A process is provided for the manufacturing of machine parts wherein a concrete polymer including a filler mixture formed of rock particles and a binding agent matrix is employed. It is provided that as the fine part of the filler mixture, particles are used that are made of mechanically resistant materials having a modulus of elasticity that is higher than the rock. It is also provided that essentially cubic broken rock particles are used and that the mixture of rock and fine particles and the binding agent system is condensed in a casting mold in such a way that as many of the adjacent particles as possible contact one another.

The present invention relates to a process for the manufacturing of articles, particularly of machine parts, such as engine beds, machine tool tables, measuring tables or similar objects made of concrete polymer and articles made by each such process, wherein a filler mixture of rock particles is mixed with a system of binding agents consisting of resin, hardeners and admixtures. The filler mixture and binding agent system are filled into a casting mold and condensed. Particles broken from rocks of a high hardness in a mixing ratio defined by a particle-size distribution curve are employed, and a binding agent system is used which, in its liquid state, wets the particles and causes a lubricating effect during the condensing.
In the case of a known processes disclosed in the publication "PLEXILITH MA-Beton Konstruktionsteile" of Rohm Gmbh, Darmstadt, rock particles are coated with a binding agent in order to achieve good cohesion. The mechanical stability and the modulus of elasticity of this type of concrete polymer are influenced considerably by the binding agent. Difficulties occur with respect to the long term behavior, particularly with respect to creep stability because stabilization occurs only after a long period of time, e.g. after a period of more than 100 days.
It has also been pointed out in a lecture (H. Tanner, Fritz Studer AG, "The Use of Concrete Polymer in Machine Tool Building", Mar. 18, 1983, Regensdorf-Zurich) that it is to be endeavored that the forces stressing an engine bed are, if possible, all to be transmitted in form closure by the rock. A binding agent system is to be used which causes a lubricating effect for the rock particles during the processing and during the condensing. In this lecture, it was also pointed out that the rock particles of the different grain sizes, the ratio of mixture of which is defined by a particle-size distribution curve, should not be weakened by microcracks. When selecting the rock, it should not be taken into account that rocks are used that have a high stability as well as a high density and a structure that, if possible, has no direction. It was stated that deep-seated rock is preferred, such as basalt, flint, gabbro, greenstone, diabase and diorite. It was also pointed out that the break structure of the surfaces and the shaping of the rock are of considerable significance.
An objective of the present invention is the provision of a process of the initially mentioned type by means of which articles, particularly machine parts, can be manufactured that have a higher stability as well as a good long term behavior and good creep stability.
Another objective of the present invention is the provision of articles made from concrete polymer mixtures which exhibit high stability, great strength and good long term creep resistance.
These and other objectives of the present invention are attained by the provision of a process wherein particles of mechanically resistant substances that have a higher modulus of elasticity than the rock are employed as the fine part of the filler mixture. Essentially cubic broken rock particles are used and the mixture of rock and fine particles and a binding agent system is condensed in the casting mold in such a way that as many as possible of the adjacent particles touch one another. In this manner, the binding agent system is at least partially displaced between the particles and is driven into hollow spaces between the particles and the exterior side.
By means of this process, machine parts can be made of concrete polymer which in their characteristics are influenced only relatively little by the binding agent. By the use of a fine part for the filler mixture that is made of mechanically resistant substances, the mechanical characteristics and particularly the modulus of elasticity and the stability can be improved significantly, since up to now, the fine part was responsible to a considerable degree for a lowering of these values. A concrete polymer of this type has characteristics that come very close to the characteristics of natural rock, and even results in certain improvements. Since the rock particles and the fine particles consisting of mechanically resistance materials rest directly against one another and support each other, applied forces are transmitted directly via the particles. The use of particles that are as cubic as possible is a considerable advantage since particles of this shape can advantageously be fitted together to a tight packing and make possible a planar contact with one another. In this case, it is also advantageous that the particles have serrated or fluted surfaces of fracture because they can then hook one another so that they can also transmit forces that are not aimed vertically to the surfaces located on one another. The particles hook into one another so that they can also no longer be slid with respect to one another. By means of the direct transmitting of applied forces between the particles made of rock and also of mechanically resistant material, while largely avoiding the binding agent, there is also almost no contracting at the dimensions of the machine parts during the hardening. The long term behavior and especially the creep stability are significantly improved.
Since very fine particles, particularly meal grain, negatively influence the creep stability and also the modulus of elasticity of the components made of concrete polymer, the proportion of the fine particles should be kept as low as possible. In a further development of the invention, it is therefore provided that the particle-size distribution curve for the ratio of mixture of the grain sizes of the rock particles is determined by tests in which test specimens are subjected to a creep test, after which, depending on the results, the proportion of very fine particles is determined. This determination takes place in such a way that on the one hand, an inadmissible creep is excluded while, on the other hand, the occurrence of hollow spaces exceeding the size of individual pores is avoided.
In a further development of the invention, rock particles made of a mechanically resistant material are used, the grain of which is larger than 1 mm. It was found that for achieving a significant improvement of the stability and of the modulus of elasticity of concrete polymer it is sufficient to provide the fine proportion up to about a grain of 1 mm of particles made of a mechanically resistant material.
In a further development of the invention, it is provided that as the fine part, particles are provided that are made of a compound selected from the group comprising aluminum oxide, silicon carbide, silicon nitride or quartz or of a mixture of these materials. These materials, on the one hand, have a very high modulus of elasticity which is even far greater than the values for steel. On the other hand, however, they are materials that are available in a sufficient quantity at a reasonable price so that, as a result, the production as a whole does not become more expensive.
The overall result is the important advantage that in the case of machine parts manufactured according to the invention, a decrease of the wall thicknesses or other dimensions is possible while, by means of the fine portion of a mechanically resistant material, the stability characteristics are clearly improved.
In a further development of the invention, it is provided that a binding agent system is used that in the liquid state has a viscosity of about 100 to 300 mPa sec. A binding agent system is suitable, for example, that consists of a biphenolic-A-epoxy resin with a hardener made of aliphatic polyamines. This bindinq agent on the one hand, has such a viscosity that it permits the rock particles to relatively easily slide into the position corresponding to the largest packing density while, on the other hand, it can just as easily be displaced between the particles. Naturally, the binding agent system must be adjusted in such a way that it does not reach its gelling point before the end of a final condensation. In practice, it was found to be advantageous when the binding agent is adjusted in such a way that the gelling point is reached after about two to three hours.
Before making concrete polymer, a suitable type of rock has to be selected. This selection is made with a view to the desired characteristics of the finished components made of concrete polymer, i.e., particularly with a view to maximum stability and a maximum modulus of elasticity. The modulus of elasticity of the rock should be above 35,000 N/mm.sup.2. Since the rock particles in the finished component made of concrete polymer are to transmit the applied forces directly among one another, they should, if possible, have no microcracks. A selection of the rock type therefore is made according to the geological origin of the rock. Deep-seated rock, such as basalt, flint, gabbro, greenstone, diabase or diorite which during their formative history were subjected to no folding or similar process so that the danger of microcracks is relatively small are preferred rocktypes. The presence of microcracks is examined by means of specimens. When the rock is selected, an analysis of the composition of the rock is also carried out as well as an examination with respect to physical and mechanical characteristics. For example, the specific weight, the thermal conductivity, the thermal coefficient of expansion, or similar characteristics as well as the modulus of elasticity and the tensile strength are tested.
After the selection of the rock type on the basis of the above-explained criteria, the rock is crushed. After the crushing, another test will take place as to whether the rock is suitable to be used for a concrete polymer in which case also at the same time the quality of the crushing is examined by a checking for microcracks. After the crushing, the shape of the broken rock particles is tested also. The rock particles are to have a particle shape that is as cubic as possible, in which case an admissible edge length ratio of about 1:1.4 is determined. The maximum allowable proportion of grains having unsuitable shapes and curves is less than 30% (by number). When the thus defined cubic shape is not obtained, the selected rock is not suitable for the manufacturing of a concrete polymer of the desired quality.
Together with cleaning and drying, the rock particles are sorted by sifting, namely ranging from meal grain (about 4 microns) to coarse grain (16 mm and larger). The sorting takes place in at least five steps. The sorted rock particles having a grain size starting at about 1 mm are filled into containers or receptacles corresponding to their grain size. From these receptacles or containers, the rock particles of the various grain sizes are taken in amounts which, according to a particle size distribution curve that was determined previously for each rock type, are added together in a defined ratio of mixture. It will be explained later how the particle size distribution curve is determined.
The fine particles, i.e., rock particles up to a size of about 1 mm, are not used. Instead, particles of a mechanically resistant material are used, i.e., of a material that has a higher modulus of elasticity and also a higher tensile strength than the rock. Preferably aluminum oxide, silicon carbide, silicon nitride or quartz are each provided alone or in mixtures as the mechanically resistant material. These mechanically resistant materials can be made available in sufficiently large quantities at a reasonable price. Metals may also be provided as mechanically resistant materials, such as steel or gray cast iron particles by means of which an improvement of the characteristics of the concrete polymer can also be achieved. Such metallic materials should, however, only be used when it is known that the machine parts made of concrete polymer are subjected to no significant thermal stress. Otherwise, particularly as a result of different thermal expansions, damage may arise in the concrete polymer. The mentioned materials, in addition, as compared to metals, have the advantage that their modulus of elasticity is at least twice as high as the modulus of elasticity of steel, so that the desired effect can be realized to a greater degree.
Further objects, features, and advantages of the present invention will become more apparent from the following description when taken with the accompanying drawings(s) which show, for purposes of illustration only, an embodiment/several embodiments in accordance with the present invention.

Polymer concrete articles and process for manufacturing same


A modified aluminosilicate in powder form comprising alkali metal silicate deposited onto aluminosilicate of the zeolite P type particles presents increased Liquid Carrying Capacity.

The present invention relates to a modified aluminosilicate and more specifically to a modified aluminosilicate of the zeolite P type particularly useful in detergent compositions.
The usefulness of zeolite P in detergent formulations has been acknowledged, for example in European Patent Application 0384070 (Unilever).
The zeolite P class includes a series of synthetic zeolite phases which may be in cubic configuration (also termed B or Pc) or tetragonal configuration (also termed P1) but is not limited to these forms. The structure and characteristics of the zeolite P class are given in xe2x80x9cZeolite Molecular Sievesxe2x80x9d of Donald W Breck (published 1974 and 1984 by Robert E Krieger of Florida USA). The zeolite P class has the typical oxide formula:
M{fraction (2/n)}O. Al2O3. 1.80-5.00 SiO2. 5H2O
M is an n-valent cation which for this invention is an alkali-metal, that is lithium, potassium, sodium, cesium or rubidium with sodium and potassium being preferred and sodium being the cation normally used in commercial processes.
Thus sodium may be present as the major cation with another alkali metal present in a minor proportion to provide a specific benefit.
Now, zeolites used in detergents compositions must, on top of their detergent characteristics such as Calcium Binding Capacity, Calcium Effective Binding Capacity and Calcium uptake rate, exhibit other characteristics which render them usable as builders in concentrated detergents compositions.
The ability for a builder to be used in such concentrated formulations relates directly to its Liquid Carrying Capacity also referred to as Oil Absorption. The higher the Liquid Carrying Capacity the more concentrated can be the detergents composition.
Moreover, whereas in the past powder detergents composition were produced by spray drying, a new manufacturing processes, known as non spray drying processes, have been proposed. In these processes, the Liquid Carrying Capacity of the builder is of even greater importance.
Now, it is known that, depending on the drying conditions, the Liquid Carrying Capacity of certain products can vary within a great range. For example, the zeolite P disclosed in EP-B-0384070 can have, depending on its drying conditions, a Liquid Carrying Capacity of from 50-65% to 100-110%, the lower values being reached with industrial drying conditions such as spray drying, turbo drying, flash drying or flash-ring drying.
Therefore, even though the Liquid Carrying Capacity of the zeolite P disclosed in EP-B-0384070 already enables it to be used as a builder in concentrated detergent compositions, there is nevertheless a need for increasing even more the Liquid Carrying Capacity in case of industrial drying conditions.
In other respects, even though the addition of silicates in detergents compositions is particularly useful to avoid corrosion, to improve bleach stability in the wash and to act as an anti-redeposition agent, its use in detergent compositions has dramatically decreased for a series of reasons.
First of all, the major detergent compositions are still using zeolite A (such as Doucil P, obtainable from Crosfield ltd.) as their builder. Now, it is known that when drying together zeolite A and silicate, large lumps of insoluble materials are formed something which gives rise to residues on the fabrics.
Secondly, sodium silicates with a SiO2:Na2O molar ratio of between 1.6 and 3.2 are being avoided for safety reasons since they are classified as irritant due to their alkalinity. Silicates with a ratio of 3.3 or above are safe but do not dissolve easily and with a ratio of below 1.6 they are corrosive. Therefore there is a need for a new way to introduce alkali metal silicate in detergent compositions which obviate the above mentioned problems.
Now, it has been found that a specific combination of aluminosilicates of the zeolite P type and alkali metal silicate can, on the one hand dramatically increase the Liquid Carrying Capacity of the zeolite while, on the other hand, leading to a product which is no longer irritant and does not contribute significantly to the occurrence of residues on fabrics.
Tests and Definitions
i) Average weight particle size, d50
The quantity xe2x80x9cd50xe2x80x9d indicates that 50% by weight of the particles have a diameter smaller than that figure, and may be measured using a Sedigraph (Trade Mark), type 5100, ex Micromeritics.
ii) pH
pH measurements were performed by making a 5% dispersion of zeolite (dry solids basis) in demineralised water, followed by measurement with a Orion EA940 ion analyzer, using a Orion 9173b pH-electrode.
iii) CEBC (Calcium Effective Binding Capacity)
The CEBC was measured in the presence of a background electrolyte to provide a realistic indicator of calcium ion uptake in a wash liquor environment. A sample of each zeolite was first equilibrated to constant weight over a saturated sodium chloride solution and the water content measured. Each equilibrated sample was dispersed in water (1 cm3) in an amount corresponding to 1 g dmxe2x88x923 (dry), and the resulting dispersion (1 cm3) was injected into a stirred solution, consisting of 0.01 M NaCl solution (50 cm3) and 0.05M CaCl2 (3.923 cm3), therefore producing a solution of total volume 54.923 cm3. This corresponded to a concentration of 200 mg CaO per liter, i.e. just greater than the theoretical maximum amount (197 mg) that can be taken up by a zeolite of Si:Al ratio 1.00. The change in Ca2+ ion concentration was measured by using a Ca2+ ion selective electrode, the final reading being taken after 15 minutes. The temperature was maintained at 25xc2x0 C. throughout. The Ca2+ ion concentration measured was subtracted from the initial concentration, to give the effective calcium binding capacity of the zeolite sample as mg CaO/g zeolite (on dry basis).
iv) LCC (Liquid Carrying Capacity
This was determined on the basis of the ASTM spatula rub-out method (American of Test Material Standards D281). The test is based on the principle of mixing nonionic (Synperonic A3, available from ICI) with the particulate zeolite by rubbing with a spatula on a smooth surface until a stiff putty like paste is formed which will not break or separate when it is cut with the spatula. The weight of nonionic used is then put into the equation:                     LCC        =                                            g                                            xe2x80x83                                          nonionic                                            xe2x80x83                                          absorbed                                      wt                                            xe2x80x83                                          of                                            xe2x80x83                                          zeolite                                            xe2x80x83                                                          (                gms                )                                              xc3x97          100                                        =                  g                                xe2x80x83                                          nonionic            /            100                                          xe2x80x83                              g                                xe2x80x83                              zeolite
v) Grit
Grit is defined here as the percentage of particles which are left behind on a 45 xcexcm sieve. Zeolite is slurried with water in a beaker, ultrasonically treated for 15 minutes and next placed in the sieving machine (Mocker). This machine is subsequently flushed with water (water pressure 4 bar) for a certain period of time.
The sieve is removed from the machine and dried in an oven (90xc2x0 C., 15 min.) and the amount of residue determined.       grit              xe2x80x83                  (      %      )        =      residue          wt                    xe2x80x83                  of                    xe2x80x83                  zeolite                    xe2x80x83                          (                  dry                                xe2x80x83                              basis                )
General Description of the Invention
It is a first object of the present invention to provide a modified aluminosilicate in powder form comprising alkali metal silicate deposited onto aluminosilicate of the zeolite P type particles.
Preferably, the aluminosilicate of the zeolite P type has a silicon to aluminium ratio not greater than 1.33, preferably not greater than 1.07. Preferably also it has a Calcium Effective Binding Capacity of at least 140 mg CaO/g zeolite (on dry basis).
By having the alkali metal silicate deposited onto the aluminosilicate, a completely homogeneous mixture of the two products is achieved something which means that, when introduced into a detergent composition the two products are evenly distributed and that there is no local variation in the aluminosilicate/alkali metal silicate weight ratio in the detergent composition.
The modified aluminosilicate according to the present invention has a pH of between 10 and 12. This relatively low alkalinity renders the product not irritant. Moreover, the fact that the alkali metal silicate and the aluminosilicate are evenly distributed means, particularly, that no pH variation can occur due to local variation in the aluminosilicate/alkali metal silicate weight ratio something which renders the modified aluminosilicate according to the present invention particularly safe.
Typically, the modified aluminosilicate in powder form according to the present invention contains 0% to 25% water, preferably not more than 12% by weight.
Preferably, the modified aluminosilicate comprises 65 to 90%, preferably 70 to 87%, most preferably 75 to 85% by weight (on dry basis) of aluminosilicate of the zeolite P type and 1 to 20%, preferably 3 to 15%, most preferably 5 to 10% by weight (on dry basis) of alkali metal silicate. More preferably the (aluminosilicate of the zeolite P type/alkali metal silicate) weight ratio is within the range of 100/20 to 100/1, preferably 100/15 to 100/3, more preferably 100/10 to 100/5.
Also preferably, the alkali metal silicate is sodium silicate having a SiO2:Na2O molar ratio of between 1.6 and 4.
Preferably also the modified aluminosilicate according to the present invention has an average weight particle size of 1 xcexcm to 10 xcexcm, preferably between 1.5 xcexcm and 6 xcexcm, more preferably between 2.5 xcexcm and 5 xcexcm. Such a particle size distribution contributes to the avoidance of residues on fabrics.
The modified aluminosilicate according to the present invention exhibits good detergent characteristics, the CEBC being typically between 110 and 160 mg CaO/g modified aluminosilicate (on dry basis), more preferably between 130 and 155 mg CaO/g modified aluminosilicate (on dry basis).
Various other additives can be added to the modified aluminosilicate of the invention and it can further contain an effective amount of additive selected from the group consisting of phosphonates, amino carboxylates, polycarboxylates, citrates, and mixtures thereof, usually at levels from 0.3% to 5.0% by weight of said modified aluminosilicate (on dry basis).
The modified aluminosilicate according to the present invention can be further granulated according to standard granulating/agglomerating processes.
It is a second object of the present invention to provide a process for the production of a modified aluminosilicate wherein to a slurry of aluminosilicate of the zeolite P type, containing 20 to 46% solids, more preferably 30-40% solids, is added an alkali metal silicate, the resulting mixture being further dried.
Preferably, the alkali metal silicate is sodium silicate having a SiO2:Na2O molar ratio of between 1.6 and 4.
Preferably also, alkali metal silicate is added as a solution but could also be in powder form.
Preferably the alkali metal silicate solution is added to a slurry of undried zeolite P obtained for example as in example 11 of EP-A-565,364. By undried zeolite P, it is understood a zeolite P as obtained after washing and filtering but before drying.
It has been noted that, when fast drying the filter cake obtained in the process disclosed in EP-A-565,364, the average particle size of the zeolite P decreases from about 3 xcexcm to about 1 xcexcm. Now, if at least 3-4% sodium silicate is added before drying, the average particle size of the product remains unchanged. This behaviour leads to the surprising result that, with a higher particle size, the Liquid Carrying Capacity of the end product (modified alumino silicate of the invention) is increased whereas all the prior art teaches that Liquid Carrying Capacity is increased when particle size is decreased.
Upon milling of this material, the Liquid Carrying Capacity of the modified aluminosilicate according to the present invention can be reduced.
Preferably, carbon dioxide is introduced during the drying process. By doing so, the alkali metal silicate is, at least partially, neutralized.
The modified aluminosilicate according to the present invention may be incorporated in detergent compositions of all physical types, for example, powders, liquids, gels and solid bars, at the levels normally used for detergency builders.
The modified aluminosilicate material of the invention may be used as a sole detergency builder, or it may be used in conjunction with other builder materials such zeolite A or zeolite P. As well as the crystalline aluminosilicate builders already mentioned, other inorganic or organic builders may be present. Inorganic builders that may be present include sodium carbonate, amorphous aluminosilicates, and phosphate builders, for example, sodium orthophosphate, pyrophosphate and tripolyphosphate.
The total amount of detergency builder in the composition will suitably range from 20 to 80% by weight, and this may be constituted wholly or partially by the modified aluminosilicate material of the invention. The modified aluminosilicate material of the invention may if desired be used in combination with other aluminosilicates, for example, zeolite A. The total amount of aluminosilicate material in the composition may, for example, range from about 5 to 80% by weight preferably from 10 to 60% by weight.
Organic builders that may additionally be present include polycarboxylate polymers such as polyacrylates and acrylic/maleic copolymers; monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, glycerol mono-, di- and trisuccinates, carboxymethyloxysuccinates, carboxymethyloxymalonates, dipicolinates, hydroxyethyliminodiacetates, alkyl- and alkenylmalonates and succinates; and sulphonated fatty acid salts.
Especially preferred organic builders are citrates, suitably used in amounts of from 5 to 30 wt %, preferably from 10 to 25 wt %; and acrylic polymers, more especially acrylic/maleic copolymers, suitably used in amounts of from 0.5 to 15 wt %, preferably from 1 to 10 wt %.
Builders, both inorganic and organic, are preferably present in alkali metal salt, especially sodium salt, form.
The modified aluminosilicate of the invention is of especial applicability to detergent compositions containing no, or reduced levels of, inorganic phosphate builders such as sodium tripolyphosphate, orthophosphate and pyrophosphate.
Detergent compositions containing the modified aluminosilicate of the invention will also contain, as essential ingredients, one or more detergent-active compounds which may be chosen from soap and non-soap anionic, cationic, nonionic, amphoteric and zwitterionic detergent-active compounds, and mixtures thereof. Many suitable detergent-active compounds are available and are fully described in the literature, for example, in xe2x80x9cSurface-Active Agents and Detergentsxe2x80x9d, Volumes I and II, by Schwartz, Perry and Berch.
The preferred detergent-active compounds that can be used are soaps and synthetic non-soap anionic and nonionic compounds.
Anionic surfactants are well-known to those skilled in the art. Examples include alkylbenzene sulphonates, particularly linear alkylbenzene sulphonates having an alkyl chain length of C8-C15; primary and secondary alkylsulphates, particularly C8-C15 primary alkyl sulphates; alkyl ether sulphates; olefin sulphonates; alkyl xylene sulphonates; dialkyl sulphosuccinates; and fatty acid ester sulphonates. Sodium salts are generally preferred.
Nonionic surfactants that may be used include the primary and secondary alcohol ethoxylates, especially the C8-C20 aliphatic alcohols ethoxylated with an average of from 1 to 20 moles of ethylene oxide per mole of alcohol, and more especially the C10-C15 primary and secondary aliphatic alcohols ethoxylated with an average of from 1 to 10 moles of ethylene oxide per mole of alcohol. Non-ethoxylated nonionic surfactants include alkylpolyglycosides, glycerol monoethers, and polyhydroxyamides (glucamide).
The choice of detergent-active compound (surfactant), and the amount present, will depend on the intended use of the detergent composition. For example, for machine dishwashing a relatively low level of a low-foaming nonionic surfactant is generally preferred. In fabric washing compositions, different surfactant systems may be chosen, as is well known to the skilled formulator, for handwashing products and for products intended for use in different types of washing machine.
The total amount of surfactant present will also depend on the intended end use and may be as low as 0.5 wt %, for example, in a machine dishwashing composition, or as high as 60 wt %, for example, in a composition for washing fabrics by hand. In compositions for machine washing of fabrics, an amount of from 5 to 40 wt % is generally appropriate.
Detergent compositions suitable for use in most automatic fabric washing machines generally contain anionic non-soap surfactant, or nonionic surfactant, or combinations of the two in any ratio, optionally together with soap.
Anionic surfactants, soaps and higher-ethoxylated nonionic surfactants may generally be included in the base powder. Lower-ethoxylated surfactants may more suitably be post-added.
Detergent compositions containing the modified alumino-silicate according to the invention may also suitably contain a bleach system. The invention is especially concerned with compositions containing peroxy bleach compounds capable of yielding hydrogen peroxide in aqueous solution, for example inorganic or organic peroxyacids, and inorganic persalts such as the alkali metal perborates, percarbonates, perphosphates, persilicates and persulphates. As indicated above, the invention is more especially concerned with compositions containing sodium percarbonate.
Bleach ingredients are invariably postdosed.
The sodium percarbonate may have a protective coating against destabilisation by moisture. Sodium percarbonate having a protective coating comprising sodium metaborate and sodium silicate is disclosed in GB 2 123 044B (Kao).
The peroxy bleach compound, for example sodium percarbonate, is suitably present in an amount of from 5 to 35 wt %, preferably from 10 to 25 wt %.
The peroxy bleach compound, for example sodium percarbonate, may be used in conjunction with a bleach activator (bleach precursor) to improve bleaching action at low wash temperatures. The bleach precursor is suitably present in an amount of from 1 to 8 wt %, preferably from 2 to 5 wt %.
Preferred bleach precursors are peroxycarboxylic acid precursors, more especially peracetic acid precursors and peroxybenzoic acid precursors; and peroxycarbonic acid precursors. An especially preferred bleach precursor suitable for use in the present invention is N,N,Nxe2x80x2,Nxe2x80x2-tetracetyl ethylenediamine (TAED).
A bleach stabiliser (heavy metal sequestrant) may also be present. Suitable bleach stabilisers include ethylenediamine tetraacetate (EDTA) and the polyphosphonates such as Dequest (Trade Mark), EDTMP.
Other materials that may be present in detergent compositions containing the modified aluminosilicate of the invention such as alkali metal, preferably sodium, carbonate, in order to increase detergency and ease processing. Sodium carbonate may suitably be present in amounts ranging from 1 to 60 wt %, preferably from 2 to 40 wt %. However, compositions containing little or no sodium carbonate are also within the scope of the invention. Sodium carbonate may be included in the base powder, or postdosed, or both.
Powder flow may be improved by the incorporation of a small amount of a powder structurant, for example, a fatty acid (or fatty acid soap), a sugar, an acrylate or acrylate/maleate polymer, in the base powder. A preferred powder structurant is fatty acid soap, suitably present in an amount of from 1 to 5 wt %.
Other materials that may be present in detergent compositions of the invention include antiredeposition agents such as cellulosic polymers; soil release polymers; fluorescers; inorganic salts such as sodium sulphate; lather control agents or lather boosters as appropriate; proteolytic and lipolytic enzymes; dyes; coloured speckles; perfumes; foam controllers; and fabric softening compounds.
Detergent compositions containing the modified aluminosilicate of the invention may be prepared by any suitable method. Detergent powders can suitably be prepared by spray-drying a slurry of compatible heat-insensitive components, and then spraying on or postdosing those ingredients unsuitable for processing via the slurry. Detergent compositions containing the modified aluminosilicate of the invention are preferably prepared by non-spray-drying (non-tower) processes. The base powder is prepared by mixing and granulation, and other ingredients subsequently admixed (postdosed).
The base powder may suitably be prepared using a high-speed mixer/granulator. Processes using high-speed mixer/granulators are disclosed, for example, in EP 340 013A, EP 367 339A, EP 390 251A and EP 420 317A (Unilever).
Specific Description of the Invention
The present invention will be further described in the following examples.


An internal combustion engine includes a crankcase and a cylinder head which covers a cylinder of the crankcase and in which a fresh-gas channel and an exhaust-gas channel are made which open on a cylinder-head longitudinal side and are connected to in each case a fresh-gas line and an exhaust-gas collection line, and wherein there is an exhaust-gas recirculation system, including an exhaust-gas recirculation line and a control valve. An internal combustion engine having an exhaust-gas recirculation system is provided, in which the exhaust-gas recirculation system remains uninfluenced by the exhaust-gas collection line which is hot during operation. This is achieved in that the exhaust-gas recirculation system is arranged on that cylinder-head side which lies opposite the fresh-gas line and the exhaust-gas collection line. This arrangement away from the exhaust-gas collection line which is substantially hotter than other components during operation has the consequence of a direct reduction of the temperature of the recirculated exhaust-gas amount, without further special cooling measures being provided.

An internal combustion engine of this kind is known from DE 693 00 649 T2. This internal combustion engine has a cylinder head in the case of which the fresh-gas channels and the exhaust-gas channels of the individual cylinders lead out on a longitudinal side of the cylinder head that is formed as a cylinder-head block. The exhaust manifold has a special connection for attaching the exhaust-gas recirculation system, in particular a control valve for controlling the recirculated exhaust volume. To introduce the exhaust gas, that is to be recirculated, into the fresh-gas channels, a special component referred to as a ramp is used between these channels and the fresh-gas manifold. This design has the inherent disadvantage that insertion of the ramp necessitates modifying the exhaust manifold and increasing the overall height of the internal combustion engine. Moreover, the control valve, in particular, projects beyond the given lateral contour of the internal combustion engine. A cooling of the recirculated exhaust gas is not provided and is made more difficult by the immediate proximity to the exhaust manifold that is hot during operation.
An object of the present invention is to devise an internal combustion engine having an exhaust-gas recirculation system that will remain unaffected by the exhaust manifold that is hot during operation.
The present invention provides a exhaust-gas recirculation system is located on the cylinder head side opposite the fresh-gas line and the exhaust manifold. This configuration at a distance from the exhaust manifold, which is substantially hotter than other components during operation, has the effect of directly lowering the temperature of the recirculated exhaust volume, without the need for other special cooling measures. The cylinder head is preferably an individual cylinder head, which is bolted, together with the corresponding cylinder, to the crankcase. As a matter of course, the present invention may also be generally used for a block cylinder head and for cylinders that are fabricated in one piece together with the crankcase.
In a further refinement of the present invention, channels which open out on the cylinder head side and communicate with the fresh-gas channel and the exhaust-gas channel, respectively, are recessed in the cylinder head (the fresh-gas channel and the exhaust-gas channel connect gas-exchange valves in the cylinder head to the fresh-gas line and, respectively, to the exhaust manifold). The channels, whose cross section may be dimensioned to be substantially smaller than the aforementioned gas channels, may be configured at an appropriate location in the cylinder head and be included as integrally cast channels during manufacture of the cylinder head or be subsequently introduced in a mechanical machining process. These channels are preferably introduced into the cylinder head in a subsequent mechanical machining process, making it possible for the design of the cylinder head blank to be identical for internal combustion engine versions which are equipped with exhaust gas recirculation and for those that are not. An exhaust-gas recirculation system, which includes an exhaust-gas recirculation manifold, an exhaust-gas recirculation control valve and an exhaust-gas-recirculation distribution line, may then be readily mounted at these channels which open out on the cylinder head side. In this context, a further advantage is derived in that the exhaust manifold may remain unchanged as compared to a design without exhaust-gas recirculation. This is particularly advantageous when different types of exhaust manifolds having different connections for directing the exhaust gases, for example, are provided for various application purposes and customer requirements. In addition, the construction volume of the internal combustion engine that is relevant for an installation is not affected by this design and arrangement of the exhaust-gas recirculation system, so that the need is eliminated for distinguishing between an internal combustion engine equipped with exhaust-gas recirculation and one that is not. This is especially advantageous in terms of the interchangeability of equivalent internal combustion engines that are installed in construction machinery or agricultural machines.
In a further refinement of the present invention, the internal combustion engine has a cooling-air blower, and the exhaust-gas recirculation system is configured directly in the cooling-air flow supplied by the cooling-air blower, within a cooling-air duct housing. In the first place, this arrangement allows the recirculated exhaust gas to be effectively cooled without requiring any further outlay. In addition, the exhaust-gas recirculation system may be integrated in a cooling-air duct which is formed from a cooling-air duct housing and is configured along the cylinder head side and thus, in any case, does not constitute a component that projects beyond a given lateral contour, thereby ensuring that an internal combustion engine correspondingly equipped with an exhaust-gas recirculation system is readily interchangeable with an identical internal combustion engine that is not equipped with an exhaust-gas recirculation system. An internal combustion engine of this kind is preferably an air-cooled internal combustion engine. However, it may also be an internal combustion engine having a combination cooling system, the blower cooling the cooling medium, for example oil and/or water and, if indicated, being additionally utilized for air cooling the cylinder head and/or a heat exchanger, for example.
In a further embodiment, the exhaust-gas recirculation control valve is disposed adjacently to the cooling-air blower, thereby providing a particularly effective and intensive cooling of this thermally sensitive component. Finally, to enhance the cooling capacity, the exhaust-gas recirculation system may, in particular, have an outer ribbing, particularly with regard to optimized fluid mechanics, it being possible for this outer ribbing to be oriented in the direction of the cooling-air flow.
Other advantageous embodiments of the present invention may be inferred from the description of the drawings, in which an exemplary embodiment of the present invention illustrated in the figures is described in greater detail.
The internal combustion engine in accordance with FIG. 1 has a crankcase 1, which is sealed at the bottom by an oil pan 2. Attached to crankcase 1 in a configuration facing opposite oil pan 2 are cylindrical pipes which are covered, in turn, by cylinder heads 3. The exemplary embodiment refers to a four-cylinder internal combustion engine, so that, altogether, four cylindrical pipes and four cylinder heads 3 are installed. Moreover, the internal combustion engine is air-cooled and, accordingly, the cylinder pipes and cylinder heads 3 are provided with cooling ribs 4.
Fastened at the front end of the internal combustion engine to a crankshaft supported in crankcase 1 is a double-belt pulley 5 which is operatively connected via a first V-belt 6a to a generator 7 and via a second V-belt 16b to a cooling-air blower 9, a tensioning roller 8 being interposed therebetween.
Cooling-air blower 9 is configured laterally above crankcase 1, essentially in the area next to the cylinder pipes and cylinder heads 3, and delivers cooling air drawn in from the ambient environment into a cooling-air duct housing 10, which extends from cooling-air blower 9 to an opposite output end 11 of the internal combustion engine and distributes the delivered cooling air across the internal combustion engine along the cylinder pipes and cylinder heads 3. In FIG. 1, a maintenance lid of cooling-air duct housing 10 is removed, and cooling-air duct housing 10 is shown in a partial cut-way view in the region of cooling-air blower 9, revealing the interior of cooling-air duct housing 10.
Mounted below cooling-air duct housing 10 is an in-line injection pump 12, which communicates via injection lines 13a, 13b (shown in an interrupted view) with fuel injectors installed in cylinder heads 3. Each fuel injector is secured by clamping claws 14 to the cylinder head and is laterally contiguous to a valve cover 15 which extends to a cylinder-head longitudinal side opposite the cylinder-head side on the side of the cooling-air duct housing. A fresh-gas line 16 and an exhaust manifold 17 are configured on this cylinder-head longitudinal side. In the region above, between and below fresh-gas line 16 and exhaust manifold 17, a significant portion of the cooling air delivered by cooling-air blower 9 flows back into the ambient environment again.
The combustion chambers located in the cylinders between individual cylinder heads 3 and the vertically reciprocating pistons in the respective cylinders, are each in fluid communication via gas-exchange valves and gas-exchange channels with fresh-gas line 16 and exhaust manifold 17. On the opposite cylinder-head side, channels 18a, 18b (FIG. 2) are incorporated into cylinder heads 3. In a side-by-side configuration, one channel 18a communicates with a gas-exchange exhaust port and channel 18b with a gas-exchange intake port. These channels 18a, 18b extend in a lower region of cylinder head 3 to the cylinder head side on the cooling-air blower side and are provided with mating coupling devices 19a, 19b.
An exhaust-gas recirculation system, which connects channels 18a to channels 18b in a controllable or adjustable manner, is configured in cooling-air duct housing 10. To that end, channels 18a are interconnected with a common manifold 20 which extends in the area of output end 11 via an elbow 21 into a feed pipe 22 to exhaust-gas recirculation control valve 23. Connected to exhaust-gas recirculation control valve 23 on the side opposite feed pipe 22 is a deflector elbow 24 which leads into a distribution line 25 that is configured approximately in parallel below manifold 20 and is connected, in turn, to channels 18b of individual cylinder heads 3.
The entire exhaust-gas recirculation system is located within cooling-air duct housing 10. On the one hand, therefore, it is not visible from the outside when cooling-air duct housing is closed, and, on the other hand, it does not affect the outer dimensions of the internal combustion engine. In addition, by configuring the exhaust-gas recirculation device completely inside of cooling-air duct housing 10, an effective cooling of the components of the exhaust-gas recirculation system is achieved. The individual pipes and elbows, as well as the exhaust-gas recirculation-control valve housing may also be additionally provided with inner and/or outer cooling ribs to enhance the transfer of heat.
In-line injection pump 12 is equipped with a governor that is designed as a mechanical governor. To facilitate actuation of exhaust-gas recirculation control valve 23 without the use of a complicated and expensive electronic control device, the position of a control rod provided in in-line injection pump 12 is picked off in a contactless manner, and this position is utilized for controlling exhaust-gas recirculation control valve 23 via a mechanical or electrical transmitting device.
To this end, an electrical control analyzes a control-rod displacement signal. In this context, a Hall-effect sensor is preferably used, which is switched via one or more magnets integrated in the control rod. A Hall-effect sensor of this kind is a very reliable electrical switch which may be used for switching the exhaust-gas recirculation on and off. In another embodiment of the present invention, the exhaust-gas recirculation is switched off above an injected fuel quantity that corresponds to a load greater than three fourths of the full load. In this full-load range, no exhaust gas is recirculated, since an exhaust-gas recirculation carried out in the full-load range would lead to a degradation of the exhaust emissions. To this end, one preferred specific embodiment provides for a plurality of small magnets to be inserted side-by-side in bores, in the region of the control rod that covers this injected fuel-quantity range. These magnets switch the Hall-effect sensor that is mounted on the exterior of the pump housing of the injector. This method, respectively this embodiment, is extremely reliable, since this electrical control, in particular, is not an electronic control device.
In a further embodiment of the present invention, the exhaust-gas recirculation is switched off at a speed below an elevated idling speed. This switching function is provided when, in response to decreasing speeds, for example to speeds below a threshold of 1500 rpm, there is the risk of smoke problems occurring during an exhaust-gas recirculation, due to the design of the injection system. For that reason, an inductive tachymetric switch is provided, which is likewise installed on the pump housing and emits the appropriate switch signal, in particular below a speed of 1450 rpm.

Exhaust-gas recirculation in an air-cooled internal combustion engine


A pharmaceutical composition comprising a lyophilizate of non-liposomal complex of a water insoluble camptothecin and a phospholipid, said lyophilizate additionally containing a pharmaceutically acceptable lyophilization excipient, wherein the weight ratio of said camptothecin to said phospholipid in said composition is about 1:80 to 1:5.

The present invention relates to a pharmaceutically acceptable dosage form for water insoluble camptothecins and, more particularly 9-amino 20(S)-camptothecin (hereafter 9-AC) and 9-amino-20(R)-camptothecin which can be reconstituted and administered to a patient intravenously or subcutaneously or formulated for oral use in the treatment of cancer and other diseases.
Camptothecin and analogues thereof, display antitumor activities against colon cancer, leukemia, and experimentally transplanted carcinoma such as leukemia L-1210 in mice or Walker 256 tumors in rats. See Potsmiesel, M., DNA Topoisomerases in Cancer. Camptothecin is a pentacyclic alkaloid including a characteristic fused 5-ring system of quinoline (rings A and B), pyroline (ring C), xcex1-pyridone (ring D) and a six-membered lactone (ring E). The intact lactone ring, ring E, and hydroxyl group at position 20 have been found to be essential to its antitumor activity.
Studies of camptothecin analogs have suggested a correlation between the compound""s ability to induce DNA breakage and its antitumor activity. It has a unique mechanism of action which produces DNA damage in the presence of topoisomerase I, a monomeric enzyme that is capable of altering DNA topology in eukaryotic cells. Topoisomerase I binds to the DNA to allow the double helix to unwind and subsequently reseals the break before dissociating from the DNA strand. Camptothecin is believed to bind to and stabilize a covalent DNA-topoisomerase I complex in which one strand of the DNA helix is broken and thereby prevent the DNA from recombining.
The therapeutic use of camptothecin and its analogs has been severely limited by their poor water solubility and high toxicity. A number of attempts have been made to reduce the toxicity of camptothecin without reducing its antitumor activity through the development of derivatives. Camptothecin derivatives substituted at the 5-, 7-, 9-, 10-, and 11-positions have been investigated. At least three camptothecin derivatives are in various stages of clinical development, namely: 7-ethyl-[14-(1-piperidino)-1-piperidine] carbonyloxycamptothecin (CPT-11); 20-(S)-camptothecin; 10-[(dimethylamino)methyl]-4-ethyl-4,9-dihydroxy-1H-pyrano[3xe2x80x2,4xe2x80x2:6,7]indolizino[1,2-b]quinoline-3,14(4H,12H)dione monohydrochloride (topotecan hydrochloride); and 9-amino-20(s)-camptothecin.
9-AC is quite water insoluble (0.002 mg/ml). This makes it difficult to formulate as a sterile, storage stable, dosage form. In studies carried out by the National Cancer Institute (NCI) 9-AC was formulated in an organic solvent, dimethylacetamide (DMA), to overcome the solubility limitations of the drug. The NCI formulation consists of 5 mg of 9-AC in 1 ml of DMA. At the point of use, the product is diluted using a diluent consisting of polyethylene glycol 400, USP, and phosphoric acid. The diluent is added to the NCI formulation in an amount of 49 ml diluent to 1 ml formulation.
The NCI formulation has drawbacks which make the formulation inconvenient for commercial use. Because the DMAC attacks rubber stoppers, the product cannot be supplied in stoppered vials and must be supplied in ampules. Ampules are inconvenient to use because they must be scored and broken to open them and this presents some risk of injury and contamination to workers. Additionally, glass chips in the product from breaking open the ampules need to be filtered out.
DMA is not a desirable vehicle for intravenous (IV) administration and a potential source of toxic side effects. DMA has an LD50 value of 5.4 ml/kg, which is a factor which also must be considered in administering the drug.
Another approach to designing camptothecin dosage forms which has been investigated involves the use of liposomes. T. G. Burke et al. in Biochemistry 1993, 32, 5352-64 (1993) suggest using liposomes as a drug delivery system for camptothecin. Burke et al. found that camptothecin binds with dimyristoylphosphatidylglycerol (DMPG) lipids and dimyristoylphosphatidylcholine (DMPC) lipids and is stable in both DMPC and DMPG liposome bilayers. They postulate that the lactone ring penetrates the liposome layer. The liposome-associated camptothecin showed stabilization of the lactone ring.
No satisfactory pharmaceutically acceptable formulation of 9-AC is currently available for administration to humans. There is a need for a stable pharmaceutical dosage form which may be conveniently administered to a cancer patient while retaining the structural elements that are essential for 9-AC""s pharmacological activity.
It is an object of the present invention to provide a pharmaceutically acceptable dosage form of 9-AC or another water insoluble camptothecin. It is another object of the present invention to provide lipid complexes of 9-AC and other water insoluble camptothecins. It is still another object of the invention to provide lyophilizates of three lipid complexes. The lyophilizate can be reconstituted with water, saline, or another electrolyte to give a colloidal dispersion for intravenous or subcutaneous administration or can be formulated into a paste or filled into a soft gelatin or hard gelatin capsule for oral administration. Previously, cam ptothecins have not been administered subcutaneously because they are necrotic. However, it appears that the lipid complex may sufficiently slow the release of water insoluble camptothecins that subcutaneous administration is possible.
While the invention will hereafter be described with respect to the preparation of lipid complexes and lyophilizates of lipid complexes of 9-AC, those skilled in the art will appreciate that the methods taught herein are also applicable to the preparation of lipid complexes and lyophilizates of other camptothecins which are considered water insoluble such as camptothecin itself.
In accordance with the present invention, a lyophilizate of a phospholipid complex of 9-AC is prepared which can be reconstituted with pharmaceutically acceptable aqueous diluent such as water for injection and which, in comparison to solutions of 9-AC in dimethylacetamide, is less toxic, more stable and particularly importantly, its formulation and administration are not limited by the solubility of 9-AC.
In accordance with the invention, the lyophilizate is prepared by a process comprising the steps of preparing a solution of 9-AC in a first organic solvent, preparing a solution of a phospholipid in a second organic solvent, mixing the phospholipid solution and the 9-AC solution, adding water to the mixed solutions to cause formation of a lipid complex of 9-AC, removing the first and second organic solvents to provide a dispersion of the lipid complex in water as an aqueous phase, dissolving a pharmaceutically acceptable excipient in the aqueous phase of the dispersion, and lyophilizing the dispersion of the lipid complex to form a lyophilizate. This lyophilizate forms a colloidal dispersion when reconstituted with a physiologically acceptable aqueous diluent.
In accordance with a preferred embodiment of the present invention, the lyophilizate is prepared by a method comprising the steps of forming a concentrated solution of 9-AC in dimethyl sulfoxide, forming a concentrated solution of the phospholipids DMPC and DMPG in chloroform, mixing the phospholipid solution and the 9-AC solution, adding an aqueous solution such as water for injection to form the lipid complex of 9-AC and provide a dispersion of the lipid complex in water as an aqueous phase, sparging and diafiltering the dispersion to remove the solvents, reducing the particle size of the dispersion of the lipid complex, adding an aqueous solution of mannitol as a pharmaceutically acceptable lyophilization excipient to the dispersion, and lyophilizing, wherein a lyophilizate is obtained which upon reconstituting with water provides a colloidal dispersion of a 9-AC lipid complex.
In accordance with a further embodiment of the present invention, a lyophilized composition containing 9-aminocamptothecin or another water insoluble camptothecin is provided which comprises 9-AC, a phospholipid and a pharmaceutically acceptable lyophilization excipient.
The term xe2x80x9cwater insoluble camptothecinxe2x80x9d as used herein means camptothecin or another pentacyclic alkaloid having the aforementioned characteristic fused 5-ring system of camptothecin having a solubility in water which is less than 0.01 mg/ml at 23xc2x0 C.
The term xe2x80x9clipid complexxe2x80x9d is an art recognized term. Lipid complexes are characterized by a noncovalent bond between the lipid and the camptothecin which is observed as a phase change in differential scanning calorimetry.
The term xe2x80x9cpharmaceutically acceptable aqueous diluentxe2x80x9d as used herein refers to water for injection, saline, and other known aqueous vehicles.
The term xe2x80x9clyophilization excipientxe2x80x9d refers to a. substance which is added to a solution prior to lyophilization to enhance characteristics such as the color, texture, strength, and volume of the cake. Examples of lyophilization excipients are provided below
9-AC has been prepared by reduction of 9-nitrocamptothecin with a reducing agent such as a combination of tin or iron with a mineral acid. (See U.S. Pat. No. 4,604,463 to Miyasaka et al.) The preparation of 9-amino-20(S)-amptothecin and 9-amino-20(R,S)-camptothecin is described in U.S. Pat. Nos. 5,106,742 and 5,225,404. Other water insoluble camptothecins are known in the art and their preparation is described in the literature.
9-Amino-20(S)-camptothecin has a chemical formula of C20 H17 N3 O4 and the structure:
In accordance with the invention a concentrated solution of 9-AC in an organic solvent is prepared. The most typical example of the solvent used to prepare this solution is dimethyl sulfoxide (DMSO). However, other organic solvents such as dimethyl formamide can be used. Useful solvents must form stable solutions with the camptothecin analogue, e.g., the solvent must not interact with, destabilize, and/or deactivate the drug. In addition, the solubility of the camptothecin analogue in the solvent must also be high enough that the camptothecin analogue can be dissolved in amounts sufficiently high to form commercially useful quantities of the lipid complex and the solvent should be capable of being removed easily from an aqueous dispersion of the lipid complex as described hereinafter. Preferably, a solution having a concentration of about 5 to 50 mg/ml, preferably about 20 to 40 mg/ml and most preferably 40 mg/ml camptothecin is used. The concentration may vary depending upon the nature of the solvent and temperature, but it is important to use a concentrated solution of the camptothecin in preparing the liquid/camptothecin complex. This minimizes the amount of solvent that must be removed later in the process, and it also assists in forcing the camptothecin out of solution and into liquid/camptothecin complex formation with the lipid with the addition of water.
The organic solvent used to prepare the solution of the phospholipids should meet similar requirements to those outlined for the camptothecin solvent. It must be compatible with the phospholipids and not destabilize them or the camptothecins. In addition, the lipids should be soluble enough in the solvent so as to be able to introduce enough of the lipid to form the complex yet minimize the amount of solvent that must be removed later. A solvent which can be readily removed from the dispersion of the lipid complex is most preferred. The solvent most typically used to prepare this solution is chloroform or methylene chloride. Typically the concentration of this phospholipid solution will range from about 10 to 250 mg/ml.
Phospholipids are amphipathic in nature, i.e., the molecules have a hydrophobic tail such as a long chain hydrocarbon, and a hydrophilic head. In an aqueous medium, such as water or saline, the tails align with each other, away from the aqueous molecules, while the heads face. outward into the aqueous phase. It is this nature of the phospholipids that makes them very useful for formulating highly insoluble drugs like 9-AC.
The phospholipids used in the invention are selected such that their phase transition temperature is about equal to or below the body temperature or 37xc2x0 C. and the complex releases the drug in the body. Representative examples of useful phospholipids include synthetic phospholipids DMPC, DMPG, dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylglycerol (DPPG), distearoylphosphatidylcholine (DSPC), or distearoylphos-phatidylglycerol (DSPG), or a combination thereof. Other examples of phospholipids can be found in the CRC Handbook of Livid Bilayers by Marsh, M. A., CRC Press (1990). When DMPC and DMPG are used in a ratio of DMPC to DMPG of about 7:3 they mimic the cell membrane.
The lipid solution is added to the 9-AC solution such that the weight ratio of the 9-AC to lipid is about 1:80 to 1:5, preferably about 1:80 to 1:10, more preferably, about 1:60 to 1:10 and still more preferably about 1:45 to 1:25.
In some applications, it has been found desirable to add cholesterol or its hemisuccinate derivatives to the lipid complex. The cholesterol is believed to cause the bilayers to pack more closely and thereby slow the release of the drug. This approach may be particularly desirable with subcutaneous formulations where severe necrosis can result if the drug is delivered too quickly. The cholesterol is added to the phospholipid solution. The cholesterol may be used in an amount of about 0.5 to 15 parts per 100 parts phospholipid.
Once the solvent solutions of the lipids and camptothecin have been mixed, water or an aqueous solution is added rapidly and with stirring for several minutes to the mixture. Addition of the water is believed to cause the 9-AC and the lipid to come out of their respective solvent solutions and complex with each other. The water is preferably added in an amount such that the 9-AC is present in an amount of about 0.05 mg to 0.5 mg per 100 ml water. It is desirable to limit the amount of water to minimize the amount of water which must be removed during the lyophilization process. Higher amounts of water are undesirable because they increase the amount of water that must be removed during the subsequent lyophilization process. It is believed complexation may be complete in about 30 minutes. However, it is desirable to stir the dispersion for about one hour to insure complexation is complete.
The lipid complex dispersion described above, is treated to remove the solvents. Any of a variety of techniques can be used for this purpose. For example, it has been found that the chloroform can be removed if the dispersion is sparged with a gas such as nitrogen. A diafiltration process (also known as a tangential flow filtration process) is used to remove the DMSO. A cartridge of hollow fiber tubes having a pore size of 5 to 150 kilodaltons can be used. A diafiltration cartridge is available from A/G Technology Corporation of Needham, Massachusetts under the tradename XPRESS, which can be used. Other techniques which can be used include centrifugation.
A pharmaceutically acceptable lyophilization excipient is dissolved in the aqueous phase of the dispersion. Mannitol is typically used as the excipient but other excipients which do not interact with the drug or the lipid complex may be used. Sodium or potassium phosphate, citric acid, tartaric acid, gelatin, and carbohydrates such as mannitol, lactose, dextrose, dextran, hetastarch, etc. are common examples of excipients which are also believed to be useful herein. The excipients can be used alone or in combinat ion to provide a cake of good quality which readily disperses in water upon reconstitution.
The excipients are typically added to the dispersion as solutions in water. Again, it is desirable to use concentrated solutions to minimize the amount of water for removal by lyophilization. The amount of the excipient is adjusted in a manner that is well known in the art to provide a cake which does not crack or shrink and is porous so that it readily dissolves and has a good appearance. Mannitol has been found to be useful. Mannitol is added to the dispersion as a solution having a concentration of about 5 to 150 g/ml. Mannitol is added in an amount of about 1 to 100 parts by weight per 1 part 9-AC.
After removing the solvents and adding the excipient, the dispersion is passed through a homogenizer (e.g., a Tekmar rotor/stator homogenizer, Model T25, or a microfluidics submerged jet homogenizer, Model M110Y). As a general rule, the smaller the particle size of the dispersion, the faster the formulation can be dried during the lyophilization cycle. A dispersion having a particle size distribution ranging from about 10 to 500 nm and averaging about 250 nm has been found to be satisfactory for lyophilization. The optimum particle size may vary depending on the mode of administration.
A typical lyophilization cycle useful in accordance with the present invention is provided below. The cycle may be varied depending upon the equipment and facilities available in a manner well known in the art.
The homogenized formulation can be poured into vials of a 5 to 50 ml nominal volume. The vials are placed into a lyophilization chamber at about 5xc2x0 C. The vial size will usually be selected such that each vial contains a single dosage of the 9-AC. The temperature of the chamber is reduced to xe2x88x9230xc2x0 C. over a period of one hour after which the temperature is maintained at xe2x88x9230xc2x0 C. for about four hours. The pressure in the lyophilization chamber is then reduced to 200-250 microns of pressure for the remainder of the cycle. After reducing the pressure in the chamber, the temperature is ramped up to +25xc2x0 C. over a period of fifteen hours and the product is held at 250C for five hours. The temperature then is ramped up to +40xc2x0 C. over a period of 20 minutes and held at 40xc2x0 C. for two hours. The lyophilized product preferably has a final moisture content of less than about 5% and typically about 1 to 2%.
For intravenous or subcutaneous administration, the lyophilizate can be reconstituted using aqueous vehicles such as water, saline or another electrolyte. The lyophilized product with the addition of water provides a colloidal dispersion of the lipid complex in an aqueous solution of the excipient. Neither the 9-AC nor the lipids are soluble in water. A colloidal dispersion consists of at least two discrete phases. The first is a dispersed or internal phase. The second is a continuous or external phase. Systems in the colloidal state contain one or more substances that have at least one dimension in the range of 10-100 xc3x85 to a few microns. See pp. 272-4 in Chapter 19, Disperse Systems, Remington""s Pharmaceutical Sciences, 18th Edition, 1990, Mack Publishing Company, Easton, Pa. 18042. In the colloidal dispersions of the present invention, the dispersed or internal phase comprises particles of 9-AC lipid complex having a particle size in the range of 10 nm to 1000 nm. In selecting the aqueous vehicle, it is recommended to use one having a specific gravity about equal to the lipid complex (est. 1.09 g/cc) to minimize the tendency for the dispersion to separate. The lyophilizate of the lipid complex can be reconstituted with water, saline, or another pharmaceutically acceptable aqueous diluent for intravenous administration. Upon reconstitution a dispersion is obtained which is suitable for injection. The lyophilizate can also be administered orally as an aqueous dispersion or as a paste. While camptothecins are not generally administered subcutaneously because they cause necrosis, it has been observed that the lipid slows the release of the camptothecin into the tissue making it potentially feasible to administer the lipid complex subcutaneously.
For oral administration, the lyophilizate can be reconstituted to form an oral dispersion or formulated into a paste. Alternatively, the lyophilizate can be filled into a soft gelatin capsule for oral administration.
Suitable dosages for 9-AC and camptothecins range from about 35 to 250 mg/m2/hour. The drug is preferably administered as a continuous infusion over 3 to 21 days using programmable continuous infusion ambulatory pump. It is anticipated that the drug will be administered with granulocyte colony stimulating factor (GCSF).
While it is contemplated herein that the lipid/camptothecin complex will be lyophilized to enhance its stability, it will be appreciated that the lipid/camptothecin complex is pharmaceutically active and can be formulated into a dosage form for oral, intravenous or subcutaneous administration without lyophilization. Formulation aids such as antibacterials and antioxidants can be used to enhance the stability of the complex.

Lyophilizate of lipid complex of water insoluble camptothecins


An ergonomic mounting arrangement for a hinged screen display for a computer, particularly a notebook or laptop computer, that will provide an option to shift the display screen to an extended position for easier viewing, and also allowing tilting the screen display back as desired. The screen display is mounted to one or more hinged support members which can be swung up from the computer casing, the screen display extendible on the support member or members to be shifted upwardly and forwardly closer to the user""s eyes. A pivotal connection allows tilt adjustment on the support member or members.

This invention relates to a mounting for computer screen displays, and particularly for notebook and laptop computers.
Ever since the introduction of the personal computer there has been a recognition that postural and visual strain are caused by extended viewing of the screen display as currently mounted, i.e., a simple hinging of the screen housing to the rear of the computer casing. Various devices in the past have been invented to alleviate these problems when using the full size personal computer. Most of these efforts have comprised a mounting that allows adjusting the tilt position of the monitor to reduce visual and postural strain.
In the notebook or laptop computer, the problem is more severe and has remained unsolved. While some inventors have recognized the need, no practical solution has been developed. The use of a portable shelf or screen tilting levers proposed in early efforts at portability have been found to be impractical. Manufacturers and users have come to accept these postural and visual problems as disadvantages to be tolerated to gain the convenience of compactness and portability of the laptops.
As an example, U.S. Pat. No. 5,590,607, issued Jan. 7, 1997, for a xe2x80x9cPortable Shelf For Notebook Computersxe2x80x9d recognizes the difficulties of long term use of a laptop, and provides a portable support shelf to adjust the computer""s height. The inventor cites the advantage of using the shelf to raise the keyboard higher than the user""s lap, but lower than normal desk top height. An important disadvantage is the lack of portability since it defeats the main advantage of using a notebook or laptop computer. There are two more serious drawbacks, which are important to appreciate, because they bring to light two serious drawbacks of notebook or laptop computer use. The first is that by lowering the keyboard below desk height to better accommodate wrist use, the postural strain on the back, and especially the neck, are actually increased over desk height use. It is a strain to try to view the screen at a low position even at desk top level. The second is that visual details of the display screen are made more difficult to distinguish when the screen is lowered. What would instead be helpful would be to raise the display screen about six inches above desk height and move it closer to the eyes. But if a portable shelf is used, or any means to raise the whole computer much above desk height, it would then make using the hands and wrists almost impossible.
In the context of personal computers and monitors, the art has recognized the advantages of screen position adjustment. A prior patent for xe2x80x9cA Compact Electronic Computerxe2x80x9d, U.S. Pat. No. 4,852,032, issued Jul. 25, 1989, describes a personal portable computer that includes a display monitor adjustment. The invention is a complete computer, portable and compact for its 1989 time period. One of its claims is a spring means for adjusting its display screen by allowing the bottom of the display screen to tip outward. While this was a helpful visual adjustment, it was limited to this specific action, accomplished by a complex ratchet mechanism. It is a design of an outmoded portable, and does not anticipate today""s notebook computer, and its operation has no relationship in design or function to the present invention.
Another prior art innovation, is described in a patent for xe2x80x9cAn Adjustable Display Panel For Portable Computerxe2x80x9d, U.S. Pat. No. 4,832,419, issued May 23, 1989. While this device relates to the personal portable computer of 1989 and does not anticipate the compact flat notebook or laptop computer, it does recognize the need for display screen adjustment. By a short set of flat levers linked by hinges and curved guide tracks, the display screen is allowed to raise in height and tilt in a fixed arc. Additional screen tilt is accomplished by a saddle that the whole computer frame rests on. It provides additional adjustment by moving in an arc on its yoke and base.
Manipulating this terminal package could provide convenience for earlier portable computers of this portable sewing machine shape, but has no way of benefitting the present day compact and light weight notebook and laptop computers built to travel in a brief case. In fact, the simple adjustment stands for today""s personal computer monitors have made this invention outmoded even for largely personal computers. It is designed for the three component system of the monitor, keyboard panel, and terminal; it cannot accommodate either personal computers or notebook types; it uses a series of flat brackets with hinges in between; it pivots on a spring mechanism; the display panel is raised following the arc of a curved track and locks in place by compression in the end of the tracks; it cannot be used with notebook computers.
Another recognition of the advantage of screen adjustment is found in a patent for a xe2x80x9cPortable Computer Provided With A Tilting Screen Articulated Thereon By Tilting Linkage With A Bent Shapexe2x80x9d, U.S. Pat. No. 5,107,402, issued Apr. 21, 1992. This patent relates to a design of an entire computer that is vertical in structure with a separate keyboard, like the personal computers used in households today. Like the previously discussed patent, it does not provide a mechanical operation that could be useful to today""s compact notebook. The working attachment to the screen section is a cranked bent lever. The screen moves from one open face vertical position to roughly the same plane, able to tilt slightly. The display screen when closing moves to its vertical resting position, is folded back against the vertical terminal, and the keyboard is then clipped onto the screen and the terminal making a total vertical package, similar in shape and size to a small traveling utility bag.
FIG. 7 of the ""402 patent shows an alternate articulation device which incorporates a connecting bar to eliminate twist or torque in the display section""s operation. In addition, the bent crank like brackets, of this prior art alternate, are controlled by a long coiled spring that exerts frictional pressure on the connecting rod by applying pressure against phalanges on a mechanism that encompasses the connecting rod. These phalanges, held against rings, maintain a selected position by friction applied by the spring and its mechanism that encircles the connecting rod or axle.
While prior art in the form of a shelf design attempts to address ergonomic problems of the notebook or laptop computer, it offers more strain than benefit. Besides being a cumbersome piece of additional equipment, it mistakenly sacrifices the needs of the back, the neck, and the eyes to protect the wrist.
U.S. Pat. No. 5,255,214 discloses a screen display support for a portable computer comprised of two arms hinged to the case and pivoted to the screen display so as to allow the screen to be swung towards the front of the case and angularly adjusted. While this allows some improvement in that the screen can be tilted up from viewing or swung towards the user, some bending over would still be necessary as the screen is not able to be moved up appreciably in relation to the viewer""s eyes in the various adjusted positions.
Other prior art does not present display screen adjustment mechanisms suitable to the notebook or laptop computers in use today. Those inventions that are available are designs for a specific computer type that bears no resemblance to what is used today. While most include attempts at screen adjustment, none have come into common use. They are intended for computer configurations no longer popular. Their mechanics offer no practical means of adjusting today""s portable designs. Their mechanics are bulky and complex and do not solve the postural and visual problems of the notebook or laptop computer.
The object of the present invention is to provide a practical ergonomic mounting for a computer display screen which allows the screen itself to be properly positioned with respect to the user to minimize eye strain and postural problems without compromising other uses of the computer.
The above recited object of the invention, as well as others which will become apparent upon a reading of the following specification and claims, are achieved by a mounting mechanism including a support structure comprised of one or more support members holding the display screen housing which support structure has a hinged connection at one end to the computer casing to allow the support and flat display screen housing to be swung up from a down position overlying the computer casing. The support member (or members) are interengaged with the display screen housing by a slidable connection creating an extension-retraction relationship allowing the screen display housing to be extended on the one or more support members so as to be shifted up to be located substantially closer to the eyes of the operator. The support member or members also have a pivotal connection to the screen display housing which allows the screen display to be tilted back for optimal viewing after being shifted to its raised position.
The one or more support members preferably comprises a single central supporting panel member having a hinged connection at one end to the rear edge of the computer casing. The panel member is normally stored flat in a recess in the back of the screen housing, when not in use. When stored, the upper end of the panel member is pushed against the top end of the recess in the display screen housing.
To deploy the display screen, the panel member and display screen are first swung up together on the hinged connection. From this upright position, the screen display housing can be pulled upwardly on the panel member, to be shifted to an extended position above the computer casing. The panel member mounts the screen display on pivot shafts which are held by attachments that are slidable down concealed spaces extending along either side of the recess in the rear of the screen display screen at it is shifted upwardly. The panel member may be tilted forwardly on its hinged connection to the computer casing to also swing the display screen forwardly as it is shifted upwardly closer to the user""s eyes. After reaching its fully extended, raised position, the display screen also can be tilted back on the pivot shaft to a desired viewing angle.
In this position, back and neck strain are reduced because the screen can be put in a closer raised position where there is no need to lean forward. What also takes place is improved readability as the closeness of the screen to the viewer""s eyes makes details and fonts sharper to the extent that the work use of the notebook computer rivals that of the personal computer.
In a second embodiment, the display screen is mounted on a pair of elongated spaced apart support arm members, each received in a respective concealed pocket in the rear of the display screen housing, and are pulled out to shift the display screen upwardly. They are each hinged at one end to the computer casing and pivoted at their other ends to the screen display housing to allow tilting adjustments.
Some of the advantages of the present invention over the prior art are:
(A) Strain on the user""s back from long term use is reduced.
(B) The neck strain from constantly leaning or hunching forward to recognize details is eliminated.
(C) Eye strain is reduced by providing better clarity by moving the screen display closer to the user""s eyes.
(D) The notebook or laptop is provided with a greater comfort level that makes it able to compete against the full sized personal computer.
(E) Greater freedom of selection of working positions is allowed, while including the option of using the standard working positions.
(F) There is no complex series of cumbersome levers and unsightly hinges.
(G) When not in use, the support components are stored unobtrusively.
(H) The same compact and light weight traveling convenience of the notebook computer is maintained, while furnishing outstanding new advantages.

Ergonomic mounting for computer screen displays


A friction roller paper currency counter. Specifically, the paper currency counter of the present invention incorporates electronic circuitry which automatically stops the mechanical motors in the event a foreign object is accidentally ingested by the counter.

Currency and document handling and counting apparatus find wide-spread use such as, for example, in banks and other commercial as well as industrial establishments and in institutions wherein it is desired to count large stacks of sheets which may include, for example, coupons, bank checks, paper currency and the like. It is important to provide apparatus capable of accurately counting and stacking such sheets at high rates of speed.
Paper currency counting equipment is designed to replace the time consuming manual tasks of counting a quantity of bills, of subdividing a quantity of bills into batches, each containing a preselected number of bills, and of certifying the count of a trap of bills. Accuracy is, of course, a primary requirement of operation of paper currency counters.
Previous attempts have been made to provide a paper currency counter machine such as described in U.S. Pat. No. 6,370,216 to Lawandy et al. ('216 patent); U.S. Pat. No. 6,324,237 to Price et al. ('237 patent); U.S. Pat. No. 5,745,540 to Okada et al. ('540 patent); U.S. Pat. No. 5,696,802 to Hafezan ('802 patent); U.S. Pat. No. 4,905,839 to Yuge et al. ('839 patent); U.S. Pat. No. 4,905,840 to Yuge et al. ('840 patent); U.S. Pat. No. 4,504,916 to Oka ('916 patent); U.S. Pat. No. 4,275,874 to DiBlasio ('874 patent); U.S. Pat. No. 3,983,367 to Kondó et al. ('367 patent); U.S. Pat. No. 3,214,096 to Buchholz et al ('096 patent); U.S. Pat. No. 3,025,771 to Uchida ('771 patent); U.S. Pat. No. 2,494,615 to Hayes ('615 patent); U.S. Pat. No. 2,271,394 to Hayes ('394 patent); U.S. Pat. No. 1,328,263 to Buckley et al. ('263 patent); and, U.S. Pat. No. 1,159,826 to Buckley et al ('826 patent) all of which are incorporated herein by reference.
The '216 patent describes a method and system for detecting a presence of more than one item at a point along a conveyance path, comprising steps of (A) generating a light beam and directing the beam through the path such that a presence of the item will cause the beam to be attenuated; (B) detecting the beam after it is attenuated by the presence of the item; and (C) determining from the amount of attenuation how many items are simultaneously present. In the preferred embodiment the item is an item of currency, and the step of generating a light beam includes a step of operating an optical source, such as an LED or a laser, to generate a beam having a wavelength in the range of about 400 nm to about 1 micrometer or longer.
The '237 patent describes a sheet counting apparatus comprising a sheet support for holding a stack of sheets to be counted. A sheet feed device moves the sheets individually from a first position to a second position while they remain held together in the stack. A counter monitors movement of the sheet as it is moved from the first position to the second position, and increments a count when such movement is detected.
The '540 patent describes a bill counter which comprises a case body formed to be a size which can be carried; a display section provided on the surface of the case body; an insertion port provided on one side of the case body which is capable of being expanded/contracted; a taking-out port provided on the other side of the case body; a first feeding-out device which is provided on the insertion port side within the case body and feeds out bills in a bundle inserted to the insertion port by a few sheets; a second feed-out device which is provided on the taking-out port side within the case body and feeds out bills one by one fed out by the first feeding-out device; a driving section which drives simultaneously the first and the second feeding-out devices; an identifying sensor which identifies bills going toward the taking-out port; and a control section which outputs a signal displaying the number of sheets by unit of each bill and the total amount at least to said display section based on the signal from the identifying sensor and a signal which stops the operation of the driving section when a forged bill is detected.
The '802 patent describes a counter for counting the number of sheets in a stack having a rotor which engages in an edge region of the stack and transfers sheets one at a time from one side of the rotor to the other upon rotor rotation. The rotor is mounted on a shaft carried by a carriage arranged for sliding movement on guides. A motor drives a lead screw, whereby the carriage is driven along the guides. The rotor may float on its shaft and its position is sensed by detector; the output of the detector is used to control motor whereby the carriage is driven substantially continuously and smoothly at a rate appropriate for a counting operation being performed.
The '839 patent describes a banknote account and arrangement apparatus, which includes a supply portion for supplying a group of banknotes in the apparatus one after another, a discrimination circuit for discriminating denomination, face, fitness, authenticity, and the like of the supplied banknotes, temporary stackers in which the banknote is stacked in an account mode, closed cassettes coupled to the temporary stackers, open pockets in which the banknote is stacked in an arrangement mode, a RAM for collecting data of the banknote stacked in the temporary stackers, a CPU for verifying the collected data of the banknote stacked in the temporary stackers with known data of the bundle of the banknotes, pushers and shutters for, only when a verification result is correct, stacking the banknote stacked in the temporary stackers in the closed cassettes, and a display portion for displaying the collected data. When an interruption command is input in the account mode, data collection is temporarily interrupted, and an operation in the arrangement mode is performed using the open pockets while storing the collected data.
The '840 patent describes a banknote account and arrangement apparatus including a supply portion for supplying a bundle of banknotes in the apparatus one after another, a discrimination circuit for discriminating denomination, face, fitness, authenticity, and the like of the supplied banknotes, temporary stackers in which the banknote is stacked in an account mode, closed cassettes coupled to the temporary stackers, open pockets in which the banknote is stacked in an arrangement mode, a RAM for collecting data of the banknote stacked in the temporary stackers, a CPU for verifying the collected data of the banknote stacked in the temporary stackers with known data of the bundle of the banknotes, pushers and shutters for, only when a verification result is correct, stacking the banknote stacked in the temporary stackers in the closed cassettes, and a display portion for displaying the collected data. Sensors detect if the temporary stackers are full. When the sensors detect that the temporary stackers are full in the account mode, a stacking destination of the paper money is changed to the open pockets while continuously collecting the data. After the temporary stackers are replaced with empty ones, the banknote stacked in the open pockets are stacked in the temporary stackers without collecting the data.
The '916 patent describes a paper sheet counting machine for feeding paper sheets, one at a time, and counting the number of the paper sheets, includes a circuit for detecting an abnormal flow of the paper sheets. In the circuit, the lengths of paper sheets are detected. A predetermined number of the detected signals are averaged. The newest length value is compared with the averaged value to provide a difference signal which determines whether an abnormal flow of the paper sheet has occurred. The averaged value is renewed to compensate for deviation of the length values.
The '874 patent describes a stacker for handling and counting documents such as, for example, paper sheets, paper currency and the like in which the documents are fed from an input tray through cooperative feeder and stripper assemblies which separate the documents to feed them in a one at a time fashion in a forward feed direction toward acceleration rollers which accelerate the single-fed documents to create a gap between documents moving along the feed path. A gap detector senses the presence of gaps for document counting purposes. An endorser and/or suspect examination detector for examining the authenticity of paper currency may be provided downstream of the first acceleration rollers. The stacker comprises second acceleration rollers cooperating with a guide plate which reverses the direction of movement of the paper documents passing through the endorser station to further accelerate the documents and urge them along a convex guide path and into the pockets of a document receiving stacker wheel assembly which delivers the documents to a stacker tray positioned substantially beneath the infeed stacker to facilitate removal and handling of stacked documents. The machine described by this patent discloses features which automatically halt the machine when it detects counterfeit currency or when it detects that bills have been double fed.
The '367 patent describes a sheet counting machine which has a sheet counting mechanism which is controlled through a coincidence detecting circuit operating to compare a number of sheets counted with a predetermined number of sheets. The coincidence detecting circuit is provided with a mode changing switch and an inverter connected thereto in the output path to relatively reverse a logical level of an output of the coincidence detecting circuit stop mode. The logical level thus relatively reversed is utilized for controlling the operation of the mechanism through switching elements and relay elements. The machine described by this patent discloses features which automatically halt the machine when a predetermined count has been reached.
The '096 patent relates to paper currency counting machines, and particularly to a paper currency counter having a central counting section, a compartment for receiving bills as a stack, and a delivery compartment for receiving counted bills, with means for removing bills singly from the stack, feeding the bills through the counting section, and conveying counted bills into the delivery compartment without danger of mutilation of bills and with assurance that each bill conveyed to the delivery compartment will be counted, together with selectable predetermined count means responsive to the passage of bills through the counting section and adapted to halt the flow of bills to the counting section upon the completion of the selected predetermined count. The currency counter described by this patent includes an "off" switch which immediately halts the operation of its motor upon being depressed.
The '771 patent describes an apparatus for counting bank notes and other similar articles. When bank notes in a pile are fed into a rotary drum having a coefficient of friction much greater than that of the bank notes to be counted and a pressing element having a coefficient of friction smaller than that of the drum but greater than that of the bank notes, the bank notes are caught by the drum one by one from the bottom of the pile and are advanced.
The '615 patent relates to roller-type paper money counting machines, and more particularly to an improved bill-callipering mechanism for use with same. The paper money counting machine described by this patent includes features which automatically halt the machine when it detects that multiple bills have stuck together.
The '394 patent describes a machine for assorting and counting paper money. The counting machine has a generally rectangular form and is divided from front to back by a number of partitions adapted to collecting paper money.
The '263 patent describes a machine for assorting and counting paper money, and is an improvement of the '826 patent. The '263 patent introduces a means to arrest the feeding means when more than one bill is introduced at the same time.
The '826 patent describes a machine for assorting and counting paper money. The machine is adapted to count bills one at a time and is comprised of a feeding means, an electric circuit adapted to be opened and closed by the feeding means, and an operating means for the counter included in the electric circuit.
None of the devices mentioned above describe a paper currency counter which incorporates electronic circuitry to automatically stop the mechanical motor in the event a foreign object is accidentally ingested by the counter.
Consequently, there is a need in the art for a paper currency counting machine that can automatically stop operation in the event of an inadvertent blockage.

Paper currency counter with emergency stop features