses the sealing member and has an orifice whose 
cross-section is substantially equal to that of the end of the sealing 
member. The barrel is connected to the valve body by resilient means 
actuatable by pressure exerted by the gelatinous semisolid material within 
the valve assembly. 
FIG. 2 is an isometric view of the valve body 106. Attached at one end is a 
lug 201, which comprises the aforementioned retaining means. The sealing 
member 202 is connected to the valve body at two diametrically situated 
points by the bifurcated shank 203. Also shown in FIG. 2 is a plurality of 
concentric grooves 204 at the end of the sealing member, which grooves 
minimize dripping of the gelatinous semisolid material. 
FIG. 3 is an isometric view of the barrel 107, which is provided at one end 
with diametrically positioned tabs 301, to which the resilient means 
connecting the barrel to the valve body is attached. 
FIG. 4 is an isometric view depicting the valve body 106, the barrel 107, 
and coil springs 401, which comprise the resilient means connecting the 
valve body at lugs 201 to the barrel at tabs 301. 
FIG. 5 is a cross-section of the valve body 106 and the sealing member 202 
connected by the coil spring 401 to the barrel 107; the circular grooved 
end of the sealing member is shown situated within the orifice 501 of the 
barrel in the valve closed position. The pressure of the gelatinous 
semisolid material at the orifice of the barrel propels the barrel away 
from the sealing member, the valve open position as depicted in FIG. 6, 
which allows the material to be forced around the sealing member and 
through the orifice. When the desired measured quantity of the gelatinous 
material has been expelled from the valve assembly, the spring relaxes and 
the barrel returns to the valve closed position. 
As shown in FIGS. 5 and 6, in a preferred embodiment of the invention a 
portion of the lower, or second end of the barrel is frusto-conically 
tapered, thereby defining the circumference of the orifice, whose circular 
cross-section is substantially equal to the cross-section of the sealing 
member. The preferred angle of the taper, as measured from the end of the 
sealing member, is about 45 degrees. The tapered inner surface of the 
barrel at the orifice causes the gelatinous semisolid material to be 
dispensed in a narrow conical flow path. 
As previously described, the circular end of the sealing member comprises a 
plurality of concentric grooves to minimize dripping of the gelatinous 
material. FIG. 7 is a cross-section depicting the detail of the grooves, 
whose walls are disposed at an angle of about 90.degree. to each other. 
The circular grooves are characterized by pitch whose width is represented 
by p, inner top lands whose width is represented by m, and an outermost 
top land whose width is represented by n. In a preferred embodiment, the 
ratio of pitch width to inner top land width, p:m, and the ratio of inner 
top land width to outermost top land width, m:n, are each from 3:1 to 5:1. 
In a more preferred embodiment, the ratio of pitch width to inner top land 
width, p:m, and the ratio of inner top land width to outermost top land 
width, m:n, are each from 3.5:1 to 4.5:1. In the most preferred 
embodiment, the ratio of pitch width to inner top land width, p:m, and the 
ratio of inner top land width and outermost top land width, m:n, are each 
4:1. 
In operation, the cylindrical housing of the valve assembly is filled with 
a known quantity of a gelatinous semisolid material. As previously 
described, this gelatinous semisolid may be gelatin used in the production 
of photographic materials and may further comprise a dispersion of a dye 
or a dye-forming coupler that may itself be colored. The piston is placed 
in the cylinder atop the gelatinous semisolid. A shaft actuatable by, for 
example, manual means such as a crank or a lever, by a linear motor, by 
hydraulic pressure or, preferably, by compressed air drives the piston 
through the throughbore to the cap. The minimal constriction within the 
valve assembly enables a desired measured quantity of gelatinous material 
to be ejected at relatively low air pressure. The gelatinous semisolid 
material is forced through the sleeve into the valve body and the barrel. 
The pressure of the semisolid material at the orifice of the barrel causes 
the coil spring resilient means connecting the barrel to the valve body to 
extend, enabling the barrel to move from the valve closed position to the 
valve open position, resulting in the reproducible dispensing of the 
desired quantity of gelatinous material into the receptacle. After the 
desired quantity of material has been ejected from the valve assembly, the 
spring resilient means relaxes and the barrel returns to the valve closed 
position. The grooves at the end of the sealing member discourage 
adherence of the gelatinous material to the end of the sealing member, 
thereby minimizing dripping. This discouraged adherence also promotes 
reproducibility in the amount dispersed. That is, since the amount of 
material adhering to the valve may be different for each usage, the 
dispersing precision would be impaired. If no material adheres, this 
variability in the system is reduced, thereby improving the precision. 
The tare mass of the valve assembly can be determined prior to introduction 
of a quantity of semisolid material by means known to those skilled in the 
art, such as a scale or balance. A gross mass comprising the tare mass and 
the mass of the semisolid material contained in the housing can similarly 
be determined by such known means. Following the dispensing of the 
material into the receptacle, an adjusted tare mass comprising the tare 
mass and any residual gelatinous material remaining within the valve 
assembly can be ascertained. The difference between the adjusted tare mass 
and the gross mass can then be determined to verify that the desired 
measured quantity of gelatinous semisolid material has been dispensed into 
the receptacle. That is: Semisolid Material Mass=Gross Mass-Tare Mass. 
Following use, the valve assembly can be readily disassembled, cleaned, 
and reassembled for subsequent use. 
The invention has been described in detail with particular reference to 
preferred embodiments thereof, but it will be understood that variations 
and modifications can be effected within the spirit and scope of the 
invention. 
TS LIST 
100 valve assembly 
101 housing 
102 piston 
103 cap 
104 gasket 
105 sleeve 
106 valve body 
107 barrel 
201 lug 
202 sealing member 
203 bifurcated shank 
204 concentric grooves 
301 tab 
401 Coil spring 
501 orifice