Method and apparatus for cleansing and disinfecting a flushing toilet

Method and apparatus for cleansing and disinfecting a flushing toilet comprising a toilet tank and a toilet bowl by treating the water discharged from the toilet tank each time the toilet is flushed. First and second passive dispensing apparatus for immersion in the toilet tank water are provided to carry out the cleansing and disinfecting method. The first passive dispensing apparatus contains a solid, water soluble, surfactant containing cake for exposure to a quantity of water to form an aqueous surfactant containing solution within the first dispensing apparatus. The second passive dispensing apparatus contains a solid, water soluble, disinfectant containing cake for exposure to a second quantity of water to form an aqueous, disinfectant containing solution within the second dispensing apparatus. Each dispensing apparatus isolates both the cake and the aqueous solution made therefrom from the water surrounding the dispensing apparatus intermediate flush cycles of the toilet and discharges a predetermined quantity of aqueous solution into the toilet tank when the toilet is flushed. The first dispensing apparatus is so constructed that the aqueous surfactant containing solution discharged therefrom is of substantially constant strength, while the second dispensing apparatus is so constructed that the aqueous disinfectant containing solution discharged therefrom is substantially free of undissolved solids. The isolation provided by each dispensing apparatus permits co-dispensing surfactant containing and disinfectant containing aqueous solutions which chemically react with one another upon contact to provide effective cleansing and disinfecting of the toilet.

FIELD OF THE INVENTION 
The present invention pertains, in general, to method and apparatus for 
cleansing and disinfecting a flushing toilet comprising a toilet tank and 
a toilet bowl each time the toilet is flushed. Because the preferred 
dispensing apparatus employed is entirely passive, i.e., it has no moving 
parts, the present invention relates to apparatus for carrying out said 
method which is both economical to manufacture and highly reliable in 
operation. Furthermore, because a predetermined quantity of solution is 
discharged each time the toilet is flushed, the present invention relates 
to plural product dispensers which are so sized with respect to one 
another that each of the product components will be consumed at about the 
same point in time, thereby minimizing waste of any particular component. 
In addition, the present invention has particular relation to cleansing 
and disinfecting apparatus which maintains each product component and the 
solution formed therefrom in isolation from the toilet tank water and from 
the other components disposed in other independent sections of the 
dispensing apparatus, thus making it possible to co-dispense aqueous 
solutions which would adversely react with one another if allowed to 
combine in sufficiently high concentration prior to flushing of the 
toilet. 
BACKGROUND OF THE INVENTION 
Various devices for cleansing and disinfecting flushing toilets are well 
known in the art. U.S. Pat. No. 1,307,535 issued to Ciancoglini on June 
24, 1919 discloses dispensing a disinfectant into a flush tank type toilet 
at the end of the flush cycle. U.S. Pat. No. 3,339,801 issued to Hronas on 
Sept. 5, 1967 discloses the introduction of various agents including 
detergents, biocides, corrosion inhibitors, scale inhibitors, deodorants, 
etc. into the flush tank as it fills, thus treating the entire water 
content of the tank. U.S. Pat. No. 3,121,236 issued to Yadro et al on Feb. 
18, 1964 discloses dispensing into the toilet tank compositions containing 
such materials as silicates, phosphates, and carbonates to treat metal 
ions in the water and thereby provide rust and scale prevention. U.S. Pat. 
No. 3,504,384 issued to Radley et al on Apr. 7, 1970 discloses apparatus 
for separately dispensing a detergent composition and a disinfecting 
composition into the flush tank of a toilet. It is indicated that dual 
dispensing is desirable since the disinfectant and detergent materials are 
often incompatible with each other. The apparatus is designed to hang 
below the high water line of the toilet tank. In a preferred embodiment of 
the Radley et al device, the detergent composition in the form of a cake 
resides in an enclosed compartment, and as the flush tank fills, water 
enters and fills the compartment, whereupon a concentrated solution of 
detergent forms in said compartment. The compartment is not, however, 
isolated from the surrounding toilet tank water. A separate compartment 
contains a disinfectant composition in cake form which is in constant 
contact with the water in the tank and gradually dissolves in the tank to 
form a dilute disinfectant solution. Upon flushing, the detergent solution 
from the first compartment flows out of the compartment when the level of 
flush water in the tank falls below the level of the compartment. 
Thus, it is clear that the desirability of separating organic materials, 
i.e., surfactants, perfumes, dyes, etc., from disinfecting agents, 
particularly those that are strong oxidizing agents is recognized in the 
prior art. If these materials are not isolated from each other prior to 
use, the organic material is susceptible to chemical interaction with the 
oxidizing agent, thereby resulting in a loss of available chlorine or 
oxygen, and a corresponding loss of disinfecting, deodorizing and cleaning 
performance. The prior art fails, however, to teach or disclose suitable 
passive dispensing apparatus capable of completely isolating the chemicals 
from the toilet tank water, and hence from one another during quiescent 
periods intermediate flushes of the toilet. 
It is further known in the prior art that disinfectant tablets or cakes, 
when submerged in water, release active ingredients to form an aqueous 
solution of the disinfectant and, in addition, may release soluble 
inorganic filler/stabilizing salts. Such solublization results in the 
formation of a concentration gradient which is highest at the bottom of 
the solution and lowest at the top surface of the solution. Furthermore, 
insoluble salts which may be formed by ion exchange with the disinfectant 
tablet materials and undissolved disinfectant particles which tend to 
break off from the tablet as it dissolves tend to settle to the bottom of 
the solution. Prior art passive dispensing apparatus, i.e., dispensing 
apparatus having no moving parts, have not solved the problem of reliably 
dispensing a predetermined quantity of such disinfectant solutions with 
each flush cycle of the toilet without simultaneously discharging these 
undissolved solid materials which are undesirable in the toilet tank and 
bowl, since they may cause corrosion of metal components within the toilet 
tank and result in a waste of disinfectant materials. 
Another problem known in the prior art when attempting to employ a 
surfactant containing cleansing cake in a prior art style toilet tank 
dispenser is that the surfactant containing cake forms a thick, densified 
solution when exposed to water, which densified solution tends to settle 
to the bottom of the solution reservoir, thereby forming viscosity and 
concentration gradients between the bottom and the top surfaces of the 
solution. Prior art style passive dispensing apparatus have not solved the 
problem of reliably discharging a predetermined quantity of such a 
surfactant containing solution of substantially constant strength each 
time the toilet is flushed. 
In summary, none of the discovered prior art has solved all of the 
aforementioned problems associated with co-dispensing a predetermined 
quantity of surfactant containing cleansing solution with a predetermined 
quantity of disinfectant containing solution in the manner of or to the 
degree provided by the present invention utilizing passive dispensing 
apparatus having no moving parts and providing complete isolation of each 
product component from the toilet tank water during quiescent periods 
intermediate flush cycles. 
SUMMARY OF THE INVENTION 
In accordance with a preferred embodiment of the present invention, a 
method for cleansing and disinfecting a flushing toilet comprising a 
toilet tank and a toilet bowl each time said toilet is flushed is 
provided. Briefly, said method comprises: (a) forming a quantity of 
surfactant containing solution by exposing a first solid, water soluble, 
surfactant containing cake to a first quantity of water within a first 
passive dispensing apparatus immersed in a toilet tank; (b) isolating said 
first cake and said surfactant containing solution in said first passive 
dispensing apparatus from the surrounding water; (c) forming a quantity of 
disinfectant containing solution by totally immersing a second solid, 
water soluble, disinfectant containing cake in a second quantity of water 
within a second passive dispensing apparatus immersed in the toilet tank; 
(d) isolating said second cake and said disinfectant containing solution 
in said second passive dispensing apparatus from the surrounding water; 
(e) flushing the toilet, thereby lowering the water level in said toilet 
tank from a first elevation to a second elevation; (f) discharging a 
predetermined quantity of said surfactant containing solution of 
substantially constant strength from said first passive dispensing 
apparatus in response to the water level in said toilet tank being lowered 
from said first elevation to said second elevation; and (g) discharging a 
predetermined quantity of said disinfectant containing solution 
substantially free of undissolved solids from said second passive 
dispensing apparatus in response to the water level in said toilet tank 
being lowered from said first elevation to said second elevation. 
Preferred apparatus for carrying out the aforementioned cleansing and 
disinfecting method are also provided.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
It is known in the art that disinfectant type cleaners are useful in 
providing cleaning, deodorizing, and disinfecting benefits when used for 
toilet bowl maintenance. The prior art makes numerous references to 
specific formulations to achieve these benefits. For example, U.S. Pat. 
No. 3,604,020 issued to Moisa on Sept. 14, 1971 suggests the use of 
calcium hypochlorite as a disinfectant agent, U.S. Pat. No. 2,497,057 
issued to Pape et al on Feb. 7, 1950 suggests the use of compressed acid 
sulfate tablets, and U.S. Pat. No. 3,504,384 issued to Radley et al on 
Apr. 7, 1970 discloses the use of trichloroisocyanuric acid as a 
disinfectant, said patents being hereby incorporated herein by reference. 
Any suitable disinfectant agent which yields active chlorine or active 
oxygen in aqueous solution can be employed to advantage in the practice of 
the present invention. This is typically the case for materials used as 
bleaching agents. Thus, bleaches represent a particularly preferred form 
of disinfecting agent suitable for use in the practice of the present 
invention. 
A highly preferred bleaching disinfecting agent is one which yields a 
hypochlorite species in aqueous solution. The hypochlorite ion is 
chemically represented by the formula OC1.sup.-. The hypochlorite ion is a 
strong oxidizing agent and for this reason materials which yield this 
species are considered to be powerful disinfecting agents. 
At lower pH levels, aqueous solutions formed by dissolving 
hypochlorite-yielding compounds contain active chlorine partially in the 
form of hypochlorous acid moieties and partially in the form of 
hypochlorite ions. At pH levels above about 10, essentially all of the 
active chlorine is in the form of hypochlorite ion. 
Those disinfecting agents which yield a hypochlorite species in aqueous 
solution include alkali metal and alkaline earth metal hypochlorites, 
hypochlorite addition products, chloramines, chlorimines, chloramides, and 
chlorimides. Specific examples of compounds of this type include lithium 
hypochlorite, calcium hypochlorite, calcium hypochlorite dihydrate, 
monobasic calcium hypochlorite, dibasic magnesium hypochlorite, 
chlorinated trisodium phosphate dodecahydrate, potassium 
dichloroisocyanurate, trichlorocyanuric acid, sodium dichloroisocyanurate, 
sodium dichloroisocyanurate dihydrate, 1,3-dichloro-5,5-dimethylhydantoin, 
N-chlorosulfamide, Chloramine T, Dichlormaine T, Chloramine B and 
Dichloramine B. A particularly preferred disinfecting formula suitable for 
use in the practice of the present invention is described in the commonly 
assigned U.S. Patent Application of John Daniel Nyquist entitled 
DISINFECTING COMPOSITION, Ser. No. 897,478, filed concurrently herewith 
and now abandoned, said patent application being hereby incorporated 
herein by reference. 
Examples of disinfecting agents which yield active oxygen in aqueous 
solution are sodium perborate and potassium monopersulfate (KHS0.sub.5). 
Although there are circumstances where the use of such disinfecting agents 
in a loose granule form may be advantageous, generally it is preferable to 
compress the disinfectant agents into a tablet or cake with the use of 
equipment such as tableting presses, extruders, chilsonaters, etc. Such 
compaction helps to regulate the solubility of the disinfecting agents 
while allowing for a more efficient use of space in relation to size and 
fit of suitable dispensing apparatus into the toilet tank of a flushing 
toilet. 
Disinfecting agents of the type described above may comprise from about 10% 
to about 100% of the disinfecting formula by weight when utilized in 
conjunction with the practice of the present invention. 
For disinfectant compositions suited for use in the practice of the present 
invention, disinfectant agent stabilization is generally achieved by 
careful selection of disinfecting agents and noninterfering inorganic 
filler salts. 
For solid systems containing bleach, it is generally desirable to include a 
stabilizer for the bleaching agents. For some types of bleaching agents, 
particularly oxygen bleaching agents, this material can be a water-soluble 
bleach stabilizing agent selected from the group consisting of alkali 
metal, alkaline earth metal, ammonium and substituted ammonium salts of an 
acid having an ionization constant at 25.degree. C., for the first 
hydrogen, of at least about 1.times.10.sup.-3. Stabilizing salts include 
the alkali metals, alkaline earth metals, ammonium, and substituted 
ammonium sulfates, bisulfates, nitrates, silicates, chlorides, phosphates, 
pyrophosphates, polyphosphates and hexametaphosphates. Specific examples 
of such materials include magnesium sulfate, sodium sulfate, potassium 
sulfate, ammonium sulfate, lithium sulfate, dimethylammonium sulfate, 
sodium chloride, lithium chloride, potassium chloride, sodium bisulfate, 
potassium bisulfate, ammonium bisulfate, sodium nitrate, magnesium 
nitrate, calcium nitrate, sodium tripolyphosphate, trisodium phosphate, 
sodium metaphosphate, sodium hexametaphosphate, potassium pyrophosphate, 
sodium tetraphosphate, sodium silicate, and sodium metasilicate. 
Stabilizing agents of this type are described more fully in U.S. Pat. No. 
3,639,285 issued to Nielsen on Feb. 1, 1972, said patent being hereby 
incorporated herein by reference. 
For chlorine bleaching agents, particularly Nchloroimides, a highly 
preferred stabilizing agent is sodium acetate. Use of this material as a 
bleach stabilizer is described more fully in U.S. Pat. No. 3,829,385 
issued to Abbott et al on Aug. 13, 1974, said patent being hereby 
incorporated herein by reference. 
In solid compositions suitable for use in the practice of the present 
invention such disinfectant stabilizing agents are preferably utilized to 
the extent of from about 1% to about 90% by weight of the composition. 
It is also known in the prior art that detergent or surfactant compositions 
are useful in providing cleansing and deodorizing benefits to a toilet 
bowl. As utilized herein, the terms detergent and surfactant are utilized 
interchangeably to refer to those surfactants which are normally utilized 
as detergent ingredients. U.S. Pat. No. 3,769,640 issued to Castronovo on 
Nov. 6, 1973, U.S. Pat. No. 3,867,101 issued to Herring on Feb. 18, 1975 
and U.S. Pat. No. 3,504,384 issued to Radley et al on Apr. 7, 1970, which 
patents are hereby incorporated herein by reference, are representative of 
the prior art. 
Surfactant compositions useful in the practice of the present invention 
preferably contain from about 20% to about 95% by weight of a surfactant 
or combination of surfactants selected from the group consisting of 
anionic, nonionic, ampholytic, and zwitterionic surface active agents. In 
addition, these compositions can include dye (0-15% by weight) as an 
indicator of dispenser functionality, perfume ingredients (0-25% by 
weight) to provide odor benefits, and salts (0-30% by weight) as 
processing aids. The aforesaid surfactant compositions are preferably used 
in connection with the practice of the present invention in the form of 
compressed cakes made via extrusion or hydraulic stamping, or as a solid 
made by pouring a melt of surfactant into a mold and allowing it to 
solidify upon cooling. 
Anionic surfactants operable in compositions suitable for use in practicing 
the present invention can be broadly described as the water-soluble salts, 
particularly the alkali metal salts, of organic sulfuric acid reaction 
products having in their molecular structure an alkyl or alkyl aryl 
radical containing from about 8 to about 22 carbon atoms and a radical 
selected from the group consisting of sulfonic acid and sulfuric acid 
ester radicals. (Included in the term alkyl is the alkyl portion of higher 
acyl radicals.) Important examples of the anionic surfactants which can be 
employed in practicing the present invention are the sodium or potassium 
alkyl sulfates, especially those obtained by sulfating the higher alcohols 
(C.sub.8 -C.sub.18 carbon atoms) produced by reducing the glycerides of 
tallow or coconut oil; sodium or potassium alkyl benzene sulfonates, in 
which the alkyl group contains from about 9 to about 15 carbon atoms, (the 
alkyl radical can be a straight or branched aliphatic chain); paraffin 
sulfonate surfactants having the general formula RSO.sub.3 M, wherein R is 
a primary or secondary alkyl group containing from about 8 to about 22 
carbon atoms (preferably 10 to 18 carbon atoms) and M is an alkali metal, 
e.g., sodium or potassium; sodium alkyl glyceryl ether sulfonates, 
especially those ethers of the higher alcohols derived from tallow and 
coconut oil; sodium coconut oil fatty acid monoglyceride sulfates and 
sulfonates; sodium or potassium salts of sulfuric acid esters of the 
reaction product of one mole of a higher fatty alcohol (e.g., tallow or 
coconut oil alcohols) and about 1 to 10 moles of ethylene oxide; sodium or 
potassium salts of alkyl phenol ethylene oxide ether sulfates with about 1 
to about 10 units of ethylene oxide per molecule and in which the alkyl 
radicals contain from 8 to about 12 carbon atoms; the reaction products of 
fatty acids esterified with isethionic acid and neutralized with sodium 
hydroxide where, for example, the fatty acids are derived from coconut 
oil; sodium or potassium salts of fatty acid amides of a methyl tauride in 
which the fatty acids, for example, are derived from coconut oil and 
sodium or potassium .beta.-acetoxy- or .beta.-acetamido-alkanesulfonates 
where the alkane has from 8 to 22 carbon atoms. 
Nonionic surface active agents operable in compositions suitable for use in 
practicing the present invention can be of three basic types--the alkylene 
oxide condensates, the amides and the semi-polar nonionics. 
The alkylene oxide condensates are broadly defined as compounds produced by 
the condensation of alkylene oxide groups (hydrophilic in nature) with an 
organic hydrophobic compound, which can be aliphatic or alkyl aromatic in 
nature. The length of the hydrophilic or polyoxyalkylene radical which is 
condensed with any particular hydrophobic group can be readily adjusted to 
yield a water-soluble-compound having the desired degree of balance 
between hydrophilic and hydrophobic elements. 
Examples of such alkylene oxide condensates include: 
1. The condensation products of aliphatic alcohols with ethylene oxide. The 
alkyl chain of the aliphatic alcohol can either be straight or branched 
and generally contains from about 8 to about 22 carbon atoms. Examples of 
such ethoxylated alcohols include the condensation product of about 6 
moles of ethylene oxide with 1 mole of tridecanol, myristyl alcohol 
condensed with about 10 moles of ethylene oxide per mole of myristyl 
alcohol, the condensation product of ethylene oxide with coconut fatty 
alcohol wherein the coconut alcohol is a mixture of fatty alcohols with 
alkyl chains varying from 10 to 14 carbon atoms and wherein the condensate 
contains about 6 moles of ethylene oxide per mole of alcohol, and the 
condensation product of about 9 moles of ethylene oxide with the 
above-described coconut alcohol. Examples of commercially available 
nonionic surfactants of this type include Tergitol 15-S-9 marketed by the 
Union Carbide Corporation, Neodol 23-6.5 marketed by the Shell Chemical 
Company and Kyro EOB marketed by The Procter & Gamble Company. 
2. The polyethylene oxide condensates of alkyl phenols. These compounds 
include the condensation products of alkyl phenols having an alkyl group 
containing from about 6 to 12 carbon atoms in either a straight chain or 
branched chain configuration, with ethylene oxide, the said ethylene oxide 
being present in amounts equal to 5 to 25 moles of ethylene oxide per mole 
of alkyl phenol. The alkyl substituent in such compounds can be derived, 
for example, from polymerized propylene, diisobutylene, octene, or nonene. 
Examples of compounds of this type include nonyl phenol condensed with 
about 9.5 moles of ethylene oxide per mole of nonyl phenol, dodecyl phenol 
condensed with about 12 moles of ethylene oxide per mole of phenol, 
dinonyl phenol condensed with about 15 moles of ethylene oxide per mole of 
phenol, di-isooctylphenol condensed with about 15 moles of ethylene oxide 
per mole of phenol. Commercially available nonionic surfactants of this 
type include Igepal CO-610 marketed by the GAF Corporation; and Triton 
X-45, X-114, X-100 and X-102, all marketed by the Rohm and Haas Company. 
3. The condensation products of ethylene oxide with a hydrophobic base 
formed by the condensation of propylene oxide with propylene glycol. The 
hydrophobic portion of these compounds has a molecular weight of from 
about 1500 to 1800 and of course exhibits water insolubility. The addition 
of polyoxyethylene moieties to this hydrophobic portion tends to increase 
the water-solubility of the molecule. Examples of compounds of this type 
include certain of the commercially available Pluronic surfactants 
marketed by the Wyandotte Chemicals Corporation. 
4. The condensation products of ethylene oxide with the product resulting 
from the reaction of propylene oxide and ethylene diamine. The hydrophobic 
base of these products consists of the reaction product of ethylene 
diamine and excess propylene oxide, said base having a molecular weight of 
from about 2500 to about 3000. This base is condensed with ethylene oxide 
to the extent that the condensation product contains from about 40% to 
about 80% by weight of polyoxyethylene and has a molecular weight of from 
about 5,000 to about 11,000. Examples of this type of nonionic surfactant 
include certain of the commercially available Tetronic compounds marketed 
by the Wyandotte Chemicals Corporation. 
Examples of the amide type of nonionic surface active agent include the 
ammonia, monoethanol and diethanol amides of fatty acids having an acyl 
moiety of from about 8 to about 18 carbon atoms. These acyl moieties are 
normally derived from naturally occurring glycerides, e.g. coconut oil, 
palm oil, soybean oil and tallow, but can be derived synthetically, e.g., 
by the oxidation of petroleum, or by hydrogenation of carbon monoxide by 
the Fischer-Tropsch process. 
Examples of the semi-polar type of nonionic surface active agents are the 
amine oxides, phosphine oxides and sulfoxides. These materials are 
described more fully in Berry, U.S. Pat. No. 3,819,528, issued June 25, 
1974, and incorporated herein by reference. 
Ampholytic surfactants operable in compositions suitable for use in 
practicing the present invention can be broadly described as derivatives 
of aliphatic amines which contain a long chain of about 8 to 18 carbon 
atoms and an anionic water-solubilizing group, e.g. carboxy, sulfo or 
sulfato. Examples of compounds falling within this definition are sodium 
3-dodecylamino-propionate, sodium-3-dodecylamino propane sulfonate, and 
dodecyl dimelthylammonium hexanoate. 
Zwitterionic surface active agents operable in compositions suitable for 
use in practicing the present invention are broadly described as 
internally-neutralized derivatives of aliphatic quaternary ammonium and 
phosphonium and tertiary sufonium compounds, in which the aliphatic 
radical can be straight chain or branched, and wherein one of the 
aliphatic substituents contains from about 8 to 18 carbon atoms and one 
contains an anionic water solubilizing group, e.g., carboxy, sulfo, 
sulfato, phosphato, or phosphono. 
Bleach-stable surfactants which are especially resistant to oxidation are 
the alkyl sulfates and paraffin sulfonates. Alkyl sulfates are the 
water-soluble salts of sulfated fatty alcohols containing from about 8 to 
18 carbon atoms in the alkyl group. Examples of suitable alcohols which 
can be employed in alkyl sulfate manufacture include decyl, lauryl, 
myristyl, palmityl and stearyl alcohols and the mixtures of fatty alcohols 
derived by reducing the glycerides of tallow and coconut oil. 
Specific examples of alkyl sulfate salts which can be employed in the 
instant surfactant compositions include sodium lauryl alkyl sulfate, 
sodium stearyl alkyl sulfate sodium palmityl alkyl sulfate, sodium decyl 
sulfate, sodium myristyl alkyl sulfate, potassium lauryl alkyl sulfate, 
potassium stearyl alkyl sulfate, potassium decyl sulfate, potassium 
palmityl alkyl sulfate, potassium myristyl alkyl sulfate, sodium dodecyl 
sulfate, potassium dodecyl sulfate, potassium tallow alkyl sulfate, sodium 
tallow alkyl sulfate, sodium coconut alkyl sulfate, potassium coconut 
alkly sulfate and mixtures of these surfactants. Highly preferred alkyl 
sulfates are sodium coconut alkyl sulfate, potassium coconut alkyl 
sulfate, potassium lauryl alkyl sulfate and sodium lauryl alkyl sulfate. 
Paraffin sulfonate surfactants have the general formula RSO.sub.3 M, 
wherein R is a primary or secondary alkyl group containing from about 8 to 
about 22 carbon atoms (preferably 10 to 18 carbon atoms) and M is an 
alkali metal, e.g., sodium or potassium. Paraffin sulfonate surfactants 
and methods for their preparation are well known in the art. They may be 
prepared, for example, by reaction of hydrocarbons with sulfur dioxide, 
oxygen and a sulfonation reaction initiator. Alternatively, they may be 
prepared by reacting an alkene and a sodium bisulfite under suitable 
radiation or catalysis, as disclosed in British Pat. No. 1,451,228 
published Sept. 29, 1976 and hereby incorporated herein by reference. 
Paraffin sulfonate surfactants are commercially available, e.g., from 
Farbwerke Hoechst A.G. 
Preferred paraffin sulfonates herein are secondary paraffin sulfonates. 
Examples of specific paraffin sulfonates herein are: 
Sodium-1-decane sulfonate; 
Potassium-2-decane sulfonate; 
Litium-1-dodecane sulfonate; 
Sodium-6-tridecane sulfonate; 
Sodium-2-tetradecane sulfonate; 
Sodium-1-hexadecane sulfonate; 
Sodium-4-octadecane sulfonate; 
Sodium-3-octadecane sulfonate. 
Normally, the paraffin sulfonates are available as mixtures of individual 
chain lengths and position isomers, and such mixtures are suitable for use 
herein. 
Passive dosing dispensers for immersion in the water contained in the 
toilet tank of a flush toilet are well known in the prior art. However, 
such known prior art dispensers are not completely suitable for 
simultaneously dispensing a disinfectant containing solution, as described 
earlier herein, in conjunction with a surfactant containing solution, as 
also described earlier herein, due to the fact that such prior art 
dispensing apparatus does not maintain the disinfectant containing tablet 
and the disinfectant containing solution formed by exposing said tablet to 
water in isolation from the toilet tank water during quiescent periods 
intermediate flush cycles of the toilet. The same is also true with 
respect to the surfactant containing tablet and the surfactant containing 
solution formed by exposing the surfactant containing tablet to water. 
Without isolation of these active materials from the toilet tank water, 
and consequently from one another, leaching of the chemicals into the tank 
and premature mixing of the chemicals with one another results. 
Highly improved and effective passive dispensing apparatus capable of 
providing the desired isolation between the tablet and solution and the 
surrounding toilet tank water are disclosed in the commonly assigned U.S. 
patent application of Robert S. Dirksing entitled PASSIVE DOSING 
DISPENSER, Ser. No. 897,477, filed concurrently herewith and now U.S. Pat. 
No. 4,171,546, and the commonly assigned U.S. patent application of Robert 
S. Dirksing entitled PASSIVE DOSING DISPENSER EMPLOYING TRAPPED AIR BUBBLE 
TO PROVIDE AIR-LOCK, Ser. No. 897,469, filed concurrently herewith and now 
abandoned, said patent applications being hereby incorporated herein by 
reference. Improved passive dispensing apparatus of the type generally 
disclosed in the aforementioned patent application of Robert S. Dirksing 
provide isolation between the tablet and solution and the toilet tank 
water by means of air-locks during quiescent periods intermediate flush 
cycles of the toilet. 
It is extremely noteworthy, however, that preferred disinfectant containing 
tablets employed in practicing the present invention have a quite 
different dissolution characteristic than the preferred surfactant 
containing tablets utilized in conjunction with said disinfectant 
containing tablets. In particular, disinfectant tablets suitable for use 
in practicing the present invention, when submerged in water, release 
active ingredients to form an aqueous solution of the disinfectant and 
soluble inorganic filler/stabilizing salts. Such solubilization results in 
the formation of a concentration gradient having greatest strength at the 
bottom of the solution and lowest strength at the surface of the solution. 
In addition, insoluble salts formed by ion exchange with materials 
contained in the particular disinfectant containing tablet and undissolved 
disinfectant particles which tend to break off from the tablet as it 
dissolves tend to settle to the bottom of the solution. 
In dispensing a predetermined quantity of said disinfectant containing 
solution from a dispensing apparatus of the type generally disclosed in 
the aforementioned patent applications of Robert S. Dirksing, it is 
generally preferable to draw from the uppermost surface of the solution, 
thereby avoiding dispensing the undesirable, corrosion causing particulate 
materials, i.e., the undissolved solids, collected at the bottom of the 
solution. Thus, for disinfectant containing solid materials, passive 
dispenser embodiments of the type generally illustrated in FIGS. 1, 10, 11 
and 12 of the aforementioned patent application of Robert S. Dirksing 
entitled PASSIVE DOSING DISPENSER, Ser. No. 897,477, and now U.S. Pat. No. 
4,171,546 and passive dispenser embodiments of the type generally 
illustrated in FIG. 9 of the aforementioned patent application of Robert 
S. Dirksing entitled PASSIVE DOSING DISPENSER EMPLOYING TRAPPED AIR BUBBLE 
TO PROVIDE AIR-LOCK, Ser. No. 897,469, now abandoned are particularly 
preferred. Drawing FIGS. 1, 10, 11 and 12 of the former application are 
substantially reproduced herein as FIGS. 1, 10, 11 and 12, respectively, 
while Drawing FIG. 9 of said latter application is substantially 
reproduced herein as FIG. 20. A feature common to the aforementioned 
dispensing embodiments is that the solid disinfectant containing cake is 
completely immersed within the solution reservoir of the dispenser, and 
the predetermined quantity of disinfectant containing solution discharged 
during each flush cycle of the toilet is withdrawn from the uppermost 
surface of the solution. The undissolved solids contained in the solution 
reservoir are allowed to settle to the bottom due to gravity, thereby 
permitting dispensing a predetermined quantity of disinfectant containing 
solution substantially free of undissolved solids with each flush cycle of 
the toilet. 
Conversely, preferred surfactant containing tablets employed in practicing 
the present invention form a thick, densified solution when exposed to 
water for prolonged periods, which densified solution tends to settle to 
the bottom of the solution reservoir, forming viscosity and concentration 
gradients between the bottom and the top surfaces of the solution. 
Accordingly, passive dispensing apparatus which draw from the uppermost 
surface of the solution and which are generally preferred for use in 
dispensing a predetermined quantity of disinfectant containing solution 
generally function with considerably less effectiveness where a surfactant 
containing solution is involved. This is due to the fact that passive 
dispensing apparatus of the type preferred for dispensing a disinfectant 
containing solution in accordance with the present invention generally 
have insufficient energy to withdraw the thick, densified surfactant 
containing solution from the lowermost reaches of the reservoir. 
Therefore, where a surfactant containing tablet is involved, it is 
generally desirable to either remove the surfactant containing solution 
directly from the lowermost reaches of the reservoir, thereby enlisting 
the assistance of the solution's gravitational head in discharging the 
viscous solution, or to limit the exposure time between the solid cake or 
tablet and the liquid solution to substantially prevent the formation of a 
relatively thick, densified surfactant containing solution. The latter 
approach may readily be carried out utilizing a dispenser embodiment of 
the type generally illustrated in FIG. 28 of the commonly assigned U.S. 
patent application of Robert S. Dirksing entitled PASSIVE DOSING 
DISPENSER, Ser. No. 897,477, filed concurrently herewith and now U.S. Pat. 
No. 4,171,546, said Figure being substantially reproduced herein as FIG. 
26. In such a dispensing embodiment, the amount of time during which the 
water contacts the surfactant containing cake is essentially limited to 
the time interval required to vacuum-transfer a predetermined quantity of 
water from the measuring cavity and inlet conduit across the lowermost 
surface of the surfactant containing cake and to collect the solution thus 
formed in the solution reservoir and discharge conduit. Because the 
measuring cavity and solution reservoir are of substantially equal volume 
and are at an elevation lower than the surfactant containing cake, the 
cake is isolated from the surfactant containing solution once the transfer 
cycle from the measuring cavity to the solution reservoir of the dispenser 
has been completed. Accordingly, a relatively thick, densified surfactant 
containing solution is not formed in the solution reservoir. 
Alternatively, passive dispenser embodiments of the type generally 
illustrated in FIG. 1 and FIG. 15 of the aforementioned commonly assigned 
U.S. patent application of Robert S. Dirksing entitled PASSIVE DOSING 
DISPENSER EMPLOYING TRAPPED AIR BUBBLE TO PROVIDE AIR-LOCK, Ser. No. 
897,469, filed concurrently herewith and now abandoned, may be employed to 
dispense a predetermined quantity of surfactant containing solution. 
Drawing FIGS. 1 and 15 of said application are substantially reproduced 
herein as FIGS. 35 and 43, respectively. In dispensing embodiments of the 
latter variety, the portion of the surfactant containing cake exposed to 
liquid may be controlled by means of a level control partition within the 
dispenser. In addition, the primary solution reservoir is located at a 
lower elevation than the surfactant containing cake within the dispenser. 
Accordingly, the gravitational head of the liquid contained within the 
dispenser assists in discharging the relatively thick, densified 
surfactant solution contained within the primary reservoir during each 
discharge cycle. 
Because a passive dispenser embodiment, as generally illustrated in FIG. 28 
of the aforementioned patent application of Robert S. Dirksing entitled 
PASSIVE DOSING DISPENSER, limits the contact time between the surfactant 
containing cake and the surfactant containing solution thus formed during 
quiescent periods intermediate flush cycles of the toilet, the solution 
discharged during each flush cycle is of substantially constant strength 
provided only that there is sufficient time for the vacuum-transfer within 
the dispenser to be carried out intermediate flush cycles of the toilet. 
Varying the length of the quiescent periods intermediate flush cycles will 
not affect the strength of solution, since there is no contact between the 
solution and the surfactant containing cake during such periods once the 
vacuum-transfer cycle has been carried out. However, in dispensers of the 
type generally illustrated in FIGS. 1 and 15 of the aforementioned patent 
application of Robert S. Dirksing entitled PASSIVE DOSING DISPENSER 
EMPLOYING TRAPPED AIR BUBBLE TO PROVIDE AIR-LOCK, there is prolonged 
contact between the surfactant containing cake and the liquid solution 
contained within the dispenser. Accordingly, the strength of the 
surfactant containing solution discharged from the latter dispensers will 
be substantially constant when the quiescent periods intermediate flush 
cycles of the toilet are sufficiently long to permit the solution to 
become saturated. When the quiescent periods are insufficient for the 
solution to become saturated, the strength of the surfactant containing 
solution discharged will still be substantially constant, provided the 
time periods intermediate said flush cycles are of substantially constant 
duration. 
Referring now to the Figures in which identical features are identically 
designated, FIG. 1 shows a dispenser 20 suitable for dispensing a 
disinfectant containing solution in accordance with the present invention. 
The dispenser 20 contains a solid, water soluble product 21. Dispenser 20 
comprises a front wall 22, a back wall 23, two side walls 25 and 26, a top 
wall 28, a bottom wall 29 (not shown in FIG. 1 but shown in FIGS. 2 
through 8 inclusive), interior partitions 31 through 34, and a baffle 36. 
The walls and partitions are rigid and define a dose-volume measuring 
cavity 41, an inlet conduit 42, a reservoir 43, and a discharge standpipe 
44. Side wall 25 has its top edge designated 51, partition 31 has its 
bottom edge designated 52, partition 33 has its top edge designated 53, 
wall 34 has its top edge designated 54, and baffle 36 has its bottom edge 
designated 55. Baffle 36 also has a beveled front edge 56. In the 
preferred embodiment dispenser 20, edge 53 is at a higher elevation than 
edge 54; edge 54 is at a greater elevation than edge 51; and edge 55 is 
lower than edge 54. The inlet and outlet ports of dispenser 20 are 
designated 57 and 58 respectively. Together, cavity 41 and conduit 42 form 
a trap-type inlet. 
Briefly, referring to FIG. 2, when a dispenser 20 containing solid product 
21 and an aqueous product solution 62 containing solid product 21 and an 
aqueous product solution 62 is disposed, for instance, in a toilet tank 
(not shown) on a bracket or other mounting means (not shown) so that the 
FULL level of water 63 in the toilet tank is sufficiently high to fill the 
cavity 41, the dispenser will respond as shown in FIGS. 2 through 8 during 
a toilet flushing cycle as the water drains from the toilet tank. This 
response causes a dose-volume of water to be vacuum-transferred from 
cavity 41 and inlet conduit 42 into reservoir 43 via inlet conduit 42, and 
a dose-volume of product solution 62 to be displaced from reservoir 43 and 
issue from the dispenser 20 via the discharge standpipe 44 and outlet port 
58. As the toilet tank refills, water rises in the discharge standpipe 44 
and displaces air therefrom which air exits the dispenser via reservoir 
43, inlet conduit 42, and cavity 41 until the cavity 41 is filled through 
its inlet port 57 with toilet tank water. The air remaining in the 
dispenser at that time forms an air-lock in the headspace 60 of the 
reservoir which causes the product 21 and the product solution 62 disposed 
in reservoir 43 to be isolated from toilet tank water disposed in the 
inlet conduit 42 and the discharge standpipe 44. 
Referring back to FIG. 1, the baffle 36 has its front edge 56 beveled so 
that it is spaced from the front wall 22 and thereby defines a vent 
passageway intermediate edge 56 and the adjacent portion of the front wall 
22. This vent passageway enables air to pass the baffle 36 as water rises 
in discharge standpipe 44 while the toilet tank is being refilled with 
water as described hereinabove; however, the vent passageway is 
sufficiently small that a rush of air through the headspace 60 of 
reservoir 43 will, at least in part, be deflected downwardly by baffle 36 
as is fully described hereinafter. 
Dispenser 20 is preferably provided with a quantity of a dry, solid type 
product 21 disposed in it as shown in FIG. 1, and may comprise means (not 
shown) for being secured in a toilet tank at such an elevation that, when 
the toilet tank is FULL, cavity 41 will be full of toilet tank water. 
Furthermore, the discharge standpipe 44 is sufficiently long and of 
sufficient volume that lowering the level of water surrounding the 
dispenser will cause a sufficient degree of vacuum in the headspace 60 of 
the dispenser that a predetermined dose-volume of water disposed in cavity 
41 will be vacuum-transferred into the reservoir 43 via inlet conduit 42 
before the discharge port 58 is uncovered. While a solid mass of product 
21 is shown in the Figures, it will be understood from the description 
contained herein, dispenser embodiments of the type generally illustrated 
in FIG. 1 may also be utilized to dispense a dose-volume of pre-mixed 
liquid product solution with each flush cycle of the toilet. In such 
embodiments, the solid, water soluble product cake is eliminated and the 
product chamber and solution reservoir are filled with either a pre-mixed 
liquid product solution or a water soluble powder which dissolves to form 
a liquid product upon immersion of the dispenser in the toilet tank. 
An exemplary embodiment of dispenser 20 has been fabricated from 1.6 mm 
thick rigid Plexiglas (registered trademark of Rohm & Haas Company) or 
such. This exemplary embodiment has a height of about 90 mm, a width of 
about 85 mm, and a thickness of about 20 mm; its edges 51 through 55 are 
spaced from top wall 28 about 8 mm, 40 mm, 3 mm, 6 mm, and 12 mm, 
respectively; cavity 41 has a dose-volume of about 6.4 cc; inlet conduit 
42 has a cross-section of about 2 mm by 20 mm; and discharge standpipe 44 
has a cross-section of about 16 mm by 20 mm. Also, baffle 36 of the 
exemplary embodiment is disposed about half way between partitions 32 and 
34. As is shown in the figures, the top end of inlet conduit 42 (which top 
end is defined as edge 53 of partition 33) extends to a greater height in 
the upper reaches of reservoir 43 than the top end of the discharge 
standpipe 44 (which top end is defined as edge 54 of partition 34). While 
this exemplary embodiment of dispenser 20 was constructed by adhesively 
securing sections of Plexiglas to one another, other relatively rigid 
materials which are substantially inert with respect to the intended 
product and aqueous solutions thereof can be used to construct dispenser 
20. Furthermore, the dispenser could be constructed or formed at high 
speed and relatively low cost utilizing various manufacturing techniques 
well known in the art. For example, the dispenser could be vacuum 
thermoformed in two sections of a material such as polyvinyl chloride 
having an initial thickness of about 0.020 inches, the solid chemical 
product 21 inserted therebetween and the two sections thereafter secured 
to one another as by heat sealing, adhesives, etc. along a line of contact 
substantially coinciding with section line 2--2 of FIG. 1. 
The inlet conduit 42 of the exemplary dispenser 20 described above has a 
relatively small volume (about 1.4 cc) and a relatively small 
cross-sectional area so that it will be substantially cleared of water 
when the headspace 60 is vented via inlet conduit 42 as described 
hereinafter. However, the cross-sectional area of inlet conduit 42 is 
sufficiently large to enable a dose-volume of water to be 
vacuum-transferred from cavity 41 and inlet conduit 42 into reservoir 43 
in less than the time which elapses as the level of toilet water 63 
recedes from the elevation of edge 51 (the bottom edge of the inlet port 
57) to the elevation of the discharge port 58. That is, if the 
cross-sectional area of inlet conduit 42 presented too great a restriction 
to flow, incomplete dose-volume transfers would result. Also, the small 
volume of inlet conduit 42 enables the headspace 60 to be vented 
therethrough during toilet tank refilling by substantially obviating a 
deep water trap in the bottom portions of cavity 41 and inlet conduit 42. 
In order for dispenser 20 to become functional, reservoir 43 is initially 
filled with water to form the solution 62, FIG. 2, having its top surface 
71 disposed at about the level of the top edge 54 of partition 34. This 
can be done, for instance, by immersing the dispenser several times in a 
body of water or by mounting the dispenser in a toilet tank and flushing 
the toilet several times. Each such immersion or flush will cause a 
dose-volume of water to be delivered to reservoir 43 from cavity 41. This 
water will cause a portion of product 21 to dissolve and thereby form the 
aqueous product solution 62. As is well known to those skilled in the art, 
dissolution will cease during protracted quiescent periods because the 
solution 62 will become saturated. 
After being placed in operation, the dispenser 20 will, during quiescent 
periods while the toilet tank is FULL of water 63, be in the state shown 
in FIG. 2. The top surface 71 of solution 62 will be slightly below top 
edge 54 of partition 34, and have a concave meniscus adjacent edge 54 as 
shown. Also, toilet tank water 63 will be disposed in cavity 41, the inlet 
conduit 42, and the discharge standpipe 44. The level of water in conduit 
42 will be about the same as in standpipe 44 which level will be below the 
top edge 54 of partition 34. This is so because edge 51 is, as stated 
hereinbefore, at a lower elevation than edge 54. Therefore, when the level 
of water rises about dispenser 20 during tank refilling, water will flood 
the cavity 41 through inlet 57 before the level of water in the standpipe 
44 reaches edge 54. This causes air to be trapped in the headspace 60 of 
the reservoir and provides an air-lock which isolates the product 21 and 
the product solution 62 from the water in the inlet conduit 42 and the 
discharge standpipe 44. 
When the toilet is flushed and the level of water 63 recedes, the top 
surface 75 of the water first passes top edge 51 of side wall 25 and 
thereby leaves the cavity 41 FULL as shown in FIG. 3. As the level of 
water 63 continues to recede, the top surface 75 thereof passes the level 
of water disposed in the discharge standpipe 44, FIG. 4 and causes a 
vacuum to be developed in the headspace 60. This vacuum enables ambient 
air in the toilet tank to displace water from the cavity 41 into inlet 
conduit 42. This water then overflows the top edge 53 of partition 33, 
FIG. 5, and runs down partition 33 and begins to mix with the portion of 
solution 62 which is disposed adjacent partition 33. This causes the top 
surface 71 of solution 62 to well up in reservoir 43 and exhibit a 
somewhat convex meniscus adjacent edge 54 as shown in FIGS. 5 and 6. At 
the time when the level of water in cavity 41 reaches the elevation of the 
bottom edge 52 of partition 31, FIG. 6, a column of water is disposed in 
the discharge standpipe 44 which column extends upwardly a distance "C" 
from the elevation of the top surface 75 of the receding water 63. Then, 
air enters the reservoir via inlet conduit 42 and vitiates the vacuum in 
the headspace 60. This precipitates the collapse of the water column of 
height "C" in the discharge standpipe 44 which collapse, in turn, 
precipitates an inrush of air through inlet conduit 42 into the portion of 
the headspace 60 disposed to the left (as shown in FIG. 7) of baffle 36. 
This inrush of air is, in part, diverted downwardly because baffle 36 
partially obstructs direct flow across the headspace. This diverted air 
pushes down on the solution 62 disposed to the left of the baffle 36 and 
the solution 62 displaced thereby, FIG. 7, causes the level of the 
solution 62 disposed to the right of baffle 36 to rise and flow across 
partition 34 and down the discharge standpipe. Thus, a dose-volume of 
solution is virtually blown out of the reservoir 43 as indicated by the 
arrows in FIG. 7. This induces a tempestuous action in the reservoir which 
results in mixing the water that has just entered the reservoir with the 
portion of solution 62 then remaining in the reservoir, and causes the 
solution to be sufficiently agitated to induce further dissolution of 
product 21. FIG. 8 shows the dispenser 20 after the tempestuous action has 
subsided and prior to the rise of water 63. After the dispenser has become 
immersed by refilling the tank, the state shown in FIG. 2 is resumed and 
will be maintained while the toilet is in a quiescent state; i.e., until 
the level of water 63 recedes when the toilet is flushed again. 
The dose-volume of dispenser 20 which dose-volume is referred to 
hereinabove is, essentially, the sum of the partial volumes of both cavity 
41 and inlet conduit 42 disposed intermediate the elevation of edges 51 
and 52: reference FIG. 3 which shows the dispenser with a dose volume of 
water disposed in cavity 41 and conduit 42, and FIG. 8 which shows the 
dispenser after a dose-volume of water has been transferred into reservoir 
43 from cavity 41 and conduit 42 in the manner described herein. 
Referring back to FIG. 7, were baffle 36 not present, the dispenser would 
simply issue a dose volume of solution 62 as it is displaced by the 
incoming dose-volume of make-up water from cavity 41. While this type 
dispenser would provide a high degree of product and product solution 
isolation from the tank water during quiescent periods, this type 
dispenser would not provide the same degree of mixing and agitation in 
reservoir 43 as compared to dispenser 20 having a baffle 36 or the 
equivalent thereof. Thus, the baffle 36 comprises means for mixing and 
agitating liquids disposed in reservoir 43 when a rush of air enters the 
headspace of the reservoir. 
FIG. 9 is a fragmentary sectional view of an alternate embodiment dispenser 
200 which view shows an alternate design baffle 236 having a bottom edge 
255, and a vent hole 237 through it subjacent the top wall 28. But for 
these differences, dispenser 200 is identical to dispenser 20. Thus, while 
a toilet tank in which dispenser 200 is disposed is being filled, air will 
be displaced from its discharge standpipe and pass through the vent hole 
237 in baffle 236 and then exit the dispenser via the inlet conduit of the 
dispenser in the manner described hereinbefore with respect to dispenser 
20. Moreover, the initial filling and the operation of dispenser 200 is 
also identical to the operation of dispenser 20 as described hereinbefore 
and therefore will not be repeated. 
FIG. 10 is a partially torn away perspective view of a dual dispenser 800 
which dispenser functionally comprises two dispenser sections 20a and 20b 
such as dispenser 20, FIG. 1, disposed in front-to-back relation. Such 
dispensers are particularly well suited for plural component products 
which need to be isolated from each other prior to use. Each dispenser 
section of such a dual or plural dispenser will maintain a product 
component in isolation from the toilet tank water and from other product 
components disposed in other independent sections. 
FIG. 11 is a partially torn away perspective view of an alternate 
embodiment plural section dispenser 900 wherein the plural sections as 
shown are two in number, are designated 20c and 20d and are disposed in 
side-by-side relation. Such a dispenser is functionally equivalent to 
dispenser 800, FIG. 10. However, dispenser 900 is thinner but wider than 
dispenser 800 and will fit into some toilet tanks which will not 
accommodate a dispenser 800. Also, the dispenser sections 20c and 20d are 
provided with two inlet ports 957, and two outlet ports 958 in the unitary 
front wall 922 rather than in the side and bottom walls as provided in 
dispenser 20, FIG. 1. While dispenser 900 is shown with its discharge 
ports spaced apart, it will be obvious that the geometry of dispenser 
section 22c can be reversed to provide adjacent discharge ports for such 
purposes as, for instance, enabling better mixing of co-dispensed product 
solutions. Also, the front discharge enables the dispenser 900 to simply 
be placed on the bottom wall of toilet tanks which drain sufficiently 
(i.e.: to below the top edges 959 of the discharge ports 958) rather than 
being supported in the tank by a bracket or the like. 
Referring again to the figures in which identical features are identically 
designated, FIG. 12 shows an alternative dispenser 120 suitable for 
dispensing a disinfectant containing solution in accordance with the 
present invention. The dispenser 120 contains a solid, water soluble 
product 121. Dispenser 120 comprises a front wall 122, a back wall 123, 
two side walls 125 and 126, a top wall 128, a bottom wall 129, interior 
partition 134 and a baffle 136. The embodiment of FIG. 12 differs from the 
embodiment of FIG. 1 in that the baffle 136 is defined by rigid partitions 
131, 133, 181, 182 and 156. The walls and partitions of the dispenser 120 
are relatively rigid and define a dose-volume measuring cavity 141, an 
inlet conduit 142, a product solution reservoir 143, and a discharge 
standpipe 144. The inlet and outlet ports of dispenser 120 are designated 
157 and 158 respectively. The bottom edge of the inlet port 157 is 
designated 151, partition 131 has its bottom edge designated 152, 
partition 133 has its top edge designated 153, partition 134 has its top 
edge designated 154, and the vent passage intermediate the top wall 128 of 
dispenser 120 and the uppermost partition 156 of baffle 136 is designated 
137. In a preferred embodiment of dispenser 120, edge 153 is at a higher 
elevation than edge 154; edge 154 is at a greater elevation than edge 151; 
and partition 181 is at a lower elevation than edge 154. Together, cavity 
141 and conduit 142 form a trap-type inlet. 
Referring to FIG. 13, when a dispenser 120 containing solid product 121 and 
an aqueous product solution 162 is disposed, for instance, in a toilet 
tank (not shown) on a bracket or other mounting means (not shown) so that 
the FULL level of water 163 in the toilet tank is sufficiently high to 
fill the cavity 141, the dispenser will respond as shown in FIGS. 13-19 
during a toilet flushing cycle as the water drains from the toilet tank. 
This response causes a dose-volume of water to be vacuum-transferred from 
cavity 141 and inlet conduit 142 into reservoir 143 via inlet conduit 142, 
and a dose-volume of product solution 162 to be displaced from reservoir 
143 and issue from the dispenser 120 via the discharge standpipe 144 and 
outlet port 158. As the toilet tank refills, water rises in the discharge 
standpipe 144 and displaces air therefrom which air exits the dispenser 
via vent passageway 137, inlet conduit 142, and cavity 141 until the 
cavity 141 is filled through its inlet port 157 with toilet tank water. 
The air remaining in the dispenser at that time forms an air-lock in the 
headspace 160 above the reservoir 143, the baffle 136 and the discharge 
standpipe 144 which causes the product 121 and the product solution 162 
disposed in reservoir 143 to be isolated from toilet tank water disposed 
in the inlet conduit 142 and the discharge standpipe 144. 
Referring back to FIG. 12, the uppermost partition 156 of baffle 136 and 
the uppermost wall 128 of the dispenser 120 define a vent passageway 137 
which enables air to pass the baffle 136 as water rises in discharge 
standpipe 144 while the toilet tank is being refilled with water as 
described hereinabove. However, the vent passageway 137 is sufficiently 
small that a rush of air through entry port 157, measuring cavity 141, 
inlet conduit 142 and the headspace 160 above the right hand portion of 
reservoir 143 (as shown in FIGS. 12-19) will at least in part be deflected 
downwardly by baffle 136 in a manner similar to that described in 
connection with baffle 36 of the dispenser embodiment 20 disclosed in FIG. 
1. 
The functional design criteria discussed in detail with respect to sizing 
the various portions of the dispenser embodiment 20 illustrated in FIG. 1, 
relative to one another, likewise have general application to a dispenser 
120 of the type illustrated in FIG. 12. 
In order for dispenser 120 to become functional, reservoir 143 is initially 
filled with water to form the solution 162, FIG. 13, having its top 
surface 171 disposed at about the level of the top edge 154 of partition 
134. As with the embodiment illustrated in FIG. 1, this can be done by 
immersing the dispenser several times in a body of water or by mounting 
the dispenser in a toilet tank and flushing the toilet several times. Each 
such immersion or flush will cause a dose-volume of water to be delivered 
to reservoir 143 from cavity 141. This water will cause a portion of 
product 121 to dissolve and thereby form the aqueous product solution 162. 
Dissolution of the product 121 will cease during protracted quiescent 
periods because the solution 162 will become saturated. 
After being placed in operation, the dispenser 120 will, during quiescent 
periods while the toilet tank is full of water 163, be in the state shown 
in FIG. 13. The top surface 171 of solution 162 will be slightly below top 
edge 154 of partition 134, and have a concave meniscus adjacent edge 154 
as shown. Also, toilet tank water 163 will be disposed in cavity 141, the 
inlet conduit 142, and the discharge standpipe 144. The level of water in 
conduit 142 will be about the same as in standpipe 144 which level will be 
below the top edge 154 of partition 134. This is so because edge 151 of 
entry port 157 is, as stated hereinbefore, at a lower elevation than edge 
154. Therefore, when the level of water rises about dispenser 120 during 
tank refilling, the water will flood the cavity 141 through inlet 157 
before the level of water in the standpipe 144 reaches edge 154. This 
causes air to be trapped in the headspace 160 above the reservoir and 
standpipe and provides an air-lock which isolates the product 121 and the 
product solution 162 from the water in the inlet conduit 142 and the 
discharge standipe 144. 
When the toilet is flushed and the level of water 163 recedes, the top 
surface 175 of the water first passes edge 151 of inlet port 157 and 
thereby leaves the cavity 141 FULL as shown in FIG. 14. As the level of 
water 163 continues to recede, the top surface 175 thereof passes the 
level of water disposed in the discharge standpipe 144, FIG. 15, and 
causes a vacuum to be developed in the headspace 160. This vacuum enables 
ambient air in the toilet tank to displace water from the cavity 141 into 
inlet conduit 142. This water then overflows the top edge 153 of partition 
133, FIG. 16, and begins to mix with the portion of solution 162 which is 
disposed adjacent partition 133. This causes the top surface 171 of 
solution 162 to well up in reservoir 143 and exhibit a somewhat convex 
meniscus adjacent edge 154 as shown in FIG. 16. At the time when the level 
of water in cavity 141 reaches the elevation of the bottom edge 152 of 
partition 131, FIG. 17, a column of water is disposed in the discharge 
standpipe 144 which column extends upwardly a distance "D" from the 
elevation of the top surface 175 of the receding water 163. Passageway 137 
is at least partially blocked at this point in the cycle by liquid 
attempting to move to the left hand side of the dispenser, and product 
solution 162 is beginning to overflow edge 154. Then, air enters the 
reservoir 143 via inlet port 157, measuring cavity 141 and inlet conduit 
142 and vitiates the vacuum in the headspace 160. This precipitates 
collapse of the water column of height "D" in the discharge standpipe 144, 
which collapse, in turn, precipitates an inrush of air through inlet 
conduit 142 into the portion of the headspace 160 disposed to the right 
(as shown in FIG. 18) of baffle 136. This inrush of air is, in part, 
diverted downwardly because baffle 136 partially obstructs direct flow 
across the headspace. Furthermore, the small size of passageway 137 which 
is at least partially blocked by water, FIG. 18, causes the inrushing air 
to take the path of least resistance, i.e., downwardly into solution 
reservoir 143, thereby virtually blowing a dose-volume of solution 162 out 
of the reservoir 143 as indicated by the arrows in FIG. 18. This induces a 
tempestuous action in the reservoir 143 which results in mixing the water 
that has just entered the reservoir with the portion of solution 162 then 
remaining in the reservoir, and causes the solution to be sufficiently 
agitated to induce further dissolution of solid product 121. FIG. 19 shows 
the dispenser 120 after tempestuous action has subsided and prior to the 
rise of water 163. After the dispenser has become immersed by refilling 
the tank, the state shown in FIG. 13 is resumed and will be maintained 
while the toilet is in a quiescent state, i.e., until the level of water 
163 recedes when the toilet is flushed again. 
The dose-volume dispenser 120 which dose-volume is referred to hereinabove 
is, essentially, the sum of the partial volumes of both cavity 141 and 
inlet conduit 142 disposed intermediate the elevation of edge 151 of entry 
port 157 and edge 152 of partition 131. Note FIG. 14 which shows the 
dispenser with a dose-volume of water disposed within cavity 141 and 
conduit 142, and FIG. 19 which shows the dispenser after a dose-volume of 
water has been transferred into reservoir 143 from cavity 141 and conduit 
142 in the manner described herein. 
As has been pointed out with respect to the embodiment illustrated in FIG. 
1, were baffle 136 not present in the embodiment illustrated in FIG. 12, 
the dispenser would simply issue a dose-volume of solution 162 as it is 
displaced by the incoming dose-volume of makeup water from cavity 141. 
While such a dispenser would provide a high degree of product and product 
solution isolation from the tank water during quiescent periods, it would 
not provide the same degree of mixing and agitation in reservoir 143 as 
compared to dispenser 120 having a baffle 136 or the equivalent thereof. 
Thus, the baffle 136 comprises means for mixing and agitating liquids 
disposed in reservoir 143 when a rush of air enters the headspace 160 of 
the reservoir. 
An exemplary embodiment of dispenser 120 has been fabricated from 1.6 
millimeter thick rigid Plexiglas (Registered trademark of Rohm & Haas 
Company) or such. This exemplary embodiment has a height of about 90 
millimeters, a width of about 90 millimeters, and a thickness of about 20 
millimeters; its edges 151-154 are spaced from the top wall 128 about 12 
millimeters, 22 millimeters, 8 millimeters and 10 millimeters, 
respectively; partition 181 is spaced approximately 28 millimeters from 
top wal 128; cavity 141 has a dose-volume of about 8 cubic centimeters; 
inlet conduit 142 has a cross-section of about 2 millimeters by about 20 
millimeters; and discharge standpipe 144 has a cross-section of about 16 
millimeters by about 20 millimeters. Also, baffle 136 of the exemplary 
embodiment illustrated in FIG. 12 is disposed about half way between 
dispenser wall 125 and partition 134 and measures approximately 50 
millimeters in width and 25 millimeters in height. Passageway 137 has a 
cross-section of about 2 millimeters by about 20 millimeters, while entry 
port 157 has a height of approximately 5 millimeters and a width of 
approximately 40 millimeters. As is shown in FIGS. 12-19, the top end of 
inlet conduit 142 (which top end is defined as edge 153 of partition 133) 
extends to a greater height in the upper reaches of reservoir 143 than the 
top end of the discharge standpipe 44 (which top end is defined as edge 
154 of partition 134). While the exemplary embodiment of the dispenser 120 
was constructed by adhesively securing sections of Plexiglass to one 
another, other relatively rigid materials which are substantially inert 
with respect to the intended product and aqueous solutions thereof can be 
used to construct dispenser 120. For example, a dispenser having the 
desired passageways could be vacuum thermoformed in two sections of a 
material such as polyvinyl chloride having an initial thickness of about 
0.020 inches, the solid chemical 121 inserted therebetween and the two 
sections thereafter secured to one another as by heat sealing, adhesives, 
etc. along a line of contact substantially coinciding with section line 
13-13 of FIG. 12. 
A dispenser 120 of the type generally illustrated in FIG. 12 permits the 
use of a symmetrically shaped, solid, water soluble product 121, increases 
the surface exposure of the solid product to the product solution 162, and 
improves the flow of incoming toilet tank water 163 across the solid 
product. Since the width to depth ratio of the solid product 121 is 
increased with the arrangement illustrated in FIG. 12 when compared to the 
arrangement illustrated in FIG. 1, agitation of the product solution 162 
by the incoming water to the lower reaches of the dispenser chemical 
chamber, i.e., the lowermost portions of reservoir 143, is also improved. 
FIG. 20 illustrates yet another embodiment of a dispenser 220 suitable for 
dispensing a disinfectant containing solution in accordance with the 
present invention. Dispenser 220 comprises a front wall 222, a back wall 
223, sidewall segments 225, 226, 231 and 236, top wall segments 228 and 
237, bottom wall 229, interior partition segments 232, 233, 234, 235, 250, 
255, 256, 257 and 258. The wall segments and partition segments are 
relatively rigid and define a syphon tube 244 having inlet/discharge port 
278 at its lowermost end and sections 285 and 286 at its uppermost end, a 
horizontal passageway 287, a vertical passageway 288 connecting with 
inlet/discharge conduit 280, said inlet/discharge conduit having an air 
trap 281 disposed adjacent thereto in a manner similar to that of 
dispenser embodiment 20' illustrated in FIG. 35, a solid product chamber 
269, a product solution reservoir 265 and vent passageways 270, 271 and 
272 connecting said solid product chamber and said solution reservoir with 
air vent 283 which coincides with edge 264 of sidewall segment 226. 
Lowermost edge of partition segment 232 is designated 262 and lowermost 
edge of partition segment 258 is designated 259. While a solid, water 
soluble product cake 221 is disposed within the lowermost portions of 
reservoir 265, it will be understood from the description contained 
herein, dispenser embodiments of the type generally illustrated in FIG. 20 
may also be utilized to dispense a dose-volume of pre-mixed liquid product 
solution with each flush cycle of the toilet. In such embodiments, the 
solid, water soluble product cake is eliminated and the product chamber 
and solution reservoir are filled with either a pre-mixed liquid product 
solution or a water soluble powder which dissolves to form a liquid 
product solution upon immersion of the dispenser in the toilet tank. 
The principles of operation of dispenser 220 illustrated in FIG. 20 are, 
with the obvious exception of relocation of the solid product 221 to the 
lower position, generally the same as those hereinafter described in 
connection with dispenser embodiment 20' of FIG. 35. As shown in FIG. 21, 
the water level 275 is rising in the toilet tank and in syphon tube 244. 
In the condition illustrated in FIG. 21, the dispenser 220 has not yet 
been completely immersed in the toilet tank. Consequently, solution 
reservoir 265 is at this point devoid of product solution. As toilet tank 
water 263 rises in syphon tube 244, air is vented through passageways 285, 
286, 287 and 288, inlet/discharge conduit 280, solution reservoir 265 and 
passageways 270, 271 and 272 to air vent 283. As shown in FIG. 22, when 
water traverses horizontal passageway 287, vertical passageway 288 and 
enters reservoir 265 via inlet/discharge conduit 280, an air bubble is 
retained within air trap 281 in a manner similar to that described in 
connection with dispenser embodiment 20' of FIG. 35. Toilet tank water 
entering solution reservoir 265 begins to dissolve the solid product 221 
to form an aqueous product solution 203. The level 201 of solution 203 
continues to rise in passageway 270 until such time as the toilet tank 
water level blocks air vent 283, at which point water ceases to flow into 
dispenser 220 via syphon tube 244. FIG. 23 depicts the condition of 
dispenser 220 when the water in the toilet tank has reached the FULL level 
and the dispenser has been fully charged with toilet tank water to form 
product solution 203. When the water ceases to flow in horizontal 
passageway 287 and vertical passageway 288, the bulk of the air bubble 
retained in air trap 281 rises and in so doing rotates about edge 259 of 
partition segment 258 to form an air-lock in horizontal passageway 287 and 
the uppermost segments of vertical passageways 286 and 288, as shown in 
FIG. 23. The condition shown in FIG. 23 will persist during quiescent 
perios intermediate flush cycles of the toilet. 
When the toilet is flushed, FIG. 24, water in the toilet tank will fall 
below air vent 283 of dispenser 220. This provides an air supply so that 
syphoning of the product solution 203 from reservoir 265 may occur. As 
shown in FIG. 24, air trap 281 is filled with product solution 203 as the 
syphoning action from the reservoir 265 to syphon tube 244 takes place. 
The syphoning action will continue until such time as the solution level 
201 reaches lowermost edge 262 of partition segment 270, at which time the 
column of liquid retained in syphon tube 244 is vented and allowed to 
discharge into the toilet tank through inlet/discharge port 278. 
After the toilet tank water has dropped beneath inlet/discharge discharge 
port 278, FIG. 25, a quantity of product solution 203 remains within 
solution reservoir 265 at a level approximating that of lowermost edge 262 
of partition segment 270. The solution remaining within dispenser 220 
serves as a buffer in providing solution for rapid multiple flushes. When 
the level of toilet tank water rises again, dispenser 220 will once more 
be restored to the condition illustrated in FIG. 23. 
FIG. 26 discloses a dispenser embodiment 620 suitable for dispensing a 
surfactant containing solution in accordance with the present invention, 
said dispenser containing a solid, water soluble product 621. Dispenser 
620 comprises a front wall 622, a back wall 623, side wall segments 625, 
626 and 650, a top wall 628, bottom wall segments 629 and 630, interior 
partitions 633, 634, 640, 645, 646, 647, 659 and product-restraining 
partitions 648 and 649. The embodiment of FIG. 26 differs from other 
dispenser embodiments described herein in that the product solution 662 
does not contact the solid product 621 during quiescent periods. The walls 
and partitions of the dispenser are relatively rigid and define a 
dose-volume measuring cavity 641, and inlet conduit 642, a product 
solution reservoir 643, a discharge conduit 692 and discharge standpipe 
644. In a particularly preferred embodiment, the dose-volume measuring 
cavity 641 and inlet conduit 642 are of substantially equal volume to the 
product solution reservoir 643 and discharge conduit 692 respectively. The 
inlet and outlet ports of dispenser 620 are designated 657 and 658 
respectively. The bottom edge of the inlet port 657 is designated 651, 
partition 633 has its bottom edge designated 652 and its top edge 
designated 653, partition 634 has its top edge designated 654, and 
partition 659 has its bottom edge designated 670. The entrance passageway 
into reservoir 643 is designated 661. In a preferred embodiment of 
dispenser 620, edge 653 is at a higher elevation than edge 654; edge 654 
is at a higher elevation than edge 651 of inlet port 657; and the 
uppermost reaches of measuring cavity 641 and product solution reservoir 
643 are at a lower elevation than solid product 621. The solid product 621 
utilized in dispenser 620 is so configured as to permit the horizontal 
passage of air across its surface between the inlet and discharge ports 
657 and 658 respectively. In the illustrated embodiment, this is provided 
by means of raised segments 690 which form longitudinally extending valley 
segments 691 intermediate the raised segments along opposite surfaces of 
the solid product. As the solid product 621 is consumed by water erosion, 
it settles by gravity against partition segment 645. Measuring cavity 641 
and inlet conduit 642 form a trap-type inlet, whle solution reservoir 643, 
discharge conduit 692 and partition 659 form an inverted trap-type outlet. 
Referring to FIG. 27, a dispenser 620 containing solid product 621 is 
initially disposed, for instance, in a toilet tank (not shown) on a 
bracket or other mounting means (not shown) and the level of water 663 in 
the toilet tank is permitted to rise, as after a flush cycle. FIGS. 28-34 
illustrate a pair of consecutive flush cycles which place the dispenser 
620 in operation. In normal operation, a dose-volume of water is 
vacuum-transferred from cavity 641 and inlet conduit 642 across the 
lowermost surface of solid product 621 and into solution reservoir 643 and 
discharge conduit 692. Once the product solution reservoir 643 and 
discharge conduit 692 have been filled with product solution 662, each 
flush cycle of the toilet will cause a dose-volume of the product solution 
to issue from the dispenser 620 via the discharge standpipe 644 and outlet 
port 658. As the toilet tank refills, water rises in the discharge 
standpipe 644 and displaces air therefrom, which air exits the dispenser 
via discharge conduit 692, product solution reservoir 643, passageway 661, 
inlet conduit 642, and dose-volume measuring cavity 641 until the cavity 
641 is filled through its inlet port 657 with toilet tank water. The air 
remaining in the dispenser at that time forms an air-lock in the headspace 
600 in the uppermost regions of the solid product chamber (FIG. 32). In 
addition, an air-lock is formed in the headspace 698 adjacent the 
uppermost regions of discharge conduit 692 and discharge standpipe 644 
(FIG. 32). The air-lock formed in the headspace 698 isolates the product 
solution 662 in the reservoir 643 and discharge conduit 692 from the 
toilet tank water in the discharge standpipe 644 while the air-lock formed 
in the headspace 600 in the uppermost regions of the dispenser isolates 
the solid product 621 from the toilet tank water disposed in the inlet 
conduit 642. 
Because the volume of reservoir 643 and discharge conduit 692 are 
substantially equal to the volume of measuring cavity 641 and inlet 
conduit 642 respectively, the toilet tank water drawn across the lowermost 
surface of the solid product cake 621 during the flushing cycle is 
completely collected within the confines of reservoir 643 and discharge 
conduit 692, thereby isolating the solid product 621 from the product 
solution 662. 
In general, the functional design criteria discussed in detail with respect 
to sizing the various portions of the dispenser embodiment illustrated in 
FIG. 1, relative to one another, are likewise applicable to a dispenser 
620 of the type illustrated in FIG. 26. 
FIG. 27 depicts the condition of a dispenser 620 prior to being filled with 
water by immersion in a toilet tank. Water continues to rise, FIG. 28, 
until it flows through inlet port 657 in the back wall 623 of the 
dispenser. As water enters the dose-volume measuring cavity 641, water 
rising in the discharge standpipe 644 ceases to rise since the air is no 
longer able to vent through discharge conduit 692, reservoir 643, 
passageway 661, across the surfaces of solid product 621, down inlet 
conduit 642 and out cavity 641 to entry port 657. Because the air vent is 
closed, air is trapped in the upper reaches or headspace 600 of the solid 
product chamber as well as in product solution reservoir 643, discharge 
conduit 692 and headspace 698 adjacent the upper reaches of discharge 
conduit 692 and discharge standpipe 644. Thus, FIG. 29 represents the 
condition of the dispenser during a quiescent period awaiting the first 
flush cycle of the toilet after toilet tank water 663 has risen to a FULL 
level 675 sufficient to block the entry port 657 of the dispenser 620. 
FIG. 30 represents the condition of the dispenser 620 after the toilet has 
been flushed and the water level in the tank has begun to drop. As the 
water in the discharge standpipe 644 attempts to fall, a partial vacuum is 
created which draws water from the inlet conduit 642 and dose-volume 
measuring cavity 641 across edge 653 of partition 633 and into contact 
with the left side (as shown in FIG. 30) of solid product 621. Because the 
solid product 621 offers at least a degree of resistance to the flow of 
water coming across its lowermost surface, it is desirable that the 
uppermost edge 653 of partition 633 be sufficiently high that the 
dose-volume of water drawn from inlet conduit 642 and measuring cavity 641 
is substantially prevented from reentering inlet conduit 642 when the 
water level in measuring cavity 641 reaches the lowermost edge 652 of 
partition 633 and the partial vacuum is broken. As can be seen in FIG. 31, 
the fresh water transferred from the measuring cavity 641 and inlet 
conduit 642 slowly trickles across the base of the solid product 621 and 
dissolves the same to form a liquid solution 662. This solution enters 
reservoir 643 through passageway 661. The product solution 662 thus 
accumulated in reservoir 643 and discharge conduit 692 becomes available 
for the next flush cycle of the toilet. 
FIG. 32 depicts the condition of the dispenser 620 when it is ready to 
dispense product solution 662 contained in reservoir 643 and discharge 
conduit 692. It should be noted that the inverted trap-type outlet in the 
upper reaches of discharge conduit 692 and discharge standpipe 644 creates 
a secondary air-lock in the headspace 698 associated therewith. This 
secondary air-lock provides isolation between the product solution 662 and 
the toilet tank water 663 in discharge standpipe 644. 
FIG. 33 depicts the condition of the dispenser 620 when vacuum-transfer of 
product solution 662 contained in reservoir 643 and discharge conduit 692 
has been initiated by the falling level of toilet tank water. This 
produces a corresponding vacuum-transfer of fresh water from measuring 
cavity 641 and inlet conduit 642 across the lowermost surfaces of the 
solid product 621. When the level of water in measuring cavity 641 reaches 
the lowermost edge 652 of partition 633, FIG. 34, air is permitted to vent 
via inlet port 657, measuring cavity 641, inlet conduit 642, across the 
surface of the solid product 621, through passageway 661 and out reservoir 
643 and discharge conduit 692, thereby venting the column of toilet tank 
water 663 and product solution 662 in discharge standpipe 644. The column 
of liquid contained in discharge standpipe 644 is thereby completely 
discharged into the toilet tank. Meanwhile the fresh water solution drawn 
from measuring cavity 641 and inlet conduit 642 trickles across the 
lowermost surfaces of the solid product cake 621 and finds its way into 
reservoir 643 and discharge conduit 692 so as to be available for the next 
flush cycle. The downward slope of the product solution reservoir bottom 
wall 630 in the direction of discharge conduit 692 promotes emptying of 
the reservoir during the vacuum-transfer portion of the cycle. 
A dispenser 620 of the type generally illustrated in FIG. 26 offers 
isolation not only of the toilet tank water 663 from the solid product 621 
and the product solution 662, but also isolation between the solid product 
621 and the product solution 662 during quiescent periods. In addition, 
because the product solution 662 has already entered the discharge 
standpipe 644 when the vacuum is broken, as shown in FIG. 34, the 
discharge of product solution is very complete and very rapid. 
Furthermore, it is near the end of the flush cycle. The former feature 
provides good dispersion of the product solution 662 in the toilet tank 
water, while the latter feature ensures that more of the product solution 
dispensed during each flush cycle will be retained in the bowl after the 
flush cycle has been completed, and thus will be at a higher concentration 
than if it were dispensed during the early portions of the flush cycle. 
This is so because of the inherent operation of a flushing toilet. 
Generally all the water from the toilet tank goes through the toilet bowl. 
However, the initial portions of water are used to initiate a syphon 
action which carries away the waste material, while the latter portions 
are used to refill the toilet bowl. By dispensing the product solution 
into the latter discharged portions of the tank water a higher solution 
concentration in the toilet bowl is provided intermediate flush cycles. If 
the product solution were dispensed into the initially discharge portions 
of the toilet tank water, a large portion of the solution would be carried 
away with the waste material so that the concentration of solution 
remaining in the toilet bowl would be greatly reduced. 
The dose-volume of product solution 662 dispensed during each flush cycle 
by dispenser 620 is, essentially, the sum of the partial volumes of both 
cavity 641 and inlet conduit 642 disposed intermediate the elevation of 
edge 651 of inlet port 657 and edge 652 of partition 633. 
An exemplary embodiment of dispenser 620 has been fabricated from 1.6 
millimeter thick rigid Plexiglas (Registered Trademark of Rohm & Haas 
Company) or such. This exemplary embodiment has an overall height of about 
75 millimeters excluding the height of discharge standpipe 644 which 
extends below wall segment 630 a distance of approximately 75 millimeters, 
an overall width of approximately 125 millimeters and an overall depth of 
approximately 20 millimeters. The centrally located solid product 621 has 
a length of approximately 75 millimeters, an initial height of 
approximately 50 millimeters and a maximum depth of approximately 20 
millimeters. Edge 653 measures approximately 40 millimeters, edge 652 
approximately 64 millimeters, edge 651 of entry port 657 approximately 55 
millimeters, partition segment 647 approximately 45 millimeters, partition 
segment 645 approximately 50 millimeters, edge 660 approximately 62 
millimeters, edge 654 approximately 50 millimeters, and the uppermost 
portion of partition 659 approximately 45 millimeters from top wall 628. 
Passageway 661 measures approximately 5 millimeters by approximately 20 
millimeters. Discharge standpipe 644 has a cross-section of approximately 
8 millimeters by approximately 20 millimeters, discharge conduit 692 a 
cross-section of approximately 3 millimeters by approximately 20 
millimeters, and inlet conduit 642 a cross-section of approximately 3 
millimeters by approximately 20 millimeters. Measuring cavity 641 and 
product solution reservoir 643 each have a volume of approximately 8 cubic 
centimeters. While this exemplary embodiment of dispenser 620 was 
constructed of Plexiglas segments adhesively bonded to one another, other 
relatively rigid materials and fabrication techniques well known to those 
skilled in the art may be utilized to construct a dispenser 620 of the 
type generally illustrated in FIG. 26. 
Referring again to the Figures in which identical features are identically 
designated, FIG. 35 shows a dispenser 20' suitable for dispensing a 
surfactant containing solution in accordance with the present invention 
and containing a solid, water soluble product 21'. Dispenser 20' comprises 
a front wall 22', a back wall 23', sidewall segments 25', 26', 31', 50', 
51', 52' and 90', a top wall 28', bottom wall segments 29', 53' and 54', 
and interior partitions 32', 33', 55', 56', 57', 58', 91', 95' and 96'. 
The walls and partitions are rigid and define a primary product reservoir 
65', a secondary product reservoir 68', a solid product chamber 69', a 
syphon tube 44' having uppermost vertical passageways 85' and 86', a 
horizontal passageway 87', a vertical passageway 88' connecting with 
inlet/discharge conduit 80', said inlet/ discharge conduit having an air 
trap 81' disposed adjacent thereto, and vent means for the product chamber 
comprising passageways 71' and 72' and air vent 83'. The lowermost edge of 
partition segment 58' is designated 59', the lowermost edge of partition 
segment 96' is designated 67', the uppermost edge of partition segment 33' 
is designated 61', the lowermost edge of level control partition 32' is 
designated 62', the uppermost edge of sidewall segment 31' is designated 
93', and the lowermost edge of sidewall segment 26', which in conjunction 
with front and back walls 22' and 23' respectively and sidewall segment 
31' define air vent 83+, is designated 64'. The inlet/discharge port of 
dispenser 20' located at the lowermost end of syphon tube 44' is 
designated 78'. 
Briefly, referring to FIG. 26 and dispenser 20' containing solid product 
21' is disposed, for instance, in a toilet tank (not shown) on a bracket 
or other mounting means (not shown) so that the FULL level of water 63' in 
the toilet tank is sufficiently high to at least reach edge 64' of 
sidewall segment 26', the dispenser will respond as shown in FIGS. 36-42 
as the level of water rises to the FULL position in the toilet tank and 
the toilet is transfer flushed. 
The dispenser 20' illustrated in FIG. 35 is shown prior to immersion in the 
toilet tank water 63'. As the toilet tank water 63' rises, it enters 
syphon tube 44' through inlet/discharge port 78'. Air within the upper 
reaches of the syphon tube is allowed to vent through vertical passageways 
85' and 86', horizontal passageway 87', vertical passageway 88', inlet/ 
discharge conduit 80', primary solution reservoir 65', vent passageways 
71' and 72' and air vent 83'. As the level of the toilet tank water 63' 
continues to rise, FIG. 37, it begins to enter horizontal passageway 87'. 
Because the difference in elevation of the water in the toilet tank and 
the water within the syphon tube is relatively small prior to air vent 83' 
becoming blocked, the water head or water pressure available to force the 
water in syphon tube 44' around the loop through vertical passageway 88' 
and into inlet/discharge conduit 80' is likewise quite small. To minimize 
the required driving force to initiate water flow through the loop, the 
dispenser 20' preferably employs a series of passageways 85', 86', 87' and 
88', each of which is smaller in cross-section than any portion of the one 
immediately preceding it, thereby providing capillary suction in the 
direction of flow which tends to draw the water from the syphon tube 44' 
into the inlet/discharge conduit 80'. This feature is more clearly 
illustrated in the enlarged fragmentary view of FIG. 38. It is of course 
recognized that a maximum degree of capillary suction may be provided by 
employing passageways 86', 87' and 88' having characteristics similar to 
passageway 85' which exhibits a continual reduction in cross-section in 
the direction of liquid flow during the dispenser charging operation. If 
desired, the entire length of the syphon tube 44' may be convergent in the 
direction of water flow during the charging operation. 
Once toilet tank water 63' enters inlet/discharge conduit 80' and begins to 
collect in primary solution reservoir 65', the condition illustrated in 
FIG. 28 prevails in the air trap 81' disposed adjacent inlet/discharge 
conduit 80'. Namely, an air bubble is retained within the confines of the 
air trap 81' defined by partition segments 55', 56', 57' and 58'. The 
condition illustrated in FIG. 38 persists as long as toilet tank water 63' 
continues to enter the dispenser 20'. 
When the level 101' of solution 103' formed by dissolution of solid product 
21' in the incoming water within dispenser product chamber 69' reaches 
lowermost edge 62' of level control partition 32', an air-lock is formed 
in the uppermost reaches of the product chamber 69', thereby preventing 
the solution level 101' from rising further within the product chamber. It 
should be noted, however, that the solution level 102' in passageway 71' 
continues to rise until such time as the toilet tank water 63' contacts 
lowermost edge 64' of sidewall segment 26' and blocks air vent 83', thus 
providing a secondary air-lock in the uppermost reaches of passageway 71' 
and passageway 72'. This secondary air-lock isolates the product solution 
103' formed by a dissolution of the solid product 21' in the toilet tank 
water introduced during the charging cycle and the toilet tank water 
blocking air vent 83'. As is apparent from FIG. 39, the level 102' of 
product solution 103' within dispenser passageway 71' is identical to the 
level of toilet tank water 63' in passageway 72'. While the level 102' of 
product solution 103' in passageway 71' is distinct from the level 101' of 
the product solution within product chamber 69' due to the presence of 
level control partition 32' in the illustrated embodiment, it should be 
noted that level control partition 32' could be eliminated from the 
dispenser 20' without adversely affecting the basic functioning thereof. 
However, the level of product solution within the product chamber 69' 
would then be controlled exclusively by the vertical location of air vent 
83'. 
As is also apparent from FIG. 39, which represents the condition of the 
dispenser 20' when the toilet tank water level 75' has reached its FULL 
position, the bulk of the air bubble retained within air trap 81' during 
the charging operation has rotated about edge 59' of partition segment 58' 
so as to substantially fill horizontal passageway 87' as well as the 
uppermost portions of vertical passageways 86' and 88', thereby isolating 
the product solution 103' contained within the inlet/discharge conduit 80' 
from the toilet tank water 63' contained within passageway 86' of syphon 
tube 44'. This feature is more clearly illustrated in FIG. 40 which is an 
enlarged fragmentary view of the air trap portion of the dispenser 20' 
illustrated in FIG. 39. It is thus clear that the product solution 103' 
contained within passageway 71', product chamber 69', primary reservoir 
65' and inlet/discharge conduit 80' is completely isolated from toilet 
tank water 63' by means of the air-lock provided in the uppermost sections 
of passageways 71' and 72' and the air-lock provided in the uppermost 
sections of passageways 86', 88' and horizontal passageway 87'. As will be 
appreciated by those skilled in the art, the toilet tank water brought 
into contact with solid product 21' during the charging cycle will 
continue to dissolve the solid product until such time as the product 
solution 103' becomes saturated or until such time as the toilet is 
flushed and a predetermined quantity or dose-volume of the solution is 
dispensed. As will also be appreciated by those skilled in the art, the 
exterior surfaces of solid product 21' are preferably so configured as to 
permit a uniform degree of surface exposure to the solution 103' along the 
entire length and width of the solid product. To this end, the exterior 
surfaces of the solid product may be longitudinally grooved, etc. Uniform 
surface exposure of the solid product 21' to the solution 103' promotes 
more uniform erosion of the solid product, and thereby more uniform 
settling of the solid product into secondary solution reservoir 68'. 
FIG. 41 represents the condition of the dispenser when the toilet is 
flushed and the tank water level drops, thereby exposing air vent 83' and 
forming a partial vacuum in the syphon tube 44'. Product solution 103' is 
drawn from the primary reservoir 65' into syphon tube 44'. Transfer of 
solution 103' from the primary reservoir 65' continues until such time as 
the solution level reaches edge 67' of partition segment 96', FIG. 42, 
thereby venting syphon tube 44' and releasing the product solution 
retained therein into the toilet tank water. 
As is also apparent from FIG. 42, uppermost edge 61' of partition segment 
33' retains a portion of the concentrated product solution 103' within 
secondary reservoir 68' after the dispensing cycle has been completed. The 
solution thus retained will be available to cover rapid multiple flushes 
of the toilet. In addition, the secondary reservoir 68' serves to prevent 
the collection of a thick concentrate of solution 103' in the lowermost 
portions of primary solution reservoir 65'. When the level 75' of the 
toilet tank water 63' returns to the FULL position illustrated in FIG. 39, 
the dispenser 20' will likewise be restored to the condition illustrated 
in FIG. 39, and will remain in that condition during the ensuing quiescent 
period awaiting the next flush cycle of the toilet. 
The dispenser embodiment 20' illustrated in FIG. 35 will discharge a 
predetermined quantity or dose-volume of product solution 103' from the 
dispenser each time the toilet is flushed. The dose-volume of solution is 
substantially equal to the quantity of solution contained within dispenser 
20' between lowermost edge 62' of level control partition 32' and 
lowermost edge 67' of partition segment 96' in addition to the column of 
product solution contained within passageway 71', but exclusive of the 
quantity of solution retained within secondary solution reservoir 68'. The 
quantity of product solution 103' retained in secondary reservoir 68' in 
turn determined by the vertical location of edge 61' of partition segment 
33'. The amount of product solution 103' dispensed during each flush cycle 
is more easily understood by comparing FIG. 39 which illustrates the 
condition of the dispenser 20' when the toilet tank water level 75' is 
FULL and air vent 83' has been blocked by the water with FIG. 42 which 
illustrates the condition of the dispenser when the solution level within 
primary solution reservoir 65' has reached lowermost edge 67' of partition 
segment 96' and the dose-volume of solution within syphon tube 44' has 
been released. 
As has been pointed out earlier herein, the solid, water soluble product 
21' contained in product chamber 69' will dissolve in the water introduced 
during each flush cycle to form product solution 103' until such time as 
the solution becomes saturated or the toilet is again flushed. As the 
lower portions of the solid product 21' are consumed by exposure to the 
liquid, the solid product will settle due to gravity into the secondary 
reservoir 68' contained within product chamber 69'. Because the volume and 
exposed surface area of solid product 21' below edge 62' of level control 
partition 32' remain essentially constant throughout the life of the solid 
product, the strength or concentration of the solution 103' remains 
essentially constant throughout the life of the dispenser 20', assuming an 
adequately long quiescent period for the solution to become saturated is 
provided intermediate flush cycles. This condition will prevail at least 
until such time as the overall height of the solid product 21' becomes 
less than the vertical distance between lowermost edge 62' of level 
control partition 32' and bottom wall segment 29' of the dispenser. 
While the dispenser embodiment illustrated in FIG. 35 incorporates a 
preferred air trap 81' disposed adjacent the inlet/discharge conduit 80', 
the air trap utilized to retain an air bubble during the water charging 
operation may take many different forms. For example, a sudden expansion 
in cross-section flow area could be provided in vertical inlet passageway 
88' followed immediately by a sudden contraction in flow area such that 
fluid entering the primary reservoir 65' through the inlet/discharge 
conduit 80' is unable to exert sufficient force on the air bubble trapped 
within the expanded flow area to expel it through the primary reservoir 
65' and out, the air vent 83'. Alternatively, the air trap could take the 
form of a partial obstruction in inlet/discharge conduit 80', which 
partial obstruction prevents fluid passing through the conduit from 
exerting sufficient force on the air bubble retained within the trap from 
being expelled through the primary reservoir 65' and out the air vent 83'. 
It is necessary only that the air trap be of sufficient volume and so 
located that upon cessation of the flow of water past the air trap the air 
bubble contained therein will attempt to rise into the uppermost reaches 
of the chamber connecting the syphon tube and the inlet/discharge conduit 
so as to completely isolate the toilet tank water 63' in the syphon tube 
from the product solution 103' contained in the inlet/discharge conduit. 
FIG. 43 is a fragmentary sectional view of an alternative embodiment of a 
dispenser 320 suitable for dispensing a surfactant containing solution in 
accordance with the present invention shown during the water charging 
operation as the level 375 of water 363 in the toilet tank is rising. The 
dispenser 320 is basically similar to the dispenser 20' illustrated in 
FIG. 35. The illustrated portions of dispenser 320 comprise top wall 328, 
bottom wall segments 329, 353, 354, and 355, sidewall segments 326, 331, 
350 and 351, interior level control partition 332, interior partition 395 
forming air trap 381 and interior partition segment 396 which in 
conjunction with the uppermost portion of wall segment 350 forms 
inlet/discharge conduit 380. As with the embodiment of FIG. 35, a solid, 
water soluble product 321 is disposed within product chamber 369 such that 
its lowermost surface rests within secondary solution reservoir 368 
defined by interior partition segment 333 having uppermost edge 361. The 
lowermost edge of level control partition 332 is designated 362, the 
uppermost edge of wall segment 331 is designated 393, the lowermost edge 
of sidewall segment 326 is designated 364, the uppermost edge of sidewall 
segment 350 is designated 359 and the lowermost edge of partition segment 
396 is designated 367. Product chamber 369 and primary solution reservoir 
365 are initially vented by means of passageways 371 and 372 and air vent 
383 defined by edge 364 of sidewall segment 326, the front and back wall 
portions (not shown) of dispenser 320 and sidewall segment 331. Syphon 
tube 344 is defined by sidwall segments 350, 351 and 390 as well as the 
corresponding front and back wall portions (not shown) of dispenser 320. 
The inlet/discharge port located at the lowermost end of syphon tube 344 
is designated 378. As with the embodiment illustrated in FIG. 35, the 
uppermost portions of the syphon tube are convergent, i.e., the radial 
distance from uppermost edge 359 of sidewall segment 350 to sidewall 
segment 390 and to interior partition 395 continually decreases in the 
direction of liquid flow, at least until the point of vertical alignment 
with sidewall segment 350. The air trap 381 formed by interior partition 
395 is located adjacent the entrance to inlet/discharge conduit 380. 
In the condition illustrated in FIG. 43, the toilet tank water 363 has 
risen sufficiently in syphon tube 344 to trap an air bubble within air 
trap 381 as it proceeds to fill primary solution reservoir 365 and the 
lowermost portions of produce chamber 369. As long as the water continues 
to flow within the syphon tube and inlet/discharge conduit, the trapped 
air bubble will remain within the confines of the air trap 381. When, 
however, air vent 383 is blocked by the rising toilet tank water 363 as 
shown in FIG. 44, fluid flow in the inlet/discharge conduit 380 ceases, 
and the trapped air bubble rises, thereby providing air-lock isolation of 
the product solution 303 and the toilet tank water 363 on opposite sides 
of edge 359 of sidewall segment 350. The product solution 303 at level 302 
within passageway 371 is likewise isolated from the toilet tank water by 
means of the air-lock contained in the uppermost reaches of passageways 
371 and 372. The level 301 of product solution 303 within dispenser 320 is 
defined by lowermost edge 362 of level control partition 332 in a manner 
similar to that described in connection with embodiment 20' of FIG. 35. 
When the toilet is flushed, dispenser embodiment 320 reacts in a manner 
similar to embodiment 20' described in connection with FIG. 35. When the 
level of solution in primary reservoir 365 reaches lowermost edges 367 of 
partition segment 396, the column of liquid retained within syphon tube 
344 is vented, thereby dispensing a predetermined quantity of product 
solution 303 into the toilet tank through inlet/discharge port 378. 
While the exemplary embodiments of dispensers 20' and 320 may be 
constructed by adhesively securing sections of relatively rigid Plexiglass 
(Registered Trademark of Rohm & Haas Company) to one another, other 
relatively rigid materials which are substantially inert with respect to 
the intended product and aqueous solutions thereof can be used to 
construct the dispensers. Furthermore, the dispensers may be constructed 
or formed at high speed and relatively low cost utilizing various 
manufacturing techniques well known in the art. For example, the 
dispensers could be vacuum thermoformed in two sections of a material such 
as polyvinyl chloride having an initial thickness of about 0.020 inches, 
the solid, water soluble product inserted therebetween and the two 
sections thereafter secured to one another as by heat sealing, adhesives, 
etc. along a line of contact substantially coinciding with the location of 
section line 36--36 of FIG. 35. 
In a particularly preferred embodiment of the present invention, a passive 
dosing dispenser of the type generally illustrated in FIG. 1 or FIG. 12 is 
utilized to dispense a predetermined quantity of disinfectant containing 
solution, while a passive dosing dispenser as generally illustrated in 
FIG. 26 or as generally illustrated in FIG. 35 or FIG. 43 is utilized to 
simultaneously dispense a predetermined quantity of surfactant containing 
solution. While such dispensing embodiments may, if desired, be integrally 
combined with one another as generally indicated in FIGS. 10 and 11, in a 
preferred embodiment the front and back sections for a dual dispensing 
apparatus are vacuum thermoformed from sheets of material such as 0.015 
inch thick polyvinyl chloride, the disinfectant containing cake and the 
surfactant containing cake are inserted intermediate the two vacuum 
thermoformed sections as generally outlined in the aforementioned patent 
applications of Robert S. Dirksing, and the two sections are thereafter 
secured to one another as by heat sealing, adhesives, etc. to form an 
integral dual dispenser. In a particularly preferred embodiment, the dual 
dispenser is so configured that the surfactant containing cake is located 
vertically overhead the disinfectant containing cake. The integral dual 
dispenser unit is preferably equipped with adjustable hanger means for 
properly positioning the apparatus relative to the FULL level of the water 
contained in the toilet tank. If desired, closure means in the form of a 
suitable cover, pressure sensitive adhesive tapes, or the like may also be 
provided with the dual dispenser to seal the entry and discharge ports of 
the dispensing apparatus upon disposal to prevent adverse chemical 
reactions from occurring once the dispensing apparatus has been removed 
from the toilet tank for disposal. 
To demostrate the effectiveness of the cleansing and disinfecting method 
described herein, an exemplary embodiment of a dual dispensing apparatus 
was constructed and subjected to testing. 
A solid, compacted disinfectant containing cake was prepared by mixing 
LiOCl (Form 2), as available from Lithium Corporation of America, Bessemer 
City, North Carolina, with HTH [65% Ca(CoCl).sub.2 ] NaCl and Na.sub.2 
SO.sub.4 in the proportions hereinafter set forth and subjecting the 
granular mixture to a compaction pressure of about 2.5 tons per square 
inch on a Stokes Model R Tablet Press: 
______________________________________ 
Ingredient Grams 
______________________________________ 
LiOCl (Form 2) 27.2 
HTH [65% Ca(OCl).sub.2 ] 
43.9 
NaCl 21.7 
Na.sub.2 SO.sub.4 7.2 
100.0 
______________________________________ 
This composition had a LiOCl:Ca(OCl).sub.2 weight ratio of about 0.29:1, 
and an available chlorine level (AvCl.sub.2) of about 38% to 39%. The cake 
had a specific gravity of about 1.7, and dimensions of about 3.5 inches by 
about 2 inches by about 0.5 inches. 
A solid, compacted surfactant containing cake was prepared by mixing the 
ingredients hereinafter set forth in a batch amalgamator, followed by 
milling and then extrusion to form a rectangular slab having dimensions of 
about 3.625 inches in width by about 2.125 inches in height by about 0.5 
inches thick: 
______________________________________ 
Ingredient Grams 
______________________________________ 
Sodium paraffin sulfonate 
52.2 
(Hostapur, approximately 
84% active, as available 
from American Hoechst, 
Somerville, N.J.) 
Acid Green 2G (as available 
3.7 
from Sandoz, Hanover, 
N.J.) 
NaBr 1.9 
Perfume 7.2 
65.0 
______________________________________ 
The surfactant containing cake was thereafter coated with talcum powder to 
prevent it from sticking to the sides of the dispensing apparatus. 
The solid disinfectant containing and surfactant containing cakes were 
incorporated in a dual compartment dispenser vacuum thermoformed in two 
segments from 0.015 inch thick polyvinyl chloride. The configuration of 
the integrally formed dual compartment dispenser was such that the 
surfactant containing cake was placed vertically overhead the disinfectant 
containing cake. The portion of the dispensing apparatus housing the 
surfactant containing cake was of a configuration generally similar to 
those described in connection with FIGS. 35 and 43, while the portion of 
the dispensing apparatus housing the disinfectant containing tablet was of 
a configuration generally similar to that described in connection with 
FIG. 12. The measuring cavity and inlet conduit of the disinfectant 
containing portion of the dual dispenser was so sized that approximately 
12 cubic centimeters of disinfectant containing solution was dispensed 
with each flush cycle of the toilet. The surfactant containing portion of 
the dispenser were so sized that approximately two cubic centimeters of 
surfactant containing solution was dispensed with each flush cycle of the 
toilet. 
The aforedescribed exemplary embodiment of a dual dispenser for carrying 
out the cleansing and disinfecting method of the present invention 
provided an excellent release of both the disinfectant containing solution 
and the surfactant containing solution throughout the life of the unit. In 
order to ascertain the effective life of the co-dispensing operation, the 
reaction of the hypochlorite contained in the disinfectant containing 
solution with the dye contained in the surfactant containing solution was 
observed in the toilet bowl. When both chemicals are present in the water 
at the same time, the color is bleached from the dye, thereby causing the 
water to change from a blue-green tint to colorless within a few minutes. 
The presence of this reaction serves as an indicator that both portions of 
the dispensing apparatus are functioning in the intended manner. 
Accordingly, when no color is visibly delivered to the toilet bowl, or 
when the color delivered is not dissipated shortly thereafter, the 
dispenser is in need of replacement. It should of course be recognized 
that several flushes of the toilet will normally be required to fill the 
solution reservoir in the disinfectant containing portion of the dispenser 
when the dispenser is initially placed in service. During this limited 
period, the aforementioned hypochlorite-dye reaction will not be present 
due to the lack of disinfectant containing solution in the water. 
While the life of the aforedescribed exemplary dispenser will vary 
depending upon the water temperature involved due to the effect of 
temperature on dissolution of this particular surfactant containing cake, 
it is anticipated that in 70.degree. F. tank water the dual dispenser 
embodiment described above will provide effective cleansing and 
disinfecting for approximately 400 flush cycles of a toilet, while in 
40.degree. F. tank water approximately 700 flush cycles are anticipated. 
Depending upon such variables as frequency of flushing, number of 
occupants in the home, etc., this typically provides a useful life ranging 
from approximately 2 to approximately 8 weeks in the home environment. 
As has been pointed out earlier herein, by appropriate sizing of the 
surfactant containing and disinfectant containing cakes, dual dispensing 
apparatus of the present invention can be provided so that both cakes are 
substantially consumed at about the same point in time, thereby minimizing 
waste of either component. 
While particular embodiments of the present invention have been described, 
it will be obvious to those skilled in the art that various changes and 
modifications can be made without departing from the spirit and scope of 
the invention and it is intended to cover, in the appended claims, all 
such modifications that are within the scope of this invention.